Simple Vacuum Table

[donek]

We've been using vacuum tables of this design since before I bought my first CNC in 1999. I've been asked many times how it works, so I made a video to illustrate the construction.

https://lh3.googleusercontent.com/-s674V4soBPs/UdzIgSr9AuI/AAAAAAAAAFw/TTAASqLFQY4/w656-h444-no/SP32-20130709-203312.jpg (http://youtu.be/fOrkvPF0pro)

[Simops]

Sean.....thanks very much for taking the time to do this video ......

Having to cut thin aluminium I'm finding more and more the need for a vacuum table. I would say it is a must as the only way to keep the thin stock flat is to use a lot of screws, which not only is a pain with locating them so you won't hit them but also with some parts I find I have to drill a hole where I don't want one. Also applying Tabs is just not practical with thin stock ally.

So have been studying the Forum for a solution with a Buddy. It's a minefield, especially with finding a suction motor that is cost effective and readily available here in Aus.....easier said then done. Doing the table and plumbing is not an issue but finding a motor is, unless you want to mortgage your house to do it......guys in the States you are really lucky with the choice and competitive pricing you enjoy, something non existent here unless you buy from a local Box store!

So your video and use of a vac has inspired me to continue on with this venture....

Cheers

[myxpykalix]

That video makes me want to go out and buy a dragknife....
Hey does anybody know where i can get a good deal on one?:rolleyes:

Great job Sean...
does having all those holes ever interfere with the dragknife's operation? I know that by now my table is probably off by several thousandths. I'm assuming that might cause it to not cut in certain parts or is it spring loaded?:confused:

[Rob Gunn]

Sean, Thank you so much for doing that video. You showed me more in 10 minutes than what I have been able to find in hours of web and forum searching. There is a lot of good vac table info on the forum but seeing it via a video is a very good tool for us that are a little slow...:D

[donek]

Sean.....thanks very much for taking the time to do this video ......

Having to cut thin aluminium I'm finding more and more the need for a vacuum table. I would say it is a must as the only way to keep the thin stock flat is to use a lot of screws, which not only is a pain with locating them so you won't hit them but also with some parts I find I have to drill a hole where I don't want one. Also applying Tabs is just not practical with thin stock ally.

So have been studying the Forum for a solution with a Buddy. It's a minefield, especially with finding a suction motor that is cost effective and readily available here in Aus.....easier said then done. Doing the table and plumbing is not an issue but finding a motor is, unless you want to mortgage your house to do it......guys in the States you are really lucky with the choice and competitive pricing you enjoy, something non existent here unless you buy from a local Box store!

So your video and use of a vac has inspired me to continue on with this venture....

Cheers

How thick is your aluminum. We cut material that is 0.030. Unfortunately you can't cut all the way through your material on this table surface. It is necessary to produce a use specific spoil board in order to make it happen. I will, at some point, produce a second video on simple, cheap spoil boards and techniques for holding and relocating small parts.

[donek]

That video makes me want to go out and buy a dragknife....
Hey does anybody know where i can get a good deal on one?:rolleyes:

Great job Sean...
does having all those holes ever interfere with the dragknife's operation? I know that by now my table is probably off by several thousandths. I'm assuming that might cause it to not cut in certain parts or is it spring loaded?:confused:

One of the primary reasons we skim the surface of our table every month is to ensure the drag knife will cut all the way through our material, or keep our z cutting at a consistent depth over the whole table. Changes in humidty, can cause the table to move slightly, but our dry climate helps reduce that.

In most materials the holes do not interfere with cutting. To cut really thin material like paper, we place a thin layer of UHWM polyethelene or ABS plastic on our table and drill 1/8in diameter holes in it. This is typically sufficient to hole light materials in place while allowing you to cut them.

[donek]

So have been studying the Forum for a solution with a Buddy. It's a minefield, especially with finding a suction motor that is cost effective and readily available here in Aus.....easier said then done. Doing the table and plumbing is not an issue but finding a motor is, unless you want to mortgage your house to do it......guys in the States you are really lucky with the choice and competitive pricing you enjoy, something non existent here unless you buy from a local Box store!

