====== Hitodama's Arm ====== ===== Checklist for mold ===== ==== Step 1 ==== * Metal rod is an exact half circle * Height and diameter of rod are rounded to the half of millimeter (Something like .4 might be harder to lathe?) * Base of mold allows for the placement of jumper cables in step2, so that they are free to exit to the body * Target silicone thickness is 1mm all around. * 4mm injection hole, with some extra space for the 'umbilical cord' * 4mm Bubble blow hole at the highest spot, when tilting the mold in injection. * Bubble blow hole has a leading funnel * Silicone flow is smooth and round all the way to the bubble hole with some extra material forming the 'umbilical cord' before the blow hole * Round side of mold contains coils that look just like the coils of the neck sausage * Pieces can be aligned to the accuracy of 0.1mm * Pieces can hold together while holding the mold in the air and tilting it (or let's build a ramp like Kari's? ^^) * Outer piece has a draft for easy release of top from base * base remains attached to rod during step 2, but can be removed after and the rod can be pulled out ==== Step 2 ==== * Box can contain and protect the end of 6 jumper cables while casting, so that in end we're left with a hole for the sensor and 6 ends of jumper cables * Is the Box milled? Printed? How is attached the the outer piece? * sensor should be around the middle of the palm. * Matti's point - the jumper cables should be a bit loose to make sure they don't create tension on the sensor when bending. * Target silicone thickness is 1mm all around, but there is a 1mm of extra at the flat end to accommodate the fabric and cables * 4mm injection hole, with some extra space for the 'umbilical cord' * 4mm Bubble blow hole at the highest spot, when tilting the mold in injection. * Silicone flow is smooth and round all the way to the bubble hole with some extra material forming the 'umbilical cord' before the blow hole * Pieces can hold together while holding the mold in the air and tilting it * Outer piece has a draft for easy release of top from base * metal rod can be pulled out after casting ===== Changes made to model for milling ===== * Smooth edges of bottom to top alignment notches. * Add 'mickey mouse ears' to the dent that houses the metal rod. * Remove injection hole. ===== Fixes checklist ===== * Fix bumps in the wrist that caused holes in the skin * Wider tunnels and exhaust holes for bubbles on the arm (Didn't some of them feel too small?) Exhaust Pools * Wider tunnel for the injection port on the arm (We had a collision with the remains of the umbilical cord) * The fix that we had to do manually for the sensor box, there was a problem with height? Make sure everything works together on first try * Any fix necessary to make sure the wires can pass through the bottom when doing step 2, instead of from the side which caused all of the leakage. * Apply any remaining Fillets from the 'mill' model version, such as the mickey mouse ears and the smooth alignment notches. * Make sure that after step 2, all of the wires will be completely immersed in silicone, isolated. including the tips that go into the sensor * Produce the mirrored arm. * Box tolerance offsets. * Step1 outer - One corner of one of the notches is missing a fillet * Step1 outer - The bottom of the mold should be "full" so the stock doesn't need to be milled from both sides * Step2 outer - Fillet the edges of the pool ===== Optional fixes ===== * Find a better sealant than Plastecine? * Can the bottom part support 're-skinning' the arm? after gluing the inflation tube it's impossible to put the arm back into the bottom mold. Probably a hole for the tube is also not enough, because of the glue that is around the tube for fixing it (Unfortunately still using that rather ad-hoc method of fixing the tube). But maybe the bottom part could be a hole all the way through? in that way it _should_ be possible to squeeze it inside for re-skinning? ===== Lessons learned from 1st prototype ===== * Avoid any possible dirt/was residue on the 1st stage mold. how to make sure the wax is super clean? * Work in a more sterile environment. * Don't use copper wires. Are the silver ones oxidizing? * Knit the wires into this net fabric instead of the hell that I did last time. * Should be more careful when removing the rod. Why actually didn't I do [[https://www.youtube.com/watch?v=YgKgAP8eEKU|this]]? * DON'T USE anything oil based to clean the silicone. Soap should work? * A better sealant than the Plasticine? * Fillet the metal rod/s + **Also top and bottom** * **Milling patterns for skin like?** Wax?