Lathe Modification ?

[Brian Greb]

I have one of those questions that start off with an explanation. I knew a guy a while back that had an old delta lathe and he had some risers made for it to increase its swing. Well fast forward to my Delta 46-460 can I add riser blocks to it to increase the swing? I have a line on a shop that can machine the parts I was just wondering if it would be a good idea. I have the usual concerns;
Can the spindle take the stress of larger blanks?
Will the bearings give out under the stress?
Can I get a bigger belt?
Would doing this mod kill a perfectly good lathe?

So as I said I know how to do it, but should I? Thanks for any help and opinions y'all may have.

BTW I'm not thinking of increasing the swing to much just raise the head stock like an inch maybe 2 inches.

[Bob Bergstrom]

Bearings and belts are replaceable. It seems documented on this site that a major weak point is banjo slippage. The size of the tool rest post would be another. With care sure it will all work, but get a bad catch and the tool rest may snap off and become a lethal shrapnel. Just my opinion, increasing the throw a little just doesn't seem worth the effort.

[Jeff Willard]

Would doing this mod kill a perfectly good lathe?


I think my concern would be for the operator.

I hope not to come across as a wiseguy here, but just how large a piece of wood do you expect to safely swing on a lathe that weighs less than 100#?

If you want to limit it to platters, where the blank is relatively light, I'd say sure, go for it. But don't fall into the temptation to turn a heavier, off-balance blank. When things start to go wrong, it happens very fast. One of the most unnerving experiences I have ever had was when I was finishing the foot on a bowl (low speed) and it flew. One second it was there, and then it just vanished. Absolutely no way to react to it.

A lathe is one of the most benign machines in a woodshop, but if things go awry, it may be the one most likely to kill you.

You'll need a rest with a longer post if you decide to follow through with this.

ETA: I just looked over the spec sheet on that machine. Am I reading it right? Is the bare minimum speed 250 RPM?

[Brian Greb]

I think my concern would be for the operator.

I hope not to come across as a wiseguy here, but just how large a piece of wood do you expect to safely swing on a lathe that weighs less than 100#?

ETA: I just looked over the spec sheet on that machine. Am I reading it right? Is the bare minimum speed 250 RPM?


Jeff, yes the slowest speed is 250 rpm... as for the 100lb weight, I have the little guy bolted to a machinists bench, the bench weighs 100lbs empty and its full of tools and ballast, so I'd guesstimate that it now weighs a ton.

[Jeff Willard]

Just some more food for thought. 250 isn't all that slow. It won't take a terribly heavy, or terribly off-balance blank to make things wonky at that speed.

Remember that, even though you may have it bolted down to a 1000# plinth, the castings are only designed to endure so much stress.

[Bernie Weishapl]

I agree with the others. Yes you can do it but I wouldn't want to put much more that a 12" piece. The ways, bearing and spindle are not machined for much more than that. If it were me I wouldn't.

[Richard Madison]

Brian, Good points by Jeff and others. A 1" lift might be satisfactory, but your lathe is not designed to handle the loads imposed by a 15" diameter, out of balance blank. With a 1" lift you will need a 1" longer tool post and a 2" longer belt.

Consider that many (most?) of us with 16" capable lathes rarely turn anything larger than 12". Larger blanks (free logs) are simply not available to many people, and the market for items larger than 12" is rather limited in most areas.

To repeat Jeff's question, what are you thinking of turning larger than 12"?

[Brian Greb]

To repeat Jeff's question, what are you thinking of turning larger than 12"?

Currently I envision turning a platter with an eccentric inlay in the bottom of it... I have worked out a method of turning the pieces of this platter to minimize it being out of balance while turning but I need a 15" capability to do this. I was also looking at doing some larger segmented hollow forms.

But from what I'm getting from this forum and some others is I'd be better off putting off my designs until I can afford a lager lathe and some space in my shop.

[Richard Madison]

But from what I'm getting from this forum and some others is I'd be better off putting off my designs until I can afford a lager lathe and some space in my shop.

That's probably the best answer. After purchasing my present lathe a few years ago I did two segmented pieces that ended up at 15-1/2" diameter x 25" tall. They required a surprisingly large pile of lumber, and have not sold. Since then have done only three pieces (commission job) that required greater than 12" diameter capacity.

I suggest that you do your intended projects in a 12" diameter format and see how you like them. You may be surprised at how big they look.