Technique problems

[surfdabbler]

I'm having an issue when turning, and wanting to get some advice.

Whenever I do a bevel-resting cut, it seems to get more unstable the further I go. For example, imagine turning a cylinder, already roughed out, and I want to take a nice light cut with a gouge to get it nice and smooth. Start at one end with the bevel resting, and then cut across the face from right to left. As I progress, the cut is no longer smooth, and by the end, I can feel it out of round, with a noticeable bump as it rotates. I find I have to go back over it with a light scraping cut to get it back to round.

Last night, I was roughing out some bowls with a bowl gouge. Again, scraping cuts, no problem, but after a couple of bevel resting cuts, it was no longer round, and the tool was jumping with each rotation. Inside the bowl was a nightmare, and bevel resting cuts were unusable, very quickly becoming out of round, and impossible to continue. I had to go back to a scraper.

I tried increasing the speed, but it didn't fix the issue, and just got scary. I've had this issue with different gouges, both on spindle turning and bowls. Gouges are sharp, and I'm taking light cuts.

Any ideas?

[smiife]

Hi surfdabbler , I would suggest you have a look at Stuart Batty,s videos , the one on bowl gouges and the 40 / 40 grind , he makes it look very easy , of course it isn,t but with practice it works very well
He also has some very interesting videos on vimeo you might find interesting
Hope this helps :2tsup:

[surfdabbler]

Thanks for the advice - I'll look into my sharpening techniques. I've also found some issues with the lathe, with some looseness in the head bearing, and the toolrest can get a bit wobbly. It needs a little tuneup!

[Skew ChiDAMN!!]

No offense intended, but from your description it sounds like you've headed your post with the answer: you need to work on your technique.

I'm guessing that as you move across the piece you're either dropping the end of the handle slightly or leaning left or right and changing the angle of the tool (compared to the length of the bed), resulting in a climbing cut.

The Turner's Tango is all about holding the tool in the correct orientation and moving your whole body from side to side (NOT just your arms and the tool!) to keep it that way.

The bevel should be resting pretty much just behind the cutting edge during the cut, so that raising or lowering the far end of a handle by only an inch or two will go from deepening the cut to climbing out. (You could think of it as like an aircraft; the controls will either climb or descend and you need to find the sweet spot between to maintain a constant 'altitude.')

It's good practice to introduce the tool so the bevel rubs in the middle, then lift the handle until it starts to cut. Effectively moving where the bevel is resting forward, to the 'right' spot.

At that point it's a 'descending' cut and you'll probably need to lower the end of the handle just slightly to maintain an even keel. Too much and you start climbing out, much as you describe.

Really, it sounds much more complicated than it really is. :rolleyes: A lot of it is just the feel, but until you learn what the right feeling is, well... In these days of social isolation I guess it's a bit awkward getting some one-on-one tutoring. :sigh:

FWIW, lathe speed will not make a difference and unless your lathe is badly out of whack, neither would the tuning you describe.

If I were you I'd just practice on scrap. At a speed you're comfortable with, rough the blank to round and try doing some roughing cuts with the bevel rubbing. ie. Just do some deep cuts and turn a blank or two away into match sticks until you feel you're getting the hang of controlling the depth of cut while also keeping the bevel rubbing.

Unless you have this control, any fine, dressing cuts are gonna be destined to be roller-coasters!

As with anything in turning, practice, practice, practice! :D

(My apologies if you know all this already. But all I have to go on is what you wrote...)