Mini lathe upgrade: motor-to-spindle belt drive

[Lestat]

Hi chaps,

I have a Arceurotrade C3 7x12 mini lathe and looking to upgrade the motor-to-spindle drive system. At the moment I'm running uprated steel gears on the original design, but there is way too much slack between the cogs. They simply made the cogs too small, probably to minimize losses due to out of spec manufacturing.

I can think of any practical way to raise the lower shaft 1-2mm towards the spindle, so the only solution is this: completely bypass the gears inside and drive the spindle directly from the motor shaft at a 4:1 ratio. I will only have one spindle speed at 1500rpm instead of the dual 1200/3000rpm, but I'm perfectly fine with that. I won't miss the higher gear as I hardly spin over 1500, and the amount of torque lost at 1500 vs 1200 with the original lower gear is insignificant.

I could get 2 timing pulleys relatively cheap - 15mm wide, 12 tooth/19mm for the motor shaft and 48 tooth/76mm for the spindle. I'm pretty sure it will work but not sure how smooth it will be. About £25 all in, including belt.

The alternative is to use multi vee pulleys but I'm having a hard time sourcing them in the right size - 20 and 80mm. Some of the belt manufacturers are listing 20mm as the min. pulley size so again, I'm thinking it should work.

Any thoughts?

Cheers

[ken572]

Hello, Lestat.

Here you go.

http://torquetrans.com/pulleys/multi-v- ... ulleys.htm

Ken.

[Lestat]

Hello, Lestat.

Here you go.

http://torquetrans.com/pulleys/multi-v- ... ulleys.htm

Ken.

That's great Ken, thanks!

I've sent them an email with requirements, will see what they say. Only snag is I'm on the other side of the pond

[ken572]

That's great Ken, thanks!

I've sent them an email with requirements, will see what they say.
Only snag is I'm on the other side of the pond

Lestat,
I almost forgot

Welcome to The Home Machinist

You might want to put your exact Worldly Location in your profile,
so it will show under your name, to the left of your post's.

Ken.

[Lestat]

That's great Ken, thanks!

I've sent them an email with requirements, will see what they say.
Only snag is I'm on the other side of the pond

Lestat,
I almost forgot

Welcome to The Home Machinist

You might want to put your exact Worldly Location in your profile,
so it will show under your name, to the left of your post's.

Ken.

Fixed that, and thank you for the warm welcome

I'll report back with pictures once I get it up and running.

[ken572]

Lestat,

This one is from the UK.

http://www.rdgtools.co.uk/acatalog/MULT ... LLEYS.html

Scroll Down,
3rd from the top.

Ken.

[Lestat]

Lestat,

This one is from the UK.

http://www.rdgtools.co.uk/acatalog/MULT ... LLEYS.html

Scroll Down,
3rd from the top.

Ken.

Thanks Ken, I checked those ones too but the small pulley is too big at 2''. It has to be around 1'' at the motor otherwise spindle pulley gets to be too big and won't fit in the casing.

I pulled the trigger on those HTD pulleys, although I went slightly smaller in size at 3mm pitch/9mm belt width. I'm a bit nervous about the smaller width/pitch but if a 5mm will take about 2-3KW, I figured I'll be good for 350W with a 3mm pitch.

No luck with torquetrans.com, no multi vee pulleys in my size

[ken572]

Lestat,

Looks like it might be time to make your own...

Ken.