Attorney Docket No.7813P0030PC INTERLOCKING DISC TOY AND ASSEMBLY This application claim the benefit of and priority to U.S. Patent Application No.63/414,782, filed October 10, 2022. FIELD This disclosure is related in general to interlocking disc toys and assemblies. BACKGROUND Building toys enable construction of shapes and objects limited only by a child's imagination. Different shapes, sizes and combinations provide different building capabilities. US Patent 11,123,650 is directed to an interlocking disc toy. The present inventors recognized the opportunity for new features in and for an interlocking disc toy and assemblies. SUMMARY An interlocking disc according to an exemplary embodiment of this disclosure includes, among other possible things, a hub, a plurality of petals, a plurality of notches, and a catch on each of the petals. At least one petal has a button protruding from a first side of the petal and a button housing on a opposite second side of the petal. The hub has a stop between an inner area and an outer area. The plurality of petals are circumferentially spaced apart and extend radially outward from the hub. The plurality of notches are defined between adjacent petals of the plurality of petals. The catch is Attorney Docket No.7813P0030PC disposed on each of the plurality of petals and is configured to engage a stop of another interlocking disc to inhibit disassembly. Each of the plurality of petals are disposed within a common plane. A disc stacking device according to an exemplary embodiment of this disclosure includes, a shaft and a first cap disc. The shaft has a first end and a second end. A first cap disk is connected to the first end. A second cap disc may be connected to the second end. The first cap disc comprising a hub, a plurality of petals, a plurality of notches. The hub comprising a stop between an inner area and an outer area. The plurality of petals circumferentially spaced apart and extending radially outward from the hub. Each of the plurality of petals are disposed within a common plane and comprise a catch on sides transverse to the common plane. The plurality of notches are defined between adjacent petals. The first cap disc and/or second cap disc may be releasably connected to the first end of the shaft at the hub. The first or second cap discs may comprise a plurality of buttons extending from a first side of the petals. The buttons can be used to support the first or second cap disc, and the stacking device on an exterior surface. A disc base for holding upright an interlocking disc having a plurality of petals according to an exemplary embodiment of this disclosure includes, a body having a top, a first housing, and a second housing. The top has a first aperture in communication with the first housing and a second aperture in communication with the second housing. The first housing is spaced apart from the second housing. A ball joint connector for an interlocking disc according to an exemplary embodiment of this disclosure includes a ball connector and a cup connector. The ball connector has a ball, a first shaft, and a first fork. The ball and the first fork are connected to opposite ends of the first Attorney Docket No.7813P0030PC shaft. The fork comprises a plurality of prongs configured to engage an interlocking disc. The cup connector has a cup, a second shaft, and a second fork. The cup and the second fork are connected to opposite ends of the second shaft. The second fork comprises a plurality of prongs configured to engage an interlocking disc. The ball is engaged in the cup. The ball and the cup are is rotationally movable relative to the other. The ball joint connector may provide three dimensional movement of the ball connector and cup connector while the ball is engaged with the cup. Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. Numerous other advantages and features will become readily apparent from the following detailed description and the embodiments thereof, from the claims, and from the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of several example structures built with a plurality of example interlocking discs. Figure 2 is a front view of an example interlocking disc embodiment. Figure 3 is a side view of the example interlocking disc. Figure 4 is a perspective view of a first interlocking disc engaged to a second interlocking disc. Figure 5 is an enlarged view of a notch of an example interlocking disc Figure 6 is a perspective view of a surface of an example interlocking disc Attorney Docket No.7813P0030PC Figure 7 is a perspective view of a first interlocking disc engaging a second interlocking disc. Figure 8 is a perspective view of a first interlocking disc locked to a second interlocking disc. Figure 9 is a front view of another example interlocking disc embodiment. Figure 10 is a perspective view of a first interlocking disc of figure 9 engaged to a second interlocking disc of figure 9. Figure 11 is a rear view of the interlocking disc of figure 9. Figure 12 is a side section view of a portion of a petal of the interlocking disc of figure 9 taken along plane 9 – 9 of figure 9. Figure 13 is a side section view of a portion of a petal of the interlocking disc of figure 9 engaged with a petal of a second interlocking disc of the type of figure 9. Figure 14 is a front view of another example interlocking disc embodiment. Figure 15 is an enlarged cross-section of a first interlocking disc locked to a second interlocking disc. Figure 16 is a further enlarged cross-section of the first interlocking disc locked to the second interlocking disc. Figure 17 is a perspective view of the first interlocking disc locked to the second interlocking disc. Figure 18 is a perspective view of another example interlocking disc embodiment. Figure 19 is a side view of the disc of figure 18. Figure 20 is a front view of the disc of figure 18. Figure 21 is a rear view of the disc of figure 18. Figure 22 is a perspective view of the disc of figure 18 joined with another disc in a first configuration. Figure 23 is a perspective view of the disc of figure 18 joined with another disc in a second configuration. Figure 24 is a partial sectional view of another example interlocking disc. Attorney Docket No.7813P0030PC Figure 25 is an enlarged sectional view of an interface between interlocked discs. Figure 26 is a front view of another example disc embodiment. Figure 27 is a side view of an example disc stacking device embodiment. Figure 28 is a side view of the disc stacking device of figure 27 with a plurality of discs and without a top cap disc shown. Figure 29 is a side view of a shaft of the disc stacking device of figure 27. Figure 30 is a perspective view of an end of the shaft of figure 29. Figure 31 is a front perspective view of a cap disc of the disc stacking device of figure 27. Figure 32 is a rear perspective view of the cap disc of figure 31. Figure 33 is a front view of the cap disc of figure 31. Figure 34 is a rear view of the cap disc of figure 31. Figure 35 is a side view of another embodiment shaft usable with the disc stacking device of figure 27. Figure 36 is a perspective view of a female end of the shaft of figure 35. Figure 37 is a rear perspective view of another embodiment cap disc usable with the shaft of figure 35. Figure 38 is a front perspective view of the cap disc of figure 37. Figure 39 is a perspective view of an example base embodiment holding an interlocking disc. Figure 40 is a perspective view of the base of figure 39. Figure 41 is a side view of the base of figure 39. Figure 42 is a top view of the base of figure 39. Figure 43A is a bottom view of the base of figure 39. Figure 43B is an enlarged bottom view of a portion of the base of figure 39. Figure 43C is a side section view taken along plane 43C – 43C of figure 42. Attorney Docket No.7813P0030PC Figure 44 is a perspective view of a ball connector of an example ball joint connection embodiment of figure 46. Figure 45 is a perspective view of a cup connector of an example ball joint connection embodiment of figure 46. Figure 46 is a side view of the ball connector of figure 44. Figure 47 is a side perspective view of the ball connector of figure 44. Figure 