An Electronic Lead Screw controller using a Teensy 4.1

[dkemppai]

...One has to recognize the limits of one's machines and not ask them to perform at levels far beyond their design points. Otherwise one finds other more expensive limits, like breakage. So probably won't ask my 10 x 22 lathe to cut 2 TPI threads on a 10" diameter piece of 304, or more difficult material.

If you needed a multiple lead screw, 4TPI might be handy.

This lathe is not much bigger than yours. It's a 10" also. The ways are actually pretty small, and it's clear that is was never intended for heavy work. Which is fine, it never gets used for big parts anyway.

I always like watching Abom79 turn big parts, but that takes a lot of lathe. Something that a lot of us probably don't need or want.

 

[WobblyHand]

If you needed a multiple lead screw, 4TPI might be handy.

This lathe is not much bigger than yours. It's a 10" also. The ways are actually pretty small, and it's clear that is was never intended for heavy work. Which is fine, it never gets used for big parts anyway.

I always like watching Abom79 turn big parts, but that takes a lot of lathe. Something that a lot of us probably don't need or want.

It's not that I don't like trying to push the envelope. But going far beyond the design points means things break, or other limits are reached. Fixing the limits and going further often isn't cost effective. Little fixes can help a lot, but there's a reason for the bigger machines, they have bigger work envelopes and are far more rigid.

It was neat to make the thread, but it showed the limits of the set up. Something was stalling or bending, there were moments of hesitation in the cut. I suspect that the part deflected, and wouldn't be surprised that the CL stepper jumped a little to avoid missing steps after the mini stall. This tells me that I was at the limits for this set up. I will try a bigger diameter screw, but I need to find a piece of stock that I can "waste". Usually I buy larger diameter stuff for a project. The price of stock has gone up a lot so I don't have lots of bigger diameter stuff sitting around. Haven't found cheap local places that carry cut offs of rounds. Every other shape I can get, but not round stock.

 

[dkemppai]

I will try a bigger diameter screw, but I need to find a piece of stock that I can "waste". Usually I buy larger diameter stuff for a project. The price of stock has gone up a lot so I don't have lots of bigger diameter stuff sitting around. Haven't found cheap local places that carry cut offs of rounds. Every other shape I can get, but not round stock.

Yeah, that's getting to be a problem everywhere. We used to have a local welding shop here that sold off cuts by weight, and had a pretty good selection of mostly structural stuff. That was great for small projects, until they went under. Now getting anything is a pain. Eventually I just set up an account with steel supplier that runs a truck here (to our area) weekly.

I have most of a 20' bar of 1/1-2 hot rolled, but shipping a chunk of that is probably prohibitive...

 

[jwmelvin]

Now you can do this too.

 

[WobblyHand]

Now you can do this too.

Speak Russian? I didn't catch how the bit was timed. Seems something was left out, or was explained perfectly in Russian. Interesting, but don't understand the timing yet.

 

[RJSakowski]

Speak Russian? I didn't catch how the bit was timed. Seems something was left out, or was explained perfectly in Russian. Interesting, but don't understand the timing yet.

The cutter wheel is synched with the lead screw which is in turn synched with the spindle by virtue if the change gears. The genius is knowing that the path traced out on the part is a flat. Not intuitively obvious, to me at least. t would be a useful tool but I have other options; CNC mill and/or Vertical RT and manual mill.

 

[WobblyHand]

The cutter wheel is synched with the lead screw which is in turn synched with the spindle by virtue if the change gears. The genius is knowing that the path traced out on the part is a flat. Not intuitively obvious, to me at least. t would be a useful tool but I have other options; CNC mill and/or Vertical RT and manual mill.

I understood the physical connection but didn't understand how one determined what polygon would be cut. Was interesting to see some of the machining of the required pieces on the lathe. Like you, I would have done some of those operations on something other than a lathe

 

[WobblyHand]

According to tracking, my PCB's should be delivered today. Not sure if I believe it, but it would be nice, indeed. Anticipation!

Not 10 minutes later, they were delivered! Whoohoo! Gee, they look just like what I designed, imagine that.

Kind of a primitive first design. Well have to assemble things, have work to do.

 

[jwmelvin]

Looks great. I’ve always found it very rewarding to get a board I designed (only a few).

 

[RJSakowski]

I understood the physical connection but didn't understand how one determined what polygon would be cut. Was interesting to see some of the machining of the required pieces on the lathe. Like you, I would have done some of those operations on something other than a lathe

The number of sides on the polygon would be determined by the number of cutters on the disk and the gear ratios. With a single cutter and the lead screw rotating at 3x the spindle speed, you would get three sides. Add a second cutter to the disk and you would have a hexagon.