Grizzly 4003G Spider Chuck Mod

C

crb

Ray Brooks
When Shiraz did the drawings he didn't have his chief beancounter OK them :D;):p Just kidding !!!

I end up messing with bbls that are just short enough to be a problem and any excess length in the chuck forces me to work in very close proximity to the chuck face.

I don't know the manufacturing process but it does seem like the bolts could be moved closer to the chuck mounting face and the front face of the chuck is definitely longer than is necessary to support the threaded holes. All I can do with my equipment is cut back the front face. WOW what a pile of messy chips !!!! :eek:

Modifiedspiderchuck.jpg
 
Net reduction in headstock length

Have you figured how much this spider reduces your headstock length ?

How much further reduction after facing off the front surface ?

A. Weldy
 
As produced it probably is an inch longer than it needs to be. I probably knocked .300 to .400" of the front face. It's far better than the 4 jaw chuck but it seems a shame to not take full advantage of the design concept.
 
I have been waiting for a solution to that issue and I may have had my eureka moment. How about a ring plastic bored to slip over the snout and drilled radially so that the bolt heads are down in the plastic ring ? This way you still have the large hex wrench which gives more control when centering the work piece.
 
The plastic ring sounds like a good idea. - I'd use shorter screws too, to keep the diameter of the plastic ring down.
 
Does the reduced diameter part of the chuck, the part with the spider bolts, bolt to the backing plate or is it one piece? If it bolts on, take it off, reverse it, center it in your 4J and machine off the excess material on the back. Then convert the bolts to brass tipped set screws. You don't need much torque to hold the barrel so the smaller allen size should be OK.

Fitch
 
I have been thinking about building one.

My PM1236 is a D1-4 chuck mount, and so will not take the Grizzly right side of headstock spider.

The advantages are:
1) Shorter barrels will fit through headstock.
2) Eliminates the Copper wire gimbal in the 4 jaw


My headstock is not so long, but I have had barrels slip.
I don't just 4 bolts with non ferrous tips will grip any better than the #10 Copper wire in the 4 jaw.

Probably what is best for me is to just remember to cut thread relief slowly back and forth, so the barrel will not slip.
 
You must log in or register to reply here.
Back
Top