48 is a top view of a fork of the ball connector or of the cup connector. Figure 49 is a top view of the cup connector of figure 45 without a portal. Figure 50 is a perspective view of the fork of ball connector or of the cup connector interlocked with an interlocking disc. Figure 51 is a perspective view of the example ball joint connection embodiment connected to two interlocking discs. DETAILED DESCRIPTION Referring to Figure 1, several example structures 18A-F are shown that are made from a plurality of identically configured interlocking discs 20. Each interlocking disc 20 includes features that enable locking engagement with one or more other interlocking discs 20. The discs 20 are configured to be interlocked to each other in various arrangements that enable creation many different structures limited only by the imagination of a user. The disclosed interlocking disc 20 includes features to enable easy connection with both physical and audible feedback that confirms a good connection. The disclosed interlocking disc 20 further includes features that maintain the connection once made to keep interlocked structures together. Each of the disclosed example discs, include a catch and stop that both are flat, non-rounded Attorney Docket No.7813P0030PC surfaces that require a greater level of force to disassembly than to assembly. Moreover, disclosed example discs include rounded and ramped surfaces that ease assembly and provide a positive physical feedback with a sudden stop once the stop and catch are engaged accompanied by an audible snap that reinforces that a connection is made. The contrast between relatively easy forces required to connect two discs and the increased force required to pull parts apart provide an intuitive and satisfying experience to a user that encourages continued use and creation. Referring to Figures 2, 3 and 4 with continued reference to Figure 1, the example disc 20 includes a plurality of petals 32 and a hub 22. The petals 32 are spaced circumferentially apart about the hub 22. The petals 32 extend radially outward from the hub 22. In this disclosed example, eight (8) petals 32 are evenly spaced about a periphery of the hub 22. The space between the petals 32 defines a notch 34. The notch 34 is a space for interlocking another disc 20. Interlocking of one disc 20 to another disc 20 is accomplished by aligning notches 34 in each disc 20 and pushing the discs 20 together. Each disc 20 can be connected to another disc 20 in each of the notches 34. In this example, each disc 20 may be interlocked with eight (8) other discs 20. As appreciated, although the example disclosed discs 20 include eight (8) petals 32 and eight (8) notches 34, other numbers of petals 32 and notches 34 could be utilized and are within the scope and contemplation of this disclosure. Each disc 20 is identically configured and shaped and includes features that enable interlocking connections between discs 20 together to maintain the structure. Each disc 20 is a substantially flat structure disposed within a common plane 36. The disc 20 includes a thickness 40 in a direction transverse to the common plane 36 indicated by arrow 38. The thickness 40 is indicated at a location Attorney Docket No.7813P0030PC on the petals 32 spaced apart from the hub 22. Thicknesses vary at different radial locations of each of the discs 20 to provide features that provide engagement and securement. A first disc 20A is shown interlocked to a second disc 20B in Figure 4. The references to a first disc 20A and second disc 20B are provided for descriptive purposes and are not indicative of any difference in configuration or shape. Both the first disc 20A and the second disc 20B are identically configured. In the interlocked condition, a hub 22 of each of the first disc 20A and the second disc 20B is received within a notch 34 of the other one of the first disc 20A and 20B. The hub 22 of the first disc 20A is thereby captured between petals 32 of the second disc 20B. The hub 22 of the second disc 20B is thereby captured between petals 32 of the first disc 20A. The petals 32 define the open space therebetween that is the notch 34. Inner surfaces of the petals 32 include features that enable assembly and that maintain the discs 20A, 20B in the interlocked condition shown in Figure 4. Referring to Figures 4, 5 and 6 with continued reference to Figures 2 and 3, the notch 34 of each disc 20 is an open space defined between adjacent petals 32. Each petal 32 includes an inner side 35 that defines the outer sides of the notch 34. The inner side 35 includes features that provide for attachment and securement of the discs 20 in the interlocked condition. In this embodiment, the inner side 35 includes a catch 42 that engages a stop 30 defined on the hub 22. The hub 22 includes an inner area 26 and an outer area 28 that is separated by the stop 30. The stop 30 is a circular step between the outer area 28 and the inner area 26. The inner area 26 is of a reduced thickness transverse to the plane as indicated by the arrows 38 in Figure 3. The stop 30 in this example is circular about the central opening 24. The stop 30 is a flat surface that is transverse to the plane 36. Attorney Docket No.7813P0030PC The catch 42 on the inner side 35 is a flat surface that engages the stop 30 once petals 32 of one disc 20 are inserted over the hub 22 of another disc 20. Referring to Figures 7 and 8 with continued reference to Figures 2, 3, 4, 5 and 6, assembly of the first disc 20A and the second disc 20B are shown. In Figure 7, petals 32 of the first disc 20A is partially assembled to the hub 22 of the second disc 20B. The petals 32 are pushed onto the hub 22 of the other disc 20 until the catch 42 snaps over the stop 30. Once over the outer area 28, the catch 42 snaps into the reduced thickness of the inner area 26. The spacing between catches 42 on either side of the notch 34 is such that the petals 32 expand outwardly, as the disc 20 is pushed onto another disc 20. Once the petals 32 are fully seated within the notch 34 of the other disc 20, the petals 32 snap back to nearly the normal non-assembled state. In the assembled interlocked condition shown in Figure 8, the catch 42 is aligned with the stop 30. The catch 42 and the stop 30 are two flat surfaces that are transverse to the plane 36. The aligned flat surfaces of the catch 42 and stop 30 inhibit disassembly by providing flat contact surfaces that abut in a direction that the discs 20 need to be moved for disassembly. The flat surfaces provide an interface that requires a higher force requirement to pull the discs 20 apart than to assemble the discs 20. Accordingly, the catch 42 and the stop 30 provide for maintaining discs 20 in an assembled interlocked condition. Each disc 20 is formed from a resilient plastic material that enables some bending and give when assembled. However, the material is also provided to return to the overall shape once a force is removed. In one disclosed embodiment, the interlocking disc 20 is formed from one of a polyethylene, polypropylene material or acrylonitrile butadiene styrene (ABS). It should be understood, that the disclosed materials are only disclosed examples and that other materials and mixtures of materials are within the scope and contemplation of this disclosure. Attorney Docket No.7813P0030PC Moreover, the spacing between petals 32 is provided to generate a slight interference fit therebetween when in an assembled interlocked condition. Accordingly, a distance 45 between catches 42 shown in Figure 5 on either side of a notch 34 is equal to or less than a thickness 43 shown schematically in Figure 6 of the inner area 26 radially inward of the stop 30. A distance 47 between inner sides 35 of the notch 34 radially inward of the catches 42 is equal to or less than a thickness 49 of the outer area 28. Both the thickness 43 and 49 are in the direction 38 transverse to the plane 36 shown in Figure 3. The difference in distances 45, 47 and thicknesses 43 and 49 generate a slight interference fit that keeps the discs 20 within the interlocked condition. Referring to Figure 9 to 13, another disclosed example disc 29 embodiment includes features that aid in