Author Topic: A Tangential Toolholder for the Sherline  (Read 14754 times)

Offline Bernd

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A Tangential Toolholder for the Sherline
« on: December 30, 2008, 09:58:48 PM »
Those are words on my just received "The Home Shop Machinist". (January/February 2009)

Nice article on how to make a tangential holder for the Sherline. The guy is not in the US, but was nice enough to put the dimensions in imperial. So the Coke Bottle engine is going to have a "work hold order" put on it until I make one of these.

I'll post some pics as I make it. No sense in a build thread since it's all in the magizne. I know not everybody gets this magazine and some might not have this samll machine.

Might begin on it tomorrow, I said MIGHT.  :)

Bernd
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Offline Brass_Machine

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Re: A Tangential Toolholder for the Sherline
« Reply #1 on: December 30, 2008, 10:24:50 PM »
Gonna have to get that issue. I want to make one of those.

Eric
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Offline cedge

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Re: A Tangential Toolholder for the Sherline
« Reply #2 on: December 30, 2008, 10:26:19 PM »
Bernd
While I  haven't read the whole article yet, I've had a bit of time to look at the photos and I'm not sure that it's going to perform as well as other designs do. Unless I missed a view, the appears the tool is only offset in one angle. I'll get a bit of time this evening to read it and see. I'm definitely a fan of these cutters.

Steve

Offline kellswaterri

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Re: A Tangential Toolholder for the Sherline
« Reply #3 on: December 31, 2008, 07:16:25 AM »
Yes Bernd...would very much like to see that.
                                                            John.

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #4 on: December 31, 2008, 10:18:30 AM »
Steve,

I think he said that the tool is off set 12 degrees both ways, with a 30 degress backslope(? is that the word I'm looking for). I think he went through a lot of chuckings in his vice to get to where he ended up. I'd post a pic of it but can't because of copy right. So those who don't get the magazine, I'm sorry, you'll try to have to carry along with out pictures until I make take my own.

Anyway what have I got to loose but a few pleasent hours of shop time. (Oh darn, forgot the wife wants her pantry done :whip:)

Well, I'll find a way to sneak it in, making the tool that is. (some how that doesn't sound right ::))

Bernd
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Offline cedge

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Re: A Tangential Toolholder for the Sherline
« Reply #5 on: December 31, 2008, 09:09:32 PM »
Bernd
As long as he's specified the compounded angle the tool will work fine. 12°, 12° and a 30° tool rake is what seems the be the common consensus. You'll be pleasantly surprised the first time you cut with it.

Steve

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #6 on: January 03, 2009, 11:41:23 AM »
Steve,

That's what I've read about it also. Rudy Kouhoupt was a great fan of that tool form. He liked it very much.

Once these holidays are out of the way and wife goes back to work I can get some shop time in and start working on my tangential toolholder.  :)

Bernd
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Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #7 on: January 04, 2009, 05:43:36 PM »
Well I made a prototype today. Looks like it might work. Need to finish it first before I build the next and record for a build thread. Want to make sure it works before I do that.

Ya I know  :worthless:, but hang in there, it's coming soon to a PC near you. :D

Bernd
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Offline kellswaterri

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Re: A Tangential Toolholder for the Sherline
« Reply #8 on: January 05, 2009, 09:05:41 AM »
Hi all...spotted this on another site...might be useful...

http://www.gadgetbuilder.com/ToolHolders.html#Tangent

All the best for now,
                           John.


Offline Darren

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Re: A Tangential Toolholder for the Sherline
« Reply #9 on: January 05, 2009, 09:17:03 AM »
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #10 on: January 05, 2009, 09:55:04 AM »
John,

I've seen that one. Great idea for a QCTP and simple to make.

Bernd
You can't fix "STUPID".

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #11 on: January 07, 2009, 09:22:05 PM »
Ok, just to show I haven't totaly been goofing off. I've got the prototype tool holder done. I just need to make a tee nut and a tool clamp. Here's two pics with the cutter being held by a rubber band, just for show.  :)





Hopefuly I can get the two items I mentioned above finished by next week and give the tool a test drive. BTW, this is a 1/4" HSS tool bit I'm using. If this works I'm going to make two more. One for a 3/16" tool bit and one for a 1/8" tool bit. Why? Because the mill is all set up to mill the angles and I want to see if there is any difference in the size tools used to cut stock.

Bernd
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Offline Brass_Machine

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Re: A Tangential Toolholder for the Sherline
« Reply #12 on: January 07, 2009, 09:26:35 PM »
Looking good. I can't wait to see how it works.
Science is fun.

