[PLAN] Replace glove design with rings for each individual finger

[xjjak]

Describe the vision. What is to be achieved? What does the end-result look like? Is it a specific feature? Instead of having the SenseUnits attached to a glove, 3D printed rings for each finger and some kind of strap for the motherboard should be the way to wear the glove. This would not only be a sleeker design, but also more lightweight and a more individual fit.

One problem to consider is how the individual rings are held together, since the cables as they are, are not enough. Perhaps a sleeved cable would be enough, there needs to be a strain relief before the connectors though.

[xjjak]

After fiddling with old USB cables, I concluded that they were either too brittle, or too stiff or even not even the right size, so I settled for the usual 4 individual wires with some heatshrink before the connectors as strain reliefs, which seem to work surprisingly well. Additionally, the wires get twisted to make them less flimsy.

By now, the ring design has gone through multiple iterations. Mounting the SenseUnits works by just pushing them into slots, which stick out too much, though. Instead of two connected (or even separated) rings is trashed. The thickness definitely has to be minimized, and hasn't yet been pushed to its limit. The right offset is also to be determined. Putting gaps in the rings where the palm is may improve comfort and ability to wear the glove constantly, but while figuring out the right size and fit, it may be better to remove them. Only the thumb requires them anyway, since the ring would otherwise hit the typing surface. There it could also be sufficient to put the ring on the first finger segment.

Here the current version of the rings can be seen in comparison to the first prototype. The size need to be adjusted as they are quite uncomfortable to wear as they are. They are also too thick.

[xjjak]

After adjusting the rings' sizes a first iteration of a palm strap mount was designed (one prong snapped with the base being too thin, and it was too large):

After thickening the base to 2mm and fixing the offset parameter to be in the right direction, a first fit was achieved:

Slimming down the design by removing the overhangs over the ESP and the SD-card:

Followed by adding a cage for the battery:

Which had the issue of blocking the Mobo from sliding in fully due to the battery port (which broke off slightly on the secondary Mobo while testing)

The next iteration included some size adjustments and a slot for the battery port:

[xjjak]

While the 3D print designs are mostly done, the actual strap is not. It remains to figure out the proper width and right fabric to use. The strap shown in the last picture is too broad and tight. The fabric may also be too thick, as a simple strap made from the softer black fabric was much more comfortable. But that may be fixable with the right size. That is to say, the strap made from the black had its own issues, as it was almost too loose, and the mount didn't hold on to it extremely well. That may also be resolvable by decreasing the prong clearance though to account for the thinner fabric.

[xjjak]

The OpenSCAD design will be done at a later point in time #17.

[xjjak]

The white strap material provides better stability, although a bit less comfortable. It should be attempted to decrease its width. If a cut made to decrease the strap by 5mm for example does not lead to it unraveling, this material would probably be the better choice when the right length is chosen, though then perhaps limiting the range of different users for whom the gloves fits comfortably. The last consideration would be a possible overlap, to strap the MoBo onto, or if a single layer is sufficient.

[xjjak]

There are now two straps in different sizes, one for each of us. They are slimmed down to about 25mm and just sewed together at the ends with an overlap of a bit more than 5mm.

I adjusted the MoBo-mount accordingly, but also flipped the prongs to make them counter a pull-on motion, which seems more practical than supporting strap-already-on-hand mounting. Another small addition were small catches opposite of the prongs holding the strap better. The underside of the design now looks like this:

[xjjak]

The changes work quite well, the only issue is the stand-off caused by the strap underneath the MoBo. The thickness parameter could be the solution to lessen the strain on the PCB. One other idea is to "emboss" the strap into the prongs, making only them 1mm thick with the surrounding base remaining at 2mm thickness, to reduce the offset under the MoBo.

[xjjak]

Embedding the strap worked very well.

I also adjusted a few more parameters, thickening the base, enlarging the strap catch and adjusting the MoBo width. These are now the current parameters, which make for a snug fit:

The end result: