Going for a stronger Vacuum chuck system

[Roger Chandler]

I have the Holdfast Vacuum chuck system that runs off a compressor with a venturi box.......it has done fairly well most of the time, but at times I seem not to be able to get more than 15 hg in vacuum. While on my trip, I picked up this little gem........I hope it works well!

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_11372.jpgI am going to need to get a working understanding of the particulars I will need to get this turned into the heart of a good vacuum system........

I am thinking about using the vacuum chuck heads I have with the Holdfast system only using the more powerful pump.

Knowing virtually nothing about this, but what I have seen posted from time to time......I sure could use some specifics on the fittings, vacuum gauge, valves tubing and even perhaps rotorary adapter .....my Grizzly lathe has a 0.393 hole through the spindle.......the 3/8" threaded lamp rod on my Holdfast system goes through it, but I was hoping to eliminate that and just use the bigger bore size of the spindle itself, if I could.

Even good information on the necessary components would be helpful. This pump is a 3 cfm, 2 stage rotary vane pump that uses oil lubrication.........I want to avoid oil contamination on a finish and such....


thank you everyone who can contribute to my success in getting this up an running!

[Ralph Lindberg]

Roger, I'm guessing that this is the Harbor Freight two-stage. I've been using the Harbor Freight single-stage for some years with good results. The one I use has a lower CFM. I also use a 3/8 lamp rod to a hold-fast chuck.
I haven't bothered, but some friends have put an oil recovery system using PVC pipe.

[Greg Ketell]

One of the best tutorials I've seen was done by our esteemed Steve Schlumpf. http://www.sawmillcreek.org/showthread.php?75579-Vacuum-Chuck-System-%96-How-I-Built-Mine (http://www.sawmillcreek.org/showthread.php?75579-Vacuum-Chuck-System-%96-How-I-Built-Mine&highlight=Vacuum+pump)

As for your rotary adapter, you can pretty easily make one out of Corian and a double-sealed bearing. That being said, both of the ones I made broke because I wasn't careful enough so I bought a commercial one out of aluminum.

Gk

[Jeffrey J Smith]

Roger: after putting together two systems and helping a friend put his together, I vote for buying a system with all the components you need. I put my first system together from scratch, wound up with a box full of stuff that didn't work out before finding the right parts. I bought two adapters one from each end of the expense spectrum, and found myself still chasing leaks on occasion.
When I got a new lathe, the adapter they offer as an option was the one made by JT Turning Tools. I was very impressed with it. A very solid piece of equipment. They also sell a complete system with the manifold, gauge, valve and filter. A friend got it, and, again, very solid stuff.

I bought the package from Craft Supply that has the gauge, manifold, valve and a mounting bar. I cut most of the bar off and bent the remainder to mount a magnetic base. It sits on the headstock, is easily moved, and holds the adapter ready to roll whenever needed. All I had to do was supply the filter.

I vote for buying a package. It's mostly all there, depending on which one you get, and I haven't been chasing leaks. If you need chucks, the vacuum hub JT has also works well.253967253968

[David C. Roseman]

Roger, my experience may be useful to you. I have the Grizzly G0733 (as you know, essentially same as your G0698, with a different motor and inverter). I got my fittings from Joe Gorleski ("Joe Woodworker"), who has two websites: www.veneersupplies.com (http://www.veneersupplies.com) and www.joewoodworker.com (http://www.joewoodworker.com)). I use a rebuilt Reitschle-Thomas pump w/ 3.15 cfm (also from Joe). With a shop-built handwheel/vacuum adapter and vacuum chuck, I pull 25 inHg at the outboard end of the chuck, directly through the spindle. Don't see why you couldn't get similar with your pump. Happy to send you some pics and info.

David

[Bernie Weishapl]

Roger like Steve Schlumpf I got my kit from here. http://jtturningtools.com/vacuumpumps-kits and his vacuum adapter http://jtturningtools.com/vacuum-adapters He makes adapters for several different lathes. I didn't see grizzly but I would call him. I couldn't find a vacuum pump I could afford at the time so I bought his pump also. I have been pleased and it works well. I bought the Holdfast chuck heads and the system works well.