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bogstandard

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Re: A Tangential Toolholder for the Sherline
« Reply #13 on: January 08, 2009, 12:23:56 AM »
Bernd,

I definitely think that is stretching it a bit, hoping that rubber band will hold while taking a cut. :)

Or are you expecting the elastic band to play music while you cut? :)

Bogs

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Re: A Tangential Toolholder for the Sherline
« Reply #14 on: January 08, 2009, 04:33:48 AM »
Its what you call flexible tooling  :lol: :lol: :lol:
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #15 on: January 08, 2009, 10:18:45 AM »
Good one guys.  :lol:
You can't fix "STUPID".

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #16 on: January 14, 2009, 06:38:02 PM »
Ok, finally got a clamp plate made for the tool holder and a clamp post to hold it down to the cross slide.
It works but I'm not happy with the finish it gives. Tried a few different cuts. Seems like about a .002" deep cut gives a good finish as apposed to a .020" deep cut. Leaves a rough surface as if you are working with a damaged tool. I need to investigate this further.

And I know that  :worthless: so I've got a few pics.


Here I'm getting the hieght set using the tailstock center.


Here I've cut up to the chuck. I still have some clearence problems to take care of. I'm turning 3/8" square stock to make the next tool post bolt.


Finally got to the depth were there are no more square sides to cut. This is where I tested the deepth of cuts and the finish.



That's it for now. I have some more expermentation to do before the verdict will be in, but that won't be till after Cabin Fever. If I can get myself unfrozen by Friday. :)

Bernd
You can't fix "STUPID".

bogstandard

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Re: A Tangential Toolholder for the Sherline
« Reply #17 on: January 14, 2009, 07:08:45 PM »
Bernd,

If I could make a suggstion without offending.

Instead of using your tailstock centre to set tool height, use the ruler against the workpiece method, it should work out a little more accurate.

Tailstocks with centres in are renowned for not being very accurate, especially on these smaller machines. On larger machines, they sometimes have a setting mark on the tailstock ram, and if so I would use that, but not on the centre end unless it was fully cleaned down and bedded into the taper. Even a minute particle of something on the centre can knock it out of wack when stuck in the taper.

Bogs

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #18 on: January 14, 2009, 10:22:05 PM »
John,

I can take constructive criticism, never hesitate to point out something to me. I can't keep track of everthing I've ever read about or learned.

That was just a quick and dirty setup. What I should make is a tool to set the center hieght. That will be next.

The method you suggested would be a bit tough to do on such small machine, though I guess I could use it to see if I had set the tool right.

Stay tuned for more developments in the making. But not till after Cabin Fever. :D

Bernd
You can't fix "STUPID".

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #19 on: January 15, 2009, 12:38:29 PM »
John,

I did the ruler against the workpiece method just for curiousty. Here's the pic.


As you can see I'm a bit low with the tool. BTW That's a piece of .020" feeler stock I'm using. The scale didn't work do to the engraved numbers.

Question: I know it's important to try and get the cutting tool right dead center, but there must be some leeway. I would think that it also depends on the diameter of the piece you are cutting. The larger the diameter the less you need to be right dead center. The smaller the piece the closer you need to be on center. Is my thinking correct here? Also I was turning a piece of square stock so I couldn't use this method first.

I'm thinking of making a gage the will aid in the setting of the center hieght using the lathe itself to create the gage.

Bernd
You can't fix "STUPID".

bogstandard

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Re: A Tangential Toolholder for the Sherline
« Reply #20 on: January 15, 2009, 02:28:47 PM »
Bernd,

It always used to be recognised that the tool should be set a few thou low, but nowadays, with harder materials for both jobs and tooling the general concensus seems to be to set exactly on centre height.

For very heavy cutting, especially parting off at high speed and power, I personally set the tools a few thou high, to allow for downwards tool deflection. But you should never set tools high for normal machining, as the tool will 'rub' rather than cut. Set too low and the tool can be 'grabbed' and pushed under the job.

Instead of using a rule for setting height, just get a plain bit of strip, that will get over the graduations problems.

Hope this helps.

John

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #21 on: January 15, 2009, 07:47:20 PM »
Thanks John.

If you look close at that last pic you'll see I used a piece of .020" (.5mm) feeler stock. Worked great.

Tried turning a piece of brass. Got a poor finish on that too. Time for investigating to see if I made the tool right.

Well tomorrow it's off to Cabin Fever and I'm hoping to see the boss there (Eric).

Bernd
You can't fix "STUPID".

bogstandard

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Re: A Tangential Toolholder for the Sherline
« Reply #22 on: January 16, 2009, 01:26:28 AM »
Bernd,

As with most HSS tooling, if you can get away with a very small tip radius, then a quick swipe across the nose with a stone works wonders. I use an Arkansas stone.

