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Vacuum Pump Mount and Arrangement

Tom Gall

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This thread has been a huge help in figuring out what I need for my vacuum chuck system. The pump (Gast 0523) and manifold parts are arriving today and my rotary adapter and chuck are finished. The manifold will have a needle type bleed valve and a ball valve for vacuum shutoff, filter at the pump, no quick connectors, and every other recommendation from this thread that I could incorporate. One operational question remains. Is it bad for the pump to be on while the vacuum is cut off by the ball valve? Obviously, I wouldn't leave it running that way any longer than needed, but I'm curious what effect that has on the pump.
NO! After doing that on my system for 26 yrs. I've never had a problem. Basically when you close the ball valve the pump (assuming no leaks) is pulling maximum vacuum - that's what it is designed to do. Back in the days when I used vacuum for some semi-production runs I would leave the pump running for 3-4 hours at a time. I did add a fan to cool off the motor & pump though. It goes on whenever the pump is on.
 

Tom Gall

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Ric, I’m hardly an expert, so take this with a grain of salt. I recently built my system, with much advice from here. I’ve only finished three bowl bottoms with it so far, but it’s been working great. I did decide to go with quick connect fittings, as, like Steve (above) mentioned, I want to be able to, at some point in the future, use the pump to evacuate a vacuum chamber for stabilizing wood. I added those after first using the system on one bowl, when I realized I already had the fittings from an old compressor I no longer use. After installing the quick connects in the vacuum line, I experienced the same 24” of vacuum in my system. It still holds the vacuum for a good 30 seconds after turning off the pump. I realize that this may change over time, but I’ll keep my eyes on the gauge and watch for leaks. Good luck with yours!
I have three in my system and haven't had any problems. One is right next to my primary gauge where I have a swivel fitting (not really necessary but installed for any future modifications) which allows easy insertion & removal of my rotary adapter from the spindle (see photo in previous post). The other two are at the pump. One is on the pump where the filter is attached - and the other on the filter to attach my vacuum hose. This is to make it easier & quicker to remove the entire filter for cleaning ..... can't remember the last time I did that! :rolleyes:
 
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Tom Gall

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Thanks Gary, that's what I was hoping to hear. The pump seems to max out at 22", so it may need a rebuild kit if I find I need a little more vacuum, though I suspect it'll be fine as is, for anything I'm likely to be working on in the foreseeable future.
That should do for most of your needs. I assume the 22" reading is directly at the pump and not after all the hoses & fittings.....the most likely culprit for any leaks. Also, I've found that gauges can be off a little - so just use them as a reference for unexplained changes.
 
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Thanks guys! I've said it before, but the biggest thing that got me hooked on woodturning is the universal attitude of the people openly sharing information, advice, instruction, welcoming new people and the emphasis on mentoring each other. I've been in other (non-woodturning) activities where the environment was quite the opposite. I like this a lot more!
 
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More adventures in vacuum-pumpology. Glad this is a learning experience...
Got the system together last night and did some more testing, only to find that among other things, the cheap bearings I (knowingly) bought don't seal very well and are sucking air through the seals and sucking the lube out, leaving me with about 17.5 inches of maximum vacuum with the system in the working configuration. I kind of expected it from 8 for $10 bearings. Anyone know of a quality bearing dealer online?
During the testing the pump motor started acting up and wouldn't start properly. Great. After doing some checking online last night, I tore it down today and found that, as expected, the centrifugal switch contacts were dirty and weren't letting the startup windings do their job. Now it's starts up like it should. During reassembly I inspected the vanes and pump body and found that the vanes were in bad shape. Just about every corner on each vane were chipped off and ragged and there's a tear in the main pump gasket. Probably time for a rebuild kit. Got it all back together and have reliable startups, but the max vacuum is now down to 17.5 7.5 at the pump. Definitely time for a rebuild kit! That should be here next week, then the adventure continues.
 
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I got my bearings from McMaster-Carr. I think they were $18 each. They ship next day and don’t charge a fortune for shipping.
Correction: just looked it up. They were $14 each. I bought two just to have a reserve, but one is working fine for me. Their part number is 6384k74. I don’t know how to copy the item, but if you go to McMaster-Carr’s site and put this # in the search box, you’ll get it.
Just figured it out! Here is the link:

Ball Bearing, Light Duty, Sealed, Number 3021-2RS, for 1/2" Shaft Diameter

https://www.mcmaster.com/6384K74
 
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Thanks Lou! I buy from M-C fairly regularly, but I didn't know how good their bearings are. Have you had any problems with air leakage or grease getting sucked out? Once I get the pump working as well as possible, if the adapter is still leaking too much to get a good vacuum, I'll try some of those. The size I need are about $11 each.
 
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Ric, I’ve only had the system up and running for a week or two. Only turned off three bowls with it, but so far the bearing seems great. But no loss of vacuum since I’ve started it up. I’ve also got a used pump - formerly a goat milker! But it seems to be giving me a consistent 24” of vacuum.
 
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Sorry if we've inadvertently hijacked this thread...

I don't know what kind of environment my pump operated in, but judging by the inside of the tubing that was still attached and the crud on the internal filter, it was a pretty dirty one. Don't know if that's what caused the chipped up vanes, but I don't know why else they'd be so rough.
It's a good thing I like to tinker with things and see what's inside. I'm usually able to get them all back together, but nothing is safe from my curiosity.

