Cole, Bowl, Adjustable Jaws...Same Thing?

[Burt Alcantara]

Still having problems with my HoldFast which is not holding at all. If I put a flat board on the chuck, it holds it with 19" hg. Won't hold anything I turn.

I'm using the 6" vacuum chuck as a tape down so I can begin to finish the bottoms of my bowls. I see that a lot of people use the Vicmarc or OneWay Bowl/Adjustable Jaws. Most of the posts I'ver read about Cole jaws have been negative.

Aren't they all the same? I'm thinking of picking up a Vicmarc or OneWay to get my backlog cleared (sounds important but it's not. Just need to recover the floor space).

My intent is to make a doughnut jaw but just another thing I haven't gotten around to doing. I'm hoping to get some positive feedback about these jaws but won't be crushed it not.

Thanks,
Burt

[Tom Hamilton]

Burt, for what it's worth, I've got a 10 inch and 16 inch Oneway jaw set. I use both regularly and have only launched one of probably 65 bowls. The rim design did not allow for adequate gripping. I should have used some flat string (4 " saran wrap) to secure it. So operator error, not product issue.

Go for it.

Tom, in Houston, who packed the shop yesterday for a move to Douglasville GA.

[Steve Schlumpf]

Burt - not to deviate to far from your post but did you check your vac system for leaks? I know a few folks who have the Holdfast system and do not have any problems. 19 hg seems a little on the low side - especially if it is max vacuum. Just curious....

[Larry Marley]

I have the Hold-fast, don't use the vacuum generator any more.
I think at best the Hold-fast draws is about 1 CFM. And I have doubts about that number. If you use it to reverse chuck a bowl with a finished interior it will work just fine if you get a good seal on the chuck. If you are trying to hold an unfinished bowl with a thin sidewall or base you will not have much luck. There is just too much air pulling through the wood for the vacuum generator to over come.
I would say that the general consensus here is 4CFM + is ideal.

I also use the cole jaws. If the rim of the bowl is perpendicular to the jaws, preventing the jaws from getting a good hold, I will use a support with rubber bands as shown here...

[Wally Dickerman]

I've used the cole jaws quite a lot, expecially when teaching classes. I've never had a flying bowl, but I don't 100% trust the jaws. If you keep the tool rest close to the bottom of the bowl, the piece can't back all the way off if it comes loose. I take very light cuts.

Cole jaws work well by expanding into a wide mouth hollow form.

If you're turning a piece that's more than 4 inches deep it's a good idea to use the tailstock for support through most of the process.

Wally

[Burt Alcantara]

Steve,
I've never gotten more the 19hg on the HoldFast. At their site, they claim that 12 hg is all you need. I managed to get a bowl on today that sucked up to 19hg. Was able to make a nice bottom finish...finally.

One of my next short-list projects is to build a vac system from scratch, ala your excellent tutorial.

Burt

[Steve Schlumpf]

Burt - glad to hear you were finally able to use the Holdfast. Sounds like it has been a challenge so far! When you decide to build your own system - be sure to let me know if you have any questions.

[Burt Alcantara]

I just ordered a Gast from Surplus Supply as they are back in stock. This will be another project where I buy the parts and forget where I put them.

[Richard Madison]

Burt, Lacking a vacuum system and/or expensive chuck jaws, I frequently use a home made doughnut chuck. Have several sizes of "doughnuts" (the OSB piece) with padded edges. Only takes a few minutes to make a new size when needed. Maybe not so good where speed of production is important, but functions well. Have a couple Longworth chucks and never use them anymore.