View Full Version : Shaper tooling and geometry...

Doc Nickel
03-08-2008, 12:01 AM
I just picked up a nice older textbook called Machine Shop Operations and Setups, stamped on the inside cover with the label declaring it the property of the "Area Vocational School of Staples, Minn", dated August 1st, 1969.

It has an excellent section on shapers and planers, arguably better and more informative than the entirety of the South bend shaper booklet.

Anyway, while it describes in detail tip grinds and suchlike, other than keyway cutters and similar items, 99% of the tools they show are standard Armstrong-style toolposts and tool holders. Even the picture of an interesting Cincinnati hydraulic contour shaper with three heads (for cutting three identical pieces) shows this kind of tool and holder.

I'm looking to get a 16" shaper before too long, but it comes with zero tooling. I have an old rocker toolpost and some tool holders, but they're a bit undersized, meant for 9" and 10" lathes and taking 1/4" square bits. The shaper has a post, but no holders, so I figured I'd make one or two tool holders- and that, of course, got me thinking what would be the best kind of holder to make.

I've seen several designs over the years, but I'm not sure just what works best- or is most versatile, or most rigid, or what have you. I've noted the "gooseneck" styles, and the ones that try to place the cutting edge on the pivot centerline with the clapper hinge- I understand the reasoning behind these, but is that geometry really necessary? None of my (now four) books on shapers even mention them.

I have a large handful of 1/2" square HSS lathe tools (ground and unground) so I figured I'd make a toolholder that would accept these. Should I make a straight, right and left set, or one holder that allows the bit to index to different angles?

Making the holder straight out from the post would be easiest, but if there's a valid reason to have the cutting edge behind the face and/or in line with the pivot, that wouldn't be a huge problem. Is it worth the effort?

I'm sure I'll have more questions once I get the machine installed and running, but this'll get me thinking (well, more...)


Ian B
03-08-2008, 12:15 AM

fwiw, when I bought my shaper, it also didn't have any tooling. I first bought a handful of old HSS lathe tools with 1" x 5/8" shanks, pretty much the biggest the toolpost would accept. Car boot sale, about $2 each. Plan was to then make the posh toolholders with adjustable angles etc. So far, I've managed to do everything I need with the half dozen solid tools.

What is the logic of putting the cutting tip on the clapper box centreline? I'd have thought you would want it in front of the CL, so that on the reverse stroke, the too lifts rather than rubbing or trying to jam.

Is it to prevent dig-ins? I can't see how - a seated clapper box can't go any further back, can it?

Personally, I'd go for the least possible overhang, simplest and most rigid setup that your shaper will allow.


Doc Nickel
03-08-2008, 01:26 AM
Well, the theory of having the cutting edge on center with the clapper pivot is that the tool, if it "digs in", will tend to pivot away from the workpiece, rather than wedging itself deeper.

Except that, unless the clapper box has a lot of slop, or the ram ways are really loose (or the workpiece comes loose) there's no way for the tool to "dig in"- while in the cut, forces should be pretty well balanced and everything should be pretty rigid. So putting the tool on the pivot centerline sounds like an unneeded solution to a nonexistent problem.

BUT... I also realize I'm a green newbie when it comes to shapers, and just because the idea isn't in a 40-year-old textbook doesn't mean it isn't a valid one.

I've seen some of the various toolholders posted here and at PM, that allow the tool to be rotated to various angles, and this design typically tends to have the tool behind the toolholder arm, and thus closer to the clapper pivot. But here, I think it's more for construction convenience than the supposed geometrical convenience.

The shaper I'm looking at appears to take a maximum of 5/8" by 1" toolholders as well- did you just get the Armstrong-style lathe-like toolholders, or was it something different?


Forrest Addy
03-08-2008, 03:16 AM
You don't want to use a rocker on a shaper tool post. There's no center to adjust to. A simple ring will do.

Also if you can, get the Armstrong holders made for carbide. They have zero tool rake. For a 16" shaper 3/8 tools are more appropiate. The holders come on eBay once in a while so look in every fre days.

Also the Armstong #39(?) is a superior holder to the lathe tool holders. Keep an eye peeled for it. Williams make one sililar. For that matter they are easy to make.

Izzat enough "alsos"?

Doc Nickel
03-08-2008, 05:23 AM
You don't want to use a rocker on a shaper tool post. There's no center to adjust to. A simple ring will do.

-Actually, I did know that. I just used that term to describe the type of toolpost, since I couldn't recall a more proper name. They're not called "Armstrong" toolposts are they? I thought that was just a popular manufacturer of the tool holders that go into the tool posts.

And a "lantern" style is the square, blocky post, right?

But I digress... I've been spoiled by using quickchange posts since the very beginning. :D

Also the Armstong #39(?) is a superior holder to the lathe tool holders. Keep an eye peeled for it. Williams make one sililar.

-I can't find any images of a "#39" holder- what makes it superior? Is there a specific shape I'm looking for?


03-08-2008, 07:13 AM
and a pic of a Armstrong holder 1/3 way down.. http://www.jamesriser.com/Machinery/AtlasShaper/AtlasShaper.html

03-08-2008, 10:09 AM
Doc, How big is your shaper? I only ask because I have a spare clapper setup for a S/B or Atlas.

Al Messer
03-08-2008, 12:14 PM
Doc, my South Bend came with no tooling as well, like the previously owned Atlas. I just ground a 3/8" square HHS tool bit and put it in the tool post with a 3/8" square "backer". The Atlas performed well for 16 years and the South Bend has been preforming satisfactorily for several years as well.

