PDA

View Full Version : worm (wood) screws


Bill Clark De
07-10-2010, 6:46 PM
Recently i decided to try to turn some finials -instead of using my standard chucks -i wanted to use my wood screw worm.... I drilled my 7 MM hole as written in the directions but my wood worm will not even start into a 7 mm ....so i drilled a 8 mm which worked however it also split the wood..i think i missed something .any ideas
Tim Rinehart
07-10-2010, 6:55 PM
Splitting sounds like either the wood is too hard/dry for the size drilled, or too small in diameter to absorb the stresses of the threads being cut in.

You stated that you're turning finials, so what diameter are you intending to use the worm screw for? I'm having a tough time envisioning using a worm screw for finial stock.

If you do have plenty of diameter (but doesn't sound like it), it seems reasonable to increase size a little to make firm but not stressed hold.

One last thing...I would assume you're still using the jaws as a vertical face to tighten the blank against, and not just relying on the worm screw itself. I doubt you could safely use a worm screw without having it backed against jaws.
Steve Schlumpf
07-10-2010, 7:14 PM
Bill - every finial I have ever turned was endgrain. Using a screw to hold the blank seems like it would be inviting trouble and almost guarantee the wood splitting. I always use the smallest jaws for my chuck (Talon #1 step jaws) and have not had a problem with the wood splitting on me.
Bill Clark De
07-10-2010, 8:16 PM
thank you/// gives me pause
Tim Rinehart
07-10-2010, 8:42 PM
Bill - every finial I have ever turned was endgrain. Using a screw to hold the blank seems like it would be inviting trouble and almost guarantee the wood splitting. I always use the smallest jaws for my chuck (Talon #1 step jaws) and have not had a problem with the wood splitting on me.
Great point Steve...I didn't even think of that since I've not tried mounting a worm in endgrain...that would be troublesome.
Bernie Weishapl
07-10-2010, 10:59 PM
Ditto what Steve said. I have the this one from Penn State Industries. It works well for finials.

http://www.pennstateind.com/store/LCDOWEL.html?mybuyscid=5959990175
Matt Hutchinson
07-11-2010, 11:16 AM
I use these spigot/deep jaws (vicmarc shark jaws) for a lot of work, including finials. I just clamp down on the square stock and got to work.

http://www.packardwoodworks.com/Merchant2/graphics/00000001/118110-img.jpg

I don't recommend regular depth jaws, cuz one catch, or agressive roughing, could knock the blank off center or off the lathe.

Hutch