# Making lathe QC tool post tool holder without dovetail tool?



## ErichKeane (Oct 2, 2018)

Hi all-
I have an Aloris BXA tool post on my lathe (kind with center 'button' that pushes out to tension).  I want a dial indicator holder, but I don't have a dovetail cutter.  I don't see myself getting one anytime soon (nothing else on my projects list uses one), so I had an idea to simply cut the dovetails with a normal endmill and a sin-bar.  

Obviously there would be a depression in the flat, but I'm thinking that if I can keep it away from the center 'button' part that I'd be alright.

So my question is, is there something obvious I'm missing here? Will this not work for some obvious reason? Cutting out of some sort of aluminum drop I got at a local store if that changes the answer.


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## Bob Korves (Oct 2, 2018)

A dial indicator does not need a robust setup, so your idea will probably work just fine for that use.  It would probably give up some rigidity with tooling that would work it harder, but might be OK.  60 degree dovetail cutters are not cheap, but they do have many other uses besides tool post dovetails.  The insertable single insert type will last much longer than a solid HSS multi flute type, they are resharpenable, but not easily or cheap.  Randy Richard makes a really nice dovetail cutter and sells them himself.  I have one and it works great.  I do not know how much he currently charges for one.  Here is a video where Randy shows how he makes them, in case you want to make your own:


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## ErichKeane (Oct 2, 2018)

Bob Korves said:


> A dial indicator does not need a robust setup, so your idea will probably work just fine for that use.  It would probably give up some rigidity with tooling that would work it harder, but might be OK.  60 degree dovetail cutters are not cheap, but they do have many other uses besides tool post dovetails.  The insertable single insert type will last much longer than a solid HSS multi flute type, they are resharpenable, but not easily or cheap.  Randy Richard makes a really nice dovetail cutter and sells them himself.  I have one and it works great.  I do not know how much he currently charges for one.  Here is a video where Randy shows how he makes them, in case you want to make your own:



Ooh, interesting!  I DO have a bunch of cheapish carbide inserts, so perhaps I can run one of those instead!  I DID just pick up an 1 1/4" steel drop from a local supplier, so this might be a fun project 'first'


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## 4ssss (Oct 2, 2018)

Cut the notch square oversize and add a triangle piece to it.


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## homebrewed (Oct 2, 2018)

You can make a pair of dovetails by cutting or milling two pieces of steel plate at 60 degrees, then bolt them to the body of your holder.  Of course, they have to be spaced to match the Aloris.  I have seen a description of this approach showing a real-life example but I can't find the web site now (sorry about that).  Hopefully someone else will come up with the link.


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## mikey (Oct 2, 2018)

ErichKeane said:


> I want a dial indicator holder, but I don't have a dovetail cutter.


 Why not make a dial indicator holder that simply fits in a standard tool holder? Most of us do that.


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## Bob Korves (Oct 2, 2018)

ErichKeane said:


> Ooh, interesting!  I DO have a bunch of cheapish carbide inserts, so perhaps I can run one of those instead!  I DID just pick up an 1 1/4" steel drop from a local supplier, so this might be a fun project 'first'


The dovetail cutter is cutting small radii, and therefor needs inserts with a large relief angle behind the cutting edge to clear the radii.  Randy uses TiN coated TPGB321 inserts and they work very nicely on steel, and are easy to find.  Typical turning inserts will not work, not enough clearance, they will rub.


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## ErichKeane (Oct 2, 2018)

I ended up not having any inserts that would work, so I decided to try my original plan with a 3/8" endmill.  

Sadly, I accidentially tried to copy from 2 different existing tool holders (1 Accusize, 1 Aloris), so I ended up cutting it too large slighty by getting the largest of both dimensions!  

It works perfect on 1 of my 2 tool-post locations, but is too loose  to lock up on the other.  I left plenty of material (since I screw up often ) so I'll likely reface it and start again tomorrow!


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## Bob Korves (Oct 3, 2018)

ErichKeane said:


> Sadly, I accidentially tried to copy from 2 different existing tool holders (1 Accusize, 1 Aloris), so I ended up cutting it too large slighty by getting the largest of both dimensions!


It is extremely easy to go from undersize to oversize when cutting dovetails to fit a QCTP.  You REALLY have to sneak up on it.  It is better if you make a plug gage that fits the OEM tool holders well, and then use it to test the one you are making.  The depth of the dovetail also needs to be spot on.  You can measure the dovetail spacing by using a couple dowel pins that seat somewhere in the center of the dovetails, and also on the register on the flat  inside, then measure the pins carefully and accurately for height and spacing.  There is little wiggle room, especially if you want the QQCTP handle to tighten to the same clock position with all of your tool holders.


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## Bob Korves (Oct 3, 2018)

ErichKeane said:


> Sadly, I accidentially tried to copy from 2 different existing tool holders (1 Accusize, 1 Aloris), so I ended up cutting it too large slighty by getting the largest of both dimensions!


