Vacuum system finished.

[Dan Forman]

I finally finished assembling my vacuum chuck system, but was disappointed to find that it only pulls just under 22" HG. I partially disassembled it an connected the gauge directly to the the input hose, and it didn't change. It's the familiar Gast 0523 from Surplus. It did suffer a fall of about two feet when it got knocked off of it's perch quite some time ago, doesn't rattle or anything, but bent one of the mounting feet a bit. Does anyone here know what is involved in a rebuild? I haven't tried it yet, don't know how much vac is really needed for our purposes, but I'd like to use it for veneering too.
Anyway, here are some pics of the system. I borrowed both from Steve and from Christopher Hartley. I decided to make a cabinet that would give me some additional storage space, and figured I might as well make full use of it by hanging tools on the outside. http://i98.photobucket.com/albums/l279/T-Caster/P1030528.jpg
http://i98.photobucket.com/albums/l279/T-Caster/P1030530.jpg
http://i98.photobucket.com/albums/l279/T-Caster/P1030531.jpg


The back doesn't go down all the way to the bottom, ends a little above the pump, and there is a cutout on the left side as well, to aid in air circulation, and allow access for blowing out the motor now and then to clear sawdust.

I came up with a cheap and easy way to make the racks, using a 1 1/16" Forstner bit, which left a very slight gap around the 1 3/64 od pvc pipe. I was afraid that if I used screws to fasten the tubes in place, sooner or later I would hit one with a tool and damage an edge. So to deal with the slight amount of slack, I took the drilled pice to the bandsaw, and sliced it in half lengthwise. The dabbed a bit of epoxy in each of the depressions, laid the pipes in, and screwed the pieces back together. They now fit tight, and I don't think they will go anywhere. Each rack is held on the cart by three screws, and the whole arrangement seems quite solid. Most of the tools stored in the rack are easily identified by their handles, so not being able to see the business end is not a problem. The center cut is pretty ragged, probably should have changed bandsaw blades before making the cut, but I was thinking more of utility than beauty for these. http://i98.photobucket.com/albums/l279/T-Caster/P1030535.jpg

And here it is in place, with the final electrical connections made. I haven't filled up the shelves yet, still deciding what will go where. The cabinet shouldn't get hit with too many shavings in this position.
http://i98.photobucket.com/albums/l279/T-Caster/P1030539.jpg

Dan

[Joe Mioux]

dan, I can't see the attachments

[Doug Wolf]

Can't see the attachments but to answer your question:

I haven't tried it yet, don't know how much vac is really needed for our purposes, but I'd like to use it for veneering too.

I finished the bottom yesterday on a 22" platter with my 10" diameter vac chuck and held it at 4" of mecury so I wouldn't suck in the bottom. Had it up to 600 rpm and it worked fine. I can only pull 22" here at 5000 feet so your probably losing a little at your elevation in Spokane.

[Alan Zenreich]

If it dropped, it's possible the one or more of the vanes are stuck and not moving freely. Have you taken the front plate off and inspected that the vanes are ok? It's just 4 bolts, no washers or gaskets, so it takes only a minute or two to check it out.

[Paul Gilbert]

as Alan said, it is just 4 bolts. While you have the front plate off check the clearance between the rotor and the ring at the top. It should be less than .005". There are two bolts that hold the ring. You can loosen them and adjust the clearance.

[Dan Forman]

Took it apart and everything seems to be in order, good tight clearance and the vanes all move. It's a deceptively simple mechanism, I had no idea how it worked before seeing it, in fact, when I saw the two collapsed vanes, I thought that was the problem, until I advanced it and saw that they slide back and forth. Curious, mine has six bolts holding the front plate, not four, and they were pretty corroded. I have them soaking in Kroil, and a plastic bag over the front end to keep dust out until morning. The inside of the cylinder seemed to be smooth and in good shape.

Dan

[Fred Perreault]

Dan, a nice looking, functional rig. I created a vac system more than a year ago, using Steves' ideas and other sources. It works fine, and draws only 22-23 HG. It has been enough for all that I have put on my Nova 1624. I have been up to 1000 rpm a couple of times, but usually 684 rpm. And I have cracked/collapsed a couple of bottoms. There are many, many places for tiny leaks to occur that add up to 2-4 HG, and the spindle to chuck can be one easily overlooked. I would suggest that 22HG is adequate but we'll see what others chime in with.... :)

By the way, I think that having the vac system on a wheeled cart is the cat's meow.