[Dave Mueller]

Roger,
Like Ralph, I have been using the Harbor Freight single stage oil vacuum pump for several years on my Vicmarc VL300 long bed lathe with no problems. I bought the vacuum adapter from Stubby Lathe USA (http://stubbylatheusa.com/cgi-bin/onlinestore.py#Rotary Vacuum Adaptor Kit ) and find it to be well made and pretty inexpensive relative to other adapters. It uses a "lamp rod" to go through the headstock spindle and I made a small tapered plug to go on it to center it in the headstock spindle (see the attached picture). I also use the HF vacuum pump to vacuum infuse wood with Turntex's Cactus Juice, and routinely get 30" of vacuum on the gauge. On my lathe, I can get in excess of 25", depending on the wood I'm turning and how porous it is. I have never had any problems with the 3 CFM air flow rate, however, I have not tried it with a really porous wood.

One thing I learned was that all oil vacuum pumps will produce a very fine oil mist out of the pump exhaust port. This mist is not good to breathe and hard to capture. I eventually figured out how to make an inexpensive filter to put on the exhaust port that stops the mist. If you are interested, send me an e-mail and I'll send you a PDF on how to make it.

Bottom line, the HF pump, Stubby vacuum adapter and all of the other necessary parts (bleed valve, filter, quick disconnects and hoses) will produce good a vacuum.

Dave

253979

[Steve Mawson]

I set up my system from Steve's instruction. Using JT equipment on the lathe. Not hard to get 25" unless you have a big air leak.

[Roger Chandler]

I have checked with Tom STeyer at Jt turning tools and he does not make an adapter to fit my lathe..........he turned me down when I first started thinking about one for it after I got the lathe 3 years ago........not sure what I will do yet, but making my own does have an appeal......just hope I can make one where the bearing seals stay intact........I might use the one with my Holdfast System....I have two of their adaptors, but I was hoping to avoid the threaded lamp rod........might not be possible in my situation.........thanks everyone!

[Roger Chandler]

Roger, my experience may be useful to you. I have the Grizzly G0733 (as you know, essentially same as your G0698, with a different motor and inverter). I got my fittings from Joe Gorleski ("Joe Woodworker"), who has two websites: www.veneersupplies.com (http://www.veneersupplies.com) and www.joewoodworker.com (http://www.joewoodworker.com)). I use a rebuilt Reitschle-Thomas pump w/ 3.15 cfm (also from Joe). With a shop-built handwheel/vacuum adapter and vacuum chuck, I pull 25 inHg at the outboard end of the chuck, directly through the spindle. Don't see why you couldn't get similar with your pump. Happy to send you some pics and info.

David


David........PM sent! :)

[Thom Sturgill]

Roger, If your Holdfast was holding 15 hg when normally it held 25, then you have a leakage problem, probably the end-grain on the piece you are trying to hold. I pump with a higher CFM will probably solve the problem, but so might sanding sealer. I moved away from a HoldFast when I upgraded lathes, not because of holding problems, but because of the noise level of the pancake compressor I was then using. I still use the Holdfast on the small lathe.

[Hayes Rutherford]

Roger, if your new vacuum pump creates an oil mist, maybe you could set it up in a different location like outside(?) Mine sits up above the shop ceiling and just a valve, gauge, filter, on-off switch, and short length of hose are mounted on a short post that comes down through the ceiling up above the headstock. When not in use everything is up and out of the way and when in use I can hardly hear it. That way there is nothing to roll out and set up every time you want to use it.

[Roger Chandler]

Roger, if your new vacuum pump creates an oil mist, maybe you could set it up in a different location like outside(?) Mine sits up above the shop ceiling and just a valve, gauge, filter, on-off switch, and short length of hose are mounted on a short post that comes down through the ceiling up above the headstock. When not in use everything is up and out of the way and when in use I can hardly hear it. That way there is nothing to roll out and set up every time you want to use it.


