Catches

[dartman]

I have a question,no wait two questions.I was trying to turn a bowl this afternoon and had a heck of a time hollowing it.Walnut,about six inch's across and two inch's deep.I had it mounted with a dovetail in the chuck with a tapered center in the hole from the worm screw I had used to turn the base and sides.There was catch after catch.I tried fast and slow,push cut and pull cut.I was using a new round carbide cutter.Sometimes as soon as the cutter would make contact,I would have a violent catch.I just don't know what to do.This is far from my first bowl so I am at a loss.Also,how do you guys get rid of tear out? Again ,fast,slow,push and pull cuts with a brand new cutter.Sanding takes forever and I hate sanding.

[Jim Pilsner]

I got a carbide cutter from rockler some years ago. The carbide cutter on it is slightly dished and it cuts SOOO agressively that I found it unuseable.

Is it a round bar? If so, try rotating the cutter to not cut at 90 degrees. You can still do that with a square bar but it's not as easy. You'll get a much finer cut and find it much less aggressive. But, you won't have as much control over the flatness, but it's a tradeoff.

Above all, get the tool rest in as close as you can to what you're cutting. Sometimes a catch just happens because you don't have enough leverage over the cut itself.

Rather than holding the far end of the handle thinking you're getting a TON of support, you lost control. I find that if I support the handle under my forearm I get way more support and gain a lot of control.

[dartman]

I use a round tool rest so I can get close.It is a square bar and I have tried tilting the tool also.I am using a short EWT bar and handle.I have also tried raising and lowering the rest.Unfortunately I have to sit while turning so I don't get the leverage of a long tool.

[jerickson]

What angle is the grind on the cutter? If the angle is too sharp, it might help to back it off to around 80 degrees.

[dartman]

It is an easy wood tool carbide cutter so all I can do is change the angle of the tool on the rest.

[dartman]

I also tried to use a round nose scraper and it was better but still catchy.

[NCPaladin]

I have a square cutter but have only used it for roughing the outside. Getting an immediated catch I assume you are presenting it at an upward angle. The tool rest should be higher than center and the entire tool sloped down slightly (or dead level) and cutting at, or just above, center. Just like any other scraper.

I have had a round cutter Jim described from Rockler for a couple of months but have not used it yet.
It has the cupped edge.
Here is a video by John Lucas on using the cupped cutter (his by Hunter Tools). It can not be used flat but must be at an angle.
https://www.youtube.com/watch?v=nfp2kvhH6Mo

[robo hippy]

Would you be using it with the handle low, and the cutting edge pointing up into the spinning wood? This tool is a scraper, and scrapers are always used with the handle high, and the cutter pointing slightly down. On the outside of the bowl, you want the cutter at center height or slightly below, and on the inside you want the cutter slightly above center height. Other than that, I would need a hands on session. I do have a number of You Tube clips up about bowl turning, and use scrapers a lot. Type in robo hippy.

robo hippy

[dartman]

robo hippy said:

---

Would you be using it with the handle low, and the cutting edge pointing up into the spinning wood? This tool is a scraper, and scrapers are always used with the handle high, and the cutter pointing slightly down. On the outside of the bowl, you want the cutter at center height or slightly below, and on the inside you want the cutter slightly above center height. Other than that, I would need a hands on session. I do have a number of You Tube clips up about bowl turning, and use scrapers a lot. Type in robo hippy.

robo hippy

---

Thanks,I will try that tomorrow.with a fresh head.

[DFJarvie]

Check your speed. I've found the slower the better. Look up the speed for the size of the bowl. Also take very light passes starting from the center and work out. I've had the same issue and this seemed to help.