Off centre bowl

[Hitch]

Im attempting to turn a bowl of sorts, Its a yew blank about 180mm diam, 40mm thick. I mounted to the face plate and trued it up a bit, and roughed the outer shape.
Now im attempting to turn a shallow hollow dish (100mm dia roughly) into it, but to one side.
I moved the face plate off to the side to give me the centre where i wanted it, but as you can imagine, its severly out of ballance.

The lathe i have is pretty poor attempt (clarke), not the most ridgid thing in the world, and lowest speed is 850rpm.

Any tricks to get over this? I though about screwing a weight onto the opposite side to balance it out?
Worth a go?
Could do with running a bit slower aswell i guess?

 

[Bodrighy]

Adding weights is one way of doing it. It's the way a lot of the old timers used to do it. IME there is a limit to how off balance you can be depending on your lathe. Mine has a sloest speed of 500 and that's too fast for some of the things that I turn. I suspect that with the cheaper lathes that many of us use we are also in danger of ruining the bearings if we are not acreful, not to mention the safety aspect. Welcome to the frustration zone.

Pete

 

[CHJ]

Try mounting your turning on a larger (trued up) blank of scrap wood on your faceplate, then screw on a crescent shaped shaped section of wood, or series of dense wood offcuts to the scrap to equalise your offset blank.

Metal washers or large metal nuts/penny washers are an option but not quite as forgiving if you trim your knuckles on them.

If you can, disconnect the drive belt so that the spindle rotates freely whilst you are checking balance.

 

[TEP]

Mornin' Hitch.

All good suggestions so far, but as you have probably found it can be frustrating/time consuming to get the thing in some sort of balance.

Chas's ideas of the large plate with counter weights is good I have used it before.

One thing as to spindle speed, one thing that does work if you wish to go lower than your lowest pulley is a slack drive belt drive. You slack off the drive belt slightly, then use the cut of the tool to control how fast the work turns, the harder you cut the slower the work will turn. Not easy to do and takes quite a bit of practice, but it does teach you how to cut lightly.

Good luck, and one thing I would suggest is that you try out all these methods on a small light piece first. Just to see how things go. It can get really exciting dodging bits of timber orbiting the workshop. :twisted:

 

[Hitch]

Cheers for the tips guys.

I might look at mounting it on a disc then, with a crescent shaped weight.
Sounds like the easiest way to get near balance.

As i said the lathe is pretty poor, probably wouldnt be half as bad on a more solid machine.

 

[CHJ]

As i said the lathe is pretty poor, probably wouldnt be half as bad on a more solid machine.

Does not matter what machine you have Hitch, the correct way, and the way that is most likely to give you the best finish is to balance the rotating work piece, don't get too frustrated at the limitations of your machine, overcoming them usually leads to you being more aware of best practice.

 

[Bodrighy]

I have a Perform CCl which is very much a low range lathe. A lot of the stuff that I turn tends to be unbalanced.

These were all off balance and turned on this lathe so it can be done.

Top view then underneath

Top view then underneath

Pete

 

[Hitch]

Once again, thanks for the tips.
DId some of it tonight, got the offset bowl section turned out.

Took some tension off the belt, it stalled the blank easily, so had to have a sharpen up, not ideal, but got the speed down.
I weighted it with a few M20 nuts screwed on one side. didnt get it perfect, but with the reduced speed it was adequate 8)