# Round carbide inserts?



## Mapster (Jan 30, 2012)

I have a woodchuck and have found that it doesn't like my lathe and set up. It has too much contact and it is scraping more than cutting. I am going to make a round tool and was wondering what insert to use.

I have done some research, but there are too many possibilities to even think about. I am looking for one that has a relief on the top, similar to the picture below...





I feel this would cut smoother with less pressure than the woodchuck. All help and information is greatly appreciated


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## glen r (Jan 30, 2012)

Have you tried cutting with the shaft turned?  Usually these work great when used like a skew instead of like a scraper.  Experiment with the best angle that works for you.


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## Mapster (Jan 30, 2012)

I have tried turning the shaft, but it is pretty difficult to do... I love the tool, but when I get to the center of a blank it starts to squeal and leaves a rough finish... Which is vibration. I feel like it is due to the pressure the tool exerts on the material because it isn't "cutting" the material. But I may be wrong, that is why I come to you guys! I will try that again though and see what happens


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## tool-man (Jan 30, 2012)

This thread has some relevant info you might be able to use. http://www.penturners.org/forum/f30/how-carbide-tip-turning-tool-91939/

Many carbide inserts are made for cutting metal and not wood.  The metal cutting inserts IMHO are not as sharp as those made for cutting wood.  I have had excellent results when I purchase the special wood cutting inserts.  

I have had OK results when using metal inserts (flat top) and resharpening then myself using a diamond hone. If the top of the insert is not flat (such as the one pictured above) resharpening would be a real challenge.:biggrin:

As glen r stated, I too have had very good results with round inserts when I rotate the tool shaft about 30 degrees so the insert performs more of a cutting, slicing action.


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## jjudge (Jan 31, 2012)

Both the round and square bits do better for me when angled a bit.

I find the round bit can dig in quickly, if I'm not paying attention.
Same with the corners of the square bits.

I just ordered radiused square bits -- hoping this will reduce my need for 110% concentration ;-)


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## spanky239 (Jan 31, 2012)

Where are you ording the radiused square bits from?

Aloha,
Stacey


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## darthintel (Feb 4, 2012)

I bought the Woodchuck pen pro and started turning with it this week.The slightly radius tip wouldn't cut unless I used the corner of the blade. I tried rotating the tool...but with very poor results. It would squeal and try to take chunks out of the blank.  I fought this on several wood blanks, when I decided to go buy and try the round carbide tip. WOW...what a difference! The round carbide tip cut and threw chips like a hot knife through butter! What took me over an hour to do with the slightly radius tip I could now complete in 5 minutes with the circular carbide tip. 
What works for me is to keep the carbide cutter positioned in the middle of the blank, and held flat ( level). Also what helps a lot is to keep the tool rest right behind the allen set screw which mounts the carbide tip to the tool. 
Keeping the tool rest this close prevents any possibility of the tool to catch and chatter. Also, I tried different angles of the tool, but straight into the blank with a very light touch works best. 
Maybe this method that works for me may help someone else. 

"If you're not turning - you're not learning"


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## juteck (Feb 4, 2012)

I use the 10mm RCGT from carbidedepot.com:

Product Detail

with these screws:

Product Detail


...and try this for some help on deciphering the insert codes:

Insert Designation Chart - provides ANSI and ISO designation code definitions for carbide insert shapes, relief angles, tolerances, chipbreaker codes, hole types, size values, thickness values, radius values, wiper lead angle, wiper clearance angle, 


These cutters have the relief you are looking for, and are "similar" to the Hunter-style cutters commercially available.

We just bought some of the 6mm cutters to try and make a small hollowing tool like the Hunter #1 tools. (The inserts: Product Detail  and the screws: Product Detail /  Search Results )


And as others have already mentioned, there is a "sweet spot" for cutting with the round bits - for me it's somewhere between ~ 30-40 degrees or so.


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## dankc908 (Feb 4, 2012)

darthintel said:


> I bought the Woodchuck pen pro and started turning with it this week.The slightly radius tip wouldn't cut unless I used the corner of the blade. I tried rotating the tool...but with very poor results. It would squeal and try to take chunks out of the blank.  I fought this on several wood blanks, when I decided to go buy and try the round carbide tip. WOW...what a difference! The round carbide tip cut and threw chips like a hot knife through butter! What took me over an hour to do with the slightly radius tip I could now complete in 5 minutes with the circular carbide tip.
> What works for me is to keep the carbide cutter positioned in the middle of the blank, and held flat ( level). Also what helps a lot is to keep the tool rest right behind the allen set screw which mounts the carbide tip to the tool.
> Keeping the tool rest this close prevents any possibility of the tool to catch and chatter. Also, I tried different angles of the tool, but straight into the blank with a very light touch works best.
> Maybe this method that works for me may help someone else.
> ...



Rick -

Are you using the round cutter on your pen pro?  I have the pen pro and am considering buying the round tool, however, if I can get by with just the cutter I might give that a try before buying the entire tool.  I do like the Woodchuck Pen Pro and it has given me great results but I am always looking for something to do other tasks (like bottle stoppers, etc.) a bit better!

Dan


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## randyrls (Feb 4, 2012)

John;  Thanks for posting that reference material.  Safely saved in my bookmarks!!:good:


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## darthintel (Feb 4, 2012)

dankc908 said:


> darthintel said:
> 
> 
> > I bought the Woodchuck pen pro and started turning with it this week.The slightly radius tip wouldn't cut unless I used the corner of the blade. I tried rotating the tool...but with very poor results. It would squeal and try to take chunks out of the blank.  I fought this on several wood blanks, when I decided to go buy and try the round carbide tip. WOW...what a difference! The round carbide tip cut and threw chips like a hot knife through butter! What took me over an hour to do with the slightly radius tip I could now complete in 5 minutes with the circular carbide tip.
> ...



Dan,
Yes...I'm using the round cutter on my Woodchuck Pen Pro ....I bought the round cutter from Woodcraft ...It's not made specifically for the Woodchuck, but it fits as the instructions for the Pen Pro indicated other brands would fit their tool and they were right. I would give that a try before buying a whole new tool.


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