Hayes.......I would love to see a pic or two of your setup on this......perhaps I won't have to try and re-invent the wheel and there are a lot of good ideas and creativity from some of the folks who participate in this forum.......thanks!!!

[Dan Hintz]

When I was deciding upon a pump, I wanted to avoid the hassle of dealing with refilling oil, capturing the mist, etc. I went with a dry vane pump (Gast 0823) and I'm quite happy with it... I can pull 27" with it all day, and with an 8CFM draw I can work on really punky / porous stuff without worrying about it losing suction.

[Hayes Rutherford]

Roger, here is a shot of how I hook up to vacuum. The upper green hose comes from the Gast pump up above shop, the on/off switch is next to the duplex recep., there is a brass cross with valve and two fuel filters. 254073

[Chip Sutherland]

I am building my pump now and it is a recycled piston pump. So far I am pulling 25-6" through the headstock and I haven't tried to seal anything yet. Mine is based exactly off of a friends I had to borrow when my Holdfast failed 15 hrs before delivering 6 collection plates. I much prefer my rotary vane pump sound than my compressor cycling.

Coincidentally, my woodturning club (Golden Triangle Woodturners) just did a demo on how to build one for our Feb meeting. When the demo video & presentation are updated I will try to remember to update this thread. There is an older presentation our our site http://(http://www.goldentrianglewoodturners.org/GTW/Documents_files/Building%20a%20vacuum%20Chuck2008.pdf)
but there are a couple of differences: 1) head stock adapter is now 2 bearings instead of one 2) the inline filter is between the Gauge and the pump. There are some good sources (joewoodworker & veneersupplies) in the PDF which have been mentioned in this thread already.

When I go to SWAT this year I will likely budget for the jt turning tools adapter to replace the one I am currently building. I do plan to reuse my Holdfast vacuum chuck heads plus make a few different sized using PVC couplers (not pipe). That's my 2 cents.

[Doug Wolf]

Hi Rodger, If your headstock spindle is vacuum tight, IE no holes inside, you can build the spindle adaptor like the one I made for my Powermatic 3520B. The instructions can be found at : http://www.pueblowoodturners.org/Members/wolfd/How%20To%20Make%20A%20Vacuum%20Adaptor%20For%20A%2 0Powermatic%203520b%20Headst.pdf . I've been using it for several years and several others have built one of their own following my plans. You can plug off your spindle and see if it will hold a vacuum or look in your manual to make sure the spindle is solid all the way through.

[Roger Chandler]

Hi Rodger, If your headstock spindle is vacuum tight, IE no holes inside, you can build the spindle adaptor like the one I made for my Powermatic 3520B. The instructions can be found at : http://www.pueblowoodturners.org/Members/wolfd/How%20To%20Make%20A%20Vacuum%20Adaptor%20For%20A%2 0Powermatic%203520b%20Headst.pdf . I've been using it for several years and several others have built one of their own following my plans. You can plug off your spindle and see if it will hold a vacuum or look in your manual to make sure the spindle is solid all the way through.


Thanks Doug......I saved a copy of those plans......much appreciated!

[Roger Chandler]

Roger, If your Holdfast was holding 15 hg when normally it held 25, then you have a leakage problem, probably the end-grain on the piece you are trying to hold. I pump with a higher CFM will probably solve the problem, but so might sanding sealer. I moved away from a HoldFast when I upgraded lathes, not because of holding problems, but because of the noise level of the pancake compressor I was then using. I still use the Holdfast on the small lathe.

That is what I thought also, Thom......at the venturi box, with nothing else attached and using my finger to cover the suction port.......the best I can get now is 19 hg, and that is after replacing the hose, the quick connect fitting and re-taping the connections with teflon thread seal tape.

The venturi unit did fall off my work bench to the floor a few months ago........nothing appears to be out of order in the unit when I took the box apart and inspected everything........it just seems to not have the suction it one time did, or perhaps the gauge is off and needs to be replaced.....I may call HOLDFAST and see what they say about it.