assembly and maintaining of the assembled interlocked condition. Features common with disc 20 are numbered the same as previously disclosed and described. Disc 29 is the same as disc 20 except that disc 29 comprises two buttons 33 and two button housings 41 on two of the petals 32. Each button 33 protrudes from a top surface 27 on a top first side 31 of the petal 32. The button 33 comprises a perimeter wall 37 and a top wall 39. The button may have a curved edge 39a between the top wall 39 and the perimeter wall 37. The perimeter wall 37 is a cylindrical perimeter wall. The perimeter wall 37 may be made with no draft or inward taper. Below the button 33 is a button housing 41. The button housing 41 is open on a bottom second side 47 of the petal opposite of the top side 31 and opposite of the button 33. The housing extends from the second surface 45 of the second side 47 of the petal toward the button and the top side 31. The housing comprises a perimeter wall 51 and a top or terminal wall 53. The top wall comprises an aperture providing access to a second chamber 55 above the housing 41. The second chamber 55 comprises a cylindrical or Attorney Docket No.7813P0030PC slightly conical perimeter wall 59 and a top wall 59. The second chamber may avoid a sink mark in a part molding or forming process. The top surface 27, the top wall 99, the bottom surface 45, and the terminal wall 53 may be transverse to the inner sides 35 of the petal. While the button 33 protrudes from the first side 31 and the button housing is open on the second side 47, the elements could be reversed such that the button housing is open on the second side 47 and the button protruding from the first side 31. The button 33 is receivable in and removable from the button housing of another disc. The button is sized to fit within, and preferably friction fit within the width or diameter of the button housing 41. The button 33 comprises a width or diameter 61 that is sized to fit, and preferably friction fit, within the width or diameter 63 of the button housing 41. Therefore, the button housing 41 width or diameter 63 may be the same or slightly larger than the width or diameter 61 of the button 33. The button may comprise a height 66 that is the same, less than, or greater than a height 68 of the housing 41. The button 33 may be vertically aligned with the button housing 41, such as shown in figure 12. The button 33 and button housing 41 may have a common centerline or central axis 67. The common centerline or central axis 67 may be normal to the common plane 36. Further, the side wall 37 of the button may be aligned with the side wall 51 of the button housing. In some embodiments, the button housing may comprise a larger width or diameter 63 than the with or diameter 61 of the button 33, and therefore the side wall 51 of the button housing may be offset laterally from the side wall 37 of the button, even when the button and button housing have a common centerline or central axis 67. Attorney Docket No.7813P0030PC Figure 13 shows a portion of a first disc 29A engaged with a portion of a second disc 29B. Both the first disc 29A and the second disc 29B are identically configured and are the same as disc 29. The button 33 of the first disc 29A is received in the button housing 41 of the second disc 29B. The button 33 is frictionally received in the housing 41, such that the perimeter wall 37 of the button 33 is frictionally fitted/engaged with the perimeter wall 51 of the housing 41. The friction fit maintains the first disc 29A connected to the second disc 28B until a predetermined separating force is applied to one or both discs 29A, 29B. The discs 29A, 29B can be disengaged from each other and the button 33 of disc 29A withdrawn from the housing 41 by moving, such as by pulling one disc away from the other in the direction 69 or 71 and/or pulling both discs 29A, 29B away from each other in the directions 69, 71. When a sufficient separating force is applied to one or both of the discs 29A, 28B, the friction fit between the button and the housing will be overcome and the button will withdraw from the housing and/or the housing will be removed from the button. Therefore, two or more discs can be connected to each other at a button, button housing combination between pairs of discs. The buttons and button housing provide an alternative and/or additional means and locations of connecting discs in the alternative or in addition to connecting discs at the notches 34. While the disc 29 of figure 9 is shown with a button 33 on two of the petals 32, a disc may be provided with one, or more, or all of the petals 32 having a button 33. The button 33 and button housing 41 also allow the discs to connect with other building elements, such as toy blocks, such as LEGO toy blocks or parts, that have buttons or button housings. Referring to Figure 14, another disclosed example disc 70 embodiment includes features that aid in assembly and maintaining of the assembled interlocked condition. Features common with disc 20 are numbered the same as previously disclosed and described. The disc 70 includes a ramp portion Attorney Docket No.7813P0030PC 44 aligned with an end of each of the notches 34 that aids in assembly be reducing the amount of force required to insert petals 32 of one disc 70 onto a hub 22 of a corresponding disc 70. The disc 70 further includes nodes 46 on the inner sides 35 that provide stability in the assembled interlocked condition. The nodes 46 are a radial distance 60 from a central point 25 within the center opening 24. The catch 42 is a radial distance 62 from the central point 25 within the center opening 24. The radial distance 62 is larger than the radial distance 60 such that the catch 42 is spaced radially outward of the nodes 46. An outer perimeter of the central opening 24 is spaced apart from the ramp portion 44 a distance equal to or greater than a radial length 68 of the notch 34 from the ramp 44 to an outer perimeter of the plurality of petals 32. Referring to Figures 15, 16 and 17 with continued reference to Figure 14, the ramp portion 44 includes a ramp entrance 54 that is disposed at a radially innermost location of each notch 34. The ramp portion 44 includes angled surfaces that transition from an entrance thickness 56 to an end thickness 57. The entrance thickness 56 is less than the end thickness 57. The entrance thickness 56 is less than a spacing 52 between inner sides 35 of the petals 32 as shown in Figure 14 and is identical on either side and symmetrical about the plane 36 indicated in Figure 15. The thickness tapers from the smaller entrance thickness 56 to the larger thickness 57 to reduce the force required to assemble two discs 70 together. The ramp portion 44 includes a width 64 that corresponds with the thickness of the petals 32. The ramp portion 44 begins ends a radial distance 66 from an outer periphery of the opening 24. The notch 34 includes a radial length 68 and a spacing 48 radially between the catch 42 and the node 46. The spacing 48 corresponds with the thickness 49 of the outer area 28. A spacing 50 is provided between inner sides 35 at the nodes 46. The spacing 50 is a distance that corresponds with a Attorney Docket No.7813P0030PC thickness at the ramped portion 44. The nodes 46 are spaced radially between the catch 42 and the ramped portion 44. As is appreciated from Figures 15 and 16, when two discs 70 are assembled, a gap 72 is partially formed near the ramped portions 44. The nodes 46 project outward from the inner sides 35 and at least partially engage the ramped portion 44 of the other disc 70. Engagement between the ramped portions 44 and a corresponding node 46 stabilizes the interlocked connection. The location of the inner area 26 and the outer area 28 are shown in view of cross-section of interconnected discs 70 in Figure 16. The inner area 26 is set radially inward of the catch 42 when assembled. The outer area 28 is radially outward of the stop 30 and the catch 42 in the assembled condition. The thickness 49 of the outer area 28 therefore corresponds with the spacing 48 between sides 35 of the notch 34. The thickness 49 of the outer area 28 is greater than the thickness 43 of