Pretty big problem

[Art Brazee]

Guys (generically including girls),


I've got an overarching problem that I can't seem to solve. I need some good direction.

It's perplexed the hell out of me. I continually have feedback on my tool which ends up creating a wave pattern on the work. It happens on bowls, between centers, and just about everywhere in between. It's particularly evil when I'm trying to get a smoothing cut, but it happens other times too. It occurs with a skew, bowl gouge, fingernail ground gouge, soft wood, hard wood, inside, outside, ignores grain, and generally gives me huge problems. I can't seem to get rid of it - heavy cut, light cut, low pressure, heavy handed tool pressure, speed, reversing grain direction/attack, changing blade angle - you name it. Oh yes, it isn't the lathe either. HELP

I'm a medium skilled turner, self-taught, but a long time woodworker. I've got to overcome this issue. THANKS in advance!

[curtis rosche]

Sounds like your headstock spindle is loose or has runout. Or you arent holding your tool solidly.

[Art Brazee]

It's not the lathe. I've got a big powermatic and there's no runout. I've got solid tool control; handle on hip, hip moving the tool. I'd go for this answer, but I've tried to resolve things this way. It could be though...I'll try anything.

[Steve Mawson]

Art,
Any chance you have a turning club close? Might be someone with some experience that is not too far away that could see what is going on up close.

[curtis rosche]

It's not the lathe. I've got a big powermatic and there's no runout. I've got solid tool control; handle on hip, hip moving the tool. I'd go for this answer, but I've tried to resolve things this way. It could be though...I'll try anything.

hold the tool tight against the toolrest? Or maybe your wood is flexing. If Im not mistaken, the way "waves" are made is movement back and forth in relation to tool and wood, right?
got any pictures of the wood?

[robert baccus]

I'm not sure about all those tools but too much down pressure on the gouge bevel will produce waves. I rediscover this about every two years and the solution is not intuitive. Put your effort into the tool tip and very little on the bevel. Only does this to mewhile point cutting.

[Chris Studley]

A basic, top down logical approach is best before going too crazy...

I would verify the basics like your sliding headstock is secured, tailstock alignment, tool rest tight and at proper height for cut being made. If tour tools aren't sharp or have a funky bevel funny things happen.

I'm my limited experience I find that when you find the issue realize how obvious it should have been.

Good luck..

[John Keeton]

I would start with more speed and a.better/sharper grind. Quality of cut issues are normally related to edge quality and tool presentation, but too slow a speed can cause issues, as well.

[Paul Singer]

I get this very same problem at times and I always try to blame it on the wood. Normally though if I take my tool and put a fresh edge on it then work my way past the problem slowly with very fine cuts I can smooth it out. Sometimes it takes some patience but it is normally me and not the wood. It seems like once it starts it only gets worse with each pass until I do the above mentioned procedure.

[charlie knighton]

+1 on increase speed on finishing cuts per JK

[Prashun Patel]

Does it only happen when the pieces are thin? I get waves when finish turning near the ri. For me its vibration. Can u use a steady?

Also, on bowls especially green ones i get chatter because the grain direction switches play tricks on the tool. The solution there has been to sharpen afresh.

[Robert Henrickson]

I would agree with increased speed, and sharpening as possible solutions. The two places I most likely would have this problem is with plates/platters and long slender spindles -- both almost certainly due to the wood flexing. Often I can remove the waves by cutting in the opposite direction -- e.g., if I have been using a PUSH cut, I would make several very light PULL cuts in the opposite direction. I rarely use scrapers; my experience is with gouges (bowl and spindle). Contacting a local turning group is also a good idea -- an experienced turner may be able to identify something you are doing.

[Don Orr]

Is your tool rest close enough to the wood? Too much tool overhang can cause your problem.

[Jerry Marcantel]

It's not the lathe. I've got a big powermatic and there's no runout. I've got solid tool control; handle on hip, hip moving the tool. I'd go for this answer, but I've tried to resolve things this way. It could be though...I'll try anything.

Art, how new is this big Powermatic? I'm asking because if you aren't the original owner, someone could have done something to it earlier in it's life that wouldn't be detected. I had the same problem before with a Delta Homecraft I bought used in '83. It was complete with a Delta motor and step pulley. All I did was mount it to a bench, and turn it on. I had this one spot that always left tearout, was never completely balanced, and I couldn't figure it out. It wasn't until 2009 that I just happened to be looking at the motor pulley as it was winding down and saw the pulley was out of round. It turns out that the motor has a 1/2" arbor, the pulley has a 5/8" hole, and the bushing was about 1/2" x 9/16". There were no problems after I corrected things.... Jerry (in Tucson)

[Michael Stafford]

Sounds like you are pushing too hard against the wood. DAMHIKT! Lots of time people think that riding the bevel entails lots of pressure against the wood where the cutting edge and heel of the bevel both contact the wood and you can get some bouncing and resonance causing the ripples you describe. It is sort of like the process involved in using a chattering tool on end grain. Bounce and cut, bounce and cut except with the gouge you get bounce, cut and bruise as the heel burnishes the wood behind the cut.

Instead of riding the bevel glide on the bevel and let the cutting edge do the work. Sharp tools make this process easier.

P.S. This effect can be magnified by how far the cutting edge is over the tool rest so the closer the rest to the work the better.