[John Keeton]

Dan, on my Holdfast, I can pull about 24", and that seems to be plenty for everything I have done. The big factor is the amount of surface area on which the vacuum is effecting. With the 10" chuck that Doug Wolf is using, he will have a lot more holding power than would I with a 3" chuck - even with the same amount of vacuum.

[Dale Bright]

Dan,

You have built a very nice rig for your storage and vacuum system. I have pretty much the same system, except for the cart. I have found that anything over 15" HG holds well and anything over 20" holds very well. The max I have seen on my system is 26" HG. Like John, said, the chuck area is very important.

I have to ask about the cinder blocks on your head stock. What are they doing there?

Dale

[Josh Bowman]

Dan, first try another gauge. Second take the pump back apart and use some electronics cleaner and try again. 3rd you can buy those vains from several places, Gast and Grainger being an example. 4th live with it since you don't really need over 17 to 20".

[Tim Rinehart]

Echo the comments on anything over 20" likely fine. I have similar (522 series though) and it holds about same, 22" Hg on a good day. The only thing you need any concern on will be the smaller stuff, where your area pulled gets smaller. On larger diameter pieces, 3" and up...I think you've got plenty of oomph there. Remember, use the tailstock as long as you can and make only very light cuts when using the vacuum chuck only.
Also...I like using a healthy dose of masking tape holding a piece to the vac chuck. This adds additional sealing to porous woods and provides a little safety margin. In fact...I've had some pieces so porous or with inclusions...I used the soft interface of my chuck with tape only...no vacuum, to make final cleanup on bottom.

Your setup looks great...I wish now I had done something similar, besides a single use cabinet...may have to change.

One last question...do you turn with the concrete blocks on the headstock for vibration reduction, or are they just there temporary like. Never seen that done before.

[bob svoboda]

Looks like a nice setup, Dan. Mine will pull 26/27" but I rarely run it over 20--have sucked the bottom out of a couple bowls using more.

[Duff Bement]

You might want to unscrew the hose nipples (intake and outlet) out of the housing and make sure that they are not partially blocked. That was what was wrong with mine. Let us know how it turns out. looks like a great up though. Cool lathe too.

[Alan Zenreich]

There are a couple of things to check.

If you plug the input next to the gauge (remove the hose going to the lathe), does the vacuum increase? If so, you have a leak at the headstock somewhere. If it does not, a leak maybe elsewhere (at connections to the filters, etc.). This is all assuming that there is a leak.

But what if there's no leak? Josh is right... it might be the gauge that's off. Trying another gauge might be give a different reading.

There's an old saying "A man with a watch always knows the time... a man with two watches is never sure"

[Steve Schlumpf]

Dan - congrats on getting your system up and running! My vac system can only pull about 23 hg but I have never used more than 20 on any project. You may be able to replace the vanes in your pump - but if you only use a max of 20 hg - is it really needed at this point in time?

[Doug W Swanson]

Looks like a nice setup. I'm going to try building a system one of these days....

I'm not the only one that noticed the cement blocks. I thought that the mustard monster you have was plenty beefy enough and wouldn't need extra ballast there!

[James Roberts]

There is an article in the latest American Woodturner (AAW) about vacuum chucking systems. One suggestion from the article; have you tried Teflon tape on the spindle threads before attaching your vac chuck?

[Cathy Schaewe]

mine pulls about 23 hg, and I've never had anything come off a chuck that was bigger than 2". I doubt you'll have any problems -

[Dan Forman]

Thanks for all of the replies and suggestions. I think the only thing left to check would be the connections coming off of the pump as Duff suggested, or maybe a bad gauge. As long as it's partially disassembled again, I'll check those out. At any rate, it looks like it should end up being enough suction. I checked the Joe Woodworker site for veneering info, and he says that 21" is about ideal for that, so I should be covered. It would be nice though to have a little more leeway.

I sure am happy having the additional tool storage, so I'm not forever moving the extras off of the jointer bed. I even have a couple of extra slots (for the moment).

Dan

[Dan Forman]

Update---I reassembled using thread goop instead of tape going into and out of the pump. Change = 0. But, I did eek an additional 1/2"+ by removing the silencer, which was apparently impeding air flow out of the system, and there was no increase in noise from the pump. I asked the guy at House Of Hose about the accuracy of the gauges, he said they are spec'd to + or - 3 inches of HG, so there is a reasonably good chance that mine is just reading lower than it really is. He said for $200 I could upgrade to a more accurate gauge. ): I think I'll pass, and leave it at that unless there is trouble down the line with holding power.

