Vacuum table option?

[chodges]

I have found a 20 hp squirrel cage blower at a local salvage yard.

Would that be appropriate to use as the basis for a 4' x 8' 4-zone vacuum table setup?

Thanks!

[Brady Watson]

No. It won't generate enough negative pressure to give you suction/hold down power. It would be similar to using a dust collector as a vacuum source. The impeller to housing clearance is too big to generate usable pressure, even though it puts out a lot of air flow.

-B

[steve_g]

Charlie:

The average HVAC system is designed to operate at about .5 inches of static pressure. I believe that converts to .018PSI or .0367 inches HG, not nearly enough for material hold down, but... 20 hp! that might even make my Texas shop feel comfortable, It'll move a lot of air!

Steve

[srwtlc]

A squirrel on steroids! :eek:

That would make a great whole shop air scrubber. Build a tower on casters and put a bunch of furnace filters in it or line it with dust collector fabric. Or a sanding table/air scrubber.

[geneb]

Not only will the filters help keep the dust down, but it'll keep it from clogging with employees. :D

g.

[steve_g]

I hate it when the employees start clogging... I much prefer a waltz .:D

[bleeth]

I have had enough of issues with employees waltzing around. I need them doing the jump!

[Brady Watson]

I hate it when the employees start clogging... I much prefer a waltz .:D

*smacks forehead*... :rolleyes:

:D

-B

[CNYDWW]

I can't wait to see the first 3D clog made on a SB. On a different and more pertinent note. Would a larger dust collection unit provide enough vacuum to hold ply flat. Not asking if it'll be enough to withstand any amount of cutting force but enough to flatten the sheet while cutting with other hold down means applied to the edges.

[steve_g]

Randy:

My 3hp Oneida DC will develop about 17" of static pressure with all gates closed. I tried to use it to hold small plastic parts (2"X3" acrylic) in place with a fully gasketed plenum. I was only successful when I used tabs to hold all parts together as a unit. It might take a slight bow out of a sheet of plywood... but I wouldn't count on it.

Steve

[Brady Watson]

My 3hp Oneida DC will develop about 17" of static pressure with all gates closed.

17" of water = 1.2 Hg" = 0.58 lbs/sqft

You really need a bare minimum of 5" Hg to do anything worth while.

-B

[CNYDWW]

Thanks for the info guys. I was looking just to do periodic pieces of ply. Most of my work is mill work and signs not as much casework. I usually only need a few clamping hold downs. Maybe one of the larger Rigid or ShopVac units will do for now.

Thanks Again
Randy

[Brady Watson]

Randy,
There is a ton of info on here about making your own vac hold down system on the cheap. You could have a decent vac system for under $200 including vac motor and bleeder - Lighthouse motor + BradyVac I.

Search the board & you'll get a TON of info...

-B

[CNYDWW]

Thanks Brady

Sometimes a TON of info is too much. I'm often forced to do things on the cheap side which i don't like. That's mainly the reason i like to find most of what i need locally. Much easier to get replaced when i does go down. I've already got a vac plenum in the table with four zones that is setup for 5' x 9'. I'm going to cut it down by sealing off what i don't need with a permanent gasket. Depending on what vac setup i do get i may just limit it to two zones for the purpose stated. For now i'll use this plenum. Over the winter when things slow down and i move into snow removal i'm going to rebuild the bed with some modifications. I have been on the Lighthouse website but the first religious quote made me shut it down without looking too much in depth. I am planning on setting up a BradyVac system with the rebuild.

Thanks Again
Randy

[Brady Watson]

I have been on the Lighthouse website but the first religious quote made me shut it down without looking too much in depth.


Yeah. I know. :rolleyes:

BUT...he sells a good product at a good price & is a nice man to talk to on the phone if you need support. I've never experienced any evangelizing - it's always been 100% professional from a business standpoint.

Alternatively you can spend a bit more on a good quality vacuum pump that isn't screaming @ 20,000+ RPM - and generally provide more airflow and better overall efficiency. There's LOTS of used pumps out there at a fraction of what you'd pay new. If you know what you are looking for, then you can get a good deal. The limiting factor being what type of power you have at your shop. 3 phase is king...

-B

[srwtlc]

I have been on the Lighthouse website but the first religious quote made me shut it down without looking too much in depth. I am planning on setting

Hmmm... Tolerance for all EXCEPT Christianity?? Can't even stand to see a man's faith - even if he isn't speaking directly to you face to face?