[Roger Chandler]

This is the venturi vacuum generator that comes with the HOLDFAST system. I can't hardly stand when something does not work correctly.....after doing some thinking, I went back and took the thing apart.......

http://www.woodturnerscatalog.com/images/prod/400/hol_v810r_vac_gen.jpgI found out what part of my problem was with not being able to get the vacuum I was when the unit was new. If you look at the picture, and see the regulator knob.......the metal knurled stem out the bottom in the middle.........I took this whole unit out of the box, and found out that for some reason.......perhaps a burr or something, the inside of this regulator unit was sticking, even though the knob would turn, it was hard to do so and when I took the knob all the way out of the regulator unit, the inside piece slid up and down freely........and I put the knob back in and adjusted everything for optimal air flow........

I am now getting 22 hg in vacuum, and that is with a 50 ft, 1/4" coiled plastic hose.........I do not know if I switched to a 3/8" inside diameter hose if it would send more air through the unit and make even more vacuum.

That leads me to a question......I read that with 55-65 lbs of pressure you can get 22 hg.......I think that was either on Packards website or another site I was looking for the above pic....it plainly says on the box as you can see that a minimum of 70 psi is required..........I have my compressor set to put in about 85-90 lbs.........am I putting in too much air? Would backing the pressure off, and putting on a larger diameter air hose make a difference?

[Fred Belknap]

I am now getting 22 hg in vacuum, and that is with a 50 ft, 1/4" coiled plastic hose.........I do not know if I switched to a 3/8" inside diameter hose if it would send more air through the unit and make even more vacuum.

Roger I doubt that it would help. It says it required 2cfm which a 1/4" hose should easily supply unless it is kinked or someway obstructed.

[Roger Chandler]

Roger I doubt that it would help. It says it required 2cfm which a 1/4" hose should easily supply unless it is kinked or someway obstructed.


Thanks Fred.......good info......thanks!!!!

[David C. Roseman]

Roger, glad you were able to improve the vacuum to 22 inHg. That actually seems pretty good for vacuum chucking with any system.

Your question on air hose sizing and compressor pressure got me curious about this. We all know that a hose that's too small can impair the function of a pneumatic tool. A 1/4" air hose induces more friction and cavitation to the air flow than a 3/8" hose, so it logically reduces psi delivered to the tool. In fact, it causes about nine times the air pressure drop as a 3/8" hose. So, I'm thinking, why wouldn't this apply equally to the venturi valve in your Holdfast system? A little bit of research and an online air pressure drop calculator taught me something very surprising, and turns out Fred is spot on! The relatively low 2 cfm requirement of your venturi makes all the difference in whether the hose size matters much. If you were driving an air sander that uses 10 cfm, your 50 feet of 1/4" coiled plastic hose would cause a loss of about 22.7 psi. If your compressor cycles on at 85 psi, you'd have only 62.3 psi at the tool! A 3/8" hose would result in only about a 2.7 psi loss. But when you change the requirement to only 2 cfm, the total psi loss with 1/4" hose is only .9 psi, vs. .1 psi for 3/8" hose. It's still nine times more of a loss, but you are still well above the minimum 70 psi that Holdfast says you need.

The calculator I used is here http://www.gates.com/industrial/pressure/airflow.cfm?location_id=3043

That said, if you happen to have 50 feet of standard 3/8" rubber or PVC air hose handy, I'd be inclined to hook it up in place of your 1/4" just to confirm this! :)

David

[Roger Chandler]

Roger, glad you were able to improve the vacuum to 22 inHg. That actually seems pretty good for vacuum chucking with any system.

