Scroll-Type Chuck & Jacob's Style Chuck

[GMH]

Does anyone know what a "Scroll-Type" chuck is?

Also, what is a "Jacob's" style chuck for tailstocks?

I am wanting to turn on my lathe, a blank that is similar to a pen/pencil blank (3/4" x 3/4" x 5"), without drilling a through hole. How do I chuck it up on my Shopsmith?

Thanks,
GMH

[terrydowning]

GMH,

A Jacobs type chuck is a drill chuck with three jaws, typically with a 1/2 inch capacity designed to hold round stock (like drill bits). These can be mounted to the tail stock either using this http://www.shopsmith.com/ownersite/catalog/l_lathearbors.htm or by purchasing a drill chuck already mounted to a MT2 adapter. NOTE: the drill doesn't turn, the stock does. I wish had gone ahead and paid for the SS Adapter. I bought a cheapy Harbor freight Chuck, whose key does not match my SS Drill chuck,, quality is not as good and I have to make sure I don't lose yet another chuck key.

Scroll Chucks http://www.shopsmith.com/ownersite/catalog/nova_g3.htm

A Scroll type lathe chuck is typically a 4 jaw chuck whose capacity is determined by the jaw that are mounted on it. The 4 jaws move symmetrically using either tommy bars or a key like a drill chuck. the 4 jaws scroll in and out so either square or round stock can be securely held. The jaw movement is also self centering. Typically items are supported from the tail stock end with a live center, these are also a great choice for center drilling a blank in lathe mode. There are also independent 3 and 4 jaws chucks that can be used. As the name implies, the jaws are positioned independently allowing off center turning. Centering stock on these requires skill and practice. Typically these are seldom used in wood turning and mostly seen on metal lathes.

The easiest way to turn a small spindle would be to turn it between centers. (TBC)

Here is how I prepare and mount a solid spindle for TBC.

you will need:
a spur center (Item A in the photo below)
live center (Item C) or cup center (Item B)

and all of the other lathe items used to turn wood on a SS

Prepare the blank:
Draw a line from corner to corner on each end of your blank making an X this will locate the center on each end.

On each end of the blank drill a 1/8 inch diamter hole approx 1/4 inch deep these will align the points on the center or spur. Then on the headstock end use a narrow saw and make a kerf on the x for the blades of the spur to engage the blank and turn the blank. Some people tap the drive center into the wood with a mallet. I prefer to use a saw kerf.

Prepare the SS:
On the quill of your SS mount the spur drive. In the tail stock mount either the live center or the cup center. NOTE: If using a cup center have some bees wax available to lubricate the end as the cup center does not turn, the stock turns on the point. Just load the cup with the soft bees wax, it will melt and lubricate as it heats up. Also mount the tool rest and tailstock. double check the alignment of your tailstock. Slide the headstock as close to the tailstock as you can and lock the headstock in place (this can slightly affect alignment), then use the quill advance to move the center of the spur drive to the center of the tailstock center, adjust the eccentric or tailsock as required to make sure these line up. (Unless you want out of round turning).

Mount the Blank on the lathe:
Roughly position you head stock so the distance between the drive spur and the center is that of your blank. Place the tail stock end on the center and use the quill advance to fine tune and engage the spur drive to the blank. Not too tight, just enough to hold the wood in place and drive the blank.

Position the tool rest so it is approximately 1/8" away from the widest part of your spindle, you may need to adjust this during the turning process as the diameter of the spindle decreases. Try to keep the tool rest close to the spindle, your cuts will be much cleaner.

Test the distance by rotating the stock several revolutions by hand before powering the lathe make sure that the blank clears the tool rest.

Make sure your chisels are sharp.

double check the headstock is locked, quill is locked, carriage is locked and tool rest is locked in position. BEFORE powering on or making sawdust.

Enjoy turning.

[dusty]

Excellent explanations, Terry. Even I understood.

[terrydowning]

Thanks Dusty.

[GMH]

Terry:

Thanks for the time you spent responding to my question. I really appreciate it.

Thanks again,

Gary