So your video and use of a vac has inspired me to continue on with this venture....

Cheers

I forgot to mention earlier that any cast off vacuum cleaner will work. It's usually best to remove the filter or bag to get the most suction. There was a time when I had the word out to relatives to never throw away an old vacuum cleaner. The 1 1/4in hose is an industry standard, so you can almost always plug in any vacuum to your table or hold down system.

[Simops]

How thick is your aluminum. We cut material that is 0.030. Unfortunately you can't cut all the way through your material on this table surface. It is necessary to produce a use specific spoil board in order to make it happen. I will, at some point, produce a second video on simple, cheap spoil boards and techniques for holding and relocating small parts.

Sean.....90% of the aluminium I cut is 2mm (5/64")......

Cheers

[Brady Watson]

Neat video, Sean. Thanks for posting.

Those interested in vacuum should check out the BradyVac (http://www.shopbotblog.com/index.php/2006/11/a-removable-vacuum-plenum-that-maximizes-hold-down-potential/). It's just a single sheet of Trupan Ultralight MDF with a grid machined into the back of it. It's a plenum grid & bleeder board all in one! For specific production based high performance vacuum jigs, see the BradyVac II (http://www.shopbotblog.com/index.php/2007/07/the-bradyvac-ii-%E2%80%93-a-production-vacuum-fixture-on-a-shoestring-budget/), which maximizes your hold down potential regardless of your vacuum source.

-B

[donek]

Sean.....90% of the aluminium I cut is 2mm (5/64")......

Cheers

Sounds like a 2 pass cut with an o-flute bit. As long as they fit within a standard cutting area and are large enough, you can easily make a simple spoil board to cut them out. You simply cover the entire table with something thin and cheap. We use 1/8in masonite (also called hardboard - it's used for making concrete forms usually) You don't always get good cuts with this material, but that's not really a big deal. You essentially want to generate a cutout or pocket a bit smaller that the part you intend to cut. This provides a large surface area for holding your material, but allows you to cut slightly into the surrounding material without breaking vacuum. With your thin material, you may experience some sagging into your vacuum pocket. Either drop strips of your masonite into the pocket to support your material or make your pocket a series of pockets.

In many cases, we don't even cut these pockets, we just cut strips of masonite, and tape them together.

https://lh3.googleusercontent.com/-Dj7_apzTKMo/Ud36WYghCSI/AAAAAAAAAGk/vThpSxoW_ak/w1000-h665-no/DSC_0568.JPG

[Simops]

Neat video, Sean. Thanks for posting.

Those interested in vacuum should check out the BradyVac (http://www.shopbotblog.com/index.php/2006/11/a-removable-vacuum-plenum-that-maximizes-hold-down-potential/). It's just a single sheet of Trupan Ultralight MDF with a grid machined into the back of it. It's a plenum grid & bleeder board all in one! For specific production based high performance vacuum jigs, see the BradyVac II (http://www.shopbotblog.com/index.php/2007/07/the-bradyvac-ii-%E2%80%93-a-production-vacuum-fixture-on-a-shoestring-budget/), which maximizes your hold down potential regardless of your vacuum source.

-B

Yes Brady have already checked out the Bradyvac many a times and pretty well what I want to do for the Buddy.....I didn't want to invest in thousands of $$ for a vac motor....only option here is to pay big bucks for purpose vac motors. Hence my interest was aroused again with Sean's use of simple shop vacs. If I could marry up the two...excellent but not sure if that's possible.....suppose could do some experimenting and see where it gets me:rolleyes:

Also Trupan / ultralight MDF is non-existent here in Aus.....not that I could find after months of searching.....tried specialty plywood / MDF suppliers and they just look at me blankly when I ask for Trupan or ultra light MDF. Apparently if I'm interested in importing a shipping container worth they may consider looking into it :eek:. No demand it seems for it here!!!!