I'm also a strong believer in the Law of Inanimate Reproduction:
"If you take something apart and put it back together enough times, you will eventually have enough parts left over to make another one."

And let's not forget Fudd's 1st Law of Opposition:
"If you push something hard enough, it will fall over."
(Obscure, but revealing, '70s pop culture reference. Bonus points to anyone who knows the source.)
 

Bill Boehme

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And let's not forget Fudd's 1st Law of Opposition:
"If you push something hard enough, it will fall over."
(Obscure, but revealing, '70s pop culture reference. Bonus points to anyone who knows the source.)

I think we're all Bozos on this bus.

The 70's was after my time, but Google knows everything.
 

Tom Gall

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Thanks Lou! I buy from M-C fairly regularly, but I didn't know how good their bearings are. Have you had any problems with air leakage or grease getting sucked out? Once I get the pump working as well as possible, if the adapter is still leaking too much to get a good vacuum, I'll try some of those. The size I need are about $11 each.
Ric, since you are a tinkerer you may not be interested in this. I don't know what kind of lathe you have but CS has a very nice vacuum adapter with two bearings for $65. I even bought one hoping it would fit the the spindle on my General 260 .... it didn't!
I didn't want to order one of each to find one that may fit and then return the rest. :D My homemade one serves me well.
https://www.woodturnerscatalog.com/p/102/6659/precision-machine-Rotary-Vacuum-Chuck-Adapter?term=precision+machine&term=precision machine
 
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I originally was going to order one of these, but the size to fit my lathe, PM 3520 is out of stock and not expected until January. In hindsight, I’m not unhappy that I made my own.
 
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Ric, since you are a tinkerer you may not be interested in this. I don't know what kind of lathe you have but CS has a very nice vacuum adapter with two bearings for $65. I even bought one hoping it would fit the the spindle on my General 260 .... it didn't!
I didn't want to order one of each to find one that may fit and then return the rest. :D My homemade one serves me well.
https://www.woodturnerscatalog.com/p/102/6659/precision-machine-Rotary-Vacuum-Chuck-Adapter?term=precision+machine&term=precision machine

That was part of my original plan, but the ones for Powermatic 3520 lathes are out of stock until January of 2021. Plus, my lathe is a 3520C which, from what I've seen in other adapter listings, takes a different adapter than previous 3520's. At that point I decided to make my own which, except for the cheap, leaky bearings I started with, seems to work ok.

Plus, why buy something when I can make one myself, for twice the cost, half the quality, in triple the time it would take to order and receive one? o_O
 
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Geez, I thought I was the only person that would remember Fire Sign Theater (or at least admit to it).

Mark, you're not alone, because you're not the only one who utters strange phrases like:
"Sure, understanding today's complex world of the future is a little like having bees live in your head. But, there they are."
or
"We know for certain, for instance, for some reason for some time in the beginning there were hot lumps.
Cold and lonely, they whirled noiselessly through the black holes of space. These insignificant lumps came
together to form the first union: our Sun, the heating system."
 
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... my lathe is a 3520C which, from what I've seen in other adapter listings, takes a different adapter than previous 3520's.

I have the adapter from Craft Supplies. I have used it on both my lathe, a 3520C, and a 3520B at the school where I teach.
 
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I have the adapter from Craft Supplies. I have used it on both my lathe, a 3520C, and a 3520B at the school where I teach.

Well, I stand corrected. I only assumed that they were different because I saw one adapter for a 3520B that said it won't work with a3520C.
If I was a patient man, I'd wait until January for them to be in stock again. But, I'm not, so I'll get better bearings for the DIY one I've got and hope it works.
 
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I make a lot of my stuff since I'm a shade tree machinist. This is a picture of my vacuum adapter for my General 260-20.

DSCF9008.JPG

From the left top downward there are two cheap no name sealed bearings. Than the black thing is a grease seal, it was hard to source. Next is a reddish brown hose washer followed by two black "O" rings that seal in the spindle. I've not had any trouble since making it four years ago and I use it a lot.

I should add something about vacuum pump location. Today my Gast quit. Hit the switch and got a hum. First thought was a bad capacitor, but it was good. Next thought was a bad or sticking centrifugal switch. Pulled the end bell off the motor and the switch looked good. Spun the shaft and the rotor was locked. The motor is an open drip proof design. Apparently a wood chip or perhaps corrosion from all the green wood I turn had locked the rotor. I was able to free the rotor and blew it out with air. Tomorrow I'm going to put the pump someplace where it will be impossible for wood chips to come close.
 

Tom Gall

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I make a lot of my stuff since I'm a shade tree machinist. This is a picture of my vacuum adapter for my General 260-20.

View attachment 35398

Apparently a wood chip or perhaps corrosion from all the green wood I turn had locked the rotor. I was able to free the rotor and blew it out with air. Tomorrow I'm going to put the pump someplace where it will be impossible for wood chips to come close.
Good looking adapter, Larry. Do you use an additional fitting to attach your hose not shown in the photo?

That is why I put my pump 15' away from my lathe....also decreases any noise substantially.
 
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