woodworm screw

Re: woodworm screw

Barry Turner

>A woodworm screw is used to turn a 4-jaw chuck into a screw chuck. A hole is drilled into the center of the blank. The woodworm screw is held in the chuck jaws and the blank screwed onto the screw. It's an amazingly quick and simple way to mount a blank. The woodworm holds very well, too.

Re: woodworm screw

Dennis Taylor (Akron, Ohio)

>do you know the size of hole for soft & hard wood?..Dennis

Re: woodworm screw

Carole in VA

>Hope we get an answer to that question! I haven't use the woodworm that came with my Nova Midi yet for that reason. Also, to me it didn't look like a very secure way to hold a blank

Re: woodworm screw

TheHeretic

>Carole it is a very good way to mount blank to chuck. I did three rough bowls tonite using a Nova Midi chuck on a JET mini and the woodworm screw. I honestly dont remember the drill bit size as I have it marked and set aside just for drillin holes in blanks for this.

Once the hole is drilled I will mount the woodworm in the chuck and turn the block onto the protruding screw. After it is screwed in all the way, or as deep as the blank will allow and still be able to put a tenon on it, I will loosen the jaws and make sure the blank rests tight agains the jaws and tighten it up again.

Works great. I do this with green blanks as I have a hard time otherwise getting glue to stick for a waste block and many of my rough cut blanks dont have a flat surface to get the faceplate screwed on.

Dean

Columbus OH

Re: woodworm screw

Lyn J. Mangiameli

>Just take a calipers and measure the root diameter (that is the diameter of the screw in the space between the raised threads). On most it is about 3/8 (essentially 10mm), but I don't recall exactly what it is on the new Midi screw. If I remember correctly, it is 1/4 on the small Glaser screw. For dry wood, you want the root diameter. For very soft green wood, you can sometimes go a 32nd under to get some precompression of the wood that will help prevent tearing/stripping out. By the way, the very best way to prevent stripping out is to make sure that the depth of your pilot hole is sufficient. If for some reason you can not drill to the entire depth necessary for the screw, make up a spacer you can put between the screw and the jaw/base so that the blank will seat firmly up against the base (which on a scroll chuck, will be the front rim of the jaws).

Re: woodworm screw

Brad Vietje

>Carole,

Its a very secure grip if the following 3 conditions are met:

1. Hole is not too big

2. Blank is flat where you're chucking it (I wouldn't recommend chuckiing a natural-edge bowl this way, at least not from the bark side, as you would have very poor contact unless you carved away the bark to make a flat surface).

3. Blank is held tightly against the top face of the jaws. The screw doesn't provide the stability in holding the blank, the jaws do -- the screw just pulls the wood tightly against the jaws. DON'T use it unless the wood tightens down very firmly against the tops of the jaws.

Safe Spinning,

Brad Vietje

Thetford, VT

Re: woodworm screw

Bud Gabaree

>In all of the posts below, nobody mentions the capacity of the woodworm. What's the largest blank that can be safely used with the woodworm?

TIA, Bud

Re: woodworm screw

TheHeretic

>my personal largest as limited by my lathe was 9 1/2" dia and 5" deep rounded on bandsaw blank of wet black cherry.

Re: woodworm screw

Barry Irby

>The woodworm screw is one of my favorite parts of the chuck.

Prepare a bowl blank with the top side (opening) of the bowl flat. Drill the hole in the center of the bowl The root diameter of the scew. If you use a band saw you can make a circle cutting fixture and use this hole to trim the blank also.

With fairly large but shallow jaws (100 mm) on the chuck and the screw in the center, screw the blank tight against the chuck. On blanks near the capacity of the lathe (sixteen inches) I bring the tail stock up against the blank also.

I clean up the outside of the blank and cut a chuck foot that will fit the chuck jaws holding the screw. Then I unscrew the blank, flip it, and chuck it. Then either proceed to rough the bowl or I core it. If I core it, I flip the core and put it back on the same screw and cut another chuck foot and start again.

If I am green turning the bowls, I can finish them as I go. If I am preping blanks to let dry and turn later, I put them in paper bags.

I suppose I could core from the inside out, taking the little core first, working up to the larger one, but I like trying to take the bigger one first. I am most interested in "saving" the largest bowl. The cores are wonderful, but of secondary interest.

I suppose I could leave the woodworm screw in place and just release it by opening the jaws, but I like setting it accurately in place by itself.

Re: woodworm screw

Dave MacLuskie

>I'm not sure what you're are suppose to do, but I've turned 11 1/2" diamater maple, walnut and oak on my Jet 1236 with the Oneway Talon and wormwood screw (uses a 3/8" hole).

I'm quite careful to always ensure the wood is very tight against the jaw faces. Tight enough that's it's often trick to get off.

One disadvantage to the wormwood screw, vs, say, between centers, is that you cant' shift the wood if you don't like the way the grain is aligned. That being said, I still use a wormwood screw most of the time.

Re: woodworm screw

Roger

>Dennis,

I have a Talon with a 3/8" dia. woodworm screw. I use an 11/32" bit, it holds very well. This is the size drill the instructions said to use. I also use the tail center, as long as practical on unbalanced pieces. Good luck.

Roger