Cheers

[donek]

Yes Brady have already checked out the Bradyvac many a times and pretty well what I want to do for the Buddy.....I didn't want to invest in thousands of $$ for a vac motor....only option here is to pay big bucks for purpose vac motors. Hence my interest was aroused again with Sean's use of simple shop vacs. If I could marry up the two...excellent but not sure if that's possible.....suppose could do some experimenting and see where it gets me:rolleyes:

Also Trupan / ultralight MDF is non-existent here in Aus.....not that I could find after months of searching.....tried specialty plywood / MDF suppliers and they just look at me blankly when I ask for Trupan or ultra light MDF. Apparently if I'm interested in importing a shipping container worth they may consider looking into it :eek:. No demand it seems for it here!!!!

Cheers

I would contact the manufacturer here in the US (I assume) and ask who is importing it to Australia. Someone else has to be doing so. Usually the simplest approach is to go straight to the source and get them to tell you where to get it near you. You might also try calling CNC distributors. I know I've been contacted by a couple about carrying the drag knife. They should be able to help you find what you need locally as well.

[Brady Watson]

Mike,
I get a lot of emails from people asking about a "BradyVac setup", when in fact they are erroneously referencing the open source vacuum thread I started years ago (the 9-15 project), that uses Lighthouse brand vacuum motors for a vacuum power plant. Gary Campbell did a nice job creating a multi-vac setup using these motors. Search for 'Black Box Vac Source' to read it. So the point in my posting was to provide some clarity and remind others not to reinvent the wheel or get too confused if they are new to vacuum - but by all means, play, experiment and do your own R&D, like Sean has displayed here.

The whole idea years ago, was to get Fein Turbo III power for around $100 per unit instead of $500-600 USD. The Lighthouse brand motors do this, and you only need 1 or 2 max on a BT to have a serious setup. I know you should be able to get a Fein or Festool unit where you are, but they are a bit pricey.

If you can't find Ultralight where you are...don't give up! Keep looking. Believe it or not there are still plenty of areas in the US that give the same strange look when asked. It is still a specialty item here, and not something that Joe Public is going to get at the local big box store. Trupan comes from Chile and it says Trupan on the edge of the sheet. If you are really stuck with no other possibility for bleeder material, try to get your hands on some Homasote (http://www.homasote.com/products/440-Soundbarrier.aspx?gclid=CJ2IjMG0qLgCFZSi4Aod5xcA1g ) (or similar brand and consistency) sound barrier. Vacuum will pull through it...it's cheap and would be a good sacrificial layer for a number of applications. It would at least 'get you in the game'.

-B

[bleeth]

There is a huge amount of mdf, both regular and "lite" made in New Zealand. You might want to start looking at your end through distributers of NZ made product. But don't freak out about it! Although the best is Ultralite or Trupan if you set up the universal vacuum system (black box-and you don't have to get your motors from Lighthouse either-they are simply a stateside distributor of house vac system parts and I'm sure you can get those motors in Aussie) then regular MDF will work fine. Just skin off the bottom side before you flip it, and flatten the other. It's not quite as good as a bleeder/spoil board but does work fine. I went through a period when local sources of both Ultralite and Trupan were empty with no reasonable date and the difference in holding power was pretty small.

[Bob Eustace]

Brady how long do you think a Festool would last using in 6 hour stinks? They are price y here but seem to last forever doing normal dust collection ($600 to $1250). You do have to swallow hard buying your first unit!

[jerry_stanek]

I run my turbo III's for 3 to 8 hours at a time when doing 3d work Got mine 5 years ago

[Simops]

I run my turbo III's for 3 to 8 hours at a time when doing 3d work Got mine 5 years ago

Jerry....Do you mean this one:
http://www.amazon.com/Fein-9-20-26-15-Gallon-Vacuum-Auto-Start/dp/B001GCVJ56

Cheers

[Simops]

if you set up the universal vacuum system (black box-.

Sorry Dave....just remind me again what you mean by 'black box'?