Your question on air hose sizing and compressor pressure got me curious about this. We all know that a hose that's too small can impair the function of a pneumatic tool. A 1/4" air hose induces more friction and cavitation to the air flow than a 3/8" hose, so it logically reduces psi delivered to the tool. In fact, it causes about nine times the air pressure drop as a 3/8" hose. So, I'm thinking, why wouldn't this apply equally to the venturi valve in your Holdfast system? A little bit of research and an online air pressure drop calculator taught me something very surprising, and turns out Fred is spot on! The relatively low 2 cfm requirement of your venturi makes all the difference in whether the hose size matters much. If you were driving an air sander that uses 10 cfm, your 50 feet of 1/4" coiled plastic hose would cause a loss of about 22.7 psi. If your compressor cycles on at 85 psi, you'd have only 62.3 psi at the tool! A 3/8" hose would result in only about a 2.7 psi loss. But when you change the requirement to only 2 cfm, the total psi loss with 1/4" hose is only .9 psi, vs. .1 psi for 3/8" hose. It's still nine times more of a loss, but you are still well above the minimum 70 psi that Holdfast says you need.

The calculator I used is here http://www.gates.com/industrial/pressure/airflow.cfm?location_id=3043

That said, if you happen to have 50 feet of standard 3/8" rubber or PVC air hose handy, I'd be inclined to hook it up in place of your 1/4" just to confirm this! :)

David

Wow, David......great info! I am presently gathering items for my vacuum pump [fittings etc] I may give you a call and talk with you some about the .pdf you sent.....maybe we could work out a time for a creeker visit, and get this thing up and going, if you would be willing........

The 22 hg is at the box with my finger on the port for total seal......I hope to be able to do better with a pump........others have mentioned 29 hg with pumps, and mine is a two stage 3 cfm pump.....hopefully, I can get it better!

[Steve Peterson]

I have checked with Tom STeyer at Jt turning tools and he does not make an adapter to fit my lathe..........he turned me down when I first started thinking about one for it after I got the lathe 3 years ago........not sure what I will do yet, but making my own does have an appeal......just hope I can make one where the bearing seals stay intact........I might use the one with my Holdfast System....I have two of their adaptors, but I was hoping to avoid the threaded lamp rod........might not be possible in my situation.........thanks everyone!

I use an adapter from http://www.harrisonspecialties.com that can be ordered to fit many different threads. It works great for me with a 8-1 thread on my lathe. It uses a 3/8" OD metal rod that should just fit inside a 0.393" bore.

Steve

[Roger Chandler]

I use an adapter from http://www.harrisonspecialties.com that can be ordered to fit many different threads. It works great for me with a 8-1 thread on my lathe. It uses a 3/8" OD metal rod that should just fit inside a 0.393" bore.

Steve

Thanks for the link, Steve!

[Peter Fabricius]

Hi Roger;
I built my Vacuum Adaptor from a sealed bearing and a few plumbing parts. The Cherry Wood Handwheel fits around the DVR XP Steel handwheel and holds the Vac Adaptor inside. I made the fittings so I can still get the knock out rod through the copper fitting on the end.
The pic shows the Vac pump sitting on a small shelf beside the Lathe and the hose connected with a Brass screw on fitting.
Hope this helps.
I also have info on building your own Vacuum Chucks and I sell the Silicone Seals that fit on the 3, 2 and 1.5" PVC pipe sizes.
good luck with your system.
Peter F.

[Roger Chandler]

Hi Roger;
I built my Vacuum Adaptor from a sealed bearing and a few plumbing parts. The Cherry Wood Handwheel fits around the DVR XP Steel handwheel and holds the Vac Adaptor inside. I made the fittings so I can still get the knock out rod through the copper fitting on the end.
The pic shows the Vac pump sitting on a small shelf beside the Lathe and the hose connected with a Brass screw on fitting.
Hope this helps.
I also have info on building your own Vacuum Chucks and I sell the Silicone Seals that fit on the 3, 2 and 1.5" PVC pipe sizes.
good luck with your system.
Peter F.

Peter........I don't see the pics you are referring to..........did they not load, or are they on a website you have? :confused: I would like to see what you are speaking of, so if you have additional info, I appreciate your input!

[Peter Fabricius]

Hi Roger;
I do not want to push my thoughts on anyone, but you asked so here goes.
Two PDF files attached with the info you need.
Good luck.
Peter F. Edit: the PDF with the pictures is 159KB and did not upload, too big. Perhaps I can send it to one of the Admins and they can put it in here? Just a thought.