PDA

View Full Version : Turning green Elm



B-Daddy
25th December 2006, 03:35 AM
... and it's not cooperating. My father-in-law is using his Shopsmith and cannot get this 14" blank (7" radius, 7" long from the chuck) to be round. It seems unbalanced. Any suggestion (other than upgrading the lathe as I asked in a pervious post)? Is it possible that a green blank is not a uniform density causing it to vibrate on the chuck?

Thanks,
B-Daddy

Tony Morton
25th December 2006, 08:54 AM
Hi B-Daddy

I had the same problem with green liquid amber perfectly round blank but very out of ballance threw it of the lathe at high revs then slowed down and persisted with it dancing around, hense the term "dancing with lathes'. Yes he may have to up grade to something with a bit more beef to tunrn this kind of timber.

Cheers Tony

rsser
25th December 2006, 12:06 PM
Yeah, with English elm there is a big diff in density between heart and sap wood.

So: wheel balancing weights glued to the piece?

Or: persist

Or: as you turn the blank dries and loosens off in the chuck. So retighten often.

For outside roughing: bring up the tailstock to stabilise the piece.

Good luck.

ptc
26th December 2006, 09:59 AM
I only turn dry stuff.

Wayne Blanch
26th December 2006, 10:50 AM
I recently turned a bowl of about 300mm which had a large bark inclusion on one side. This made it very much out of balance. I started with the tail stock in place whilst roughing out and forming the outside. Even with the tail stock in place I had to keep the speed down. Once re-chucked and turning the inside I had to slow it even further. It took a degree of patients but I ended up happy with the result. What would have normally taken me about two hours took me almost four hours but the result was worth it. So the people who I gave it to said anyway.:D

rsser
26th December 2006, 11:44 AM
Green English elm is usually like butter to turn: deep choc heartwood and cream sapwood. Regrettably as the UV gets to it it turns it all a boring beige.

rodent
27th December 2006, 09:52 AM
TRY this turn your blank by hand with the lathe out of gear ie belts out when the blank swings down screw a tyre weight to the top in place where you wont be turning first . RE connect belts on slowest speed and start too balance blank out then remove balance weight and away you go.

B-Daddy
27th December 2006, 11:27 AM
Thanks gents for the quick replies. I'll pass this along to my father-in-law and let him deal with the problem.

B-Daddy:H