|Erik Shepherd||16/01/2021 22:08:08|
|2 forum posts|
Good evening chaps.
My first post here, although I've been an active browser for some time now, so apologies if it's in the wrong place.
I've recently bought a Chester 920 lathe from someone, who clearly never used. Bargain, I reckon. Anyway, it has clearly been neglected as the leadscrew was disconnected, the thread cutting lever was completely jammed up and some other things not quite the way I would like them. Oh - and it was missing the 127 tooth gear, which after several evenings of googling turns out to be unobtainium, so I 3D printed my own and it's been running brilliantly.(if anyone is in a similar predicament as me, drop me a message. Happy to help)
Anyway, onto my question -
The lathe runs great, but it has a rather alarming issue - when starting the motor, it makes quite a horrible noise. Sounds a bit like gears mashing together, but it comes from the motor itself. Also, it seems to bog down quite easily when taking deep cuts and on few occasions has even stalled, resulting in a horrid noise that made my cats jump.
I was wondering if anyone had similar experiences and recommendations for the best way to remedy this. Currently I'm making the 4 bolt cross slide clamp as the factory one is far too loose and wobbly for my liking(I've used Colchester lathes at uni, so I'm aware that this won't be anywhere near the power or rigidity of what I'm used to, but a 0.1mm facing cut really shouldn't be a problem...)
Thanks in advance.
|Niels Abildgaard||17/01/2021 08:06:49|
|369 forum posts|
Throw old AC motor out and put a sewing machine motor on.
I did and it sounded very nice and was easy to alter speed.
|Howard Lewis||17/01/2021 10:34:19|
|4441 forum posts|
Sounds like someone had ABused the machine!
Does the motor make strange sounds when starting, without the belt?
Is the pulley tight on the motor shaft, rather than slipping?
Is the belt a toothed one?
If YES, Could it be slipping?
Are the motor bearings worn?
If you can eliminate each possible cause of the noise, you will eventually find the cause and be able to do something to cure it.
409 forum posts
I've got an early Taiwanese 9x20, not sure if they're exactly the same, I had a noise coming from that area that was remedied by tightening the cap head screw in the centre of the pulleys, might be worth checking.
|Erik Shepherd||17/01/2021 22:30:58|
|2 forum posts|
Thanks for all the advice everyone. Greatly appreciated.
Got to the root of the problem - it wasn't the motor at all, but instead the belt that connects the pulley to the geartrain was criminally loose! Took the lathe apart, dropped the motor down in the mounts and now it's tight as a drum and runs 10x better. The noise was coming from the toothed belt rubbing against the pulley when the lathe stalled(which it did very easily)
|Howard Lewis||18/01/2021 18:34:10|
|4441 forum posts|
Thanks for letting us know.
Glad that it was a simple problem with zero cost / trouble solution.
You may have made life and sleep easier for someone else who has similar problems.
|Ron Laden||18/01/2021 20:19:16|
2132 forum posts
Good you found the problem Erik but a correctly adjusted toothed belt shouldnt be like you say "as tight as a drum" it needs easing back a touch. If you take the flat of the belt between your thumb and forefinger you should just be able to twist the belt through 90 degrees that should be about correct for a belt of that size.
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.