An Electronic Lead Screw controller using a Teensy 4.1

[AlanB]

Sometimes I 3D print holders or spacers to facilitate machining.

 

[WobblyHand]

Sometimes I 3D print holders or spacers to facilitate machining.

That would be helpful, if I had a 3D printer. But I don't have one right now. If I did have one, I suspect there's a significant learning curve to become productive. Might be able to get one by the end of the year. In the interim however, need to come up with something.

Think I will have to "wing it" on this. The fixture I was imagining is more complicated than it is worth. It requires me to make or buy a bunch of stuff, that might be handy, but isn't important for me to have. I'm going to drill holes and make some slots and get it to work. It was a matter of pride to get it nice, but ultimately, it doesn't have to be perfect to be functional. If I dislike the outcome, I'll try something different. Hopefully the first try, even if it fails, will give me some additional insight on a better approach.

My approach will be to drill the mount holes for the brackets. (Probably slots, since I will need them for belt adjustment on the lathe.) Then drill the fixture plate for the matching holes. Drill a hole for a stud in the fixture plate that is centered by the encoder plate hole (0,0) Bolt the brackets to the fixture plate. Thread in a stud, put the encoder bracket over the stud, then a washer and a nut. Adjust the plate until it is squared to the bracket tops. Then drill through the plate and into the bracket with the tap size. Followed by drilling through the top plate with a clearance hole for the hardware, and finally tapping the hole. I think I can do this in a couple of setups, without crazy clamping. Think I will use some 1/4" aluminum plate for this, as I hate to waste thicker material on this plate.

 

[WobblyHand]

Thought of some other way to do this. It didn't quite end up as lined up as I wanted so I fly cut off some of the evidence! I fly cut both ends of the assembly to make them flat and even. It was just a skim cut, but it annoyed me. As it turns out, it will be useful for the next step.

For the slots in the bracket feet, I will flip over the assembly, clamp the assembly between the two machined flat faces in the vise, and mill them as an assembly. Hope it will work, since I don't want to take the aluminum bits apart again. Needed to use some pursuation to get the bracket feet holes to line up and start the screws. This was the price I paid for not fixturing it and drilling it all on the fixture. Oh well, this worked out ok.

I hope to get to mill the slots this weekend. When I am done with this it should look like this: (top view)

 

[mattthemuppet2]

I dunno, that's looking pretty good to me!

 

[AlanB]

Doesn't need to be pretty. Nice when it is, but functional is adequate. Better is the enemy of good enough.

 

[WobblyHand]

The machining is complete for the encoder bracket - or at least until I do the final fitting Decided to countersink the encoder screws and go with M3 flat head screws. It is the most prudent thing to do. Otherwise the SHCS holding the encoder to the plate will foul the timing pulley. Lets just call it a design blip, shall we? Sounds nicer than a blunder. Used a 90 degree chamfer mill to go in 3mm. Calculated that would give me a 6mm width, which is the head size of the M3 flat head.

 

[AlanB]

Looks Good!

 

[AlanB]

One thing I like about 3d printed parts. Usually the third design/print iteration is the best. Hard to justify making three parts by hand, but easy to print.

 

[WobblyHand]

Gee whiz, can't seem to catch a break here. Installed a VM to run my Teensy stuff, hoping for some isolation from crashing. Nope. Took down both the VM and the real machine. As soon as I connected the USB port to the Teensy identified port in my virtual instance of Arduino, everything froze. Then everything turned off about 20 seconds later. What a crappy thing to debug.

 

[AlanB]

It was working before, what changed?