Tangential tool holder

[Mark_f]

I couldn't leave it alone. This is the revised clamp for this tool holder.


Mark Frazier

OK ... I finished the tangential tool holder.

View attachment 91503 These are the parts , minus the bit and a 1 inch 6-32 SHCS to hold it together.
View attachment 91504 This is the completed holder , ready to cut. It works fine but have not done any HEAVY cutting to see where the point is the bit will slip in the holder ( if it even will). I am very satisfied with the outcome of this project. The tool works fine. there is a revision which I may or may not add. If it causes a problem I will do it , but so far it really isn't needed. The revision is a spacer under the clamp outside diameter .070" thick to keep the clamp from "cocking" . When tightened, the clamp cocked slightly, but it seems to be OK.

View attachment 91505 This is the print for my holder, if anyone wants to experiment with it.

This project works and so I will call it complete. I am satisfied with it.

Mark Frazier :victory:

 

[MikeWi]

The biggest difference is in the chips, it creates long continuous strands.

That's why I don't use mine so much anymore. I like the more manageable chips I get with a "conventional" tool bit.

 

[Mark_f]

That's why I don't use mine so much anymore. I like the more manageable chips I get with a "conventional" tool bit.

A lot of times I get a long string chip with the conventional tool also. It has a lot to do with feeds and speeds, but mostly the feed rate.

I made the revised clamp and it is much much better. One note here: I found if I filed a relief in both directions in the corner of the clamp washer, it seats much better. I believe it will take a lot to make the bit slip , if it will at all. I haven't tried an interrupted cut, but this tool seems to handle anything I do. I am really impressed with it.

Now to make the sharpening jig.

:victory:

 

[caster]

Here is a picture of the center cutter. Its a 1/4" round hss ground at 12 deg, presented to the work at 12 deg, held in place with a set screw from behind. The finish of this cutter is amazing, don't know if its because its tangential or round. Either way its a great tool.

Caster

 

[Doubleeboy]

Here is a picture of the center cutter. Its a 1/4" round hss ground at 12 deg, presented to the work at 12 deg, held in place with a set screw from behind. The finish of this cutter is amazing, don't know if its because its tangential or round. Either way its a great tool.

Caster

View attachment 91532

Caster, That is a great looking tool. Any chance you could put up a short clip of it in action? Do you have to take very light cuts to get the good finish?

Thanks
michael

 

[ogberi]

A lot of times I get a long string chip with the conventional tool also. It has a lot to do with feeds and speeds, but mostly the feed rate.

I made the revised clamp and it is much much better. One note here: I found if I filed a relief in both directions in the corner of the clamp washer, it seats much better. I believe it will take a lot to make the bit slip , if it will at all. I haven't tried an interrupted cut, but this tool seems to handle anything I do. I am really impressed with it.

Now to make the sharpening jig.

:victory:

If the interrupted cut hammers the tool lower, you can always do revision 3 of the clamp, and support the tool on the bottom. On my Taig, the toolpost sits right on the cross slide, so I had no trouble adding a grub screw to it. I can adjust tool height, and it doesn't hammer lower. You can see the grub in the lower left corner of the toolholder. I cut my toolbit into thirds with a Dremel tool and a fine thin cutoff wheel, then sharpened. You can get away with a more solid clamp, and simply adjust the QCTP holder.

 

[Mark_f]

If the interrupted cut is a problem, I have plenty of meat on the holder to install a bottom stop and correct the problem.
I'll find out when I do an interrupted cut.

If the interrupted cut hammers the tool lower, you can always do revision 3 of the clamp, and support the tool on the bottom. On my Taig, the toolpost sits right on the cross slide, so I had no trouble adding a grub screw to it. I can adjust tool height, and it doesn't hammer lower. You can see the grub in the lower left corner of the toolholder. I cut my toolbit into thirds with a Dremel tool and a fine thin cutoff wheel, then sharpened. You can get away with a more solid clamp, and simply adjust the QCTP holder.
View attachment 91533

 

[caster]

Hi Michael,

Used to have an office in Eugene, made it there once a month for several years. Nice place.

Here is a pic comparing the result of the tangential 30 thou (60 thou off the dia) cut with a similar cut with a carbide insert. You can still see a chip on the tool and some strands in the background.

Caster

 

[Doubleeboy]

Hi Michael,

Used to have an office in Eugene, made it there once a month for several years. Nice place.

Here is a pic comparing the result of the tangential 30 thou (60 thou off the dia) cut with a similar cut with a carbide insert. You can still see a chip on the tool and some strands in the background.

Caster

View attachment 91536

Great photo, does the finish improve if you take a cut of a few thou or does it get worse?

Grew up in NJ, played a lot of hockey at South Mt. Arena, amongst other rinks in the area. Long , long time ago.
Thanks for the clip
michael

 

[Hawkeye]

Mark, if you find that your clamp screw sometimes gets in the way when you're working close to the chuck, you can easily modify the clamp with a larger size SHCS threaded into the clamp and coming in from the other side. The one I made for my big lathe is quite similar in design to yours, especially the clamp. IIRC, the shank is around 1" x 3/4".


Here's the cap screw. Notice the sandblasted finish of the toolholder.