Thread: Sheraton 9 A 1167

Bigcam,

Thanks for the belt type, but I cannot read the lengths in the photo.
Could you please check the lengths for me ?

It has been 10 years since I dismantled the lathe, so everything is new again for me !
I hope I don't fall in love with it a second time as I really don't need two lathes.

Thanks, John,

2 x B43

pipeclay and Bigcam,

Thanks for the details and confirmation, you can see how long it is since I considered belt details.

A special invitation for you to come to lunch next Tuesday.

John.

Originally Posted by electrosteam

Progress.

Cleared-out a lot of rubbish from the workshop, had a 12 mm ply ceiling installed, and the stripped-down Sheraton bed/stand moved to the roller door.
Now comes the re-assembly.
The original belt was cut to remove it and long-lost.

What size belt do I need ?

As the lathe may end up in the hands of a good friend, would it be better for him if I use a multi-segment belt ?
If so, any suggested sources ?

As there is no lighting yet in the workshop, photos will come 'soon'.

Keep well.
John.

Sorry I haven't posted on this forum in a long time but I may have some spare B section link belting that came with a Sheraton I bought a while ago. My shed is a mess but I can plan an archaeology dig on the weekend and let you know.

Darryn,
Thanks for the kind offer, I will PM you.

Assembly is progressing with the spindle assembly a very nice fit in the headstock.
I am using ISO 68 for lubrication.

But, before I attempt to spin the spindle up I need to do something about the headstock shims.
They are currently ground steel of about 1.8 mm thick.
I know the originals were aluminium.

As I see it, the risk with the steel is them moving out of position and rubbing on the spindle.
This may be particularly a problem with the initial running as I experiment with shim thickness and closure bolt tightness.

My research says that grinding aluminium is doable, and I have a surface grinder.

Suggestions welcomed on how to achieve acceptable shims.

Keep well,
John.

The archaeology dig was slow but successful! The belt from my lathe is in the middle, you are welcome to the one that's the longest.
PXL_20231002_020636482~3.jpg

Thanks Darryn for the belt, I will put it to good use.

Photo shows the very rough setup to run the bearings.
Running at about 200 RPM.
The DC motor is 300 W, 440 RPM at 24 Vdc.

Start conditions: 4.4 A at 10.8 Vdc.
After 14 hours: 2.0 A at 10.5 Vdc (the battery charger was losing the race !).
Bearings were virtually at room temperature.

The run was broken up into 1 to 2 h sessions.
At the start of each session the current was higher, then dropped off.
As oil was added at random, the current would increase by about 10 %, then settle back down.

Very interesting.
Note that 2.0 x 10.5 is only 21 W of electrical power (and the measurements were confirmed).
As the DC motor was warming up, the actual spindle power was less.

The new belt can be seen hanging on a pulley in the back of the photo.
That will now be installed and the spindle run by the AC lathe motor (if it still works !).

Sheraton Spindle Run-in.JPG

Keep well,
John.

Got the belt on, and ran the spindle progressively up to max speed.
Then multiple runs at max speed for progressively longer periods.
Last run was 60 minutes in 23 degrees ambient.
The bearings ended up quite warm, but far from hot.

One small problem, the thickness of the belt makes it a tight fit between the pulley and housing as speed is changed.
For anyone reading this, I think the modern tab/slot non-rivet link belt would be better in this regard,
But, the rivetted links do run nicely, it just purrs.

John.

Probably too late, but -

Originally Posted by electrosteam

I am using ISO 68 for lubrication.

I don't have a solid bearing lathe, but I had to get something thinner for the solid bearings on my surface grinder. It may be worthwhile investigating oil grades, as I am not sure (although I'm no expert) that the lubrication you are supplying will work well enough to flush while maintaining an oil film.

Originally Posted by electrosteam

My research says that grinding aluminium is doable, and I have a surface grinder.

You can, but the problem with grinding Al is that it loads up the wheel, which can then cause problems with overheating and (worse case) wheel spalling. Holding it to the chuck is another issue. We used to use a vacuum table, but if you are going to go to the trouble of making one of those, you could also then grind stainless.

Michael