1920s lathe spindle removal

I suppose I should ask the unasked question

Why do you want to remove the bull gear from the spindle?

Which screw are you referring to?

Ian P

I need to fit a new belt. It’s a continuous belt so I need to remove the spindle. I’ve loosened everything on the spindle apart from the bull wheel which I have no idea how to remove

i was referring to the screw in the picture which screws on to the bull gear

Silly question.

What happens if you take C spanners to the nuts and unscrew them?

Do they control the endfloat, acting on the adjacent bearing?

If so, unscrewing them ought to let the spindle move through the bearing and out of the Bull Wheel and three sheave pulley, to allow the new belt to be fitted.

Then just a matter of reassembly and restting bthe end float of the spindle.

Howard

I can see a long bolt sticking out of the headstock casting and the only other screw in your last picture looks to be a coarse threaded grubscrew partly unscrewed from the small sheave on the pulley.

All three pulley sheaves and the (middle) gear in your picture should be mechanically joined to each other and be capable of rotating freely in the spindle (to drive the backgear).

Is the bull wheel the only thing solidly keyed/joined/fixed to the headstock spindle?

The smallest gear in your picture I assume drives the screwcutting gearing so somehow that must be part of or fixed/keyed to the spindle.

What kind of bearings does the spindle run in?

Can you show a picture of the end view of the headstock that shows that end of the spindle

Ian P

I don’t know what this screw is for

The two other gears are keyed

To each other or to the spindle?

Ian P

The spindle

Something odd here.

If the two gears near the small end of the pulley cone are keyed or fixed to the spindle then when the backgear is engaged the whole thing will lock up.

Ian P

PS I have no idea either what the screw is for, yes its a screw but it is in, or part of something.

The small gear is keyed to the shaft, the larger gear is connected to the 3 pulleys which move freely on the spindle until they are engaged with the pin on the bull wheel. I made a mistake on my previous comment

I don’t know what this screw is for

Hi Aston, so where does it go?

Regards Nick.

That was screwed in the hole in the bull gear

Hi Aston, so why did you say earlier that you didn't know what it is for.

Regards Nick.

The screw in the pulley is just for oiling the pulley when it is running free on the spindle when using back gear. The pulleys having been remachined it may have all been reassembled wrongly with bits keyed that shouldn't be.
Often as you withdraw the spindle from the headstock the bull wheel slides along the shaft but with age or excess force the key may be kinked and stuck.

That sounds very logical, Bazyle … Although the Poly-V pulleys look very tidy, there has obviously been some abuse in the assembly department

MichaelG.

On re-reading I think you need to measure accurately the depth of the grub screw hole in the bull wheel bush. The purpose is to determine if the 'bottom' of the hole is exactly the side of the spindle, or deeper ie into a keyway, or less deep indicating there is a key in place.
I suspect the big screw thing is a bodge that was going down into the keyway or into a dimple if there is no keyway and has created a gouge and burr that is now jamming the bull wheel onto the spindle.

At the non-chuck end of the headstock have you released whatever holds the spindle in and is there a keyway right to the back end of the spindle? This would be needed for the key holding the smallest gear as the spindle is removed.

Once you are clear the small gear will be free to move, and those nuts at the chuck end are released as we don't know if they are for bearing adjustment or endfloat control, and there is no grub screw in the bull wheel hole it will be time to bash the spindle out.

From your pictures the pulleys look to be for a PolyVee belt although much wider (more ribs) than would be expected. If the old belt as wide as the pulleys then it could transmit more power than the lathe could handle although it would last an eternity.

Did you remove the belt by cutting it off and was it actually PolyVee type? and if so how wide was it? (just curious) .

Another question. Is the small gear on the end of the spindle one that is integral with the spindle i.e.machined as part of the spindle. If so then that has to pass through the front bearing at least for the spindle to be extracted.

Ian P

Thanks all I’ve managed to get it apart now, it is keyed. The problem now is getting it all back together😬

T&LM are listed on the lathes website is it one of them.I have a stub miller that is T&LM ?

Frank