the inner area 26. The thickness 43 of the inner area 26 corresponds with the spacing 52 between sides of the notch 34 as shown in Figure 14. Referring to Figure 17 with continued reference to Figures 14, 15 and 16, two discs 70 are shown in an assembled interlocked condition. In the interlocked condition, the catch 42 is engaged to the stop 30 to inhibit disassembly. The node 46 from one disc 70 is at least partially engaged to the ramp portion 44 of the other disc 70. As is shown in Figure 17, the engagement between the catch 42 and the stop 30 and between the node 46 and the ramp portion 44 are duplicated between interfaces at each disc 70. Attorney Docket No.7813P0030PC Accordingly, Figure 17 illustrates an interlocking engagement between a first disc 70A and a second disc 70B. The first disc 70A and the second disc 70B are identical and the different reference numerals are to aid in description of the disclosed interlocking condition. A catch 42 of a first disc 70 engages a stop 30 of the second disc 70B. A ramp portion 44 of the second disc 70B is engaged to a node 46 of the first disc 70A. A ramp portion 44 of the first disc 70A is engaged to a node 46 of the second disc 70B. A catch 42 of the second disc 70B is engaged to the stop 30 of the first disc 70A. The example interlocked position shown in Figure 17 provides significant rigidity to maintain discs 70A, 70B in the assembled condition to maintain created structures for as long as desired. Assembly of a first disc 70A to a second disc 70B is performed by first aligning notches 34 of each disc 70A and 70B. The user than pushes the discs 70A and 70B toward each other. Because of the notches, 34, the first contact between discs 70A and 70B are between forward portions of each petal 32 and a ramp portion 44 of the other disc 70A, 70B. The ramp portion 44 includes the entrance thickness 56 that is less than the distance 52 between petals 32. Accordingly, petals 32 on either side of the notch engage partway up the ramp portion on the other disc 70A, 70B. The tapered surface defined by the ramp portion 44 spread forces required to separate the petals 32 over a longer radial distance. Spreading of forces reduces the perceived effort to assembly discs 70A, 70B. The petals 32 spread apart and driven over the outer area 28 toward the inner area 26. Once the catch 42 is assembled over the outer area 28, the petal 32 will snap back and align the catch 42 with the stop 30. The snapping back of the petals 32 over the stop 30 provides positive feedback that a connection has been complete. The feedback includes an audible clicking sound along with a force feedback once ramp portions 44 of each notch 34 contact each other. The ramp 44 provides reduced force Attorney Docket No.7813P0030PC feedback to a user when being assembled to provide a more drastic contrast to the force feedback when fully assembled. Accordingly, the ramp 44 substantially reduces and/or eliminates false perceptions that a connection has been formed. The contrast in force along with the audible feedback provides a more intuitive and satisfying experience to a user that encourages continued use and creation. Removal requires an initial amount of force to overcome the two flat aligned surfaces of the catch 42 and stop 30. The applied force is required to spread the petals 32 apart to disengage the aligned flat surfaces of the catch 42 and the stop 30. Once the catch 42 and stop 30 are disengaged, the discs 70 are easily pulled free of each other. Referring to figures 18 to 23, another disclosed example disc 73 embodiment includes features that aid in assembly and maintaining of the assembled interlocked condition. Features common with disc 20 and or disc 70 are numbered the same as previously disclosed and described. Disc 73 is the same as disc 70 except that disc 73 comprises two buttons 33 and two button housings 41 on two of the petals 32 and disc 73 lacks nodes. The buttons 33 and the button housings 41 are the same, including structurally and functionally, as described above regarding the buttons 33 and button housings 41 of disc 29. Figure 22 shows two discs 73A, 73B, which are each the same as disc 73, are connected, and completely or substantially overlapping, such that each of the buttons (not shown) of disc 73B are engaged in to each of the button housings 41 of disc 73A. Disc 73A, 73B can be joined at the buttons and button housings and separated in the same as described with discs 29, 29A, 29B. Attorney Docket No.7813P0030PC Figure 23 shows another connected configuration of discs 73A, 73B. Discs 73A, 73B are offset and partially overlapping at one of the petals of each disc. The button (not shown) of disc 73B is engaged in the button housing 41 of disc 73A at the overlapping petals 32. While two discs 73A, 73B are shown in figures 22 and 23, more than two discs can be joined using the buttons. For example, a third disc 73 could be connected at the free button 33 of disc 73B shown in figure 19 and a fourth disc 73 could be connected at the free button 33 of disc 73A. Numerous other connection configurations could be made. Further, additional discs could be joined to one or both of discs 73A, 73B at the notches 34. Referring to Figures 24 and 25, example discs 74A, 74B are shown connected at an interface on one of the plurality of petals 32. Each of the petals 32 include an indentation 76. The indentation 76 provides for attachment of one disc 74A to another disc 74B on the petal 32 rather than within the notch 34 and to the hub 22. The indentation 76 is centered within a width of each petal 32 on both a first side 86 and a second side 88. The indentation 76 is formed from peripheral walls that surround an inner area that receives a portion 90 of a petal 32 from another disc 74. The peripheral walls are flat surfaces transverse to the common plane 36. The flat surfaces of indentation align with the flat surface of the catch 42 to inhibit separation. Each of the indentations 76 includes a width 80 and a length 78. The length 78 is in a radial direction and the width 80 is transverse to the length and a radial direction. The catch 42 is spaced a radial distance 82 from a periphery of each disc 74A, 74B. A thickness 84 of the petal 32 and the radial distance 82 correspond to align the portion 90 of the petal 32 radially outward of the catch 42. Attorney Docket No.7813P0030PC Accordingly, the portion 90 fits into the indentation 76 in a manner that provides a tight and secure fit while maintaining alignment. The indentation 76 is aligned radially such that when another disc 74 is assembled to a petal 32, the disc 74A is aligned radially and centered on the petal 32. The indentation 76 is provided on both first and second sides 86 and 88 such that attachment is made by trapping a single petal 32 of the disc 74B between two petals 32 of the disc 74A. The indentations thereby provide an alternate connection location to further expand possible orientations and structures capable of being created. Disc 74A and 74B may therefore be attached to one another both within a notch 34 and along each petal 32. While disc 74 is not shown with a button 33 or a button housing 34, disc 74 could be provided with a one or more buttons 33 replacing one or more indentions on a one or more petals 32 and one or more button housing 41 opposite the button 33. Therefore, the disc 74 could have one or more indentions on one or more first set of petals 32 and one more buttons and button housings on one or more second set of petals 32 of the disc 74. It should be appreciated, that the various features of each of the example petals 20, 29, 70, 73 and 74 can be combined in any number of manners and combinations within the contemplation of this disclosure. Specifically, each of the disclosed discs 20, 29, 70, 73 and 74 may include buttons 33, button housings 41, ramp portions 44, nodes 46, and/or indentations 76. Moreover, each of the disclosed discs 20, 29, 70, 74 and 73 include the disclosed catch 42 and stop 30. Referring to Figure 26, a disc 100 is shown that includes reference to features disclosed throughout this disclosure that are include the common reference numerals. The example disc 100 includes the