Cheers

[Brady Watson]

I refuse to buy something that has the word stool in its name. Fein makes good stuff & has a real heritage. These days I run a 3 phase vacuum pump...got it on sale, just like my original Fein. ;)

I logged 170hrs straight on my Fein Turbo III during one job without turning it off. It still runs Fein today :D

Check specs on ANYTHING you are considering buying. There will be some unit conversions that you'll have to do between metric, SAE and others. Knowledge and a little math = power & savings.

FYI - 14.7 psi = 29.92 Hg" atmospheric pressure = max vac in Hg" @ sea level

AND convert inches of water to inches of mercury by dividing by 13.6

-B

[jerry_stanek]

Yes that is like mine only the older style

[Bob Eustace]

Mike I researched Fein in the past and came up with this bunch - $400 to $650 and big jump down from Festool!

http://search.toolhq.com.au/search?SearchTerm=Fein+dust+collector

[Simops]

Mike I researched Fein in the past and came up with this bunch - $400 to $650 and big jump down from Festool!

http://search.toolhq.com.au/search?SearchTerm=Fein+dust+collector

Thanks Bob.....looks like the go .....at least affordable enough to do testing. If it doesn't cut the mustard can always use it as another shop vac;)

I have a Festool 36 vac....great machine but wouldn't like to use it for vac table....too expensive to give it that task!

Cheers

[Simops]

Hey Bob, noticed that the Fein dustlex40 is poorer cousin to the one Jerry suggested....Fein 9-20-26 turbo III .....but after some googling could not find it available herein Aus.....bummer......so typical:rolleyes:

Cheers

[bleeth]

Here is the source thread on Gary's "black box" vacuum design:

http://www.talkshopbot.com/forum/showthread.php?t=11813&page=13

[Brady Watson]

Mike - Contact Ward & tell him you are a 'ShopBot guy' after you have made a choice from the list here: http://www.centralvacuummotor.com/shopbot.htm

You can read up on shipping to AUS here: http://www.centralvacuummotor.com/shipping.htm

"We do ship to Canada, Hawaii, Alaska, Puerto Rico and foreign countries. There will be an extra shipping charge. Shipped USPS Priority Mail International to Canada and Hawaii and Alaska - all other countries we use Express Mail International (1 week service and much better tracking) unless you request another shipping method. For our Canadian customers this avoids extra courier service charges. Deliveries take 10-20 days. Please follow this procedure to make your purchase. Click on "Add to Cart" button. Follow directions and pay. When we ship the item to you we will email you the additional shipping charge. The email will contain a link to an invoice for you to pay using PayPal so you can pay this amount."

For around $100 USD + shipping, you'll have a motor that will have a little less CFM than the Fein T3, but it will pull more vacuum. It's pretty hard to beat for the money. Cheers!

-B

[Simops]

Thanks Brady.....I'll look into it!

The only concern is voltage.....we use 240 @ 50hz.......it's the frequency that worries me as motors running 60 Hz (US) don't like running on 50 Hz (Aus) ..... Slows them down and eventually ruins them.

Cheers

[genek]

Sean.....thanks very much for taking the time to do this video ......

Having to cut thin aluminium I'm finding more and more the need for a vacuum table. I would say it is a must as the only way to keep the thin stock flat is to use a lot of screws, which not only is a pain with locating them so you won't hit them but also with some parts I find I have to drill a hole where I don't want one. Also applying Tabs is just not practical with thin stock ally.

So have been studying the Forum for a solution with a Buddy. It's a minefield, especially with finding a suction motor that is cost effective and readily available here in Aus.....easier said then done. Doing the table and plumbing is not an issue but finding a motor is, unless you want to mortgage your house to do it......guys in the States you are really lucky with the choice and competitive pricing you enjoy, something non existent here unless you buy from a local Box store!

So your video and use of a vac has inspired me to continue on with this venture....

Cheers
Mr. Tavcar, I think I have come up with a way to have a vaccum table on a buddy and a cheap way to have a good vaccum. will have to draw up my plan on the vaccum table for you. but can you get cast iron air compressor that has a screw on air intake. if so take the intake off screw in a pipe make your self a pipe filter if you would like will design the whoe thing for you..
the cast iron air compressor intake will pull 29.9 inches of vaccum.

also a well pump that has a priming port will pull 29.9 inches of vaccum..

let me know if you would like for me to draw this up for you. it is free.

