# Rear Tool Post Parting Tool Holder



## Digitallad (Jun 21, 2015)

Okay gents this will be long but bear with me. ...

Some time ago I bought a parting blade (Somta Dual 20x4 blade) for a steal , the price was about $3. Around here it goes for about $ 70 new. 



So I decided to make a rear tool post parting tool holder. I also must confess that until now I have only had dreadful luck with parting.
I wanted the blade to be as upright as possible and measured the top and bottom of  the blade subtracted the two and divided by two to get the "angle" of the blade as shown here:  (also the basic design  )
	

		
			
		

		
	



Next I had to Square some stock material:


Then I had the Machinist vice (also one of my Earlier projects) to the correct "angle" I used my clock gauge for this purpose and a magnet to hold the blade here is some pictures of the setup:

The first pick is the setup before I changed the blade around ....



The measurement with the clock gauge 





After that I located the edge of the stock:


I did not take pictures of the cutting process , got caught up in the moment and forgot about the pictures. 
But I did use a dove tail cutter and wood ruff cutter to cut the slots for the bottom of the blade :


I made a dell to keep the top of the blade holder strait and are using the tool post clamp it self to clamp the blade.
Some pics of the holder in the tool post:


And YES it is cutting like a charm !!!




And the center line worked out well:


While I was at it I decided to try my hand at Chemical Etching ( The salt water method) and it came out quite nicely...



Just for fun here is my notes while I am working :



Hope you enjoyed it !!

Regards

Paul


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## jpfabricator (Jun 21, 2015)

Looks pretty good, not much nubby left on the center.

Sent from somewhere in East Texas Jake Parker


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## Mark_f (Jun 21, 2015)

That is really nice. I have a question. Why did you choose a rear mount over the front mount? Is there any particular reason?


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## Digitallad (Jun 21, 2015)

mark_f said:


> That is really nice. I have a question. Why did you choose a rear mount over the front mount? Is there any particular reason?



A couple of reasons:

1) As the rear post is one chunk of metal and the parting blade will be a lot more sturdier than would be mounted on the tool post 
2) A lot of people has the theory that if parting from the rear the cutter will have the tenancy of being thrown away rather been dragged into the work piece. 
3) The steel shavings will naturally fall away from the work piece and chances of metal build up is a lot less
4) Adding oil/ lubricant is also a lot better as you can add the oil directly to the blades tip ( as shown on the one picture)
and then there is also the matter of having the parting permanently mounted and is always available if you are going to do repeated work.

Most importantly for me is , THIS IS THE FIRST TIME that I have managed to part anything properly without my tool been dragged into the work piece


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## brino (Jun 21, 2015)

Hey Digitallad,

Nicely done! 
Good clean build and beautiful functional result.
Thanks for sharing it!!

Can you provide some more info (basic method, cost of setup, etc.) for your saltwater etching method?
Even link to where you learned it would be great.
Perhaps a new thread with an appropriate title would be easier to look-up.

Thanks
-brino


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## Jbar (Jun 21, 2015)

Im having trouble visualizing what you mean by the rear post. What do you mean by rear post?


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## mikey (Jun 21, 2015)

A rear mounted parting tool mounts at the rear of the cross slide. It is solidly bolted to the slide and the parting tool is used upside down. The work turns in the normal direction. The tip of the upside down tool should be on the exact centerline of the lathe spindle.


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## Digitallad (Jun 22, 2015)

brino said:


> Hey Digitallad,
> 
> Can you provide some more info (basic method, cost of setup, etc.) for your saltwater etching method?
> Even link to where you learned it would be great.
> ...


Hi Brino

The method is super simple you use a power supply , in my case and old pc power supply by seen guys using a 9V battery as well, connect the Positive to your object that you want to etch and then use a cotton swab covered with saltwater connected to the Negative to "burn" into the metal. What took some time is to transfer the letter onto the metal first , I use toner printed on some glossy paper and then Ironed onto the work piece but it took some 4 or 5 tries before I got a nice transfer. 
Try this link for the toner transfer :
http://www.instructables.com/id/Cheap-and-Easy-Toner-Transfer-for-PCB-Making/

and this will give an god idea of the etching proses
http://www.instructables.com/id/Salt-Water-Metal-Etching/

I will recommend that you play on some scraps first before you start marking your beloved tools 

When I do the next one I will post some pictures on a new post.

