# excitement at the lathe....



## Jim Beam (Jan 5, 2016)

excitement at the lathe is never a good thing.

I had just finished the outside of this bowl and had it in the 50 mm jaws of my Nova G3. Started to hog out the inside. I don't think I was being unusually aggressive. On the third cut the tenon let go entirely, you can see how it just sheared right off. Nothing was damaged but it sure caught my attention!



 

I've turned maybe a dozen pieces of this spalted crackberry with 50 mm tenons with no problems, but no more. Not just because of this - it is just too soft and prone to tear-out. But it has taught me how to get really good at shear scraping.

What I learned from this is to evaluate each blank in terms of weight and strength when deciding what size of tenon to use.


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## Schroedc (Jan 5, 2016)

Bet that woke you up right quick. I'm assuming no injuries and you'll be back at it momentarily?


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## Mike Mills (Jan 5, 2016)

bummer...

If you work through your old pi (r squared) you will find there is three times a much wood to break away with a 2" recess compared to a 2" tenon. This assumes your leave the suggested 1" of wood around the recess.
Or you can go with a larger tenon.


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## Jim Beam (Jan 5, 2016)

Schroedc said:


> Bet that woke you up right quick. I'm assuming no injuries and you'll be back at it momentarily?



Yeah I've turned 4 more since that one. But like I said, no more spalted hackberry. Only harder woods.


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## duncsuss (Jan 5, 2016)

Been there, done that ... and then I bought a set of 4" jaws just for those spalted/punky lumps


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## ironman123 (Jan 5, 2016)

Glad there was no damage to you Robert.


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## David Hill (Jan 5, 2016)

Welcome to the club!
Ok to respect the wood for what it could do--not just stop for what it might do.
Not stopping me from turning spalted stuff though. I sometimes use recesses if the wood will hold it. Mostly just bigger tenons then either take it off later or make it a ring bottom.


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## Nature Man (Jan 6, 2016)

It's happened to me more than once. Fortunately, I've been out of the line of fire. I'm currently working on one that I had rough turned a couple years ago that I had tried to finish when this happened. Turned it over and plugged it into my new Longworth chuck and was able to carve out the tenon more so that I was then able to regrasp it with my chuck. Definitely unnerving, and also frustrating. I have one more bowl to work on where it sheared off like yours. Chuck


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## Sidecar (Jan 6, 2016)

Glad your unscaved. ....kinda look at it as a cardio workout....
I bought a powermatic 45 off ol @CWS and it's been an cardio exercise here. It's a cardio event for me when the ol 45 and I waltz........


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## sprucegum (Jan 6, 2016)

Just getting into turning some larger things so the experiences of others good and bad interest me, I could definitely see that happening to me. Thanks


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