[Simops]

Eugene.......you have me intrigued??? Very kind of you....

If it is not too much trouble I'm sure that there would be other Buddy owners just as intrigued by your idea!

Thanks
Mike

BTW Eugene feel free to call me by first name:)!

[Brady Watson]

http://www.talkshopbot.com/forum/showthread.php?t=5365

-B

[Simops]

http://www.talkshopbot.com/forum/showthread.php?t=5365

-B

Brady,
Been eyeing your Buddy setup (read your link quite a few times)...
Would love to build a similar setup for my Buddy and Gary's Black box with the Lighthouse motors........but I just had another look at the pics of the Lighthouse motors and it says 60 Hz.......that wipes out that idea....pity. Dropped a PM to Ward and see what he says?

Looks like I'm back to either paying $1000s here for vac table motors or sticking to Sean's shopvac solution. (I'll see what Eugene comes up with as well)!

Cheers

[Simops]

Did some more Google searching today for vacuum motors and definitely cannot find Lighthouse motors here but did find the Ametek brand of vacuum motors....
http://www.au.best-price.com/search/landing/query/Vacuum+Motors/s/google/koid/7157584593/?query=Vacuum+Motors&gclid=CMLBpOatrrgCFQThpAodtEQA0A
http://www.electricalresults.com/products/vacuum-motor-ametek-119678
Can't find much info on these as far as specs to compare with the LH ones....
Any one use these or any ideas if suitable as replacement for LH motors?

Cheers

[bleeth]

Here's the Lighthouse link Bob:

http://www.centralvacuummotor.com/lighthouse.htm

[genek]

Vacuum is vacuum no matter what method you use. The problem with vacuum cleaner motor as well as most motors is heat. Electric motors are designed to run at certain rpms and with a certain amount of load.

over loading a motor cause heat build up, under loading cause heat build up.

Most Motors fail because of under load. The back emf builds up and causes the motor to over heat.

as the vacuum system removes the air and nears 29.9 vacuum the motor starts to speed up, (the load on the motor is dropping and thus heating up.

a cast iron compressor or any compressor creates a vacuum on the inlet side. if coupled with a air tank (vacuum tank) on the inlet side you can maintain a 29.9 inches of mercury which in the air conditioning field is near perfect vacuum and will boil water. how I would go about setting this up is get a cast iron air compressor that has a threaded inlet filter system; remove the filter and pipe. screw in a short nipple and enlarge to a 2 inch pipe that goes the the tanks. then from the tank to the bot table with a 2 inch pipe. You do need some sort of filter. small dust particles will end up in your vacuum system which will cause failure at some point in time.

most tables are set up to hold 5 foot wide material. I have a shop bot buddy with the 8 foot stick. which is actually 10 foot long by five foot.

for a six foot stick you can use one five by five and one three by five mdo for your base.
this gets you room all around the top to be able to attach a vacuum manifold. the buddies table only travels so far each way. leaving room for a manifold that can have a flexible hose (needs to be a semi rigid sort of like what they use on rock drills or like a fire truck would use for their suction hose. so that it will not collapse) that will be able to move with the table.
the table set up that Mr. Watson showed is a good way to set the table up or you could use 3/4 mdo as base and cut a pattern of air chambers being careful not to come close to your mounting screws, coat the inside with a wet lock type of paint. (be sure to coat the outside before you mount the mdo. ) then Mount your spoil board.

[genek]

by using a large say 70 gallon or above air tank for a vacuum tank it allows you to use a switch that will shut off the motor when the tank reaches a set vacuum thus allowing the motor to rest or cool off. the larger the tank the longer the motor on and off cycle will be. with vacuum hold down you do not need perfect vacuum pressure. easy way to maintain a good vacuum on ones table is to make sure you do not lose vacuum at any point other than where you cut material through. let say you have a buddy and are running the 6 foot stick. your cutting size is basically 4 x 4. let say you are working on a project that needs only 1 foot by 4 foot. that leaves 3 foot x 4 foot being able to pull air into the system.. you now are not getting a good hold down. simple solution clear plastic sheets like used at construction sites. cut to lay on the top of the table thus blocking air flow.

