Restoring (hopefully) my new Smart and Brown SAB

[Ben17484]

One more problem fixed today:

I made the ‘half moon’ (anyone know the real name for these?) parts to push the shoes out to engage the gear and worm drive. I made them out of brass for two reasons 1) that’s what I had to hand in roughly the right size 2) I don’t have any real dimensions for these parts. I couldn’t find that info anywhere. So I figure if they’re the wrong size and in being so cause some wear, I’d rather my parts wear instead of the shoes.

I now have a working power feed!


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[Beckerkumm]

They were probably bronze originally but those should work fine. The key to clutch shoes or gluts is that they should engage whatever they intend to and then back off a little so they aren't constantly pushing against anything. Both clutches I've had to adjust suffered from being too tight until the shoes wore down and then never quite worked correctly. Dave

 

[twhite]

Deleted wrong place

 

[Ben17484]

The OXA is now sold and the new AXA has arrived. I’ll get it properly mounted tomorrow, it’s just placed on the lathe at the moment

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[Ben17484]

Been playing around with levelling and alignment.

I bought a tailstock alignment bar:

And managed to get the alignment close enough for me:

0.007mm/0.0003inch over 4inches. Seems reasonable? Can’t imagine I’ll need better than that.

I also very quickly tried a poor version of the two collar level check by just doing a straight cut of 2thou:

That was less good and had 2 thou over 2 inches. The lathe must be very out of level for that difference?


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[Beckerkumm]

Is the far end larger or smaller than at the chuck? Turning 4" with a tailstock shows less than .0003 deviation but without .002 ? Check runout at each end of the 4" stock to determine how good the chuck is. I'd also check how easily the stock moves when you put some force on the end to see if the bearings have play. The first inch or two nearest the chuck can also have the most difference. I'd put in a larger diameter piece and go out farther and see if the difference is less over the next two to four inches. The clues will start to give you a feel for the various contributors to the problem. There are likely more than one and I doubt twist in the bed is the primary over a 4" range. Smart Brown had a stout bed for the size lathe. Dave

 

[wayback machine]

I've read through this entire thread, as I have interest in old machinery restoration, and the topics have evolved quite a bit
BUT, something has been driving me crazy the whole time, and I kept expecting someone to say something, but I don't think anyone did.

You now have a more modern tool post, so it probably irrelevant now, but it concerns the Burnerd tool post shown in many photos.
Unless I'm really off base, in every photo, it looks to be set up incorrectly - The clamp plate, under the lock down handle, needs to have a back up block, or maybe just an empty tool holder, behind the screw !
Without that, you're only getting weak hold down pressure on the tool holder, as well as putting a bending strain on the screw .
I know you've moved on to a newer tool post, but if you want to still use the Burnerd, I think you should fix this -
You'll have a much more solid and rigid set up - Probably a better surface finish on the turnings, from using it, as well.

 

[Ben17484]

I've read through this entire thread, as I have interest in old machinery restoration, and the topics have evolved quite a bit
BUT, something has been driving me crazy the whole time, and I kept expecting someone to say something, but I don't think anyone did.

You now have a more modern tool post, so it probably irrelevant now, but it concerns the Burnerd tool post shown in many photos.
Unless I'm really off base, in every photo, it looks to be set up incorrectly - The clamp plate, under the lock down handle, needs to have a back up block, or maybe just an empty tool holder, behind the screw !
Without that, you're only getting weak hold down pressure on the tool holder, as well as putting a bending strain on the screw .
I know you've moved on to a newer tool post, but if you want to still use the Burnerd, I think you should fix this -
You'll have a much more solid and rigid set up - Probably a better surface finish on the turnings, from using it, as well.

View attachment 438295

You’re correct. There’s a blank that comes with the set that sits In the slot to the right of the bolt. I usually did have something in there when I was using it. If I’m honest, I barely used the Bernerd tool post, and when it was on there it was usually just playing around with different set ups. I didn’t actually make cuts with the right hand side empty of a tool holder (well, maybe accidentally once or twice).


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[wayback machine]

Thank you - It was driving me nuts :~)

 

[Ben17484]

Is the far end larger or smaller than at the chuck? Turning 4" with a tailstock shows less than .0003 deviation but without .002 ? Check runout at each end of the 4" stock to determine how good the chuck is. I'd also check how easily the stock moves when you put some force on the end to see if the bearings have play. The first inch or two nearest the chuck can also have the most difference. I'd put in a larger diameter piece and go out farther and see if the difference is less over the next two to four inches. The clues will start to give you a feel for the various contributors to the problem. There are likely more than one and I doubt twist in the bed is the primary over a 4" range. Smart Brown had a stout bed for the size lathe. Dave

Thanks for the reply Dave.

I decided to try a larger piece of stock as it’d have a better chance at not deflecting. I chucked up a piece of 45mm (1.75 inches) steel and over a distance of about 60mm (2.5 inches), I get no measurable difference at either end of the cut. I’m now happy that my lathe is level (I guess it always was as I didn’t need to shim anything) and my tail stock is aligned! Happy me!

Next on the list is the cross slide iGaging scale. I’ve been putting this off for a while as I can’t see an easy way of mounting it. Need to get it done though.


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