Vacuum table - if you knew then what you know now.

[dubliner]

I have the opportunity to redo my table which was the standard plenum cut into 2 glued sheets of 120" mdf. I ran 2"pipe for 4 2x4 zones, and planned to tie in the others at some point. Well now I have a a 15hp Regen with 3 or 4 in outlets ( cant remember ) so either I discard all the two inch or get reducers, what would you do? I always like David & Gary's C channel let in between zones, but was it as practical as it seemed? I've spoken to Brady about his table and he milled the plenum into the underside of the spoilboard and uses different ones for different things, diverting all the power to that spot, sounds like a great idea. I never seem to cut the same thing twice so I have to keep that in mind whereas some of you do.So if you wouldn't mind indulging me in your findings and "wish I had done so & so's" I would really appreciate it. I was using the 9-15 up to now and for any new users, let a vacuum table be the first undertaking you make. It will make your life so much easier. Hats off to Brady and all that made it such a good & reasonably priced solution. Thanks Neville & thanks to all at Shopbot for developing my Little Blue Money Maker

[beacon14]

The T-track embedded in my table has come in extremely handy many times and I am very glad I put it there. I do have to remove the spoilboard to use it, which is why I only use it when vacuum just won't do the trick, usually only a couple of times a year. if I'm feeling lazy or only have a small amount of cutting to do I'll hold a scrap sheet of melamine down with the vacuum and screw whatever I need into it.

I think to get the full benefit of your massive blower you'll need to increase the pipe diameter all the way to the table if possible.

[curtiss]

My question would be,

for those who have created the 6 - 8 zone tables, after you were all done for a while, did you later feel you made things more complicated than needed ???

We need a "Shopbot quick poll" box where we can vote on things like this...

Who has the record for the # of zones ?

[fredtoo]

I took Jimmya's advice and went with just 2 zones on my 5x8 table. I just cover up the areas not in use and couldn't be happier. I have a 4x4 sheet of plywood I often throw on top of one of the zones and either screw through my material into the plywood or use some of the tapered paddle clamps I cut out with the bot to secure stuff I don't want to put holes in.

[bleeth]

I have 8 zones and use them from singly to combined sections all the time. Wouldn't have it any other way. It just seemed logical to be able to hold a 2 x 2 when I set it up.

[beacon14]

8 zones here also and would not change it. I like being able to close off whatever I don't need and concentrate all my holding power on one or two zones. I also use masks to cover unused areas but sometimes it's better to be able to just shut off the unneeded zones. I've been able to hold pretty much anything with a flat bottom - including fairly small solid wood parts - without needing custom vacuum jigs.

[myxpykalix]

I have 4 zones and don't use any of them...well hardly ever. I bought 2 feins piped it with cutoffs for four zones but have found that a majority of things i have done is either on the indexer or could be done within a 2x4ft square of the table.
For that i just have a 3x3ft piece of mdf with a 90 degree corner that i put my parts on and screw down scraps of mdf to hold it down and into the corner. Now if i'm going to cut a full sheet of something i might use it but frankly those feins collect more dust on the outside then the inside!

[jerry_stanek]

I have 4 zones and don't use any of them...well hardly ever. I bought 2 feins piped it with cutoffs for four zones but have found that a majority of things i have done is either on the indexer or could be done within a 2x4ft square of the table.
For that i just have a 3x3ft piece of mdf with a 90 degree corner that i put my parts on and screw down scraps of mdf to hold it down and into the corner. Now if i'm going to cut a full sheet of something i might use it but frankly those feins collect more dust on the outside then the inside!

That's your problem Jack the Feins are not supposed to collect dust when you use it as a vac hold down. When I need a T slots I have a 4X8 sheet of MDF with T slots that I just put on top and start my vacs to hold that down.

[ken_rychlik]

Neville,

I think it is more a matter of what YOU cut as to your table needs.

Four zones has been fine for me.

I have a friend that has a different brand machine and has a big three phase blower under his for hold down. I find it very strange that my 2 feins out perform his regen. (doesn't make sense) He has been on the phone with his mfg trying to figure it out, but so far he is still doing poorly with it.

Kenneth

[myxpykalix]

Jerry I was being (fa-zee-shus?) or better yet sarcastic...lol. I have found that most of my work is done on less the 25% of the table. When I put it together I just had to deck it out with all the bells and whistles because that is what i thought was the way i would use it.

