4 position turret tool post

This came with my lathe. I was told it came off a SB y25 I think he said. I had to raise it. It's solid as a rock but I would prefer a block spacer.

I'm learning here so bear with me but what tooling do I have? The cutters were made from 3/8 stock.

Matt_50 said:

This came with my lathe. I was told it came off a SB y25 I think he said. I had to raise it. It's solid as a rock but I would prefer a block spacer.

I'm learning here so bear with me but what tooling do I have? The cutters were made from 3/8 stock.

Click to expand...

"Block" or solid spacer is correct. Essential, really.

"At the moment..' what you have is a suicide kit for a nasty crash.

First: A(ny) 4-Way.. or any OTHER TP ... needs to have solid basing right ON the top of the cross-slide OR - second-best - the top of a compound rest.

I see "daylight" of a POST instead.

So it can and it WILL "tilt". If no mill, you can use the lathe itself to "face" a rectangular plate in a 4-Jaw or a larger round disk in a 3-Jaw to the needed rise/thickness.

Second: Do NOT try to secure a(ny) cutting-tool with but ONE setscrew...except those in a boring-bar..where you may not have a choice.,, but "usually" DO have a full-surround mounting.

SEAT them firmly in the side-slot of the 4-Way. Then use all the set-screws as will bear. I like wedges. So I don't need as many shims. But a stack of shims to adjust tool-tip height is not REALLY a "Big Deal", either.

Used-but-good 4-Ways are cheap enough - from all the noobies putting a "QCTP" onto light/medium lathes before they have even finished tearing apart to paint it and lose half the parts, n'er to go back into use.. that I can own "many".. swap the entire 4-Way with the tools still in it, stock a modest collection of shims, but have ZERO spend on QCTP "tool holders".



Third: Do NOT hang a(ny) cutting-tool the least amount further out than the minimum it needs to clear the "features" on the work.

ANY Toolpost, the closer you can get to ZERO hang out, PLUS .. the closer the tool-tip is to putting cutting down-force directly OVER the pivot of the compound (if any..) the safer and smoother the cut.

Hand-ground cutting tools are whatever shape some prior craftsman was used to for HIS work. He could as easily have been a fool as a genius.

Buy a collection or two of used ones.

"Observe"... then experiment.

It will save you time as to learning what works for YOUR needs faster than you can otherwise "try stuff" on your own.

Sharpening an already SHAPED cutting tool is quick.

It is the shaping of them from the virgin blank or re-shaping from a different and unrelated shape - that is slow.

Used, ergo "pre-shaped", HSS/Cobalt cutting tools may have as much precious TIME stored in them as they have potential sharp edges left to generate and put to work. Which is a LOT of edges, BTW.

Inserts OTOH are meant to be consumables. Recycled. AND NOT re-sharpened.

Carbides? There is TOO MUCH for you to learn in a lifetime.

Follow the lead of "exkenna". His JOB was solving other people's insert problems.

You get more than his personal 30 or 40 years experience out of following his lead.

You get about 300 years of cumulative experience:

His own.

And that of the customers he served that shared-back THEIR experience.

The cutters you have are known as HSS or high speed steel, lathe tools. You grind them yourself to what shape or angle you need, and grind to sharpen the cutting edge. Best grinding wheel for that type is white AO 46k or 60 grit.

Another type of lathe tool is brazed carbide. Also need to grind by yourself. White AO wont grind carbide though. Need green silicon wheels for that.

Another and probably prefered way is insert type lathe tools. A variety of shapes and styles for inserts. Insert type might choose a few different insert styles. Some info here:
Recommended lathe tooling insert type

That one tool hanging off the corner with one set screw is a bad idea. Though a 4 sided tool post, for practical purposes of mounting tools correctly, you will mostly use two opposing sides.

I was thinking all this, so I thought I'd better ask the experts. Thank you. I'd be open to getting a qctp. I unfortunately don't have a way to make a spacer, unless I use this setup. Which I don't think I want to do...

Unless there is someone here willing to make me a block/spacer?

Matt_50 said:

I was thinking all this, so I thought I'd better ask the experts. Thank you. I'd be open to getting a qctp. I unfortunately don't have a way to make a spacer

Click to expand...

Yes. You do have. NO toolpost is a better toolpost than a BAD toolpost.

STACK.. a cutting-tool atop solid metal to the needed height.

BOLT, one each side, a crossbar across the top of it.

Early lathes used "two-post" arrangements with a forged top-bridge and hand-forged carbon-steel cutters very much like that.

Do it right, it can still be one of the stiffest mounts you can get onto the lathe.

Disclosure: I don' use no steenkin' 3/8" cutters for that.

3/4" to 1 1/4" rather! Bigger the blank, the fewer the shims.

I did say "stiff?"

Like a wedding-night hard-on!

But the tooling STAYS stiff!

I have two of those posts that go on my two 13" lathes. I keep one cutter in each and just throw them on the machine for a quick cut on something. The modern ones are copys of posts that were used on turret lathes years ago and probably had more cutters in them. I can not tell what is going on with that one from the pictures, but the thing must sit flat on the compound.

Matt_50 said:

Unless there is someone here willing to make me a block/spacer?

Click to expand...

In your pic on post #5 it looks like the bottom section of the 4 way tool post. On the bottom of the square tool block there is a little hole should have a stiff spring and a ball bearing in it, this will locate in the 4 shallow holes drilled into the round base. It will set the tool post back in the same spot after being rotated around to use other tools. Your spacer goes under that round bottom piece, between it and the compound.