Making a new lathe compound slide?

I have an old Summit (Japanese) 11X32 lathe. It works fine, but I hate the tool post. It's actually built into the compound slide itself. Instead of a T-slot, there's a raised boss that the 4 sided tool post pivots on. I'd really much rather use an Aloris type dovetail tool post.

I could just machine the boss off of it, and machine a T-slot, but the slide is very thin, and I feel it would weaken it too much. I also considered building it up with a couple inserts bolted to the top to create a T-slot without cutting down into the slide. I'd let the inserts down into the slide slightly to key them in place. I'm not sure how well that would work in terms of rigidity, though.

The other option would be to make a new slide out of cast iron, making it taller so that I could cut a T-slot in it and still have sufficient material. There is enough spindle height for this to work with an A-sized tool post.

Any thoughts? Is there any reason whatsoever to preserve the original slide, or should I just hack it up however I see fit? If that fails, I could just make the new slide. You never know when someone is looking for a part, though. I'd hate to ruin in and then see that someone is looking for that very slide to fix up their Summit.

What is it about the turret tool post that isn't working? I would never replace a solid tool post like that with an Aloris/Dorian. Working with them for years I've never had a problem swapping tools or getting centre height quickly/accurately.

The tool post indexes on the boss in the CW direction, correct?

It's just a pain to have to shim each tool to height as opposed to just making a quick adjustment.

I should be relatively simple to replicate the top slide of your compound in such a way that you can incorporate the existing screw/dial assembly and gib into it. That way you'll still have the original slide for future use. It would be great to see a few pics of what you are working with however.

I don't know about your summit but the only one I ever used was such a POS in my mind it would never be worth that much work.

It sounds like it would be possible if you a pretty good machinist?. If you like the lathe, it's not worn out and have the time and money go for it. I would buy some Dura-Bar and make a new top slide as Cranium said. I would not ruin the existing one so you can use it if you have issues making a new one. It would be a good project so all can learn from. Please learn to take a lot of photo's and attach them to your posts. I would be happy to help you learn to scrape and fit the slide.

Another thing you could do would be to buy a complete compound side off Ebay. Or you could go to SurplusRecord.com and advertise you need a compound rest slide for your lathe. The ad for you is free and it is sent to all the used machinery dealers (world wide I think) and someone may have a parts machine and have a slide. Also measure the old slide, center height, Circle T slot diameter as you might find a slide for another brand machine would fit. G-Day...Rich
PS: Please let us know what you do :-)

The lathe seems to work pretty well. It's very stout, at 1600 lbs. for an 11" lathe. The whole thing is cast, and it's a geared head. It's my hobby lathe for home use, and I got it pretty cheap. As for machining, I've been a tool maker for almost 40 years, and have done some machine scraping and fitting, so I'm familiar with the process, and still have a couple scrapers.

Agree with Richard King.
My own experience is that I always make everything 3x++ heavier by mass and 10x more rigid in engineering terms.
This works much better, imo, ime.

My Very Humble Opinion.
Increase section sizes by 2x-3x for similar tools, if at all possible wrt clearance etc.

My stuff is typically 10-50x "stronger" by rated capacity in linear guides and 5-50x more rigid by calcs on motion control systems.
Vs "original stuff", or typical "other stuff".
I try to make everything about 10-20 more rigid.
Making it 20x more strong achieves this - with some judicious preload.

"Stronger" is not necessarily better, but preloaded stronger is typically vastly better than any other option of reasonable cost and availability and time.
Yes, details are critical.

Richard King said:

It sounds like it would be possible if you a pretty good machinist?. If you like the lathe, it's not worn out and have the time and money go for it.
I would buy some Dura-Bar and make a new top slide as Cranium said. I would not ruin the existing one so you can use it if you have issues making a new one. It would be a good project so all can learn from. Please learn to take a lot of photo's and attach them to your posts. I would be happy to help you learn to scrape and fit the slide.

Another thing you could do would be to buy a complete compound side off Ebay. Or you could go to SurplusRecord.com and advertise you need a compound rest slide for your lathe. The ad for you is free and it is sent to all the used machinery dealers (world wide I think) and someone may have a parts machine and have a slide. Also measure the old slide, center height, Circle T slot diameter as you might find a slide for another brand machine would fit. G-Day...Rich
PS: Please let us know what you do :-)

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MushCreek said:

It's just a pain to have to shim each tool to height as opposed

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OK. You don't like real and proper toolposts.

But "shims"? What is you have against wedges? Bitten by a doorstop in infancy, or what?



40 years a toolmaker? OK, then.

Instead of making a whole compound or even just the top slide of it, why not make an Aloris-clone that anchors to what you HAVE, yet takes Aloris tooling?

I have a similar "challenge" on my HBX-360-BC as it began life as an electro-hydraulic tracer model. Top of the compound is a flat surface with dowel and attach-bolt holes for a bespoke Cazeneuve design 4-way TP.

Milacron HAD a QCTP for it that I asked him to remove. I don't harbour wobbly-bobbly TP's, convenient or no, so a nice broad-assed 4-Way will be altered to fit it instead of altering the compound.

MushCreek,

I have never seen a compound with a tee slot, (was it found only on American lathes?). All the quick change (and four way) tool posts I have seen fit onto a central pivot shaft. I am not sure how the pivot shaft attaches to the compound, but perhaps threaded in or a captured bolt head from underneath. It is fixed anyway, not in a tee slot. A tee slot seems like it would unnecessarily weaken a compound? Maybe I am missing something here.

BTW, Graziano uses steel for its compound slide i.e. the moving part is steel, the swivel base is cast iron. Likewise the cross slide is steel, running on cast iron. Seems like a good way to get more strength, especially if your compound is low profile.

?? Why not just use the existing stud?