Tangential tool holder

[b.lindsey]

Mostly I am wondering if or how much the shape of the formed "diamond" may differ between the two fixtures.

Bill

[Don1966]

Thanks Arbalest for showing the original form tool. By using it on the grinder is probably why I see a dimple in the middle of my tool. Which is better 12degree or 30 degree?

Don

[Arbalest]

I'm not a Tangential tool expert, just a happy user so take the following FWIW. Maybe I was doing something wrong (quite likely!  ) but until I made my own sharpening jig I was not happy with the finish I was getting. I also found handling the home made jig much easier as, as you can see, it's quite a bit bigger. Given how simple it is to make the 30 degree jig I would not hesitate to make another if I mislaid mine!

If both jigs ultimately produce the same finished angle on the tool bit then I expect there to be no discernible difference in tool performance. The only caveat being that using a bench grinder conventionally will produce a slightly hollow grind. Not an issue for me as I seldom use one.

From what I've read about Tangential tool holders the angles used are not too critical, within limits. I've never experimented with different grind angles, perhaps I should!

[Firebird]

Hi

Making the tool holder proved to be a bit more of a challenge. I didn't have anything large enough to get the whole thing in one piece so I had to fabricate it. A square is cut out of one corner of a bit of 15mm thick steel.



Then set up in a similar fashion to the grinding jig, all angles are 12?.



Then cut a 1/4" wide slot.





a 6mm hole is drill followed bi a 5/8" cutter.



Then part from the parent material



Drill and tap 6mm some round steel bar and turn a spigot to be a tight fit in the recess machined in the other part.





Machine flats on 3 sides of the round steel bar







A trial assembly



Drill and tap  6mm close to the 1/4" slot to clamp the tool steel in position. I fettled the parts abit, removing corners and sharp edges etc then then blacked all the parts.







I can adjust the tool by turning the tool post itself and it will also turn where it is fixed together at the spigot.

After clamping the tool in the tool post I set the point of the tool steel to centre height and tightened the clamp.

The tool works beautifully, much better than I expected really.

To face the end of a work piece I just swing the tool post round a bit.



Here's a short video of the tool in action.

<a href="https://www.youtube.com/watch?v=3fZT91xPj_A" target="_blank">http://www.youtube.com/watch?v=3fZT91xPj_A</a>

Cheers

Rich

[steamer]

Seems to work Slick Rich!   I keep threatening to make one of these.......I won't say it!

 

Dave

[Firebird]

Hi

Thanks Dave.

I have made a new tool holder that has less of an overhang. I didn't experience any chatter or notice any flexing with the first attempt but it was a little bulky. This new one is much more rigid and note that on this one the tool steel is mounted from the front and not the rear. Its made in a similar fashion to first one with all angles 12?



In the tool post





The new tool holder along with the old one (Which will still be useful I'm sure ) and the grinding jig.



Cheers

Rich

[smfr]

Looks good! But isn't there a risk that the downward cutting forces will cause the end part to pivot around the socket bolt? I'd think that some kind of non-rotating joint might be better.

Simon

[Firebird]

Hi Simon

That is the weak part of the design but so far its held well. In an ideal world it would be better to hack the whole thing out of one solid piece but i don't have anything big enough. I'll keep playing with it and see how it goe's. One option would be to weld it in place.

Cheers

Rich

[smfr]

Actually that might be a feature: if you crash the part, maybe that end part will just swivel down

Simon

[Arbalest]

You need rigidity to remove metal effectively and get a good finish. That piece of metal strip you have looks just thick enough to make a one piece tool holder? When I get a minute I'll post a picture of the last one I made which is very solid and produces a great finish. Sadly it does'nt have the amount of clearance I'd prefer as I only have a small Lathe so I need to make another... 

[Arbalest]

A few pics as promised. The Black one is purchased.







I get a better finish with the home made one but ideally I'd like more clearance ... as if I needed an excuse to play in the workshop 

[Firebird]

Hi

Simon, I built that feature into the design

Arbalest, Unfortunately that strip of steel is ear marked for another project, there was just enough for me to borrow a bit off the end. As this was an experimental project I didn't want to trash a large piece of material. With my lathe and tool post set up I need the drop down part to be able to keep the tip of the cutting tool at centre height. Now I know it works (and works well) I will have another go at it when time and material permits. Meanwhile I have a tool that is easy to set up and sharpen and gets me away from expensive TCT.

Cheers

Rich

[Firebird]

Hi

Just a bit of an update here. I have been using the new tool quite a bit since I made it and I'm getting on really well with it. I am going to make 3 new tool holders now that I have got the hang of it. Each tool holder will take a different size tool steel,1/8  1/4  and  5/16. The grinding jig I made I'm quite happy with, it works well on the grinding wheel but won't accept 1/8 square tool bits so I decided to make a new one along the lines of the one shown by Arbalest. Its basically a block of ally machined to 30? with a groove across. The beauty of this design is it will take all 3 sizes of tool steel I want to use. I am using this jig on my disc sander.













Cheers

Rich

[cfellows]

Nice sharpening jig, Rich.  Lots of good ideas here for tool holders as well.

Chuck

[Arbalest]

Nice job on the jig. Don't forget you can also use round section HSS.

Vic.