Spindle belts rubbing bed

[Nooj]

Hello all, Nooj here.
I’m in the process of reassembling my late model Atlas/craftsman lathe and I’ve run into something of an issue.
The double spindle belts seem to be touching the lathe bed on the front side. I’ve loosened all bolts (bed and pan) and motivated everything with a rubber mallet, but it never seemed to move enough to give clearance between the belts and the edge of the bed they pass.
Any ideas or suggestions?

Thanks,
Nooj

 

[Nooj]

I know they look fuzzy in the pic, but those are brand new Kevlar belts.

 

[Provincial]

Are they rubbing on both sides, or just one? If just one, the countershaft may be off center. If both, someone may have put a larger pulley on the countershaft.

Those are A-section belts, right?

 

[graham-xrf]

Hi Nooj
Think back to how they were before you took the old ones off. Particularly, do you still have them around such that you could get out a caliper, and check them compared to the new ones?

The physical reasons they don't fit in that space are:

1. They have the wrong section such that they do not settle fully onto the pulley. This can include that they may have the correct angle section, but are still of a size too wide for the pulley at the bottom.

2. The height of the section is such that the belt outer sits too high beyond the pulley outer radius.

3. Include the reasons mentioned by @Provincial . There has to be some means by which the belts are tensioned, and this entails moving something about somewhere. Things may have moved a bit when you loosened it to change the belts, but clearly you have already been persuading it to it's limits. It's the position of the countershaft and pulley below that matters here.

If all adjustment options are exhausted, then suspect that the belt, even though possibly of the correct section to snug into the pulley, might simply be taller than the original.

 

[wa5cab]

Nooj,

Also, the belts appear to be loose, because they appear twisted which tightening them to normal belt tension would or should eliminate. Try taking the single belt off of the two 4-groove pulleys, loosening the four bolts in the bearing supporting the lower 2.groove pulley, pulling down on the pulley, and re-tightening the bolts. And confirm that the four bolts mounting the jack-shaft bearing are not against the bottom of the bolt holes.

Also confirm that the two belts are A-section, not B-section.

 

[Nooj]

Thank you all for the responses. I was finally able to manipulate things enough to get a smidge of clearance.

I was careful when ordering these to be sure they were the correct belts. They measure in at .46” wide and I think that causes them to ride a little high in the pulley.
I ended up using the belt tensioning lever to pull down on the countershaft bracket while tightening the bolts. Hopefully the belts aren’t too tight.

Thanks again for all the thoughts and tips to get my gears turning.

Nooj

 

[wa5cab]

If, as I did, you have a problem with the motor pulley wanting to walk off of the end of the motor shaft, get a 5/8" bore split coupling clamp like a 6436K15 from McMaster-Carr and install it on the end of the motor shaft up against the 2-groove motor pulley. If necessary, shorten the key in the pulley so that with coupling up against pulley, at least 1/4" of shaft sticks out of coupling. If neccessary, adjust motor mounting so that belt runs straight between motor pulley and countershaft pulley. I did that at least 20 years ago and haven't had the pulley move since.

When you get time, don't forget to enter info about your lathe in the thread at the top of the Atlas-Craftsman forum.