stop 30, catch 42 and notches 34 between petals 32 as described above. The disc 100 further includes ramp portions 44, nodes 46 and the indentations 76. Accordingly, the features and Attorney Docket No.7813P0030PC descriptions above with regard to discs 20, 70 and 74 are not explicitly repeated with regard to the disc 100 includes each of the above described features. Accordingly, the disclosed discs 20, 29, 70, 73, 74 and 100 include features that provide an intuitive connection with reduced forces required to interlock discs. The disclosed features further provide both audible and physical feedback to confirm connection of the discs 20, 29, 70, 73, 74100. Moreover, once connected, the discs 20, 29, 70, 73, 74 and 100 include features that maintain the connection and inhibit disassembly. Referring to figures 27 through 34, an example disc stacking device 110 embodiment is disclosed. The stacking assembly or device 110 comprises a shaft 112, and one or more cap discs 114. The discs 114 are releasably attached at opposite ends of the shaft 112. One or more other discs, such as discs 20, 29, 70, 73, 74, 75, 100, can be placed on the shaft. This can be done by placing the shaft through the central opening 24 of the disc 20 or by placing the disc on the shaft by aligning the central opening 24 with the shaft and moving the disc so the shaft is received in the central opening 24. Four discs 20 are shown stacked on the shaft 112 and resting on top of disc 114 in figure 28. However additional or fewer discs may be stacked as desired. When cap discs 114 are secured on opposite ends of the shaft, the discs 20 on the shaft are secured to the shaft against release by the cap discs 114 at opposite ends of the shaft. Therefore, the stacking device 110 provides a convenient means of organizing, storing, displaying, transporting, and/or securing one or more discs 20, 29, 70, 73, 74, 75, 100. Opposite ends 116, 118 of the shaft 112 comprise a means of releasably connecting to cap discs 114, such as threads 120. Figure 30 shows an enlarged end of the shaft. The threads 120 extend to the Attorney Docket No.7813P0030PC terminal end of the shaft on an exterior perimeter as shown in figure 30. Adjacent the threads is a cylindrical portion 122 that encompasses the shaft. The cylindrical portion 122 helps the discs 20 slide smoothly along the shaft. Adjacent the cylindrical portion 122, is a main portion 124. The main portion may comprise four bars 126 (the fourth bar not shown) spaced apart about the circumference of the shaft and four recesses 128 spaced apart about the circumference of the shaft and interspaced between the four bars 126. Each bar 126 may be spaced apart 90 degrees from each adjacent bar 126 about the shaft. Each recess 128 may be spaced apart 90 degree from each adjacent recess about the shaft. The four bars may have a curved profile such that the outer surface of the bars lie on a geometric cylinder, which is interrupted by the recesses 128. The cylindrical portion 122 and the bars 126 help the discs 20, 29, 70, 73, 74, 100 slide smoothly along the shaft. Instead of comprising bars, the shaft may comprise a completely cylindrical perimeter of the main portion 124. The bars 126 or otherwise the cylindrical perimeter of the main portion 124 can be optionally finished by a polishing method, such as SPI-A2, to provide a smooth or very smooth contact surface for discs 20 held by the shaft, so that the discs can spin and or slide easily on the shaft. The roundness of the bars or the shaft may optionally be manufactured to a tolerance of 0.05 millimeters. Referring to figure 31 through 34 with continued reference to figures 27 and 28, the cap disc 114 is the same as discs 73 except at the hub 130 and except that disc 114 has buttons 33 and button housings 41 on four petals rather than two. Further the buttons of disc 114 may have a taller height than the height 66 of button 33 shown in figure 12. The exterior perimeter of the disc 114 at the petals may be circular or cylindrical. The circular or cylindrical exterior perimeter of the disc 114 is interrupted at the notches 43. The circular or Attorney Docket No.7813P0030PC cylindrical exterior perimeter enhances the rolling capability of the disc 114, and the stacking device when provided in a horizontal orientation. The hub 130 of disc 114 comprises a raised housing 136. The top surface 138 of the housing 136 is raised to provide for a shaft chamber 156 open on a second side 134 of the disc 114. The housing 136 extends above the common plane 36. The top surface 138 of the housing 136 is raised from the surface 140 of the petals 32 on a first side 132 and is raised from the common plane 36. A perimeter side wall 144 transitions between surface 140 of the petals and the top surface 138 of the housing. The side wall 144 may be perpendicular to the top surface 138 of the housing and surface 140 of the petals 32. The perimeter of the housing 136 comprises a plurality of slots 146. The slots 146 interrupt the side wall 144. The slot comprise a floor wall 147 and a front wall 149. The slot may comprise a curved transition 151 between the floor wall 147 and the front wall 149. The slots have opposite side walls 153, 155. The slots may have a curved transition between the side walls and the floor and front wall. The opposite side walls 153, 155 can support opposite sides of a petal of another disc when such disc is received in the notch that corresponds to the slot 46. The opposite side walls 153, 155 provide lateral stability and support to the other disc engaged in the slot. That lateral stability is transverse to the common plane of that other disc. Each of the slots 146 is aligned with one of the notches 34 and one of the ramps 44 as shown in figure 31 and 33. A stop 150 is located at the beginning of each slot 146 adjacent the ramp 44 and the notch is a stop 150. The stop 150 serves the same function as stop 30, which is to engage the catch 42 of another disc 20 that is received at and in the notch 34. The stop 150 is the same as stop Attorney Docket No.7813P0030PC 30, except that stop 150 only extends the width of the slot 146. The stop is normal to the common plane 36 of disc 114. As there are multiple slots about the hub, the stops 150 of each slot form a discontinuous stop about the hub. The area inside of the stop 150 may be referred to as an inner area of disc 114. A stop 150 is located aligned with each notch 34. On a second side 134 of the disc 114, shown in figure 34, the hub 130, is the same as the center of disc 73, except that the central opening 24 is enclosed by the shaft chamber 156. The shaft chamber comprises a perimeter wall 158, which comprises threads 160, and an end wall 162. The second side 134 comprises a stop 30 separating the inner area 26 from the outer area 28. The thickness of the disc 114 between the floor wall 147 of the slot 146 and the inner area 26 surface on the opposite side of the disc 114, is the same as describe with respect the thickness 34 of the inner area of disc 20, 70, or 73. The thickness of the disc 114 between the floor 147 of the slot 146 and the inner area 26 surface on the opposite side of the disc 114, corresponds with the spacing 52 between side of the notch 34. An outer area 157 extends from the stop 150 toward the notch 34. The thickness of the disc 114 between the outer area 157 on the first side of the disc shown in figure 31 and 33 and the outer area 28 of the back side of the disc shown in figure 32 and 34 is the same as described with respect the thickness 49 of the outer area 28 of disc 20, 70, or 73, and therefore corresponds to the spacing 48 between sides 35 of the notch 34. The depth of the slot from the stop 150 to the front wall 149 is sized sufficient to receive an end portion of the petal from the catch 42 to the terminal end 154 of the petal. The curved transition Attorney Docket No.7813P0030PC 151 may correspond to the curve 159 between the end of the petal and the inner side 35 of the petal. Therefore, another disc, such as disc 20, 29, 70, 73, 74, 100, 114 can releasably interlock with disc 114 at the notches 34 of disc 114, as shown and described in connection with discs 20A and 20B, or 29A