Catches - ugh!

[AZSalsman]

Still being new to this realm of turning, I have and keep having lots of catches every time I turn something - rather discouraging and disappointing as I can seem to finish anything - at least without having to redesign whatever I am doing to "fix" scrapes and blowouts etc.

Does anyone have information on the most likely causes for tools catching (such as tool sharpness, the wood itself, technique probs)?

 

[dkulze]

AZ, my friend, the likely causes of catches are many and varried. Your one true hope is to contact the nearest turning club (just call up the president listed in the chapters listings on the main site) and arrainge for some mentoring.

Good luck and welcome to the vortex,
dietrich

 

[odie]

If you have the "Turning Wood" companion video vhs tape to the book by Richard Raffan, you'll see him have a catch.....right on the video. It wasn't a serious catch, but I'm surprised he left that in the program, but I can see why he did. It was to make us realize that even the pros have an occasional catch! In his case, it wasn't from lack of knowledge about tool handling, but pure carelessness.

There is only one way to have less catches.....practice and learn.

....odie

 

[dkulze]

Here ya go, AZ. Give em a call.

http://www.azwoodturners.org/

Dietrich

 

[John Nicholas]

Catches

Does anyone have information on the most likely causes for tools catching (such as tool sharpness, the wood itself, technique probs)?

I still get catches, been turning for a couple of years. I always forget the first 2 rules. Tool on the rest. Support the cutting edge.

John

 

[MichaelMouse]

You can think your way out of a lot of catches. Start with the rest up close, cut above centerline on convex shapes so that a drop in the handle of the tool gives you air, not wood. Raising might slap the bevel, but there's not enough room between rest and tool to wedge in, so a bevel slap pushes you into air as well.

On the inside of a bowl - concave shape, you still want to bring the rest in as close as possible, but you want to cut a bit below centerline. Keeps you from grabbing wood if the handle lowers. With a gouge ground with a consistent bevel angle, even if you roll the top edge you are limited by the bevel, and a slap kicks you into the air in the center. If you're messing around with variable grinds that get steeper on the sides you will have a pretty narrow sweet spot. If that rolls, you can broadside your way into a catch.

Don't push your way into a cut, sweep your way in. That way you can go in with small muscles locked, shifting your weight to maintain control. Gouge 101. Do your roughing in sweeps, arcing in and out, until you have a consistent surface to reference the bevel. Then follow your gouge 100 principles and roll the trailing edge a bit into cutting position, using tools and tilts that keep your gouge as close to horizontal as possible for best control.

I made an example of the sweep technique the other day and then decided to push the gouge for an example at the very last. You can hear the difference between edge and bevel, which is whacking and making it difficult to maintain cut control at the end of the clip. Even my videographer noticed the difference immeditely. Take a look at http://s108.photobucket.com/albums/n28/MichaelMouse/?action=view&current=Gouge101.flv if you're a broadbander. You'll want to look at least twice, once to see the guiding hand at the end of the gouge, then again to watch the pivot on the rest. You ears will fill in for reference. It's prime catch territory, roughing almost vertically on the endgrain, with the long grain having retracted as the piece dried. Interrupted cut, almost no peel vector at all.

 

[Martin Braun]

Here ya go, AZ. Give em a call.

http://www.azwoodturners.org/

Dietrich

AZSalsman, we have a lot of members that would be happy to spend an afternoon with you. You can even stop by & check out a meeting. If you like the meeting, you can sign up the next time you come. We have a book/video/dvd/mag library that will save you a lot of money as well. In Feb, we are hosting the Desert Woodturning Roundup Symposium which may also interest you as well.

 

[Hugh]

I took a class with John Jordan a number of years ago and he had written an answer to many problems on the chalkboard. The answer was: "The answer to your questions is SHARPEN YOUR TOOL." I realize that this is not the only reason one gets catches - but it helps with a bunch of problems.

I find I get catches when I am not paying attention to what I am cutting. I think I am - but the mind does wander. That is when I get most of my catches. Practice, Practice, Practice.
Hugh

 

[underdog]

I found that Keith Rowley, "A Foundation Course in Woodturning" was a great help in learning quite a few things, including how to avoid catches. Good foundational book!

