Cole jaws vs vacuum chucks.......

[odie]

I've been using cole jaws, both Nova and One-Way strong hold chucks, for doing the bottoms of bowls for some time now. On the expansion mode, I can go as small as a 4" rim, and can do a 15" bowl using the One-Way. They've worked very well for me.

Now, I realize vacuum chucks have been very popular for at least a decade, or so. I have zero experience with the vacuum chucks, and know very little about them. What can a vacuum chuck do for me that my cole jaws can't?

Is it difficult to get a bowl centered on the vacuum chuck?

Tell me about some of your thoughts as to the advantages of vacuum chucks.

The only real disadvantage of the cole jaws is it requires an acquired "feel" to get them tight enough......If you do thin walls and rims, you can easily apply too much pressure and crack your bowl!

Your thoughts, please?

....odie

 

[john lucas]

I like a vacuum chuck because it opens up a lot of other possibilities. You can easily reverse turn a natural edge bowl or other bowls with odd shaped rims. I've taken completely finished pieces and put them back on the lathe to alter them using the vacuum chuck. That would have been very difficult or impossible with other systems.
Oneway makes an adaptor for thier tailscenter that lets you put the chuck or faceplate on the tailstock. This makes it very easy to mount you bowl perfectly centered on the vacuum chuck. www.bestwoodtools.com also has an adaptor that has a #2 morse taper and your lathe thread. This one works like the oneway in that you finish turning the bowl while it's in the chuck, then screw it on the adaptor and stick this in the tailstock. Then you slide it up to the vacuum chuck and turn it on. remove the chuck from the bowl and slide it back and your ready to turn. Perfectly centered.
A vacuum chuck isn't a cure all for everything. If you've got a hole or large bark inclusion you may not be able to create a vacuum. Sometimes you can get around this by using cling wrap or some other method to comver the hole. Worm holes and such can also cause problems.
You can also have problems if you turn really thin pieces. 23" of mercury will crush a large thin bowl. I had the vacuum suck one out of round once.
I turned for a lot of years without a vacuum chuck but it's kind of like variable speed. I didn't have varialble speed on any of my lathes until just a few years ago and now I love it. Vacuum is the same way. Once you have it you'll find all sorts of uses for it.

 

[Bill Boehme]

John did a great job in summarizing why to have a vacuum chuck. To add just one more thing, I would say that I did not think that I needed a lathe until I discovered that I liked to turn. Having a vacuum chuck sort of fits into the same philosophy.

Bill

 

[John Nicholas]

Vacuum Chuck

What can a vacuum chuck do for me that my cole jaws can't?

Reverse a Natural Edge Bowl.

John

 

[Bill Boehme]

Reverse a Natural Edge Bowl.

John

And, then you can turn it back around again and work on the inside if necessary.

Bill

 

[MichaelMouse]

You could change your standards or style and not worry about re-working bottoms. I decided on that course of action versus others. When I need to do triple reverses I just have to plan ahead. Look at ByGeorge's bowls and you can see where he's capable of chucking from inside.

If you undercut your rims, a set of wooden/rubber jaws will do the job on a standard chuck body, others can be dovetailed to allow outside grip. It's a case of what you want and how much available cash you have.

Even the vacuum chucks have limitations, so take a look at what you want to do and figure from there. If you cut a lot of pieces with odd shapes and cracks or voids, might do well to practice the technique of prefinished bottoms first. Might even find that pleases you, even if it doesn't please your snooty turner friends. Aren't they the real reason why you reverse and redo the bottom?

Q: What does the bottom of a salad bowl really look like?

A: Mess of lettuce on the table.

 

[robert davis]

i use the longworth chuck. ifind it much easier to use than cole jaws..i never use my cole jaws .for sale cheap..vacuum chuck is good but i havent found the incentive to rig up for one..

 

[john lucas]

I should clarify and say that the vacuum chuck is definitely a nice tool but not a necessary tool. I can turn virtually anything I do with faceplates a tailstock and sometimes a jam chuck. What the vacuum chuck does is speed things up and in rare cases let you save a piece or alter it after it's been turned.
I never take my vacuum chuck with me to do demos and I turn exactly the same thing. I can just do it faster and cleaner with the vacuum chuck.
It's absolutely fabulous for crushing coke cans. I need to make another one of my can crusher adaptors I gave mine away. It fits on top of the can and you crank up the vacuum and it crushes that thing flat. Kids love it.

 

[intakexhaust]

I'm interested in learning more on the vac chucks. What do most of you with vacuum chucks use for sealing the vessel to the mount plate or cup? Is there a rubber frisbee like slip-over in various sizes available for disc? Lastly, what can one expect to pay for a complete system including pump if needed? Thanks

 

[Mark Mandell]

I'm interested in learning more on the vac chucks. What do most of you with vacuum chucks use for sealing the vessel to the mount plate or cup? Is there a rubber frisbee like slip-over in various sizes available for disc? Lastly, what can one expect to pay for a complete system including pump if needed? Thanks

Go to the "How To" section of this forum and go through the articles on vacuum chucking. Depending on how "mechanically inclined" you are, you can put together an entire vacuum chucking system for less than $50. You can also spend well over $700.

I'll also point you to Bill Noble's excellant articles on the subject on the GWG website Tech tips section

http://216.92.36.57/tech_tips/frame_1.htm

mm

 

[john lucas]

I put my first set up together for around $50 using an automotive compressor. The article on how to do this was in a past American Woodturner. My latest one was assembled using a used commercial vacuum pump that I got for $75.
I have used all sorts of gasket material. For a quick special made chuck for light use I use either the gasket material that you buy to put your topper on your pickup (that's a redneck gasket) or some thin closed cell foam I get from Hobby Lobby called Fun foam. The truck bed stuff only comes in width around 2" or less but has sticky already on one side. I put silicone rubber on the joints when I put this stuff down. The fun Foam works better most of the time. I just use contact cement to install it.
Thier are commercial vacuum gasket materials, most are made of neoprene. I got some round neoprene gasket material and it seals really good but has too much give and may throw the bowl out of alignment. Usually this isn't enough to worry about so I've used it this way for years. It holds up better than the fun foam or the truck liner material.