When I first took over my grandfathers shop. his compressor was a cast iron truck air conditioning compressor with a electric motor attached via pulleys. (the compressor was a rectangular style used on 18 wheelers.)
He used a three inch pipe for the inlet filter. I made the mistake of placing my hand over the inlet. Luckily he was close to turn off the motor. That compressor pulled a blood blister on my hand)

what would a air conditioning compressor cost at a junk yard. maybe 40.00 or less.

a well pump that has a prime port will also pull a vacuum this I found out this spring when I was working on a old farm pump. the pump had a 2 gallon priming tank which you filled with water then started the pump opened the valve and allowed the water to prime the pump till it picked up water from it source. I was trying to find why it would not pick up water so I had the inlet off and started the pump with the prime tank on to see if it was pulling boy was it pulling it pulled my hand tight against the inlet.

talk to a pump expert I bet they could come up with a water pump and vacuum tank that would work till the cows come in.



on anything you do try to use the kiss method..

[Simops]

Here's the Lighthouse link Bob:

http://www.centralvacuummotor.com/lighthouse.htm

Dave....these Lighthouse motors are unsuitable in Aus ( unless Ward can advise otherwise) as rated at 60hz....we use 50 Hz.....if I run a motor meant for 60 Hz on a 50 Hz supply the motor will run 16% slower and overheat.

Cheers

[Simops]

Eugene,

Thanks for that info.....interesting! Will re-read your messages couple more times and look into it. I gather you are not talking about ordinary air compressors are you?

Cheers

[genek]

eugene,

thanks for that info.....interesting! Will re-read your messages couple more times and look into it. I gather you are not talking about ordinary air compressors are you?

Cheers
mr. Tavcar. The air compressors that are cast iron that have a pipe screwed into it for the filter is best, but if you can make a intake manifold you can use one that has bolts for the intake filter. The reason for cast iron is they hold up much better. On you shop air compressor take the filter off, place a piece of card board or wood over it see how much vacuum it has.. Will surprise you. I test my grandfathers old one it will pull 29.9 near perfect vacuum. His was a cast iron auto ac compressor for a 18 wheeler.

My new commercial cast iron compressor sucks a whole in cardboard when i placed it over the filter..
The reason for cast iron is they do not over heat as easy and are belt driven.. So the motor keeps enough of load on it to stop over heating.

[genek]

Go to the junk yard where they have 18 wheeler (tractor trailers) buy a old cast iron compressor, fix it to a motor and foul OR HOOK 12 VOLT OR 24 DC VOLT TO the pulley on the compressor, check out the vacuum that it will produce will surprise you on how well it will pull.

Air compressors and air conditioning compressors are designed and built the same way... They both have intake valves and exhaust valves. They have to pull in the air or freon and pump it out. Both sides valves seat air tight.

How a air conditioning basicly works is it lowers the pressure on the suction side causing the freon to boil and on the compression side it pumps hot the gas and increase the pressure so that the freon when cooled will turn to a liquid.

[rawhide]

sean, would you use your concept on a desktop?

[Brady Watson]

sean, would you use your concept on a desktop?

The bed on the DT comes off...in case that isn't obvious. This opens up more possibilities for plumbing.

-B

[Brian Harnett]

This is a vacuum pump I made from a lawnmower engine I use it on my pin router for templates it averages 25 inches, sometimes 27 when it feels like it.
http://i98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/th_vacuumpump2.jpg (http://i98.photobucket.com/albums/l249/brianharnett/Modified%20and%20Made%20Machines/vacuumpump2.mp4)

[donek]

sean, would you use your concept on a desktop?

I do know of one person who has done it on a desktop, but I have not seen it yet.