Newby question: re-truing a piece of work

[pointer2null]

I was just practicing making small lidded boxed, and while paring off the lid, the tool caught and stalled the lathe.

Un-jammed the tool easily enough but then the piece was out of true. I releaxed the jaws on the chuck and reseated the tennon, but it's still out so I guess the tennon was compressed (it was a bit of spalted wood so wasn't the hardest of materials).

So in this situation what would be the best way to proceed?

 

[LancsRick]

Have you got a wooden jaw chuck? If so I'd mount up the box reversed and take very light cuts to true up the tenon.

 

[Random Orbital Bob]

Unless you're desperately wedded to the piece it might ne just as quick to start again and chalk it off to experience. If you were only just parting the lid from it's tenon I'm guessing you hadn't got that far?

Alternatively, look closely at the tenon and you might see little witness marks where the chuck jaws have bitten into the soft spalted wood. Try fiddling round with it in the chuck to reseat it exactly against those witness marks. Failing that, if you can grip the other end concentrically then you could retrue the tenon. Given you're new to it, that might be quite tricky and frankly, starting again is likely the best route for you.

 

[pointer2null]

It's the only bit of nice spalted wood I have at the moment - so will try and reseat it. It may end up a little thinner than before - see how it goes.

Thanks for the tips.

 

[SVB]

As an aside, one thing you may wish to look at is how the piece was mounted in the chuck. The 'strength' of the mounting is down to the face of the jaw against the vertical face of the mount rather than the tenon in the chuck.

This shows the key points better than I can explain in text:

https://youtu.be/7V1BHYqN0Fk

You may have this sorted but if not, worth keeping in mind when you remount.

Simon

 

[pointer2null]

Well I've lost 1/4" off the overall diameter but at least the bottom section is true again.

After watching SVB's link I wonder if the angle on my tennon is wrong. Have to experiment...

 

[Keithie]

Sorry to hear your spalted beech piece fell off.

I'm a novice and my spalted bowl came off 4 times (& hit the wall twice!) ...but it was ok enough when finished to give as a gift to an elderly relative!

I really dont like dovetail jaws at my (low) skill level so I eventually switched to an axi C type jaw on the spigot which is dead easy ...just run a 1/8" straight grove deep enough in the piece with a 1/8" parting tool and its all good. (I reversed it in coles jaws to redo the spigot). It didnt fall off again

Lidded box sounds fun.. I'll put that on my 'to do' list

good luck

 

[pointer2null]

I like boxes lol

https://www.youtube.com/watch?v=nlTLHITalTE

Been practicing with scrap wood and decided to try with a nice bit of spalted chestnut I found in the log pile lol.

First box on the left. Most recent not quite finished - still need to do inside and bottom.

 

[Keithie]

very nice ! I'll definitely give it a go!

 

[Random Orbital Bob]

I don't think that's Chestnut but rather Robinia or False Acacia.

 

[KimG]

I don't think that's Chestnut but rather Robinia or False Acacia.

Yes me too Bob.

When it comes to re-centering such a small item, that's pretty tricky. One thing I always try and do is to make a small pencil mark on the base of a piece that corresponds to a mark or feature on the chuck, that way I know I am putting the piece back in the same position relative to each jaw, but even then, you will not often get a perfect result.

 

[SVB]

Other option is to mount / hollow lid, mount base and hollow leaving tight fit and then re-skim base and press fitted top as a unit before finish turning base of base!