What is the air speed velocity of an unladen Box Elder Bee?

[Roger Chandler]

Ok. I calculated the velocity of your box elder, based on a few assumptions. I assumed a 6" diameter bowl and a speed of 1200 RPM.

Based on those assumptions, 2(π)R = 18.84" circumference @ 1200 RPM....giving you a tip velocity of 22,619 inches per minute or 376 inches per second. Travel time to breach the plane of the tool rest is approximately 50 milliseconds. Impact velocity at that point is approximately 21 miles an hour...a little faster than a typical punch by a fist attached to a man who is 6 feet tall. Add the mass of the wood....a few jags here and there, and you got a difficult combination

Increase the bowl diameter to 10 inches, and the velocity is roughly 35 mph...which is faster than a typical Kung Fu kick.

Be careful out there!!

Hart........I think you've been at the lacquer again................

rollonthefloorlaughing.gif

[Ian Parish]

Ian, it happens to all of us - and, it will happen to you again!! You didn't ask, but I would suggest you rechuck this roughout and take some off the height - for two reasons. First, it would improve the form, but, more importantly, it would get rid of the pith that appears to still be there. Removing that will decrease your chances of a crack.

Thanks for the suggestion. I knew the pith was still in the top of the bowl I was planning to remove it once the bowl is dry. I guess this is a flawed idea, as it may crack and the cracks may go beyond what I had planned for the final bowl. I did leave a lot of extra wood on this blank, the walls are 1 inch thick and the bowl is about 6 x 6. I also think I created a bit of a tin can shaped bowl vs. a basketball shape that may be more desired.

The funny thing is I have read and studied, and watched lots of live demonstrations and videos, without having much actual turning time, once I stand in front of the lathe I have that "umm, What do I do now feeling" But that is ok, I'll get it and making that huge pile of shaving was fun.

Thanks,
Ian

[Chip Sutherland]

I was sure the answer was "Warp 4... Captain"

[Dick Strauss]

A couple of things come to mind other than the other good suggestions already posted.

Don't be in a hurry and enjoy the process...it looks like you were being pretty aggressive with the inside hollowing.

Does your chuck have dovetail jaws on it? If so, it is easy to break off the tenon by too much tightening if the the tenon and jaws don't match pretty closely. The other jaws are a little more forgiving IMO.

It is best to orient the tenon in the jaws so that all of the jaws run about 45 degrees to the grain. This way you get equal grip all the way around even if the tenon shrinks during the turning process, etc. All jaws compress the wood in roughly the same direction and by the same amount.

Take care,
Dick