help a newbie: tool 'catches' in the object

There are so many factors that determine whether you get or keep from getting a catch, it would be impossible to say. The basics for a catch are using the wrong tool, improper approach angle, improper tool position, improper tool usage (cutting up, not down - even though some of us do it anyway), improper tool height off the tool rest, and on and on and on.

And since you didn't say what tool you were using, what you were trying to turn (bowls, spindles?), or even parallel or end grain, how would anyone know what to say? This is the equivalant of saying "my car isn't running right... can anyone help?"

Try searching this group. Search word, "catch".

Check out some woodturning books. Go online and look at videos. Join your local club.

If you can see or read how others turn and how they resolve their own problems it be much better than having someone here simply guess what you might be doing to cause this.

Robert

hello,

I am trying to turn the outside of a bowl with a large gauge, my toolrest is positionned as close to the workpeice as possible and roughly in the turning axis, I am turning with my tool pointing upward...

what seems to happen is that I get a 'mini' catch, which causes my tool to 'jump' from the toolrest a little bit, which causes a 2nd larger cath... etc until I loose control.

cyrille

OK - In GENERAL terms, with me trying to imagine your situation:

On the outside of the bowl, it could be that you have the tool positioned wrong for he bowl you are turning. This is what works best for ME:

1) the cutting edge of the gouge needs to be slightly below center at all times, and when cutting, it is easiest to cut down towards the foot. Cutting up needs to be done on occasion, but almost never on simple shapes and it does require practice

2) to lesson the amount you are cutting, try rolling the gouge over farther on its side. The closer the flute is to pointing up, the more material you will cut making it easier to catch.

Smooth green wood is very forgiving; but if you are turning some old hard stuff or punky logs, you need to experiment by taking small cuts until you see how the piece will respond. Each piece is different, so small cuts increasing to larger ones is the way to go

3) you may need to drop the handle of your gouge as you may be going in too level with the tool rest. Some turn at around 25 degrees or so, and some at around 45, depending on the operation (hogging, smoothing, detailing) they are doing. Without measuring, for bowl turning I think I am closer to the 45 degree position

4) keep the tools sharp. There is a camp that says catches come to experienced turners from harmonic distortion. In other words, instead of smooth cutting, micro bounces start and get bigger an bigger until you have a catch. Those little micro bounces are the vibrations you feel in the handle of you tools. Today's tools have huge handles, so you can easily control the vibrations... until you can't. Sharp tools will help ensure good cutting

As a side note, from my brief period of instructing, it sounds like you are in the first three examples somewhere. I would tend to think (especially on the outside of a bowl) that it is improper tool angle and rotation, and probably a combination of both.

Robert

Hi When i had my first turning lesson, the one and only rule that i wa taught was"keep the bevel on the wood". Your probably cutting with the point instead of laying the bevel of th gouge flat on the wood. It doesn't matter what angle the flute is at although you may find you take more aggresive cuts, just jeep the beve running on the wood. I am sure there will be several more esteemed people who follow thi post, who will be able to explain better than me.

When i started i got a free DVD from Robert Sorby and on this it showe the basic use of each type of tool, along with a few other basics. As starting point i well recommend it.

Oh and the other thing to remember is pratice, ;-)

Mar

This is like trying to learn to ride a bicycle over the telephone. You need an experienced person right there watching you. Join a club, take a class or find a friend who turns.

Start by cutting above centerline on convex and below centerline on concave surfaces. Means a touch of up won't get underneath the wood and catch, and a bump will kick the tool out away from the wood.

Then try to avoid cutting with the gouge nose up. Some people get fixated on the idea of a "bowl" gouge, and forget that a gouge is a gouge, and an edge an edge. Support close as you can, contact with the deepest point of the gouge and lean the gouge slightly left and trail the nose as you cut, making a longer area of bevel support to avoid digging.

Note how the method transitions from a push to a swoop when there's nothing to rest the bevel on. Lot safer way to do things, pivoting on the well-referenced rest rather than trying to support a bevel on air. This is basic gouge, and it works on spindle or cross-grained pieces.

Something I'm surprised no one else thought of- when you say you're "trying to turn the outside of a bowl" does that mean that you're doing the initial roughing (ie. the first cuts on the blank before it is fully round) when you have this problem?

If that is the case, there are a couple of things you can do. First, is get the blank as close to round as you can before starting. Use whatever you have to do this, it doesn't have to be perfect. I often use a 1.5" framing chisel and a hammer.

The next one, which I've learned because I'm not really that keen on using the chainsaw, is to hold the flute of your gouge with one hand, with your index finder rubbing the toolrest while sliding, and place the other hand on the furthest end of the handle for more leverage and control. The reason the front hand rubbing the toolrest is important is that you can then use it as a "depth stop"- until the piece is round, you can't really "rub" the bevel using any pressure. You just walk the tool in slowly until it starts to hit the high spots, and slowly work it down. *After* it's round, then you can use the workpiece as a guide for the tool- if you try that with a rough blank, it can easily rip the tool out of your hands.