Vacuum system

[Fred Belknap]

I am going to build or buy a vacuum system and I don't know anything about what to get.
Do you use a system that runs off your compressor or a dedicated vacuum pump?
Vacuum pumps from CSUSA run $400+
What size and type chuck is the best?
I have a Grizzly G0698 and I don't know what to use to hook up to the spindle.
Is the whole thing worth all the money???

[Roger Chandler]

I use the Hold Fast system with my G0698...........runs off the compressor and I got both the 3" and 6" heads..........I like it, as it is handy, and I have plenty of compressor to run it. The rotating adapter snugs right up to the outboard side of my spindle and it uses a 3/8" threaded lamp rod to go through to the other side, which you cut to length [about 1/2 inch beyond the spindle............then a threaded rubber nut goes on to the lamp rod to hold on center and close off the spindle to make it air tight.............

Depending on what wood I use, I can get up to 26hg vacuum on it.

[Steve Schlumpf]

Fred - when I put my system together, Tom Steyer helped me out by explaining the basics and then assisted in designing my system. He has since started his own company and now offers a complete system so you don't have to try and figure everything out. It is just an option but well worth checking it out. Vacuum System (http://www.jtturningtools.com/)

[James Combs]

Fred, I use a homemade system (http://www.sawmillcreek.org/showthread.php?162882-My-New-Vacuum-Chuck&highlight=vacuum+chuck) that I estimate that I have maybe $150-175 in. I found a new in the box v-pump at my local pawn shop at just under $100 and most of everything else I had laying around except for filters and airlines and fittings.

[Roland Martin]

Fred, I can't imagine going without a vacuum chuck. I made my own system following Steve's plans and it works great. I found a Gast pump on ebay for about $75, the whole system cost me under $200 and was kind of fun to build. The only thing I will eventually change is the pump, didn't reallize until I got it that the max HG it produces is 19. It does perform quite effectively though, but would be nice to draw a bit more vacuum.

[Andrew Kertesz]

I also have less than $200 in mine. You can check the auction site for a pump, many people use the pumps from HF that are relatively inexpensive. Plenty of help available here if you have any questions or concerns.

[Darryl Hansen]

try wbnoble.com. Bill has instructions and pumps available. He also is very free with advice. A vacuum system is worth its weight in well free ebony. Darryl

[John Keeton]

Fred, like Roger, I have the Holdfast system and I like it because of its portability and ease of setup. When not in use, I store it in a cabinet (very small and lightweight). I also have the 3" and 6" chucks, though it would be easy enough to make those. The setup time on the Holdfast is probably 2 minutes - start to finish. I do have to remove the handwheel/handle and turn my line air pressure down to 70, and those take the most time. The rest is less than 30 seconds.

As an aside, a friend was thinking of getting the Holdfast, but felt his little pancake compressor wouldn't work. I had him bring it over, and it worked as well as mine. It takes very little capacity to work effectively. The larger your tank, the less frequently the compressor would kick on. My tank is 2.5-3 gallons, and it will kick on every couple of minutes for a few seconds.

[Roger Chandler]

Fred,

I forgot to mention in my post last evening..........when I first began looking at a vac system for the Grizzly G0698, Tom at JT turning tools did not have a configuration to make his adapter to work with my unit..............that may have changed, because I do know he has done a few for the Laguna 18x47, but they had the handwheel with the longer spindle than our G0698. The Hold Fast works well for me.

[Fred Belknap]

Thanks everyone.
Steve I checked the website and bookmarked it.

John and Roger: Does the Holdfast System come with everything needed to install. Looks like what I may go with as I have two air compressors, one is 60 gal that feeds air to the shop. I like the idea of short set up time. My main concern is how strong it held. I sometimes turn rather large bowls.

This sure is a great place to mine information and I sure appreciate it.:D

[Roger Chandler]

Fred,

It comes with everything you need.............the holding power depends on a couple of factors..........the porousness of the wood,.......oak for example does not get as high a vacuum as say maple...........unless you seal it with a shot of shellac or something before you reverse........which I do sometimes if the wood is really porous or thin..........the thinner the wood on any vacuum system is going to be the same, as well as the porous factor.

On most any vac system, you want to keep the rpms at about 650 or a little less and take light cuts to clean up the bottom. That being said on a few pieces along the way, I have gone a bit over 1000 rpms...........but I had a good strong hold. The venturi box has a gauge on it to tell what that is.

I spoke to one of the tech people at holdfast sometime last year, and he told me they were coming out with a newer venturi box that was even better than the one I have. I don't know all the details, but you should ask them...........you can contact them directly and speak with someone before you make your purchase decision............that would give you a lot of info.

They do stand by their product well with service should it ever be needed.

[Alan Trout]

I made my own system as well. and it is working very well. I can pull over 28" of vacuum with mine. In reality building a system is very easy. If you use a vacuum pump you have to filter the air and the vacuum bleed needs to be filtered as well. The bleed valve can be as simple as a small ball valve. I used an HVAC vacuum pump and it works great. Many say that it will give oil in the exhaust but I put a mist filter on mine and it works like a dream with no oil exhaust and the pump is not loosing any oil. Here are the links to the threads that I started. http://www.sawmillcreek.org/showthread.php?177129-My-take-on-vacuum-pump-control&highlight= and http://www.sawmillcreek.org/showthread.php?177484-Vacuum-Chuck-Drums&highlight=

Also JT turning tools makes really nice setup and from my understanding the pump he sells is excellent as well.


