I think I have a parting problem........

I've recently tried a cheap MGEHR1212-2 insert carbide parting tool off eBay and it actually works good with 1" rounds of tool steel on my 12x36. Better than my usual M42 parting blade set up. I can only imagine that the name brand insert parting tools are even better, but the $16 tool is surprisingly a great value. Its cheaper than a single Shars parting blade shipped. I can power through hard and get a decent parting, the inserts are lasting better than expected.
 
British Steel said:
If running from a VFD, install a slide potentiometer to carriage and cross-slide, its slider goes to the VFD speed input as normal, its ends go to the wipers of a pair of rotary pots each across the VFD 10v analogue supply - hey Presto, (nearly) constant surface speed with max/min settings :)

Dave H. (the other one)
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Dave H, Thank you very much for that I'll have a very good look at it.
 
Here's the photo I said I'd post of part-off block. Upside down 32 mm blade. It is as close to center of the tool holder as I can make it, wish I had a wedge type though. Also for those interested an article by G. Thomas on parting. Again rigidity is the single biggest influence.

HPIM0153.JPG

HPIM0156.JPG
 

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LOL: I just had a "parting moment"... piece of 4140 and hardened to RC38. It was parting just fine and all the sudden, its not cutting. I push a little more, no go. I push even more... no go. What? am I losing my mind??? Take a close look... should be fine. Push a little more -Nothing, no curls coming off.

Time for a cup of coffee -which solved the problem very quickly. The blade was not sticking-out far enough. -Duh!

Ray
 
back some time ago i had a job to part a couple hundred heads off of 3/8 rivets (for an industrial look on metal furniture frames) using "separator" carbide inserts. had trouble damaging the tooling so being self taught all my life i assumed i needed to slow things down. the slower i went the worse it was. put the question to a friend who was shocked at my speeds/feeds. ended up running at my max speed (2000) @ .002ipr and it was like pushing through crisco. sometimes you need not to be scared. (my modest lathe and tooling are relatively rigid with flood coolant)
 
[QUOTE="

Time for a cup of coffee -which solved the problem very quickly. [/QUOTE]

coffee is not good for you this week. wait a month and it'll be approved again
 
I have no problem parting with my 19" Regal Leblond lathe with carbide or HSS, but do have trouble on my 10" Monarch, which is in excellent condition so far as ANY wear is concerned; I have come to the conclusion that the root of the trouble is the QC tool holder, which tends to lean over towards the chuck when the cut is made, causing the blade to bind; the reason being that the tool is overhung past the front side of the cross slide; I think, a Armstrong type holder in the original tool post would solve the problem by centering the tool over the cross slide. I have broken many HSS parting tools because the rocker wedge can slip under the cut, causing the blade to bind in the cut; This I solved on an older American lathe by replacing the rocker with a solid washer of such a height to bring the tool on center; many less broken tools after that ---
 
cg285 said:
[QUOTE="

Time for a cup of coffee -which solved the problem very quickly.
Click to expand...

coffee is not good for you this week. wait a month and it'll be approved again[/QUOTE]

Coffee only causes cancer if you live in California...

-Bear
 
I was looking at 1-cyl wooden boats on You Tube and this popped up:

I couldn't resist posting.
 
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