and 29B, or 70A and 70B. When a first disc interlocks with disc 114, a catch 42 of the first disc will engage the stop 150 on the first side of disc 114 and a catch 42 of the first disc will engage the stop 30 on the second side of the disc 114. To connect the disc 114 one or both ends 116, 118 of the shaft, the end of the shaft is aligned with the shaft chamber 156 of the disc and the disc is threaded onto the end 116, 118 and or the end of the shaft is threaded into the shaft chamber 156. The threads 120 of the shaft engage the threads 160 of the disc 114 to releasably secure the disc to the end of the shaft. In some embodiments, the length threaded portion of the end of the shaft is shorter than the depth of the shaft chamber 156 to prevent the shaft from bottoming out in the shaft chamber and to account for manufacturing tolerances. To disconnect a disc 114 from either end 116, 118 of the shaft, the disc 114 is unthreaded from the threads 120 of the end of the shaft and or the shaft is unthreaded from the shaft chamber 156. As the disc 114 has notches, stops 30, 150, buttons 33, and button housings 41, other discs 20, 29, 70, 73, 74, 100, can engage with disc 114 at the notches, buttons, and/or button housings in the same manner as described above. The top surface 39 of each of the buttons 33 is coplanar 137 with each other and with the top surface 138 of the housing 136. Therefore, the height of the button 33 from the petal to the top of the button can be the same as the height the top surface 138 of the housing 136. When the top surface of each of the buttons 33 is co-planar with the top surface 138 of the hub, the buttons and the hub provide level surfaces is to support the disc, and the stacking device, on an external surface, Attorney Docket No.7813P0030PC such as a desk, the floor or other surface. The buttons and the top surface 138 can help the stacking device stand safely and avoid wobbling on an external surface. The co-planar surfaces of the buttons and the hub provide lateral stability to the disc and to the stacking device. Figures 35 and 36 show an alternative embodiment shaft 170 usable in place of shaft 112 in stacking device 110. Shaft 170 comprises the male end 116 of shaft 112 which comprises threads. Opposite of the male end 116, is a female end 172. The female end 172 comprises a central thread housing 174. The thread housing 174 comprises a peripheral inner wall 176 comprising threads 178 and an end wall 180. The thread housing 174 is central to the end face 182. The female end 172 comprises a peripheral outer wall 184 which may be cylindrical. The width or diameter of the female end may be greater than the width or diameter of the main portion 124 of the shaft 170. The shaft 170 with opposite male end 116 and female end 172 allows multiple shafts to connected to each other. The male end 116 of a first shaft 170 can be connected to the female end of a second shaft to provide for a longer joined shaft. Any desire number of shafts 170 can be connected at male/female end connections of pairs of shafts. Figures 37 and 38 show an alternative embodiment cap disc 186 usable at the female end 172 of the shaft 170 in stacking device 110. Disc 186 is the same as disc 114 except at the hub 188. The hub 188 is the same has the hub of disc 73 except, within the stop 30 in the inner area 26 is a central shaft 189 instead of a central opening. The shaft comprises an outer perimeter having threads 190. The shaft 189 is centrally located on the disc. Opposite of the shaft 189 is a recess 192, which may extend into the shaft. Attorney Docket No.7813P0030PC To connect the disc 168 to the shaft 170, the shaft 189 is aligned with the thread housing 174. The shaft 189 is inserted into the thread housing 174 and is rotated to engage the threads 190 with the threads 178 until the shaft 189 is seated in female end 172. The disc 186 is removable from the female end 172 of the shaft by reversing the rotation of the disc and or the shaft to un-thread the disc from the shaft. As the disc 186 has notches, stops 30, 150, buttons 33, and button housings 41, other discs 20, 29, 70, 73, 74100, 114 can engage with disc 186 at the stops, catches, notches, buttons, and/or button housings in the same manner as described above regarding connection between a button and a button housing and interlocking connections between disc at notches with stops and catches. In some embodiments, the cap disc 186 does not have buttons 33 or button housings 41. The disc can rest flat on the surface of the petals on the side opposite the shaft 189, and the shaft can protect upwards and receive the female end 172 of the shaft. Therefore, the cap disc without buttons can support the shaft 189 on an exterior surface, such as a table or the floor. The shaft 189 can be place to project upward from the cap disc to support and receive interlocking discs on the shaft. Referring to figures 39 to 43, a disc base or foot 200 for a disc 75 is disclosed. Disc 75 is the same as disc 73 except that disc 75 lack buttons and button housings. While the base is shown with disc 75 in figure 39, the base can be used with the other discs such as discs 20, 29, 70, 73, 74, 100, 114, 186. The base 200 comprises a body comprising a top wall 202, a perimeter wall 204, a bottom wall 206, a first petal housing 208, and a second petal housing 210. The housings 208, 210 each have an open top 212, 214. The housing may have open bottoms 216, 218 so that they extend completely through the base 200 from the top wall 202 to the bottom wall 206. The housings 208, 210 each comprise a Attorney Docket No.7813P0030PC plurality of side walls 220, 222, 224, 226, 228, 230, 232, 234 defining the housing. Each of the side walls has a length defined between adjacent side walls and a height defined between the top wall 202 and the bottom wall 206. When the housings 208, 210 comprise a rectangular cross-section, a first pair of opposite walls 224, 226, 232, 234 comprise a length that is shorter than a length of a second pair of opposite walls 220, 222, 228, 230. The first pair of opposite walls 224, 225, 232, 234 are sized to receive a thickness 40 of a petal of a disc, such as disc 75, as shown in figure 39. Therefore, the first pair of opposite walls 224, 225, 232, 234 may have length that is the same or larger than the thickness 40 of the petal 32 of a disc. When the first pair of opposite walls 224, 225, 232, 234 and the housings 208, 210 are sized to receive the thickness 40 of the petal, the housings hold the petal in an upright or vertical orientation, as shown in figure 39, such as when the base 200 is placed on a flat or horizontal exterior surface or held horizontally. The petal is held in the housings, and by the base, transverse to the top wall 202. The housings may be sized between the second pair of opposite walls 220, 222, 228, 230 to frictionally fit and engage, or are in close proximity to, opposite sides of the petals 32 to releasably secure the petals in an upright orientation. The upright orientation is transverse to the top wall 202 of the base 200. Further, the housings may be sized between the first pair of opposite walls 224, 226, 232, 234 to frictionally fit and engage, or are in close proximity to, opposite insides 35 of the petals 32 at or adjacent the notches 34 to releasably secure the petals in an upright orientation. The bottom of the base 200, as shown in figures 43A and 43B, may comprise a plurality of chambers 236, 238. The chambers are enclosed by the top wall 202, the perimeter wall 204, and two interior housing walls 240, 242. The chambers have an open bottom. A bridge wall 244 connects housing walls 240, 242 to separate the housings 208, 210 and form portions of walls 226, 232. Attorney Docket No.7813P0030PC Referring to figures 43B and 43C, the base 200 comprises a first stop 227 and a second stop 233. The stops 227, 233 are located on walls 226, 232 of the housings 208, 210, which are adjacent the bridge 244. The stops 227, 233 are flat surfaces transverse to the walls 226, 232 and to a height of the base and the housings 208, 210. The stops 227, 233 divide the walls 226, 232 into an upper portion 229, 235 and a lower portion 231, 237. The