Noisy lathe belt

[TRM]

https://www.youtube.com/watch?v=aba9SY5h8kg

[TRM]

I have made up my mind to put a V belt setup on my lathe. I have some drive ratio options now. Since the encoder is belted 1:1 to the spindle
I can gear down my spindle to increase the torque at low rpm's. The spindle motor is rated up to 8000 RPM. I only what turn my spindle 3000.
If I belt it 1.5:1 the spindle motor will need to turn 4500 rpm, well within the it's limits.

This is my Acorn question. I was looking at the speed ratio options in wizard and I seen 3. I could type a value in 2 and 3 but option # 1 would not let me change it. Can it be changed? or do I put my ratio in option 2 and tell Acorn I'm in 2?

[Gary Campbell]

High range must be 1:1

[TRM]

Thanks Gary

[cncsnw]

... but that doesn't mean you can't have a 3:2 ratio between your motor and spindle in high range. It just means that, when you enter the maximum speed in high range, you enter spindle speed (not motor speed).

Spindle speeds in lower gear ranges are scaled from the spindle speed in high range.

In this type of setup (and most types), the control doesn't really know or care how fast the motor itself is turning.

[TRM]

Got it changed over to a V belt setup. The video don't do it justice. It is very quit and smooth. before 3000 RPM sounded scary. Now 3000 sounds like nothing. I set it up 1.5:1 and went from 100Hz to 150Hz in my VFD and that RPM scaling was right where it was with the 1:1 original setup.
I had to notch the sheet metal opening on the right side because the belt only cleared by about 1/4" and I knew there would be some movement.
I had to notch the 2 bars that the collect closer attaches to and rides on.
The top pulley bushing I had to bore to fit the spindle and the bottom motor pulley was a bolt on. It was a nice one day project.
I put the large pulley in my lathe and indicated it in axially and radially. Then I placed shim stock in the split of the bushing and installed it into the pulley and tighten the set screws as I watch the indicator to keep it square then I bored it to size. Martin makes bushing without the split for custom boring. Bushing are about $ 35.00-$40.00 depending on who has the size you need. I picked up the large 2517 bushing for $9.29 to the door via Amazon!

Some of you may find this first pic kind of a hack but let me explain the constants I was dealing with. The smallest bushing I could bore to fit my spindle was a 2517. The smallest pulley for this bushing was a 7" and I still had to notch the collect closer mounting arms. After boring there was no run for a key way. There is no way its going to slip anyway. My plan was to remove the encoder drive pulley and mill the key down that was sticking out past the encoder drive pulley and run it like that. The encoder drive pulley must be pressed on. It wouldn't budge. If I damaged it who knows where I would find another one. So I used a 90 degree 2" dish sander and sanded the key down until my bushing cleared. The ole KISS approach!

I put a indicator on both pulleys to keep them squire as I tightened the bushings. I done this on both pulleys. I suggests you do this, it will surprise you at the run out you can adjust out buy adjusting the set screws.
.001 per side on a 7" Pulley. I can live with that.
https://www.youtube.com/watch?v=_oEP9OPUjWE
https://www.youtube.com/watch?v=MWM9ttmeDMA