G0704 Belt Drive - Trials and Tribulations

In this video I summarize many different belt drive formulas for the G0704 and while providing the advantages and disadvantages of each.
In the end, it appears simple Delrin pulleys are all that is needed for a reliable stock motor belt drive at 4,200 rpm max output.
3D printed fusion design can be viewed, downloaded and modified here if someone wants to try and improve the design;
a360.co/2JwqmIi
J-belt Design can be viewed, downloaded and modified here;

[@RustyInventions-wz6ir]

Just found your channel and subscribed. Very nice work

[@GuyFawkes911]

This helps me a lot. can you make a video about your power draw bar. (what spring waschers ...)

[@LionSandwich]

Sure thing. Will do soon.

[@RVJimD]

Nice to hear you talk thru the various iterations of pulleys and belts and problems. Did you get the j belt from McMaster?

[@LionSandwich]

This is the one I used.
amzn.to/2GaVwUP

[@ryanerskine6574]

Hello, do you have a link to the J-belt design. It looks like it's missing

[@ikbendusan]

i don't know if you can conclusively say it would mess up your run-out. pushing on the column will bend the whole column anyway, so measuring from the table is not a reliable measurement; also, the spindle is supported at four different points (two tapered bearings in the quill and two holding the combo gear)

[@LionSandwich]

Agree. See definitely may increase vibrations.

[@coltenedwards2755]

you seem to be missing the J-Belt design files.

[@Martin-uj6zn]

Hey, are you able to send me the j belt design. I will try to mod/fit them to my g0781 mill. This is an awesome mod by the way. Thank you.

[@Dan-Hanisch]

I'd be interested in purchasing a pulley set from you if that offer is still open.

[@LionSandwich]

Shoot me an email. [e-mail]

[@Darkslider3000]

Can you show the link where you got the 3D printed Pulleys?

[@LionSandwich]

Sorry for the delay, here is a link to the Fusion 360 design for the 3D pulleys. You can modify or export as STL if you would like to print yourself. These did not perform as well as the J belt setup.
a360.co/2JwqmIi

[@COBRACUSTOMS]

where i can download it ?

[@darkobul1]

I got v belt as well now but my motor died so i got first treadmill motor and that was not great but then I got 1.8kw nema 42 servo motor from ebay and that is silence. I can listen music while its working. Now I added closed loop steppers i cant hear nothing now.
I highly recomend this nema42 or nema52 servo motors they go up to 3k rpm and up to 2.6kw for 500$-700$.
I want now to get LinuxCNC as you can do lot with servo spindle like rigid tapping...
This 1.8kw is very strong motor i cut steel easy on slow rpm and big end mills. But those nema52 are option if you need more power.

[@LionSandwich]

Can you provide a link to a nema52 you would suggest?

[@darkobul1]

@@LionSandwich just search for nema52 ac servo on eBay there is bunch variations in kw and rpm. They are 220v and come with driver that is easlily controled over parallel port. They can be controled with steps, quadrature, A/B and 0-10v signal so you can chose how to use them.
Some guys did conversion on youtube and they are happy as me with it. one claimed that is match with tormach in power. I am impressed but i should maybe have got nema52 instead of 42(42 fits g0704 flush while nema52 is wider) as you can get more power then 1.8kw.

[@darkobul1]

Those ac drivers have milion settings they have internal electronic gear ratios. You can set up a bunch of stuff. You have encoder output that i assume can be feed back to LinuxCNC.
I get a lot of power on low RPM and that is what impresses me. That is not the case with VFD controller that I know of.
You just need to see what rpm you need(i would not go bellow 2500rpm) and pulley ratio you want to use to up the speed on spindle.

[@LionSandwich]

@@darkobul1 yes. Linux cnc can have feedback for rigid tapping.

[@darkobul1]

@@LionSandwichi made a video for you how it looks and works. th-cam.com/video/ENFmHKaDIOM/w-d-xo.html

[@mikeouendag7323]

How did you decide on the size of your pulleys?

[@LionSandwich]

Calculated 5500rpm

[@mikeouendag7323]

@@LionSandwich could you tell me how to calculate my own?

[@SteelCogs]

I'm currently in the middle of this right now (I don't have a G0704 but a Weiss VM25L which is nearly identical). Tried timing pulleys, Poly V 6J ribbed pulleys and am in the middle of getting 4L v belt pulleys to fit (need to grind some casted letters off to make it seat correctly) and so far I've had no luck. My biggest issue is just noise. I should be able to have a conversation with the spindle running at 5000RPM (without cutting), let alone 2500. Doesn't help the only aluminum pulleys you can get off the shelf easily are timing pulleys.

[@LionSandwich]

What went wrong with your 140J6 Poly V try? I'll make you a front spindle delrin pulley for a fair price if needed.

[@SteelCogs]

@@LionSandwich The only ones premade (since I don't have a lathe and I need a 1:1 raio) that I could find were cast iron and I needed to use a bore reducer bushing from McMaster and I could never get the motor pulley to not wobble with that. Don't know if it actually caused any excess noise but I wanted to try single V belt pulleys.
Unfortunately my mill doesn't have the two M3 screws the G0704's do because the stock tachometer is one that uses magnets and not the photo sensor thing. So I don't know how I'd be able to implement your design. I'm just not sure if it's the pulleys or spindle itself causing all the noise.

[@LionSandwich]

Any photos you could post of your setup? I'm determined to figure this out now.

[@SteelCogs]

@@LionSandwich If you want you can look at a CNCzone post I made about the noise issue before I tried poly v belts. I'd link it but it would likely get marked as spam. If you go to the benchtop mill section it's the last one on the third page (currently) and titled "Help Quieting Spindle Down." I believe it has a video showing exactly what's going on. I can also provide any extra pictures/videos you want just let me know.