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Link Belts For 13" Lathe With Motor Brake

ptsmith

Cast Iron
Joined
Feb 15, 2018
I have a 2HP Jet BDB-1340A 13" X 40" belt drive lathe. I'm putting a 3 phase motor with a Sterns brake on it. I need to replace the v-belt to the motor. The motor belt goes to an idler shaft (I don't think that's the right term but I don't know what it's called). Another belt goes from the idler shaft to the spindle. To get the idler shaft out requires removing the spindle, as well as the back gear shaft.

That's a much bigger job than I want to tackle. Not having ever done that I'm sure it would take me forever. A link belt would solve that problem, but I'm not sure it would be heavy duty enough, especially considering the motor brake.

Anyone used a link belt in a similar situation?
 
Many people including me use a link belt for the same reason. It will be fine, though it will stretch a little a first and likely require removing a link or two.
 
Thanks. I'm going to buy one. There's so many options and I've been trying to sort them out. I thought I should possibly get a riveted version but I ended up going with a Fenner Power Twist.

I read these belts are directional, which is pretty obvious. The motor brake is going to load it really hard in the wrong direction. I wonder if I should run the belt backwards because of that.
 
Harbor freight actually sells a good brand of link belt in their stores. It is the only product they sell with a real brand name on it.
Bill D.
 
I saw all the good reviews on the HF link belt. Unfortunately it's 1/2" and I need 5/8".

I made an offer on the Fenner Power Twist belt on ebay and the seller refused it. That's fine because I think I'd be better off with rivet belt because of the brake loading it in the wrong direction. A lot more expensive but what the hell, it's only money.
 
I would not run it backwards. Braking is a short duration and likely less power than a good cut.

I missed this. That makes sense. And I'm guessing the riveted belts would be able to handle a reverse load better.
 
I missed this. That makes sense. And I'm guessing the riveted belts would be able to handle a reverse load better.

I stop mine in like 2 seconds with the VFD and it has not been and issue. I’m not sure I’d worry about a riveted belt. It’s not like you’re worried about slipping or anything
 
My worry is the connecting tabs folding back when the brake engages.

I bought a VFD, brake resistor and standard 3 phase motor before I lucked into the brake motor. Brand new and free. Hard to say no to that! Anyway, brake motors stop almost immediately. I'm hoping that I can I can dial some slippage in without burning it up. With the brake resistor assisting maybe it will be alright.

I made another offer on a standard 5/8" link belt and this time the seller accepted. 5 feet for $30 shipped. That's a pretty good price. He's got 2 more if anyone needs one: BROWNING PREMIUM BP 5L GRIPTWIST 5FT LINK V BELT 2708048 | eBay
 
The motor brake is for safety, not for convenience, although I guess if you need to hit the brakes because you f'ed up, it's probably too late anyway, and that's assuming you are able to hit the emergency stop. But I got it so I might as well use it.

I did end up getting a tabbed belt because it was relatively cheap.

I saw a video of a guy taking a riveted belt off of a lathe that I think he said was 45 years old. He was was an older gentleman and had owned the lathe for many years. The belt was the factory original. It was trashed, but that's impressive. As some of you have mentioned these can hold up surprisingly well. To look at them you'd never think they'd be so durable.

Here it is if anyone is interested: YouTube
 
Since you got a VFD to run the motor, you will most likely want to disable the brake.
The VFD will allow you to run slower, and the brake might try to drag or grab at reduced voltage/speed.

The VFD is very capable of stopping the lathe, as quick or smooth as you want.
 
The VFD is very capable of stopping the lathe, as quick or smooth as you want.

Actually... while slow-ramp start is magical with a VFD, most do not STOP nearly as well even when built to utilize braking resistors AND given such. Few ever are.

A Warn, Dings, Baruffaldi or similar motor-shaft brake, OTOH, is but an electrically (Or air. Or hydraulic..) engaged/released friction brake, optionally spring-wrap assisted. They generally stop well, and they generally HOLD even better.

Emergency stop can be expected to slip the belt, though. Link OR continuous.

And... if you USE one of that tribe, you will want to provide an optional over-ride switch to release it, motor OFF.

Otherwise - unless you ALSO have a clutch in the drivetrain - you'll not be able to rotate the spindle by hand when changing workholders, setting-up, nor measuring a part.
 
This is actually an old project that I haven't had much time to work on, but I have had a lot of time to think about it. Most of these things you've mentioned eventually dawned on me. To spin the chuck by hand I'll need to loosen the the belts, and there's a handle that does that so it's not much trouble. With the belts tensioned it's quite difficult to turn the chuck. It's a Chinese lathe. You get what you pay for.
 








 
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