It is extremely easy to go from undersize to oversize when cutting dovetails to fit a QCTP.  You REALLY have to sneak up on it.  It is better if you make a plug gage that fits the OEM tool holders well, and then use it to test the one you are making.  The depth of the dovetail also needs to be spot on.  You can measure the dovetail spacing by using a couple dowel pins that seat somewhere in the center of the dovetails, and also on the register on the flat  inside, then measure the pins carefully and accurately for height and spacing.  There is little wiggle room, especially if you want the QQCTP handle to tighten to the same clock position with all of your tool holders.

Edit:  Double post again.  I did nothing to cause it.


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## Glenn Goodlett (Oct 3, 2018)

I just completed two AXA tool holders. I used a cheap HSS dovetail cutter that I got from All Industrial Tool for less than $20.


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## savarin (Oct 3, 2018)

homebrewed said:


> You can make a pair of dovetails by cutting or milling two pieces of steel plate at 60 degrees, then bolt them to the body of your holder.  Of course, they have to be spaced to match the Aloris.  I have seen a description of this approach showing a real-life example but I can't find the web site now (sorry about that).  Hopefully someone else will come up with the link.


My dovetails are bolted on is this what you were looking for?
https://www.hobby-machinist.com/threads/a-vertical-slide-for-a-9x20-lathe.49724/page-2
 from message 33


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## catsparadise (Oct 3, 2018)

You could take the cheapskate approach I took - get a length of 1" silver steel, machine it on the lathe and mill to shape, then heat and quench it to harden. This won't cost me as much if I break a tooth on it. Obviously as it's carbon steel you really have to be careful milling with it so as not to overheat the edges.
I used the pictured cutter (sorry - not a very clear photo) to make a parting tool holder for my lathe.
	

		
			
		

		
	





Rob


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## homebrewed (Oct 3, 2018)

Hi Savarin,

I wasn't thinking of your build thread, but, yes, like that.  I DID eventually find the web site:  dovetail slides
-H


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## homebrewed (Oct 3, 2018)

homebrewed said:


> I wasn't thinking of your build thread, but, yes, like that. I DID eventually find the web site: dovetail slides



BTW another nice aspect of making the dovetails out of separate pieces is you can use the same setup to cut the gib strip.  Edit:  you DO need a slitting saw (and mill) for this, a non-starter if you ain't got 'em.


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## Mitch Alsup (Oct 3, 2018)

Bob Korves said:


> It is extremely easy to go from undersize to oversize when cutting dovetails to fit a QCTP.  You REALLY have to sneak up on it.  It is better if you make a plug gage that fits the OEM tool holders well, and then use it to test the one you are making.



It is good to sneak up on critical dimensions, it may be better to take measurements, 
but it is BEST to take the QCTP itself to check the fit on the QCTH being machined while it is still registered in the jaws of the vise.


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## ErichKeane (Oct 3, 2018)

Mitch Alsup said:


> It is good to sneak up on critical dimensions, it may be better to take measurements,
> but it is BEST to take the QCTP itself to check the fit on the QCTH being machined while it is still registered in the jaws of the vise.



Yep :/  I popped the QCTP off the lathe to check it before removing it (figuring I might be too tight!) and it worked fine, so I removed it.  Turns out, I needed to check both mount locations.  I left plenty of aluminum, so tonight's job is refacing the side and trying again!  This time I'll stop quite a bit early and try to sneak up on it.


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## Bob Korves (Oct 3, 2018)

Mitch Alsup said:


> It is good to sneak up on critical dimensions, it may be better to take measurements,
> but it is BEST to take the QCTP itself to check the fit on the QCTH being machined while it is still registered in the jaws of the vise.


Yes, absolutely!  It pays to make provisions for that in your setup, so the tool post can get in there to be used as a gage without upsetting the setup.


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## ErichKeane (Oct 4, 2018)

Welp, I ended up not getting a chance to work in the shop last night, so no work got done   Instead, found this guy on CL really cheap and had to jump at it.  I still have to figure out how to get it OUT of my truck and into my shop, as well as how to power it (I have 220v, so I probably need to get another VFD), but its in pretty awesome shape.  Weighs literal tons.


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## Bob Korves (Oct 4, 2018)

Looks like a B&S Micromaster.  If so, an excellent machine!


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## Bob Korves (Oct 4, 2018)

Looks like a B&S Micromaster.  If so, an excellent machine!


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## Bob Korves (Oct 4, 2018)

One post, 4 entries, AGAIN!  This is not happening anywhere besides H-M.


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## ErichKeane (Oct 4, 2018)

Bob Korves said:


> Looks like a B&S Micromaster.  If so, an excellent machine!




Yep!  Its a B&S 618 Micromaster.  I know very little about it, but I feel like it'll be a really fun addition to the shop!


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## Bob Korves (Oct 4, 2018)

That looks like a B&S Micromaster.  If so, very nice machine


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## derf (Oct 4, 2018)

Making a holder for an indicator is very simple.......................
	

		
			
		

		
	




This is made form 1" square tubing with the dovetail cut in with a bandsaw.


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## jdedmon91 (Oct 4, 2018)

I cut dovetails in tool holders all the time. I’m attaching 2 of my videos that may help. If you want you can just get the inexpensive HSS ones I used that before I got one of Randy’s cutters. If you plan to cut a lot of dovetails they are the best value. He isn’t that expensive on the cutters. 

Here is the videos 











Sent from my iPhone using Tapatalk


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