Big Jaw Problem

[LANKFORD]

Seems I always have these little problems. I bought the 8" PSI reversal chuck for my Barracuda Chuck. It takes up to 8" dia bowl and the screw pins are rubber about 5/16" diameter. Just my luck, I turned small bowls and none of them could be grabbed by the chuck. Seems there is a gap when moving the screws to a new diameter. For example you can grip a 6" dia bowl but not a 6-1/4". You need a bowl either 6" or about 6-1/2", nothing in between. Gap will apper also for smaller bowls.

I hate to let the tool dictate the diameter. Anyone have any ideas for making additional screw pins in larger diameters to use in the jaws? If the mfg had includes several sizes of rubber screw pins they would have covered the diameter gaps.

 

[MichaelMouse]

I hear ya. If it were raining soup, I'd find myself with only a fork, too. What I did with my Cole jaws was buy and make sleeves with some neoprene automotive heater hose (mine are 5/8) which I can slip over the buttons to grab the 'tweeners. I'm betting there's some hydraulic line that'll fit yours.

Of course you can turn some hard rubber or buy some hard rubber washers of different sizes, but they would demand removal and replacement of those eight screws.

 

[Ziffy]

How about buying some dowel... Oh wait..., we're woodturners. How about turning a piece to appropriate O.D., boring a 5/16" through-hole and slicing the piece into eight sections. The sections could then slip over the pins with enough friction to hold, but not so tight as to be there permanently.

Brian

 

[DeanGThomas]

I don't understand

I really don't.

I have a set of cole jaws, for a different brand chuck, but they are built similarly. They have the rows of holes and the movable screws. Do the screws not move on the Barracuda version? If so, surely the jaws have 1/2" of throw on them. That would mean that the diameters would overlap, wouldn't it??

Like I said, not being accusatory, just exploratory, having never used that brand of chuck with those jaws.

Also, can you talk PSI out of a second set of machine screws so that you could add your own bumpers to them?

 

[DickHines]

Get rid of you Cloe jaws and but a piece of MDF board and a face plate. Put the face plate on the MDF, after you cut a nice round piece, and jam your bowl between the head stock and the tail stock. Works great and you can cut the MDF to what ever size you like.

Almost forgot you will need to glue some cork on the MDF to keep the bowl from slipping.

MDF glue and a face plate will run you less then a set of jaws.

 

[John Nicholas]

Reverse Jam Chuck

You don't need MDF. 3/4 plywood will do the job.

John

 

[Hugh]

To reverse a bowl around and do the bottom - I just have a couple of chunks of wood that mount in my chuck. They are turned round with a mostly flat face and are various diameters 2", 4" and a couple of different lengths. Then I just put the block into my chuck and add a piece of foam to go between the block and the bowl that I am trying to reverse turn and bring up the tail stock to hold the bowl in place. If you turned the bowl between centers first there is a tail stock mark - usually center. If not, then you can find center. With the reversed bowl held in place by the block and the tail stock - you can turn the bottom of the bowl (all except a small tenon - which I carve off after I have the bowl off the lathe). Not fancy - but it works well for me.
Hugh

 

[pencheff]

Anyone have any ideas for making additional screw pins in larger diameters to use in the jaws? If the mfg had includes several sizes of rubber screw pins they would have covered the diameter gaps.

The screws are metric and available at any good hardware store. You could use screw on rubber "feet" ... the kind of bumpers we speaker cabinet builder guys screw onto the bottom of a cabinet. They start at about 3/4" in diameter and are usually tapered. Just mount 'em upside down onto your PSI Jumbo Jaws and you should be in business.

 

[LANKFORD]

The cabinet bumper feet sounds like it will fit the bill. I found some on the net 3/4" dia 1/4" to 1/2" tall. And the hole seems just about right for 6mm screws for the jaw holes. Thanks for the tip. They are straight with a rounded edge. Placed upside down the rounded edge should grip a bowl edge nicely.

 

[laymarcrafts]

Many years ago when I purchased my set of Cole Type Jaws, I had the very same problem.

I simply sent the Jaws back and told them they were not Fit for Purpose and unless they could rectify the problem then I wanted my Money Back in full plus all costs incurred.

I received a replacement set of Jaws which they obviously had re-designed with more Holes to allow an overlap, and is now there standard design.

Send them back and make them sort the problem out.

Richard
http://www.laymar-crafts.co.uk

 

[TurningDog]

There was actually an article in one of the recent turning mags, think it was one of the english ones that barnes and noble carries, that addressed the very issue of modifiying your cole jaws, article by joe famous turner. Next time I get up on my own I will try and find it. If there is anything worse than having a summer flu it is having it while under post op drugs.

 

[Gretch Flo]

one right after another

Turning Dog-I think you had better lead a cleaner life!!! Bummer, Gretch

 

[TurningDog]

Turning Dog-I think you had better lead a cleaner life!!! Bummer, Gretch

It would help if hadn't spent 4 hours in the rain after locking myself out of the house with no one else home.

 

[n7bsn]

Had the same problem, what I did was remove a bit of the rubber bumper from one side of each unit. Gave me enough adjustment to close on any bowl.

Adding bumper sizes might work better though