Have you considered using bulb/plus nuts for the transmission bracket?

 

I just looked into it. Those could work. Only issue is how much they would poke into the carpet. But still, may places those could be used. I'm going to have to pick that up for future use.

 

 

 

 

 

 

 

 

 

You aren't gonna wanna engage that much of the mill on a less than optimal machine.

I wouldn't run those 100% numbers those apps give on real machines rated for 100% duty, even the recommended specs from the tooling catalogs are exceedingly optimistic, less so if you're selling the tools...

I don't see any reason you couldn't make the things, although I expect getting them to fit right is going to be interesting. If it's like a tormach it hates DOC, so you're left with multiple passes. Sometimes even a 1/2" 0.010" skim pass was too much for the thing at low SFM in steel. It hasn't got the torque so you can't use large mills to try and keep some rigidity. 5/16 carbide mills were my go-to. If I had to make a large DOC finish pass, I'd have to stop and crank the ever living snot out of the drawbar to keep the R8 collet from putting wicked taper into the cut.

Between that and trying to get that almost press fit right while trying to keep the whole thing square, I personally don't see it happening without someone else touching them before boring, but I'd love to be proven wrong.

 

Yeah, it's going to be an uphill battle on the mill. Worst case I'm hoping is I can get them close, and have them touched up on a real machine like you suggested. I know a few machinist that could do that on a large manual mill.

You're 100% right about not running the numbers the software says you can run! My machine, I typically have to run it a lot softer than software says. I tried running 3 in^3/min in 6061 a while back because software said it could, that was an E-stop abort once it started cutting.

 

 

What kind of screws have you got? Doubles? Did you shim all the slop out, and have you mapped the lash across the entire travel? Same on the gibbs, you have checked all the travel?

What's it do if you don't climb?

 

I worked on this yesterday, all the gibs were really loose. I tightened them all up. I helped a bunch, but it's still making some bad sounds like in the video, and now shaking the machine more it seems.

I bought the cnc kit from arizona video if you've heard of him. Double nuts, and he said he set them up tight. But when I built the machine, it was something like 1 thou on X, 1.5 thou on Y for backlash. I didn't measure it across the entire range, just in the middle.

Not climbing is a good test to do, let me give that a shot and see what happens.

 

With that much lash I bet it will help a bit, it's a bummer but that much seems to be pretty typical for the cheap screws.

I think you might be able to shim your nuts a bit, but the cheap ballscrews are rolled and not ground or anything fancy so you can lock them up if they vary too much along the length. Might be worth a shot though, maybe you get lucky!

 

I tried conventional milling, it was much much smoother and quieter. You were right.

After that, I measured backlash. So before, it used to be about .001 on x, and .0015 or so on Y.

Now it's .0045 on X and .020" on Y!

Looks like something is really wrong with the Y axis. Planning to take it apart and investigate now.

 

 

Cant wait to see this thing finished with its new setup, especially once the big slicks are fitted. This things gonna fly!