I've started building the AR3 with some of the AR4 changes. I have both the Teensy 3.5 and now a Teensy 4.1. I have a number of encoders so I'm going to do it that way rather than use the StepperOnline motor/encoder pair. Same with a bunch of stepper motor drivers in the parts bin.
I've created Alibre PART files from the drawings which was a really useful way to learn how it was put together. Most of the bearings have arrived from various suppliers. And I'm pretty well done all the 3D printing.
To make the metal parts I'll first make patterns and then cast the rough blanks out of scrap aluminum. Then use my CNC mill and ELS controlled lathe to take them to completion.
Here are the first photos. I have my ducks in a row on the 3D printed parts.


Still need to order 3 encoders. Some of the screws have arrived. The rest are on their way. Started machining some of the parts. Will have to redo these because I put the slot up too high and the first one had way too fast a feed rate. The second came out nicely and since it's all G-Code for my LinuxCNC mill duplicating them, now with the slot in the right place will be easy.
BTW, how different is this robot arm from the AR3/AR4 system?
Life has gotten in the way over the last few months. Now have a new 3D printer and finally, after an order vanished and was reshipped have my connectors. So I've printed the box and ordered the stepper motors. Hopefully StepperOnline will ship in the next week or so.
Meanwhile time to draw up and start 3D printing and fabricating the patterns for casting the metal parts.
The 3mm x 1mm silicon tubing arrived. I'm glad I ordered the right angle connectors in addition to the quick attach ones. The silicon tubing is too soft to be tightly held by the quick attach. No problem slipping the tubing over the fitting and tightening the nut over that.