Thread: 7X12 Lathe Problems

Can you post a picture of the worn bit? A fix may be easier to suggest if we can see the part.
If it's a standard sort of belt pulley then most power transmission places would probably have something. Some of the Ag suppliers in Murray Bridge may do that stuff too.
Depending on how much meat is on the pulley hub it may be possible to sleeve it.
Can you also give the diameter of the shaft it sits on and the key dimensions?

Michael

sounds like the pulley has come lose and been flogging the keyway....your shaft isnt damaged is it?

take it down to East Bearings or Bridgeside Bearings...I reckon they should have a pulley or would be able to get one

if not come to the bigsmoke and try CBC bearings Regency park, or Southcotts in the city or Adelaide belt and hose at Mile End.

If your keyway is stuffed, see if can get a taperlock pulley in that OD size... if you fit it correctly/properly you will get away without having to use a keyway....it must be cleaned with solvent before fitting.

Also get a new belt.

Cheap bodge, that might get you out of trouble:
Drill a hole right through the pulley and shaft, and fit a roll-lock pin.

Jordan

Originally Posted by nadroj

Cheap bodge, that might get you out of trouble:
Drill a hole right through the pulley and shaft, and fit a roll-lock pin.

Jordan

change your signature to Marvel Butcher....that is not the way to do it...he is in easy reach of Adelaide, although he should be able to get the stuff locally...not a 1000 klicks from nowhwere and a do or die scenario

Well, he had the expensive suggestions, and I thought a cheaper alternative might be of interest.
Anyway, what's so bad about the roll pin?

Jordan

thats even better than what I suggested...Mechanical Butcher instead of mechanical marvel ...its fitting

If the cap fits - wear it!

Jordan

It's a toothed pulley, about 30mm diameter. The keyway slot on the motor shaft has now a V shape to it, 3mm at the back and 4.5 at the front??????
Unfortunately I don't know how to load pics on here, I'm basically computer
illigitimate!!
Thanks for the quick replies. Will try Bridge Bearings and Bolts tommorrow.
Kryn

Have you been able to workout why the keyway in the shaft has worn?

Was there a grub screw in the pulley to lock it to the key?

As long as the pulley still fits on the motor shaft and its not like a c-ck in a sock,you could replace the key and lock the grub screw up tight,if you want and providing there's room you could fit a 2nd grub screw to lock the 1st or put 2 grub screws on the key.

You could also if the pulley is serviceable leave the key out and just dimple the motor shaft with a drill bit and clamp straight to the motor shaft.

If only the keyway in the alloy pulley is buggered, you could open out the pulley keyway to a uniform size and then mill a stepped key to mate it to the spindle.

Or just cut/file another keyway 180 degrees opposite the buggered one.

Pretty easy fix.

I would be questioning why it came loose in the first place.

Rob

Originally Posted by pipeclay

Have you been able to workout why the keyway in the shaft has worn?

Was there a grub screw in the pulley to lock it to the key?

As long as the pulley still fits on the motor shaft and its not like a c-ck in a sock,you could replace the key and lock the grub screw up tight,if you want and providing there's room you could fit a 2nd grub screw to lock the 1st or put 2 grub screws on the key.

You could also if the pulley is serviceable leave the key out and just dimple the motor shaft with a drill bit and clamp straight to the motor shaft.

Unfortunately I've not been able to work out why the keyway got worn, I got it from my brother, and I don't think he abused it. Everything was out of adjustment, gibs etc.
Unfortunately the pulley is stuffed and doesn't appear to have had a grub screw, looked like it was a press fit (once).!!!!!!!

Originally Posted by nearnexus

If only the keyway in the alloy pulley is buggered, you could open out the pulley keyway to a uniform size and then mill a stepped key to mate it to the spindle.

Or just cut/file another keyway 180 degrees opposite the buggered one.

Pretty easy fix.

I would be questioning why it came loose in the first place.

Rob

Hi Rob, Unfortunately if it was that easy I would have done it already, the pulley is of a plastic nature, one end about 10mm the other worn to about 12mm as I said in the other thread it is stuffed!!!! Little Machine Shop about $8.50 plus postage.
Kryn

Looking at the pictures on there web site,the pulley seems to have a large enough boss for you to drill and tap for a grub screw to lock the pulley to the key.

If the replacement is plastic and there is enough meat on the boss you maybe able to use a 2nd grub screw to lock the 1st,this would be benaficial if the replacement is plastic.

Also if you do tap the new pulley I would suggest to also dimple the key with the end of your tapping drill this will also aid in retaining and stopping movement.

$8.50 for a replacement pulley is not too bad.