Help - Out of Balance Turning

[Gary Gronborg]

I am trying ro turn a big leaf maple burl and want to leave the natural sides on it. But this means the center is way off to one side, which throws off the balance. I have already used the band saw to take off some of the weight, but have thrown the wood off the lathe three times now. So I'm getting gun-shy. Any suggestions on how to balance the weight?

 

[john lucas]

You'll have to tell us how you are holding the piece. I frequently turn out of balance natural edge pieces on my big lathe and on my mini. I haven't lost a bowl in several years.
If you use a tenon and a chuck make the tenon short enough that the bowl will sit on the top face of the chuck jaws and make this face perfectly square so the bowl sits on this without rocking. If you have dovetail jaws cut a dovetail to match on the tenon.
If your using a faceplate make sure the screws are long enough and big enough. I drill all of my faceplates so they have more holes than they originally have. I also chamfer the holes on the side that goes on the wood so the screws don't pull fibers out and leave the bowl somewhat loose.
I also start all of my bowls between centers and don't remove the tailstock until it starts getting in the way. This way I have removed a lot of mass so even if the bowl is out of balance it is a lot lighter.

 

[MichaelMouse]

If you've trimmed where you'll cut anyway, you can try weighting the short side. Bore a nice flat-bottom forstner hole where you have wood to remove on the light side, then screw some washers into the recess. Lead's heavier, but you'd have to smash and perforate it anyway.

Getting the total mass of the piece down will stress the hold less, even if the thing's still out-of-balance.

Almost forgot. If you've got something that'll never improve, mount it through or to a block that you can bore and counterweight.

 

[Steve Worcester]

If it is that big and out of balance, I generally turn at very slow speeds.

How big is it and what is the lathes lowest speed?

 

[Jeff Jilg]

Don't be afraid to post a couple of photos. It's a lot easier than describing the whole situation. Use Manage Attachments when you do a reply. For more info look in the Help item for how to post photos.

I wouldn't proceed further with this turning until you re-engineer the situation. A piece should not fly off the lathe.

 

[Gary Gronborg]

Thanks for the replies. I have been using a oneway talon chuck with the waste block super glued to the piece, and turned between centers. Sounds like I may be better off using a face plate with some good screws instead of the chuck. I could try the washers trick, but I would probably go broke buying enough of them! Would boring some holes on the heavy side where the bowl will be cut out anyway, give me enough weight savings? As for speed, I have a Delta 1440 at the lowest speed, which I think is around 500 rpm, but don't remember for sure.

 

[MichaelMouse]

I could try the washers trick, but I would probably go broke buying enough of them! Would boring some holes on the heavy side where the bowl will be cut out anyway, give me enough weight savings? As for speed, I have a Delta 1440 at the lowest speed, which I think is around 500 rpm, but don't remember for sure.

I would give the bores a try, if they're in areas you'll hollow later. That's my preferred over adding counterweight. Might need a combination of the two to do it.

Remember - farther from the axis of rotation, greater the effect.

Check with a tire place or service station for some of the wheel weights where the clips have rusted off. Or at least they do here in salt country. Free stuff, though even fishing weights aren't dear, and can be recast and bored to fit what holes you make.

 

[JimQ]

Tire weights are lead, a hazardous material. Tire shops are required by Federal law to dispose of them only through licensed recovery companies.

JimQ