Well, it sort of sucks........

Stuart Ablett

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Tokyo Japan
.......... my new Vacuum chuck that is......

I made it up and tired it out, scary for "turning" but good for sanding and finishing.........

no_sucking.jpg
I might have to work on the seal, it is a bit thick......

sucking1.jpg
Holds the bowl on there.........

sucking2.jpg
this way round too, but the darn vacuum is sure noisy running all the time....:(

They say that the adapter is not supposed to be used with a pump, only a vacuum, but this is not held on very well, I can pull the bowl off with one had with ease, I bet a mad 6 year old could tug it off..........

Mildy disappointed...........:rolleyes:

Anyone have some tips?

Cheers!

PS that was the only piece of pipe I had, I might just make one out of MDF, it would give me a thicker rim, which would be more solid......?
 
stu, whatcha using for a pump? what i see looks like a vacuum cleaner hose.....any pump i`d trust to hold stuff would pull at least 17-18" of mercury......tod
 
Stu, I'm no expert and don't have my mustard monster set up for vacuum yet, but every demo I've seen and article I've read used a vacuum pump (Gast type, or equivalent) like those used for vacuum pressing veneers, etc. If you're using a shop vac or DC as your vac source you won't get nearly the force neccesary to safely hold an object on the lathe. Here is one link showing set up.
Here is another.
And here is yet another.

I was relatively lucky and got my Gast pump on ebay for under $100. New ones are over $300.
 
..............They say that the adapter is not supposed to be used with a pump, only a vacuum..............

Just wondering if anyone reads what I write, or if you all just look at the pics ;) :D

Teknatools..........

Safety warnings, cautions and general questions
The Vacuum coupler system is designed for high volume low pressure usually from a shop vac or household vacuum cleaner system. This allows for loss of vacuum from the fit between work piece and rubber sealing plate and the various seals and fittings. In is actually important for the vacuum cleaner type system to have a by pass flow of air to keep the motor cool.

It is essential to provide an air bleed (a deliberate leak) in this type of system to prolong the life of the vacuum cleaner as the motor relies on the air flow to keep cool. If you have a perfect seal, you will burn the cleaner motor out The vacuum type pump produces a high vacuum, but has low capacity to extract air (so that the pump cant keep ahead of the in flow of air)

It is difficult to maintain a good seal between work piece and vacuum chuck face. The high volume of the vacuum cleaner means that the pressure against the faceplate will be maintained under turning conditions regardless of the movement or flexing of the work piece. With a low volume pump there is a danger of any loss of seal causing the vacuum to de-pressurerise and the work piece coming loose. The margin between successful holding and loss of work piece pressure is very finite. It is not recommended to use a vacuum pump , but if one is used the pump needs to be able to deliver good volume.
In general vacuum chucking needs to be treated with caution and turning should always be done at low speeds , a faceplate and other precautions are required. Only light cutting and sanding finishing should be attempted.
Vacuum chucking works successfully with larger diameter pieces as the diameter reduces the pressure differential holding force reduces , small pieces may not hold successfully.
Avoid too much pressure - higher vacuums can impose high forces and break or distort a work piece , monitor pressure with a gauge and regulate with some by pass.

So I'm following the makers suggestions, and using a vacuum cleaner, but I'm wondering if I could use a vacuum pump, as this is far from secure.

I just wonder why they think that the vacuum adapter cannot be, or should not be used with a pump?

They say it is a sealed bearing, maybe it would not stand up to the pump vacuum and the seal would fail?

Cheers!
 
Stu,

Sorry for being so lax on this thread.

I haven't used a vacuum on my DVR yet but I have read about what some have done.

Sascha Gast posted a good thread on what he did for his DVR at WWA. I recall he was also active at the Creek.

http://www.woodworking.org/InfoExchange/viewtopic.php?t=1332&highlight=vacuum

Do a search for vacuum (Keyword) and sascha (Author) on the below link. There are bunch of threads but some of them are missing pics.

http://www.woodworking.org/InfoExchange/search.php?mode=results

Hope this info comes in handy.

Sorry Stu that was for the vacuum press. I do recall though that Sascha did a nice setup for a vacuum chuck on his DVR.
 
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Well, I'm in the market for a vacuum pump then!

I see that if I close up the holes in the adapter, and put an O ring in the hand wheel to seal the bearing against the handwheel, I should be good to go.

Cheers!
 
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