[CNYDWW]

Hmmm... Tolerance for all EXCEPT Christianity?? Can't even stand to see a man's faith - even if he isn't speaking directly to you face to face?

I don't have much tolerance for anyone pushing something in my face like politics or religion. I don't care if they dance naked around a fire at the summer solstice or sit in a pew every sunday. I'm not doubting the man or the "mission" I just don't want to see it and i believe it should be private.

"Thou shall keep thy religion to thyself" George Carlin

[steve_g]

Last weekend I was eating at a restaurant when a Very large gentleman was seated across from us. He was unhappy and obnoxious about every thing... a straw wrapper on the floor under the table, a swirl mark on the table from the wipe down cleaning, a knife that didn't shine bright enough, the menu offerings were not satisfactory... every thing he ordered was with special instructions... When his food arrived and after adjustments were made to satisfy his demanding personality, he bowed his head and thanked God for the food LOUDLY enoughfor the entire restaurant.

I was embarrassed... because he wasn't.

I don't mind a scripture verse on a web site or even a humble prayer offered in a restaurant... but when you do, remember... you have just said "look at me" and now your every action is seen in that light.

Steve

[CNYDWW]

Yeah. I know. :rolleyes:

BUT...he sells a good product at a good price & is a nice man to talk to on the phone if you need support. I've never experienced any evangelizing - it's always been 100% professional from a business standpoint.

Alternatively you can spend a bit more on a good quality vacuum pump that isn't screaming @ 20,000+ RPM - and generally provide more airflow and better overall efficiency. There's LOTS of used pumps out there at a fraction of what you'd pay new. If you know what you are looking for, then you can get a good deal. The limiting factor being what type of power you have at your shop. 3 phase is king...

-B
I wont have 3 phase till the lease is up on this shop. In this "Hamlet" they wont let the power company bring it in. Only reason i can run my shop here is because there's an old sawmill on the property that was under operation prior to codes enforcement in the town.

[myxpykalix]

At least it wasn't a muslim call to jihad! lol:eek:

On the vacumn front, i have installed 2 feins with a 4 zone system but unless i am cutting something like plywood that covers all 4 zones I don't trust it to not move. Maybe its just me.

But because most of what i do on the table covers only 25% of the surface and it is maybe a carving that is going to take 4-6 hours I feel more comfortable mechanically holding the material to the table instead. Also you aren'r running these motors for all those hours using lots of electricity.

I would suggest you use a combination of some of the solutions here both vacumn and mechanical hold downs. I don't think vacumn is the solution for all situations.

For smaller stuff I have a mdf jig with a 90 degree corner that i put smaller stuff on and take scraps of mdf and screw it down to butt it up against the corner aand hold down.:D

[curtiss]

Vacuum calculator in torrs, pascals, atm, mbars.... :confused::confused:

& other stuff

http://www.anver.com/document/company/Reference%20Guides/vacuum.html

[billp]

Great link Curtis, Thanks !

[Brady Watson]

Yeah - thanks for the reminder, Curtis.

Anver makes some really nice high quality stuff - It's worth a looksy on their site when you're done making calculations.

-B

[2Egress Sound & Design]

I bought two motors from Lighthouse and had some questions and Ward is a 100% stand-up guy. Called me several times just to check on me and make sure everything worked. No evangelizing either. He apparently has strong beliefs and he does a better customer service job than many others I have dealt with. Cut the guy a break.
Everyone believes in something. :) most of us used to believe in Santa Claus, Easter Bunny and most painful of all was the tooth fairy! (Sorry to shock some of you if some of you still rip out your teeth for a few bucks under your pillow!)

[pappybaynes]

Well, it's great to live in a country where everyone can express their views...if you think you are right, your right...if YOU think someone or something is wrong, your right again!

[myxpykalix]

Brock,
"most of us used to believe in Santa Claus,..."

Use to?, Use to? Please don't tell me he's not real!:eek: :rolleyes:

[utahfab]

If anyone's interested, I have a 25hp FPZ for sale. 300cfm @ 13.6"hg. Comes with the filter, safety valve, starter & misc PVC & steel conduit plumbing. Retail is around $9k. $4,000 and it's like new. Located in SLC, Utah, I'd deliver or meet someone within a reasonable distance. Contact me for photos. Thanks, Billy

[fozzyber]

Brock,
"most of us used to believe in Santa Claus,..."

Use to?, Use to? Please don't tell me he's not real!:eek: :rolleyes:

I believe, I'll have a drink before I go to bed.....:):)