C-o-C attached

John

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #23 on: January 19, 2009, 02:48:21 PM »
John,

I sharpened the tool again and gave it a couple of swipes to put a small radius on the tip. Then I put a sharp pointy tool in the chuck and set the hieght. I also turned the tool holder clockwise a few degrees to give more side clearence. It's supposed to be set square with the cross slide. I then took a small cut on the piece of brass in the picture. I then took a heavier cut also and different speeds. Finish is much better. I think both the radius and the larger clearence did the trick.

The picture below shows the piece of brass I used for the test. It shows the holder turned counter clockwise from square to the corss slide for facing. As you can see the tool is set a couple of thou low. It left a small nib in the center.

So adding more clearence and a radius seemed to work. As you can see I have some clearence issues with the tool clamp. It'll get in the way when facing larger diameters.

I'm going to leave the tool project as is for now. However I will post on how I cut the angles in the milling machine.



Hopefully I'll either have the pics posted tonight or tomorrow.

Bernd
You can't fix "STUPID".

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #24 on: January 19, 2009, 05:37:06 PM »
Here's a quick look at how I machined several pieces of aluminum to make the tangential tool holders. A version if it was written up in "The Home Shop Machinist" Jan/Feb 2009 issue. I figure there had to be a better way to mill the tool block than what the writer had shown. He made his on a Sherline. I made mine on a Grizzly Mini-Mill or X2 style milling machine. I also have a Sherline lathe/mill combo.

I'm not going into a lengthy description or give dimensions. It was a tool holder I always wanted to try, plus I wanted to see if I could use less steps to accomplish the same thing. Weather I did or not is still in the air. The proof being in the fact that I have to turn the holder clockwise or counter clockwise from square to the cross slide table. You are supposed to be able to both face and turn without having to move the holder. Not true in my case. It does cut well though.

First pic is of the vise setup. Turned 12 degrees clockwise from square.


The two blocks of aluminum. 1.5" square by about 2" long.


The first of many cuts.


One side completed.


Both parts have the first side cut at 12 degree angle.


With the vise still at 12 degree the parts are clamped on there side that was cut earlier.


The second side finish milled.


Next will be the hole for the clamp and the slot for the tool bit. The one that's completed was my prototype and has a 1/4" slot for that size tool bit. The other two will be for a 3/16" and 1/8" HSS tool bit.


A rough guestimate of where the tool clamp will be.


Disregard the dimension on the scale. Locating the hole, just approximate.


Hard tapping the hole 1/4"-20. I just tighten the drill chuck enough so that the tap won't break when it hits bottom. How do I do it? Its just a sense of touch and some guts. <grin>


Milling the 3/16" tool slot.


Checking fit of the tool bit. That's about as deep as you'd want to go.


Both slots cut. Notice that when the holder is laid down in it's cutting position that the tool will be slanted 12 degree away from the center line.


All three lined up. 1/4" left, 1/8" middle, and 3/16" right.


The tool needs to be about .560" high or thick. So I'm using the prototype to scribe a line on the other two.


A quick trip through the band saw. I use a 6 tooth per inch raker tooth. Cut's like butter. Then a quick trip through the mill to clean up the saw cut.


And here is the tool on try out cutting. The blade holder is nothing more than a piece of steel with a hole in it and one surface mill so when clamped it will be parallel with the tool.


That's it for now. I'm not going to go and develop this much beyond some clearances so I can face larger diameter pieces. I want to concentrate on building the coke bottle engine I've started. This was an experiment to see if I could do the job in less set ups than the author used in his article. I think I succeeded. I'm just not sure I have some of the angles right. I did this to see if I could make a tool to better turn the bronze material of the coke bottle engine. I think it would but will resort back to the regular tool post that came with the Sherline for now. Perhaps when I finish the engine I'll resume on the tangential tool holder.

Questions?

Regards,
Bernd
You can't fix "STUPID".

Online sbwhart

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Re: A Tangential Toolholder for the Sherline
« Reply #25 on: January 20, 2009, 03:51:35 AM »
Nice Job Bernd   :thumbup:

Tangential tool boxes were used a lot in industry on automatic cam autos, before the advent of TC and CNC machine tools, I've seen them with chip breakers ground in the top.

Look forward to seeing your Coke Botle Progress

Have
 :wave:
Fun

Stew
A little bit of clearance never got in the road
 :wave:

Location:- Crewe Cheshire

Offline Bernd

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Re: A Tangential Toolholder for the Sherline
« Reply #26 on: January 20, 2009, 08:12:09 PM »
Thanks Stew.

Yup, back to the Coke Bottle project it is.  :dremel: One piece at a time.  :thumbup:

I'm kind of wondering if I'll ever get it done.  :scratch:

bernd
You can't fix "STUPID".