Ditto on finding a club!

 

[Mike Vickery]

I am also a memeber of the AZ woodturners and it is a great club with some really talented members and a couple pro turners. Stop by a meeting, you can attend 1 with out joining and see how you like it. You are more than welcome to spend some time at my shop but I am in the SE corner of Gilbert so it may be a hike. I am far from an expert but I have been turning a couple years so I may be able to help.

 

[GA Darling]

Catches are a way of life for a woodturner. Figuring how to eliminate the catches is what makes it fun. Sharp tools are essential but not always the answer. Learning what makes the tool catch is the key. The link MichaelMouse gives above is an excellent reference. There are several good books and videos that cover catches. I'm more of a hands on type learner. If you can find someone to show you what causes your tool to catch I think you'll do better. Hook up with some one from your local woodturning club. Most of these folks are execellent turners and willing to help make you one too.

GA Darling

 

[DeanGThomas]

Hey, AZSalsman,

You've already got numbers of great answers. I agree most with John Jordan's quote. Dull tools often cause us to push too hard too fast and prompts catches, chatter, poor cuts, tear-out and more. Sharp tools helps promote good tool technique as well.

Second biggie, IMO, is tool shape and bevel angles. Angle arguements can drive ya nuts! There is a range in which tools work. In that range, they can work, well, fairly well, or very well. Outside that range they quickly move to aggressive or worthless! If you have a gouge that is mostly vertical at the front, those corners are quick to catch. Using a skew too close to either point while cutting (not scraping) can encourage that point to dig in and catch.

Buy some 2x2 pine stock at your box store and practice using good tool technique. That good tool technique is way better caught than taught. If you've got a helpful mentor looking over your shoulder and adjusting your hands and angles of attack, you're likely to learn in hours what it would taKe you months if not years to learn on your own, even with books and videos.

One man's opinions, YMMV.

 

[Sky]

One more bit of advice is to have the tool handle, your elbow or hand holding the tool handle against your body when turning. This gives you more tool control, moving your body with the cut. When your arm away it is easier for your tool to be bumped, jumped or moved into a danger zone where catchs occur.

 

[Steve Worcester]

Ride the bevel. And as far as the advice on putting the tool against your body, having been taught by David Ellsworth some number of years ago, and as I teach my students, you, the gouge and the lathe need to form a triangle of strength. The gouge is pressed down firmly with one hand and that arm usually against your side. The tool handle pressed against your (love) handle, keeping the gouge level with the floor. (Your body is the third part of the triangle).

Plan your stance (with both feet flat on the floor) so that from the entrance of the cut to the exit of the cut, you are continually in balance. It is akin to Tai Chi. (Which is slow motion Kung Fu) fluid motion and balance are more of a factor than you realize.

BTW - John Jordan's comment on go sharpen the tool is his answer to everything. And it's true. Even if the tool is already sharp, it removes your mind from the cut and then allows you to refocus once you are back at the lathe.

 

[AZSalsman]

Thanks

What a plethora of responses and worthy advice. The condition of the tools may be the biggest issues but all are part of the mix.

I just went through a rough weekend on the when everything I touched - including the one project that I had been anticipating for some time - went wrong so I got extremely frustrated and anticipated. In one case though, I know it was the wood as I was discovering some small and not so small cracks indicating some weaknesses....oh well.

I have just recently become a member of the AZ Woodturners Assoc. but am still learning who is who, etc.

 

[Martin Braun]

In the past we have had various instructors out to a members garage for a weekend of lessons as well. I found woodturning to be much more enjoyable after a weekend of instruction.

Another place for free tutorials is thewoodworkingchannel.com AAW has demos from various symposia that are played there. Usually 2 or 3 of them air a day.

 

[Martin Braun]

In the past we have had various instructors out to a members garage for a weekend of lessons as well. A bunch of folks would chip in for for the fee and attend. I found woodturning to be much more enjoyable after a weekend of instruction.

Another place for free tutorials is thewoodworkingchannel.com AAW has demos from various symposia that are played there. Usually 2 or 3 of them air a day.