View Full Version : dovetail cutting

Metal hack
01-31-2002, 02:58 PM
I know i saw an artical in hear on making tool holders for a quick change tool post but i cant find them. I need info on making the dovetails. thanks for the help


01-31-2002, 07:30 PM

This kind of what you are looking for?




01-31-2002, 11:28 PM
I don't know which issue of Projects in Metal this was in. However, book one of the Village Press publication "Mtalworking" has an article on page 34 about making a dovetail type quick change tool post.

You might get some ideas there.

02-01-2002, 01:02 PM
Thanx to both of you! I too had been trying to recall where I'd seen that article.

John Stevenson
02-01-2002, 05:57 PM
There is also this article:-

John S.

02-01-2002, 11:54 PM
The site John mentioned also has an article written by a gent that built that tool post and his experience building it - check it out.

John: That is a nice design, by the way.


John Stevenson
02-02-2002, 04:10 AM
Thanks Dave.
The design can be scaled to fit whatever.
That particular toolpost has long gone as I sold the Myford a few years ago to make room for a new TOS 14 x 40. I had already made a bigger toolpost for my CVA lathe 12 x 24 so I made an identical post for this new one.
The only differance is the hight of the top stop screw. These have been made to suit the machine so all holders will interchange between them.
On the TOS I also dispensed with the top slide to obtain more rigidity. I found that I hardly use a top slide unless it's for the odd short taper. I can swop this quick enought, two bolts, and it still has the original 4 way toolpost with a couple of tools preset in it.
The big solid spacing block made to replace the top slide has a cut away on the back so it can't foul the tailstock. I common occurance with top slides.
There is a photo at:-
of this toolpost plus a new one in bits for a third lathe of 10 x 20 size. All these carry the same holders, a selection of which are shown in the photo including some specials.

John S

02-02-2002, 08:15 AM

Are you sure you have enough tool holders?

How do you cut threads with no topslide?

BTW, thanks again for your help with T&C cutter CD, I have it working fine now. Nothing like a good supply of really sharp end mills.

02-02-2002, 12:37 PM
You can never have too many tools...

I noticed the circular saw cutoff tool. I have seen guys cut blades out of circular saw, but never an indexed entire blade! Do you cut the top teeth off when it gets dull and rotate a new one up to bat?

I am jealous about the big TOS, I really like the Polish Andrychows (almost the same, me thinks) - real beauties.

John Stevenson
02-02-2002, 04:41 PM
No I don't think I have enough holders {g}
I have about 43 between three lathes but I still have to change tools.
I screwcut with multi point chaser tools and so don't need to move the tool in at 1/2 the thread angle. In fact I've never subscribed to that camp but always fed straight in, just what I've got used to. If you go back to the toolpost pic just to the left is a thin holder that holds one piece out of a Coventry die head. You need one per pitch, i.e. a 3/8" x 16 will cut any 16 pitch thread. These are precision ground with the correct angles and radii on them. They can be picked up at tool sales very cheap as a set with one missing or damaged is useless.
Have a look at the following pic for a close up:-
In this shot of an 11 tpi chaser, it isn't actually cutting a thread but is just being plunged in to cut a J series Poly Vee pulley, but it's the same idea.
Purists will say that the flank angles are incorrect but I've made loads of specials this way with no problems even up to 9,000rpm on wood cutting spindles.

The parting off blade.
This is a 6" 16 tooth blade with 16 register holes drilled in to prevent spinning under load.
I sacrifice the first tooth to get more clearance and then just grind back when worn or chipped. Works well and is very rigid in a vertical plane but you have to make sure the tip is square to the work. Forget the tapered front or it tried to part off disk shaped. I can part off 4 1/2" diameter steel bar with this.

John S.

02-02-2002, 08:26 PM

I see a bit of chatter in there (I would expect that from a plunge cut) - do the chasers cut cleaner when fed in as in normal threading? I have thought about doing this with the full form inserts that are available ($$$ - Gaaack!) especially for the Acme form but wince at the cost of the little buggers. The thread chaser is a good alternative - but do require glass smooth threads. Whats the poop?

Thanks for the info on the B&D cuttoff tool. You have anymore great ideas you want to spill your guts on?


John Stevenson
02-02-2002, 08:52 PM
Threading is nice with them as they have a lead in portion. Give me a day or so and I'll get some more shots, this time of threading. The chasers are all ground finish so they cut good.
As regards the other stuff if I was to tell you I'd have to kill you {g}
If you go to my web site, web page is too grand a word for it, at
You will see a series of files, mainly jpg's
Have a look thru, no secrets, and give a shout if something catches your eye.
I just drop stuff here for folks to look at. It really needs a bit of a prune.

John S.