I was up until 4:30am last night working on the fifth attempt to design the arm.  Previous post on HAD.io were of (at best) study 4.  I reached a point in the design where I'd found enough mistakes that it was easier to restart and use the existing design files as a reference to do a better job.  I believe that - after three days of work - I've got something that solves all my previous issues and has fewer prints. 

With lessons from the previous attempts, this time I built things in large passes:
place all the things that can't be negotiated (bearings, motors, screws in motor faces)

1. build the bones to hold the parts together as rough blocks
2. plan where to cut the bones for printing
3. add the screw holes, screws, and nuts to each block
4. cut the bones into pieces
5. calculate bill of materials
6. order missing mechanical parts
7. adjust each piece for printer tolerance and print.  <-- I am here
8. the rest of the Gantt chart

Speaking of BOM, here are some stats:

• 218 fasteners
• 34 mechanical parts off the shelf, including the drivers and the controller
• 35 printed parts using ~1.8kg of filament at 20% infill will take 65h of continuous printing.

Cost for raw goods and DIY printed parts is matching my expectations.  The long pole is the 8 larger bearings.  I got them from VXB.com and they're about $250+shipping.  Ugh!

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