I finally had the time to sit down, re-model the Raptor Reloaded proximals (and distals) to be completely driven by a suite of parameters that are turn tied to a master scale factor. This allows the independent sizing of the macro-geometry from function-critical elements like the joints, which will be a huge step forward from the current linear scaling method. Using the above-mentioned script from friend and colleague Hans Kellner, I've created several lookup tables for every size between 100% and 200% for three clearance values, ranging from Rep2-tight to looser. All is available in this project's directory on my github
I designed the parametrics of this two new implementations of the Raptor Reloaded fingers to be compatible with the existing palm and snap pins, meaning that we can make big improvements to functionality across the whole range of sizes by just replacing these two parts and not touching the palm or other snap pins. Peter Binkley observed months ago that the proximals would be the best candidates for parametric conversion and extending upon that, we can get improved performance out of a design by making just one of any two interfacing parts parametric. In the case of the Raptor Reloaded, 10 our of 12 joints can be improved moderately with just the substitution of the proximals, and can be significantly improved with the substitution of the proximals and the distals.
This semi-parametric workflow has implications in overall device architecture and fulfillment strategies:
- Handomatic can leverage this lookup table to rapidly serve properly-scaled geometry to users.
- We can leverage kits very effectively and include fewer redundant sizes of screws, making the devices easier to assemble.
- We can design around specific off-the-shelf components, such as stainless steel dowel pins, to create more robust designs and mechanisms.
- Now that we can hold certain interfaces constant, we can start talking about manufacturing large quantities of high value/function parts, such as the differential tensioner (gripper box) via mass community manufacture or injection molding.
- We can match clearance settings to particular machines for more consistent quality across the aggregate.
- Tighter and more consistent clearances all around, leading to better functioning and quieter devices.
Apologies if the red prints in the images below don't show up well on some screens-- they display with reasonable contrast on my macbook pro, but are a bit washed out on my external display. The CAD snapshots illustrate the differences well and test prints from my github repo can illustrate physically. While configuring the distals to parametric control, I also fixed a long-time bug in the geometry leading to persistent dropped filaments on the snap pin head recess. I am also nearly done testing a parametric proximal for the Phoenix hand. That proximal can be set up to use the same rubber band across all sizes if that is demonstrated to be necessary.