...ah, you're one step ahead of me.
| Official Luthiers Forum! http://w-ww.luthiersforum.com/forum/ |
|
| Vacuum pumps http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=10607 |
Page 1 of 1 |
| Author: | Andy Zimmerman [ Mon Jan 29, 2007 5:33 am ] |
| Post subject: | |
Hi I am building a vacuum system and I am going to ask all of you about pumps. I have asked a few individually. What are the best pumps? Which ones are quiet? How much vac do you need. Some say that you need 25 HG or so.but many pumps are listed by CFM. (cubic feet/min) Some are 1.5 some are 2 some are 3. What CFM is adequate??? Thanks |
|
| Author: | Bill Greene [ Mon Jan 29, 2007 5:41 am ] |
| Post subject: | |
...ah, you're one step ahead of me.
|
|
| Author: | Shane Neifer [ Mon Jan 29, 2007 6:00 am ] |
| Post subject: | |
Andy, I just used a fridge compressor and it draws to 27 HG. Cost....free. I have friend though that is an appliance guy, so he set me up with the valves and gauges but JoeWoodworker has all of that. The fridge compressors are whisper quiet. I have another more industrial one that I am going hook up (compressor off of a larger refridgeration unit) and see if there is much of a difference in speed/volume. Shane |
|
| Author: | Andy Zimmerman [ Mon Jan 29, 2007 6:05 am ] |
| Post subject: | |
Shane What kind of fridge compressor do you have. In other words if i was going into an appliance repair shop etc. to find one what would I look for. Are there different strengths/power?? Thanks |
|
| Author: | crazymanmichael [ Mon Jan 29, 2007 6:10 am ] |
| Post subject: | |
the tighter your vacuum source, up to about one bar, the better your clamping can be. you can always lower the vacuum pressure the set will give below its maximum, but rather difficult to increase it above the line. i used a couple of old tard sale vac pumps for years and still have them. they still work well. but i switched over to a venturi system driven by the compressor a few years ago. higher capacity means that your vacuum chamber will evacuate quicker to whatever vacuum standard the source will deliver. i would strongly urge you to go to joewoodworker.com and read up on his systems. he offers the best prices i know of outside of ebay on system components including valves, pumps, venturis, sealing tape, etc.. his plans for reservoir based systems are very good and simple to build. i found the vacuum clamping to be much more efficient with a reservoir. a typical brace clamping frame will have about .5 cf of volume to evacuate, and keep evacuated for the duration of your clamping time. so a 3 cfm pump will get it down to the systems specs in no less than 10 sec. with a reservoir it takes about a sec to do the same thing. if you are using vacuum work clamps it is a pain to wait for the clamp to grab the work before you can do anything. |
|
| Author: | Andy Zimmerman [ Mon Jan 29, 2007 6:25 am ] |
| Post subject: | |
Thanks As far as the Joe Woodworker set ups with a resevoir, are any of them better for our use. Venturi, Electric,etc??? |
|
| Author: | Don Williams [ Mon Jan 29, 2007 7:21 am ] |
| Post subject: | |
Michael, I'm curious about the venturi systems...are they noisy? Does your compressor run non-stop? What advantages/disadvantages to a venturi setup? I've never experienced one. I would like to replace my crappy Thomas pump, which takes 20 seconds to evacuate the air out of my press, but before I spring $350 on a real pump, I thought I would ask the questions... |
|
| Author: | Dave Rector [ Mon Jan 29, 2007 8:05 am ] |
| Post subject: | |
I bought a nice Thomas vac pump that pulls 27hg off eBay that was brand new in box for $100 including shipping. So far all I have used it for is the LMI vacuum bridge clamp but it works very well and is also very quiet. I need to build a Joe Woodworker resevoir setup to go with it and I think it'll be even better. |
|
| Author: | Brock Poling [ Mon Jan 29, 2007 8:13 am ] |
| Post subject: | |
My Vac Pump |
|
| Author: | Shane Neifer [ Mon Jan 29, 2007 8:28 am ] |
| Post subject: | |
Just the extact same on as the one in the fridge in your kitchen. They are about the same. THe other one I have is from a cooler like the kind you see in grocery stores that hold milk and stuff like that. On the unit I have now I have 20 pound bottle that was empty taht I use as a reservior. The pump is silent, I mean, if you have any music or a noisy flouresent tube light ballast you will not know that the pump is running. And it works GREAT! I will take a pic in a few days and post it. I think it is in the archives somewhere on a "show us your tools/jig" thread. Shane |
|
| Author: | Bob Long [ Mon Jan 29, 2007 10:44 am ] |
| Post subject: | |
The current issue of the GAL journal #88 has a feature about Charles Fox's set up. It's a refer pump and a air-compressor tank for a holding tank. long |
|
| Author: | John Mayes [ Mon Jan 29, 2007 12:24 pm ] |
| Post subject: | |
I have two Gast pumps. On is a dual piston pump one is a smaller diaphragm pump. Both pull at least 25HG. the rock. One cost me about $50, one about $130 |
|
| Author: | crazymanmichael [ Mon Jan 29, 2007 2:17 pm ] |
| Post subject: | |
the venturi will bleed air when generating vacuum, a noticable hiss. the compressor only runs when its reservoir needs filling. the size of the vacuum reservoir and the tightness of the seal on your jig will determine how often that is. |
|
| Author: | John How [ Mon Jan 29, 2007 2:34 pm ] |
| Post subject: | |
I'm building a venturi system right now but have not finished it yet. Mine is one of the Joewoodworker kits and is supposed to run only until the vacuum is made and them cycle as often as necessary to keep it. I hope to have it together soon and will make a report. |
|
| Author: | Bob Garrish [ Mon Jan 29, 2007 2:48 pm ] |
| Post subject: | |
Venturis, if there is just a stub for the exhaust, are quite loud and hissy. I've discovered, if you attach a hose (5-6' in my case) to the exhaust so it needs to go a longer way, the pump is almost silent. I don't think there's any need for explaining the 'why', but it works quite well. |
|
| Author: | Barry Daniels [ Tue Jan 30, 2007 8:02 am ] |
| Post subject: | |
My venturi came with a plastic muffler that screws onto the exhaust. Same principal as the long hose. I plumbed a small check valve into the vacuum line to stop the leakage when the pump turns off. Works fine. |
|
| Page 1 of 1 | All times are UTC - 5 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|