Hi there everyone! I recently completed my first hand as a part of 3D Hubs’ partnering with E-Nable to print the newly revised Experiment v5 hand.
^ This hand is actually going to a training workshop to teach people how to assemble the hands and then will be donated to charity. I’ll divide this post in to three major parts. The print, the process, and my take away.
The print popped up in my 3Dhubs ordering feed last week for one of my printers. At first glance, I actually didn’t realize this was one of the opt-in for charity hands. Several of the parts had an error “Part may be too small to have accurately calculated cost.” and were all listed at $0.00 (or rather, 0.00cm^3) Also, there were quite a few duplicate parts and “extra” parts. The requested print contained palms for both the left and right hand, but only one wrist support. It also only contained enough pins for one hand.
The e-nable hand is a relatively complex design. To ensure there is a proper checklist for all needed parts, requestors should upload a blueprint like so. http://c.searspartsdirect.com/lis_png/PLDM/50034474-00001.png
The file names themselves actually had the naming convention “Part_leftorright_quantity.stl” This was great, except was horribly inaccurate. For instance, it only called for one knuckle pin when 4 are needed. I had to base what parts were needed on previous revisions as I could not download the v5 source from anywhere. The uploaded parts were also missing the supported version of the left palm and I had to mirror the right-palm.
All of the parts pictured were printed with:
TL;DR? There needs to be a better parts list, and a schematic of all the needed parts. Less experienced hubs are going to miss a few parts with such a large print-job request. E-nable should present the parts pre-plated to simplify.
One great thing about printing the e-nable hands is the baked-in support lattice. There’s even a “support test piece” included for you to ensure your printer can print the single-wall support without issue. Where this may become a problem, is when the print gets scaled up as mine was.
The hand I printed was requested to be scaled to 135% size. This being an option that 3D hubs should be able to facilitate. With an increase in scale, often comes sloppier tolerances and you guessed it, bigger walls. The support walls for right palm caused the print to fail twice for me. Unfortunately, if a printer hits resonant frequency infilling a .5mm wide gap, things get messy. I had to manually scale the support structure in X and Z ignoring Y (to prevent the problematic double-wall from occurring.) E-Nable should provide several 1wall thickness support latices for different scaled hands. In 5% increments from 50% to 150% should be sufficient. This would prevent other users from having problems.
The process itself, I already touched on a tad. It was somewhat jarring to see what a print I’d normally charge ~$100 for come in to a whopping $0.00 in my hub. I spent around 20 minutes fiddling with all the parts in my slicer before realizing that this was a for-charity print. 3D hubs needs to have a clear notification (like a blue ribbon or badge) that shows this is a probono print. In fact, that would be a cool thing to have on my hub after completing such a print.
The person ordering the print did not have much experience with 3D printing or the technology required. They were also sometimes sluggish to respond to the needs for the printed part (see parts list being wonky) What I did find out is that they had several other local hubs printing extra pins and smaller parts. My hub was used to print this part mainly because the other hubs had issues printing the palms and gauntlets.
Otherwise, the process was just like any normal customer print. It took a little longer than I’d have liked totaling in at 14 hours of print time stretched over a week so I could supervise. A total of ~17 hours if including the time I took to reorient the parts, plate them, clean off burrs, and package them.
I absolutely love the fact that I am providing a training aid and ultimately a hand. A freaking hand. From my humble desk, I am giving someone something I take for granted every day. No, its not the absolute most flexible hand, but it’s good enough to tie shoes! I hope to continue on with the 3Dhubs charity project, and most importantly, helping people. AMaA!