stops 227, 232 are configured to engage the catches 42 of a disc in the same or similar manner as stop 30 of a disc . The width of the bridge between the upper wall portions 229 and 235 corresponds to the distance 47 or 48 between insides of the notch 43, which is the area interior of the catch 42 in the notch 34. The width of the bridge between the lower wall portions 231, 237 corresponds to the distance 45 or 52, which is in the area between the inside of the notch 43 from the catch radially outward. The height of each housing between the stop 227, 233 and the top 202 corresponds to a distance between the catch 42 and the end of the notch adjacent the hub of a disc. Therefore, a disc, such as discs 20, 29, 70, 73, 74, 75 can be interlocked with the base in the same manner as the discs can interlock with each other between adjacent petals at a notch. For example, assembly of a disc 75 to the base 200 is performed by first aligning a notch 34 of the disc 75 with the bridge 244. The user then pushes the disc 75 and the bridge toward each other or one towards the other. Because of the notch 34 the first contact between the base and the disc are between forward portions of petal 32 and the bridge. The petals 32 are spread apart and driven over the bridge 244 toward the lower portions 231, 237. Once the catch 42 of the disc is assembled over the upper portions 229, 235, the petals 32 will snap back and align the catches 42 with the stop 227, 233. Attorney Docket No.7813P0030PC The snapping back of the petals 32 over the stop 227, 233 provides positive feedback that a connection has been complete. The feedback may include an audible clicking sound along with a force feedback once ramp portions 44 or the end of the notch adjacent the hub and the bridge 244 contact each other. Removal requires an initial amount of force to overcome the two flat aligned surfaces of the catch 42 and the stops 227, 233. The applied force is required to spread petals 32 apart to disengage the aligned flat surfaces of the catch 42 and the stop 227, 233. Once the catch 42 and the stop 227, 233 are disengaged, the disc can be pulled free of the base. Discs 100, 114, and 186, could be used with the base if two consecutive petals do not have a button 33 or if the petal housings 208 and/or 210 have a configuration to accommodate a button 33. The perimeter wall 204 has a height that is less than the width or diameter of the top wall 202, and the base 200 has a height that his less than a width or diameter of the base. The perimeter wall 204 can be optionally finished by a polishing method, such as SPI-A2, to provide a smooth or very smooth for the base 200 to turn smoothy on an exterior surface The roundness of the perimeter wall optionally be manufactured to a tolerance of 0.05 millimeters. The base 200 can be used with a disc, such as disc 20, 29, 70, 73, 74, 100, 114, 186, to support the disc in a raised or upright position. Further, other discs can be attached to the disc that is supported by the base 200, so that the base can support a plurality of connected discs. For example, one or more bases 200 could be deployed on selected discs 20 of structures 18A-F of Figure 1 to support Attorney Docket No.7813P0030PC the structures on an exterior surface, such as a table or floor, rather than or in addition to allowing the discs to directly contact the exterior surface. Referring to figures 44 to 51, a ball-joint connector 250 is disclosed comprising a ball connector 252 and a cup connector 254. The ball connector 252 comprises a ball 256, a shaft 258, and a fork 260. The ball is connected to the shaft. The shaft is connected to the fork. The connections of the ball to the shaft and/or the fork to the shaft may comprise integrally forming the ball and the fork to or with the shaft. The ball comprises a spherical exterior surface 262. The ball may be completely spherical outside of the connection to the shaft or the spherical exterior surface 262 may be interrupted by a tunnel 264. The tunnel may comprise a cylindrical side wall 266 defining the tunnel between an open first end 268 and an opposite open second end 270. The tunnel may avoid a sink mark in a part molding or forming process and/or may provide other functionality. The shaft may comprise one, two, or more rails 272, 274, 276, 278. Rails 272, 274 are on a first side 280 of the shaft 258 and rails 276, 278 are on an opposite second side 282 of the shaft 258. Rails 276, 278 are the same as rails 272, 274. The shaft may have a square or rectangular cross-section along a portion of or along its entire length between the ball and the fork. The rails extend above the main surface 284, 286 and therefore form a channel 288, 290 between the rails. Rail 272 is aligned across the shaft 258 with rail 276 perpendicular to a centerline 289 of the shaft 258, including in at least one plane perpendicular to the centerline. Rail 274 is aligned across the shaft with rail 278 perpendicular to a centerline 289 of the shaft 258, including in at least one plane Attorney Docket No.7813P0030PC perpendicular to the centerline. The channel 288 is aligned across the shaft 258 with channel 290 perpendicular to a centerline 289 of the shaft, including in at least one plane perpendicular to the centerline. Therefore, each of the pairs of rail 272 and rail 276, as well as 274 and 278, as well as channels 288 and 290, are at the same position along the shaft on opposite sides. The channels are configured to be received in a notch 34 of a disc, such as disc 20, 29, 70, 73, 74, 75 100, 114, 186. The length of the channel 288, 290, between a first sidewall 291 and a second sidewall 293 may be sized to match to the length of the notch 35 of a disc between the catch 42 and entrance 54 of the ramp 44 or end of the notch adjacent the stop 30 (if no ramp). Therefore, a disc may be releasably engaged with the shaft 258 at the channel 288, 290 secured against excess lateral movement by the rails 272, 274, 276, 278. The catch 42 of the disc may engage with the first or second sidewall 291, 293 depending on the direction that the disc engages the channel. Therefore, the first or second sidewall 291, 293 may act as a stop. The disc can be removed from the channel by applying a pulling force to overcome the catch engagement with the first or second sidewall 291, 293 and to withdraw the disc from the channel. The fork 260 comprises a first prong 294 and a second prong 296 and a bridge 298 connecting the first prong to the second prong. The prongs may be generally parallel to each other and the bridge 298 is transverse to the prongs. The prongs are disposed in a common plane 321. A notch 300 is formed between the prongs, which is the same as the notch 34. The notch comprises a catch 302 on each inner wall 307 of the prongs. The catches 302 are the same as catch 42. The catch 302 is a flat surface that engages the stop 30 of a disc. The end of the notch 300 comprises ramps 304 (not shown for bottom side 282) on opposite sides 280, 282. The ramps 304 are the same as ramp portion 44. Attorney Docket No.7813P0030PC The fork comprises a stop 306, which operates in the same manner as stop 30. The fork may comprise a stop on both sides 323, 325 of the fork as shown in figures 46 and 47. The stop 306 may be a is a flat surface transverse to the common plane 321 that the prongs 294, 296 are disposed in. The spacing 309 between the portions 315 of the inner walls 307 of the prongs before the catch 302 is the same as spacing 48. The spacing 311 between the portions 313 of the inner wall 307 beyond the catch is the same as spacing 52. Therefore, the fork and prongs 296, 294 will operate in the same manner as two adjacent petals 32 of a disc forming a notch 34 between for engaging another disc with the fork. As shown in figure 50 and 51, the fork engages at the notch 34 of disc 75. Each catch 302 of the prongs 294, 296 is engaged with or engageable with a stop 30 on each side of disc 75 and the catch 42 of the disc 275 is engaged or engageable with the stop 306 on each side 323, 325 of the fork to releasably secure the fork 260 and ball connector 252 to the disc 75 in the same manner that two discs, such as disc 20A, 20B or 70A, 