Record Power - Excellent Service

[sammo]

Been having a few problems with my CL-4 lathe. Some time ago the main spindle seized (I posted on this back last summer) - anyway it happened again, and after taking it all apart it there was some serious scoring on the inner surfaces of the bronze bearing.
So gave Record power a call ordered a replacement, and whilst I was about it ordered the rear bearing as well...

Both arrived within a couple of days - all good so far...

Spent Saturday, taking of the rear bearing (thank goodness for Dremel!) and cleaned everything, ready to put it all back together again.

Then disaster...

I hadn't screwed the thread protector on fully - and believe me it takes some determined whacks with a mallet to get that rear bearing seated, result one cross thread, and an equally cross "wood turner" After a few choice words, and kicking myself around the workshop; took everything apart again and called Record Power this morning - part in stock and will be posted straight away, and they even decided that they wouldn't charge me for postage, as I had only ordered the other parts the week before.

Great Service in my opinion - well done guys.

Chris

 

[CHJ]

......- and believe me it takes some determined whacks with a mallet to get that rear bearing seated, .... .....

I'm a bit perturbed about the "determined whacks with a mallet " on the end of the spindle to fit the rear bearing.

Whether this is to fit the outer of the race already mounted on the spindle in the headstock or if it is the fitting of the spindle in the bore of a race already mounted in the headstock doing so by applying the driving force across the race bearings can only do harm.

Fitting inner races to shafts should be done with a tube driver to press on the inner race only not the outer.
Fitting of an outer race in a housing should be done with a suitable driver located only on the outer.

 

[sammo]

Chas

The manual is a little vague about the whole process, other that showing pictures of a well used mallet.

For example for fitting the rear bearing it says
"18. Place the back bearing on the end of the spindle up against the step in the shaft. Once fitted this back bearing should be offered up to the fitting area in the back of the headstock ready to be re-seated. Fig. 11.18."

As if the bearing will simply glide on to the shaft.

So what I did was...

Line the bearing with its hole in the back of the head stock - then using using a G-Clamp and two bits of ply - eased it in as far as I could - I was a little wary that the bearing was not going in straight, so once it seemed ok, I then offered the shaft to the bearing - at this point it took some gentle taps to set it on the shaft - but to get it into the head stock, took more determined effort - that said I am using a fairly light mallet, not a club hammer!

I don't have a tube driver - where would I get one?

My main error was that I didn't fully tighten the thread protector - I got the feeling from Record Power that I was not the first :-(

Chris

 

[CHJ]

The basic error is that the final seating being it on the shaft or in the headstock was relying on a shock load applied across the bearing race.
Be it ball or rollers there is serious risk of damage to the hardened balls or race walls.

The bearing should be checked in the headstock for fit and if not an easy push fit, such as can be achieved with your G clamps the housing should be checked and cleaned out.
The application of a hair drier to the casting/housing for 20-30 minutes or more may help considerably.

The bearing should be a similar firm fit on the shaft but nothing that a gentle tapping with a piece of tubing registering on the inner race only won't fix. (so there is no load on the balls/rollers)

Put the new shaft in a plastic bag and leave in the freezer for several hours.
Just before fitting the bearing warm the bearing up until its just still comfortable to hold but not hot enough to loose any grease.
Slip it on the shaft and quickly press home.

Now refreeze the shaft and bearing before offering it up to the heated headstock.


So doing the above:-
Bearing will be at max diameter, shaft will be at minimum diameter.

Bearing on shaft will be at minimum diameter, housing will be at max diameter.

If the bearing is already in the housing when you come to fit the new shaft then freeze the shaft and warm up the headstock casting and bearing.

Not personally worked on a bronze front bearing record but the shaft/rear bearing mounting must have some measure of lateral movement available to allow the adjustment of the front bearing, unless of course the front bearing adjustment is independent of shaft position. I'm surprised that the fit to housing or shaft is that tight.

 

[sammo]

Thanks Chas - will do all you suggest, especially as there is a freezer in the workshop.
The bronze bearing and the main shaft are tapered, you then (using two large "nuts") simply squeeze the bearing on to the shaft - then starts the dark art of adjustment - and I quote
"Bearing test guidelines
A simple test to see if the bearing is correctly adjusted is to hold the spindle between finger and thumb and turn it:
• On a correctly adjusted bearing resistance will be felt but the spindle should still rotate.
• If the spindle rotates freely, it is too loose
• If the spindle cannot be rotated, it is too tight."

Or in my previous experience if oil comes flying out and sprays you from head to toe it's too loose, if no oil comes out it's too tight


I think that the previous owner had not used the lathe for some time, and the bearing dried out - then it seized; from then on it was a bit of a compromise; however once I get the right shaft from Record Power - and follow the advice given I am sure I will be back enjoying myself again.

Thanks for your time and advice.

Chris