Regards

Paul


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## Ulma Doctor (Jun 22, 2015)

Nice work on the holder!


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## mattthemuppet2 (Jun 22, 2015)

that's really cool and on my to do list as well!


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## Kernbigo (Jun 22, 2015)

what lathe do you have? I would like to make a set up for a 9" south bend wide bed.


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## Digitallad (Jun 22, 2015)

Kernbigo said:


> what lathe do you have? I would like to make a set up for a 9" south bend wide bed.


I have a Colchester Bantam Lathe.


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## bpratl (Jun 23, 2015)

Paul, very nice design on the parting tool setup. Did you fabricate the rear T-Slot mount? Bob


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## Digitallad (Jun 23, 2015)

bpratl said:


> Paul, very nice design on the parting tool setup. Did you fabricate the rear T-Slot mount? Bob


Hi Bob

Bought the lathe with them I would assume that it came with the T slots originally as the mount is also an original. The guy that I bought the lathe from paid only $150.00  for it ( That will never happen to me) But I still got it for a good price from him ....


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## bpratl (Jun 23, 2015)

Digitallad said:


> Hi Bob
> 
> Bought the lathe with them I would assume that it came with the T slots originally as the mount is also an original. The guy that I bought the lathe from paid only $150.00  for it ( That will never happen to me) But I still got it for a good price from him ....


Thanks Paul, it looks like both of you guys got a good deal, that is a nice lathe.
It looks like I will have to fabricate a rear mount for my lathe. You post inspired me to do it. Bob


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## Digitallad (Jun 23, 2015)

bpratl said:


> Thanks Paul, it looks like both of you guys got a good deal, that is a nice lathe.
> It looks like I will have to fabricate a rear mount for my lathe. You post inspired me to do it. Bob


You wont be sorry !!!


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## Silverbullet (Jun 24, 2015)

Nice job , we had our turret lathes set up like that , I noticed you have the same qctp that I have mine came from enco originally . I've never had a problem with mine but don't see them much anymore. You'll never be sorry you made the cutoff tool. You could make knurling tool off the back too. It's nice to watch the knurls form when from the back. Somethings just work better that way.


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## Digitallad (Jun 25, 2015)

Silverbullet said:


> Nice job , we had our turret lathes set up like that , I noticed you have the same qctp that I have mine came from enco originally . I've never had a problem with mine but don't see them much anymore. You'll never be sorry you made the cutoff tool. You could make knurling tool off the back too. It's nice to watch the knurls form when from the back. Somethings just work better that way.



Ah man .... Now I will have to look into that .....


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## NEL957 (Feb 12, 2016)

Those that own South Bend Lathes can purchase a casting from

http://www.statecollegecentral.com/metallathe/S-4382.html

Machining required.


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## mikey (Feb 13, 2016)

NEL957 said:


> Those that own South Bend Lathes can purchase a casting from
> 
> http://www.statecollegecentral.com/metallathe/S-4382.html
> 
> Machining required.



Very cool link, Nel. If I owned a SB lathe I would definitely be looking at this. Parting from the rear makes parting a non-event. As mentioned above, knurling from the rear is also more controlled and it gets the tool out of the way so you can see. Maybe someone here will do the mod so we can see how it works out.


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## NEL957 (Feb 13, 2016)

It is not just meant for South Bend. You can use it if it is close to the size of your cross slide. It said it will fit Logan and some other lathes. The casting has a lot of metal. Just check the size of your lathe and if it will work on yours.


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## mikey (Feb 13, 2016)

NEL957 said:


> It is not just meant for South Bend. You can use it if it is close to the size of your cross slide. It said it will fit Logan and some other lathes. The casting has a lot of metal. Just check the size of your lathe and if it will work on yours.



Better yet. My lathe already has T-slots so no issues here but there are a lot of old lathes out there that would benefit from this mod.


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## Firestopper (Jun 25, 2016)

Nicely done! Making your own tools that work better than expected is always satisfying. I like the etching as well.


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