Dan

[James Combs]

This is something I have been wanting to add to my to do list and will as soon as I find a good used pump.

[Bernie Weishapl]

Congrats Dan on a fine looking system. Mine pulls 22 to 23 but seldom do I let it get over 20 hg.

[Allen stagg]

Mine shows around 23 - 24" when I use it. I recently got a vac pump and built the system based on a copy of someone else I saw with very simular system or almost identical which I really liked. I only need to build a cover over the pump to keep some of chips out of the air intake of vacuum pump motor. Again, this is not my design but I just liked it from another I saw somewhere on internet.

I really do like your rolling stand however and can hold tools which could sure come in handy. I like your design. I don't really do bowls however, but just in case, I'm ready.


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http://www.sawmillcreek.org/images/misc/pencil.png

[Baxter Smith]

Nice looking system. Sure comes in handy!

[Dan Forman]

Thanks for the latest comments. I forgot to explain the concrete blocks --- some time back when we were discussing ballast and vibration problems, someone said that ballast was most effective when near the center of gravity of the lathe. Most folks add sandbags very near the floor, which while adding weight, lowers the center of gravity, making it easier for the bed to vibrate. See posts 15 and 16 of the following thread for details: http://www.sawmillcreek.org/showthread.php?101271-Vibration-after-adding-ballast&highlight=vibration .

I had already built a ballast box at the usual location, but adding the concrete blocks helped. Someday I'll have to try building something that will move the sandbags higher, near the bed. Maybe then the blocks won't be needed. The holes in the blocks make nice little storage holes for drive centers and chuck jaw adjusting thingies. ?

[Charles Drake]

Dan, if necessary, you can buy a kit (new vanes, gaskets, filters) to repair your 0523 (I think they are about $60). I repaired mine with good results (was pulling about 20 inches and now about 26 inches). You might google Septic Sewage Pumps-the kit number is k478 (the main use for these pumps are as an air compressor for aerobic septic systems). Good luck, Charlie

[Peter Fabricius]

Nice set up Dan;
I have a question for anyone having built a vac system for the Nova DVR XP. I have all the pieces and in testing I find that the NOVA bearing that is set into the handwheel leaks like a sive. I thought that the bearings used for vac systems were sealed and would not let air through???
The pump is working great and when I cover the end of the tube I get 23 -24 inches of Mercury shown on the gauge. But, when I set the bearing with a sealing gasket in the handwheel I only get 4 inches at the spindle end....???
Help please.
Peter F.

[Christopher K. Hartley]

Dan, good looking setup. I like what you've done here.

[Josh Bowman]

Nice set up Dan;
I have a question for anyone having built a vac system for the Nova DVR XP. I have all the pieces and in testing I find that the NOVA bearing that is set into the handwheel leaks like a sive. I thought that the bearings used for vac systems were sealed and would not let air through???
The pump is working great and when I cover the end of the tube I get 23 -24 inches of Mercury shown on the gauge. But, when I set the bearing with a sealing gasket in the handwheel I only get 4 inches at the spindle end....???
Help please.
Peter F.
This should solve your problem, it bypasses the lathe head stock. Make him and offer between 35 and 40 should do the trick. Even though I made a rotating union and chuck for my lathe, I find I use this one, since it's simple.
http://cgi.ebay.com/Vacuum-Drum-Chuck-head-wood-turning-lathe-turner-/200569549325?pt=LH_DefaultDomain_0&hash=item2eb2e0720d

[Dan Forman]

Thanks for the info. The pump was never used, the vanes look to be in good shape, not sure about the gaskets. Unless I start having problems, I'm going to assume that the gauge is off.

[John McCaskill]

What's the VFD on yours used for, Allen?


Mine shows around 23 - 24" when I use it. I recently got a vac pump and built the system based on a copy of someone else I saw with very simular system or almost identical which I really liked. I only need to build a cover over the pump to keep some of chips out of the air intake of vacuum pump motor. Again, this is not my design but I just liked it from another I saw somewhere on internet.

I really do like your rolling stand however and can hold tools which could sure come in handy. I like your design. I don't really do bowls however, but just in case, I'm ready.


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http://www.sawmillcreek.org/images/misc/pencil.png

[Allen stagg]

What's the VFD on yours used for, Allen?

VFD? I assume you mean the white box? It is the 3 phase converter that comes on the Mustard Monsters. It comes standard. Otherwise, not sure what you are referring to?