70B, or others, can be releasably interlocked at notches 34 as described above herein. For example, assembly of the ball connector 252 to a disc 75 is performed by first aligning a notch 34 of the disc 75 with notch 300 of the fork 260. The user then pushes the fork 260 and the disc 75 toward each other. Because of the notches 34, 300, the first contact between the fork and the disk 75 are between forward portions of petal 32 and the ramp portion 304 of the fork and between the forward portion of the prongs 294, 296 and the ramp portion 44 of the disc 75. The ramp 304 includes the entrance thickness 305 that is less than the distance 52 between petals 32. The ramp 44 entrance thickness 56 is less than the distance between 311 between the prongs 294, 296. Accordingly, prongs 294, 296 on either side of the notch 300 engage partway up the ramp portion 44 of the disc 75. And, petals 32 on either side of the notch 34 engage partway up the ramp portion Attorney Docket No.7813P0030PC 304 on the fork. The tapered surface defined by the ramp portions 44, 304 spread forces required to separate the petals 32 and the prongs 294, 296 over a longer radial distance of the disc and a longitudinal distance of the fork 260. The fork prongs 294, 296 spread apart and are driven over the outer area 28 toward the inner area 26. And the petals 32 are spread apart and driven over the bridge 298 toward the inner area 301. Once the catch 302 of the fork is assembled over the outer area 28, the prongs 294, 296 will snap back and align the catch 302 with the stop 30. Once the catch 42 of the petals of the disc 75 is assembled over the bridge 298, the petals 32 will snap back and align the catch 42 with the stop 306. The snapping back of the prongs 294, 296 over the stop 30 provides positive feedback that a connection has been complete. The snapping back of the petals 32 over the stop 306 provides positive feedback that a connection has been complete. The feedback includes an audible clicking sound along with a force feedback once ramp portions 44, 304 of the notch 34 of the disc 75 and notch 300 contact each other. The ramps 44, 304 provides a reduced force feedback to a user when being assembled to provide a more drastic contrast to the force feedback when fully assembled. Accordingly, the ramp 44, 304 substantially reduces and/or eliminates false perceptions that a connection has been formed. The contrast in force along with the audible feedback provides a more intuitive and satisfying experience to a user that encourages continued use and creation. Removal requires an initial amount of force to overcome the two flat aligned surfaces of the catch 302 and stop 30 and catch 42 and stop 306. The applied force is required to spread the prongs 294, 296 apart to disengage the aligned flat surfaces of the catch 302 and the stop 30 and the applied force is required to spread petals 32 apart to disengage the aligned flat surfaces of the catch 42 and Attorney Docket No.7813P0030PC the stop 306. Once the catch 302, 42 and stop 30, 306 are disengaged, the disc 75 is easily pulled free of the fork 260. Figure 45 and 49 shows the cup connector 254. The cup connector comprises a cup 310, a shaft 258, and a fork 260. The shaft 258 and the fork 260 of the cup connector 254 are each the same as the shaft 258 and a fork 260 of the ball connector 252. Therefore, the fork 260 of the cup connector 254 is assembled to the disc 75 and removed from the disk in the same manner as described for the fork 260 of the ball connector 252. The cup 310 is connected to the shaft. The cup comprises a concave chamber 312. The chamber has a concave interior surface 314. The interior surface 314 may be spherical or partially spherical. The chamber and surface 314 is shaped to conform to and mate with the spherical exterior surface 262 of the ball 256. The chamber may be sized to receive at least half of the ball as shown in figure 51. The chamber may be sized to surround more than half of the ball to further inhibit the balls removal from the chamber. A rim 316 surrounds the chamber 312. In some embodiments, the rim, the interior surface 314, and the chamber 312 may be interrupted by a portal 318. The portal 318 is aligned with the longitudinal centerline of the shaft 258 and is located opposite of the shaft as shown in figure 45. The portal allows an increased range of motion of the ball connector. It allows the shaft 258 of the ball connector to extend through the portal so the shaft of the ball connector is linearly aligned (180 degrees) with the shaft of the cup connector. Therefore, the centerlines of each shaft can be co-linear. In some embodiments, the cup connector 254 does not comprise a portal and the rim 316 may extend about the chamber 312 in the same geometric plane uninterrupted, such as shown in figure 49 and 51. Attorney Docket No.7813P0030PC The ball-joint connector 250 allows a range of motion between the ball connector and the cup connector. The ball connector is rotatable 360 degrees about the longitudinal axis or centerline 320 of the shaft 258 of the ball connector 252. Exemplary movement directions A and B for the cup 310 and the ball 256, the associated connectors, are shown in figure 51, but movement is not limited to only those directions. The ball connector is moveable in three dimensions x, y, z. The ball connector is movable about the connection with the cup connector and the cup connector is movable about the connection with the ball connector. The ball can rotate within the chamber 312 of the cup in any direction while the ball is seated in the cup and the cup can rotate about the ball in any direction, until the shaft 258 of the ball connector reaches the rim 316 of the cup. If the cup comprises a portal, then the shaft can also move into the portal. The ball-joint connector connects two discs to be joined but moveable relative to each other within a range of motion allowed by the ball and cup. As each of the cup connector and ball connector is able to move, so too is/are the disc(s) attached to the cup connector and/or ball connector. Therefore, the ball joint allows a range of locations and orientations of a disc held by or connected to the ball-joint connector. The ball 256 and/or the cup 310 may be sized for friction fit engagement with each other so that a predetermined separating force is required to remove the ball 256 from the cup 310. The ball-joint connector 250 can be used with any of the discs 20, 29, 70, 73, 74, 75, 100, 114, 186, disclosed herein and the fork of each of the ball connector and cup connector can connect to, interlock, and release from such discs. It should be appreciated, that the various features of each of the example petals of the discs 20, 29, 70, 73, 74, 75, 100, 114, 186 can be combined in any number of manners and combinations within the contemplation of this disclosure. Specifically, each of the disclosed discs 20, 29, 70, 73, 74, 75, Attorney Docket No.7813P0030PC 114, and 186 may include buttons 33, button housings 41, ramp portions 44, nodes 46, and indentations 76. Moreover, each of the disclosed discs 20, 29, 70, 73, 74, 75, 100, 114, 186 include the disclosed catch 42 and stop 30 or stop 150. The disclosed discs 20, 29, 70, 73, 74, 75, 100, 114, 186 include features that provide an intuitive connection with reduced forces required to interlock discs. The disclosed features further provide both audible and physical feedback to confirm connection of the discs 20, 29, 70, 73, 74, 75, 100, 114, 186. Moreover, once connected, the discs 20, 29, 70, 73, 74, 75, 100, 114, and 186 include features that maintain the connection and inhibit disassembly. Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. From the foregoing, it will be observed that numerous variations and modifications may be affected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. For example, one or more component embodiments may be combined, modified, removed, or Attorney Docket No.7813P0030PC supplemented to form further embodiments within the scope of the invention. Further, steps could be added or removed from the processes described. Therefore, other embodiments and implementations are within the scope of the invention.