Good Luck

Alan

[James Combs]

Thanks everyone.
Steve I checked the website and bookmarked it.

John and Roger: Does the Holdfast System come with everything needed to install. Looks like what I may go with as I have two air compressors, one is 60 gal that feeds air to the shop. I like the idea of short set up time. My main concern is how strong it held. I sometimes turn rather large bowls.

This sure is a great place to mine information and I sure appreciate it.:D

Fred, as far as setup time is concerned, some have mentioned portability and storage but mine is basically setup all the time, all I have to do is dismount my scroll chuck and mount the vacuum chuck, that's all of 20 seconds or so then turn on the pump. Another factor in holding ability which I don't see mentioned is the size of the chuck. The larger the chuck the more holding power with a given amount of vacuum. Ornaments and other small items might require the higher vacuums that a pump can give you but in most cases I run between 20 and 25 inches of HG even though I can easily reach 29. Only on very small items do I exceed the 25 inches.

[John Giem]

1. JT Turning Tools makes one Rotary Vacuum Adapter which is sized for insertion into the outboard end of the spindle using O-rings for sealing. The adapter is sized for the Powermatic 3520 lathe. For other lathe models, Tom has handwheels machined to fit on the outboard spinlde threads. The end of the handwhell opposite the threaded section (away from the headstock) is bored to be same as the Powermatic. Thus, one adapter can be used on mulitple lathes by using the appropriate handwheel.
2. I see quotes of vacuum levels as high as 29 in Hg. That is fine for 'flat landers' and at sea level. Remember that the air pressure decreases with altitude, about 1 in Hg per 1000 feet, thus the achievable vacuum also is decreased. The weather also changes the barometric pressure which in turn changes the achievable vacuum.
3. Above there are references to the holding force for a vacuum chuck: Force = Area X pressure. This sets an upper limit for the holding force for your turning. This can be a significant problem if you are trying to mount a small object. There are other problems also, shape, perforations, leakage through the wood, etc. I have solved most of these challenges with what I call a Complant Vacuum Chuck. I have an article on it to be published in the American Woodturner early 2012. If you want more info, go the AAW Forums, www. aawforum.org, and look up the thread 'Update on Vacuum Chucking Systems'. This thread discusses this chuck and its operation and usage.

Let me know if you have any questions. BTW, I wrote the article on vaccuum chucking systems in the Feburary 2011 issue of the American Woodturner.

John Giem

[Nate Davey]

I made my own vacuum chuck that runs off my shop vac. Maybe $20 to put together and holds platter and bowls well.

[Fred Belknap]

Guys UPS delivered my hold fast system this afternoon. I ordered the extra chuck with it. I haven't had time to get it set up but it looks pretty easy, I'll let you know how it goes.

[Quinn McCarthy]

I built my vacuum pump from a kit. It is a venturi style. My wife was going to get me the vacuum chuck for my birthday. I said take Steve S's advice and get one from vacuum systems. After 2 months of phone calls and emails and not being able to buy a chuck I said I would take it over. I called and was told they were sorry about what happened and would call me back in 10 minutes. After 2 weeks of waiting for that call I emailed them and said you have 3 days to call me back so I can order the chuck. That didn't happen. I ended up with a oneway vacuum chuck instead.

Quinn

[John Giem]

Fred, I can't imagine going without a vacuum chuck. I made my own system following Steve's plans and it works great. I found a Gast pump on ebay for about $75, the whole system cost me under $200 and was kind of fun to build. The only thing I will eventually change is the pump, didn't reallize until I got it that the max HG it produces is 19. It does perform quite effectively though, but would be nice to draw a bit more vacuum.
Depending upon your altitude, 19 in Hg is way too low. I am assuming that you mounted the gauge directly to the pump without anything else connected. The 19 in Hg implies leakage around the seals in the pump. Gast makes good high quality vacuum pumps. You may want to check on getting a rebuild kit for your pump. You would probably wind up with a better overall solution.

[John Giem]

I also have less than $200 in mine. You can check the auction site for a pump, many people use the pumps from HF that are relatively inexpensive. Plenty of help available here if you have any questions or concerns.

Be careful. I tried a vacuum pump from HF and was disappointed. The pump pulled a good vacuum and seemed to 'work' OK. The pump was a rotary vane pump that used oil in it. When running, an excessive amount of oil was expelled from the exhaust port really making a mess. After running about three hours, I had to refill it wil vacuum pump oil. (You can get vacuum pump oil from NAPA.) I went back to HF and did an exchange. The second pump expelled an excessive amount of oil also. I returned it for a refund.
Gast makes an excellent rotary vane pump that is made well enough that it runs dry, no oil so it cannot expell oil from its exhaust. All wet (uses oil) rotary vane pumps eject oil from their exhaust ports when running. I have seen a couple of them that performed well enough that I would not object to having them in my shop. Just be aware of what you are buying.