03-08-2008, 12:48 PM
There's a PDF of various Armstrong and Williams offerings here:


Well worth going to:


to peruse the other offerings.

03-08-2008, 07:16 PM
Doc, I have been under the impression that shaper tool holders held the tool itself at 90 degrees to the work and lathe tool holders held the tool with the predetermined 15 degree rake. I have heard that you can use the lathe tool holders but your tool needs to be ground accordingly to subtract for the holders built in angle. Maybe someone can correct me if I am wrong. Jay:)

03-08-2008, 08:14 PM
What I seam to remember from running Shapers many many years ago . Was even though the tool holders looked like lathe tool holders they were not . T on shaper holders on shaper holders from lathe holders the angle the tool fit in was different. And you did not use a rocker but the ring plate was cut with 3 or4 steps that the tool holder would fit in so you could index it up or down.

03-08-2008, 09:53 PM
Another page on James Riser's site shows his Sheldon 12" shaper. I have one too and have saved off a lot of the pics for later use when I get around to restoring mine.


One of the things he mentions there is that he often just uses large, solid tool bits as others mentioned here. He does also show a couple of holders including one of the Armstrong gooseneck tool holders that are normally considered to be threading tool holders, but which supposedly work pretty well for the same reason. The goose neck is designed to flex away from the work under heavy load rather than digging.

A guy could probably forge a similar gooseneck in a tool holder he was making for himself.


Al Messer
03-08-2008, 10:12 PM
Jay, I think that you are spot on.

Ian B
03-09-2008, 01:19 AM
I'm at a bit of a loss to see the difference between lathe tools and shaper tools here. I always thought the lathe tool holders had the built-in top rake to give longer tool bit life between regrinds (you don't need to gouge a top rake into the toolbit - just grind from the front face).

The only logic I can think of is that the shaper always cuts intermittently, and a sloping toolholder *might* allow the bit to move back in the holder. However, 15 degrees isn't much of a slope - 60 degrees would be far more likely to allow the tool to slip.

As far as the cutting geometry goes, a shaper must be pretty similar to a lathe machining, say, a 6" cylinder if the tool's set at centre height.

Proof of the pudding is, lathe tools work just fine in a shaper...


03-10-2008, 10:29 PM
i'm not sure if that fancy Armstrong tool holder is really needed. the clapper box can be rotated, the "lantern" post can be rotated, and you can grind the cutting bit to whatever angle you want. i am not a shaper expert, but in playing around with my old G&E 20", about the biggest concern is that the back of the cutting bit is ground with enough relief so when the ram moves back and the clapper lifts, that the tool can swing up out of the way. other than that, i just grind the tool or adjust the mounting angle so it cuts the shape i want.

about the only use i could see for that special Armstrong holder would be to position the cutting tool for something like cutting into the base of a dovetail. you could probably make the cut without it by grinding the bit differently or mounting the work in a position to allow easier access.

andy b.

Mark Hockett
03-11-2008, 01:23 AM
I also agree with everyone who said just use the largest HSS blank that will fit right in the lantern tool holder. I have a 16" shaper and it will accept a 5/8" x 1-1/4" tool holder. I use a 5/8" square mounted directly in it. I have the Armstrong #39 holder but rarely use it because it is so much more rigid without it. Using the 5/8" HSS allows me to take a 3/8" deep cut with no problem. Here is what it looks like with the tool in it, BTW that is not the vise that normally lives on that machine, it normally has a 12" wide shaper vise on it,

03-12-2008, 05:41 PM
Here are a couple of pictures of Armstrong tool holders, I think they will clarify what I was trying to say in my last post. I would have posted them the other day, but have been having trouble with photobucket. :)




I hope this works. I started a myspace account to try and upload these. Jay

03-12-2008, 05:44 PM
Now, I am not meaning to imply that you can not use lathe tool holders in a shaper or create you own variations, I have done that in the past. I am just trying to show the differences. Take care all, Jay :D

03-12-2008, 06:58 PM
I would hope not,It has been done For many decades.

BTW Jay, I have been to your nice town during Loyalty Days in '77 perhaps you remember a navy ship in port? Your town was very hospitable.

03-12-2008, 10:38 PM
I have an Atlas 7" and have used bits directly in the tool post as well as a lathe bit holder in the toolpost. Naturally, the angles ground on the bits differ because the lathe tool holder has rake built in.

I built one of the holders with 3 built in angles per Art Volz design found in this Yahoo Group's files as holder1.jpg:
The bit is 1/4". Bolt is purchased, head was rounded, hole was cross drilled and filed square.

My first attempt at silver brazing so the braze went where it wanted but it seems to be strong despite my technique.




J Tiers
03-12-2008, 10:58 PM
Actually, using the bit directly may be BETTER in some ways than using the holder. The way the holder is, the bit dips farther into the work if the holder moves at all, or deflects under the load. That's because the bit is held way out in front of the clapper surface.

The bit directly in the lantern post still will, but the amount is lots less. So less chance of chatter.

For best finish, a spring tool with the cutter in line with the clapper surface is probably best.

That said, the multi-position Armstrong holder is nice for angles, dovetails etc.

03-13-2008, 06:24 PM
Gagit,I like it.

03-13-2008, 10:29 PM
I use big bits directly, have some up to 1 1/4 square, some 1/2 x 1, etc. The biggest problem with those things is grinding them takes a long time unless you have a grinder with serious power.