Vacuum Chucks

[dai sensei]

I was thinking that if it weren't for the temperature issue, it's easy to but a blower nozzle in the end of the outlet hose with the trigger taped down.

Unless you have a really good compressor, this would mean it runs continuously, which isn't the best for the compressor.

[Hermit]

Unless you have a really good compressor, this would mean it runs continuously, which isn't the best for the compressor.

Yep. That's the main problem, but I just had a thought - what if the blower was pointed at the compressor's head to help keep it cool for the 30min or so it takes to finish & sand the bottom of a bowl?

[Cliff Rogers]

If you have a compressor, you can try one of these.
http://www.caasafety.com.au/industri...ping/vac-u-gun
http://www.exair.com/en-US/Primary%2...Vac-u-Gun.aspx
https://www.google.com.au/search?q=c...w=1280&bih=924
https://www.google.com.au/search?q=V...w=1280&bih=924

[Hermit]

If you have a compressor, you can try one of these.
http://www.caasafety.com.au/industri...ping/vac-u-gun
http://www.exair.com/en-US/Primary%2...Vac-u-Gun.aspx
https://www.google.com.au/search?q=c...w=1280&bih=924
https://www.google.com.au/search?q=V...w=1280&bih=924

You're always a wealth of knowledge, Cliff.

I like the look of the Vac-U-Gun, and just emailed Compressed Air Australia for more info re price and distributors. Might be just the ticket for a low-cost setup.
Definitely looks better than my silly idea earlier.

I reckon it could work, if an air bleed was added before the Vac-U-Gun, to reduce the vacuum as needed.

[Cliff Rogers]

....if an air bleed was added before the Vac-U-Gun, to reduce the vacuum as needed.

If you study that PDF link I posted, it should show how that is done. (here it is again)
http://www.carlford.info/pages/demos...hucks_Demo.pdf
Look at page 2 & page 3, the tap near the gauge is used to release the vacuum but it can also be used as a bleed to adjust the vacuum.
When you do that into a vacuum pump, you would stick a cheap fuel filter on the open side so it didn't suck dust into the system.

Have a look at these pages as well.
His set up has 2 filters, one inline before the vacuum pump & one on the bleed intake.
http://www.laymar-crafts.co.uk/tip42.htm
http://www.laymar-crafts.co.uk/tip43.htm

[Hermit]

If you study that PDF link I posted, it should show how that is done. (here it is again)
http://www.carlford.info/pages/demos...hucks_Demo.pdf
Look at page 2 & page 3, the tap near the gauge is used to release the vacuum but it can also be used as a bleed to adjust the vacuum.
When you do that into a vacuum pump, you would stick a cheap fuel filter on the open side so it didn't suck dust into the system.

Have a look at these pages as well.
His set up has 2 filters, one inline before the vacuum pump & one on the bleed intake.
http://www.laymar-crafts.co.uk/tip42.htm
http://www.laymar-crafts.co.uk/tip43.htm

Thank you Cliff, for all the links & ideas you've posted in this thread. I actually downloaded the VC Demo pdf yesterday and absorbed it's contents. I'll check out the Laymar links shortly.
Edit: I just saved copies of both Laymar pages. I'm building up a nice little library of vacuum chuck related stuff. The font in the Laymar pages is horrible, but after changing it to Arial on my saved copies, it's much more readable.

I'm not 'tight' - if I could possibly afford a commercially-made setup, I'd run out and buy one tomorrow. For me, it's a DIY vacuum chuck system or nothing.

For bowls with a lip, a plywood disc with tabs is fine, but some, like the one I'm finishing at the moment, a vacuum chuck would make me feel much more secure. I think I can get away with a plywood disc for my current one, but only just. Even considered hot-melt gluing the lip to a disc, but.....

I'm hoping that the Vac-U-Gun isn't too dear. It looks pretty cheapish. I won't need to use it very often, so it might suffice.
Otherwise, I'll do the eBay hunt for a cheap vacuum pump.

Thanks again.

[Cliff Rogers]

...
I'm hoping that the Vac-U-Gun isn't too dear. It looks pretty cheapish. I won't need to use it very often, so it might suffice.
Otherwise, I'll do the eBay hunt for a cheap vacuum pump.

Thanks again.

Don't count on the Vac-U-Gun being cheaper than a vacuum pump.

The only Vac-U-Gun I found one eBay was more than $300.
You will get a vacuum pump, brand new, for less than $100 on eBay.

[Hermit]

Don't count on the Vac-U-Gun being cheaper than a vacuum pump.

The only Vac-U-Gun I found one eBay was more than $300.
You will get a vacuum pump, brand new, for less than $100 on eBay.

Wow, they're keen! For what it is, I expected <= $50. There's almost nothing to them.

I'll give up that idea then, and buy a refrigeration vacuum pump as you suggested in an earlier post. I can get a 3.6cfm for about $90 w/ free postage, like this one: http://www.ebay.com.au/itm/Electric-...#ht_4004wt_996

[dai sensei]

Yes that vac gun is an expensive way to do it, plus your compressor must have the capacity to drive it too. I started with a venturii pump on my compressor to drive the vacuum, but ended up going for a vacuum pump as my compressor struggled a bit driving it (see https://www.woodworkforums.com/f8/vacuum-chucks-146742). That thread also shows the seal using a rubber band, but I have since removed it and glued on some closed cell foam, as the rubber kept leaving a black mark when ever it slipped.

One thing you also have to be careful of is using too much vacuum, 24" is plenty for holding most things, but even that can be too much for thin walled structures.

[Hermit]

Yes that vac gun is an expensive way to do it, plus your compressor must have the capacity to drive it too. I started with a venturii pump on my compressor to drive the vacuum, but ended up going for a vacuum pump as my compressor struggled a bit driving it (see https://www.woodworkforums.com/f8/vacuum-chucks-146742). That thread also shows the seal using a rubber band, but I have since removed it and glued on some closed cell foam, as the rubber kept leaving a black mark when ever it slipped.

One thing you also have to be careful of is using too much vacuum, 24" is plenty for holding most things, but even that can be too much for thin walled structures.

Thanks for that, Neil. It's a steep little learning curve, but I'm getting there (slowly).
I even considered cheap old second-hand vacuum cleaners from the local tip recycling section and replacing them as they died, but the cost would soon exceed that of a properly-made vacuum pump. I'll go and have a read of your thread now.
Edit: Great thread, Neil. Thanks for the link.
(I've saved it into my little vacuum chuck library folder for future reference.)

[Cliff Rogers]

That thread of Neil's is the very first link I put in this thread.

[Hermit]

That thread of Neil's is the very first link I put in this thread.

Oh. Sorry, Cliff, I don't know how I missed it.

[dai sensei]

That thread of Neil's is the very first link I put in this thread.

That's how I found it

[Hermit]

That's how I found it

That's right - rub it in.

[DaveTTC]

That's how I found it

thats funny


Dave the turning cowboy

turning wood into art