I was just not convinced having cut thru the spoilboard many times that any kind of T track was best for me and have used mechanical holddowns more then vacumn. I think I may upgrade some of my fittings on my vacumn and try some different things soon.

edit...I went back and reread your post, let me ask..you say you use a 4x8 sheet of mdf with T track to hold down smaller parts and use your vacumn to hold down the 4x8 right?
What spacing do you have for your T tracks on your 4x8 mdf?

[benchmench]

I have 7 zones on my 5/8 table with 2" plumbing and valves. This allows suction to be directed to any combination of zones from 2x2, 2x4 and 1x4 for board stock.

2 Fine vacuums work very well in most cases by covering any exposed area of the zone with 1/4" melamine. A down-cut bit also helps. When the material won't hold down due to warping or porousity, a few pin nails through the off-all of the work and into the spoilboard usually fixes things well enough to prevent lateral movement. The pin nails hold well and easily pull through the work or spoilboard without messing it up. Ditto if the router hits one - no real damage to the bit.

[Gary Campbell]

Neville...
After about 3 or 4 different versions of plenums, I am back to basics with 4 zones. I did put a twist on the "standard" zone valving tho...

My latest column: http://www.shopbotblog.com/index.php/2010/07/the-k-i-s-s-vacuum-manifold/

We lost our ability to purchase the "big regen", so we are in the process of building a system around 4 of the Lighthouse brand conical impeller pumps. These have over 11 inHg and 150 cfm each.

We are going to mount these in an enclosure to reduce noise and allow relay switching for either 2 or 4 depending on vacuum requirments. The 2 pairs will be separated by a check valve (Thanks Brady!) and controlled by an adjustable vac switch. The enclosure has separate baffled chambers for intake and exhaust cooling air along with exhaust vacuum evacuated air.

This will give us close to 600 cfm, 50% more than our previous combination, and over 11 inches max vac. The vac numbers alone are good, but the graph shows 15-20% higher vac at our normal cutting cfm. These motors may turn out to be the best under $1K vac setup yet.

So now you know what I would do differently! ;)

[gc3]

My question would be,

for those who have created the 6 - 8 zone tables, after you were all done for a while, did you later feel you made things more complicated than needed ???

We need a "Shopbot quick poll" box where we can vote on things like this...

Who has the record for the # of zones ?

maybe I or should it be me

as I have none

no zones

only screw holes in the....

so I vote for 0 Zones

which work well with no ahhhh problems?

[Brady Watson]

Since I don't cut sheet parts every day, I use 1 big zone - a BradyVac I, which is just a sheet of Trupan with a grid milled into it & flipped over. It holds down all but the most 'tater-chipped' sheets.

I voted against a dedicated vacuum grid on my machine since I get a lot of weird or exotic projects in my shop that often require me to bolt, screw or otherwise clamp the material down, which would really hamper the flexibility of my machine. 8 countersunk screws hold my BradyVac I down, plus some tape around the edges to keep the vac in.

My methods are probably a lot different than most of you in terms of how I work with vacuum. I've found that you really don't need a lot of vacuum for most things - rather, you need to use the vacuum that you do have more efficiently. I have standardized a few removable grids that I use for about 90% of the cutting that requires vacuum. I've got a 4X8, 4X4, 2X3, 6" X 8' & 6" X 4'. These sizes let me direct all the vacuum I have to these specific areas - rather than going overkill with a big pump or asking the 4X8 grid to be a 'one size fits all' - it doesn't fit smaller sized material well at all.

Stay tuned....I've got a method up my sleeve to aid in holding down very small, tightly nested parts - even if you are using a single Fein or Lighthouse motor...It's one way I steal jobs away from the shops that run 'big iron' ;)

-B

[gc3]

[QUOTE=bradywatson;98091]Since I don't cut sheet parts every day, I use 1 big zone - a BradyVac I, which is just a sheet of Trupan with a grid milled into it & flipped over. It holds down all but the most 'tater-chipped' sheets.

I voted against a dedicated vacuum grid on my machine since I get a lot of weird or exotic projects in my shop that often require me to bolt, screw or otherwise clamp the material down, which would really hamper the flexibility of my machine. 8 countersunk screws hold my BradyVac I down, plus some tape around the edges to keep the vac in.

My methods are probably a lot different than most of you in terms of how I work with vacuum. I've found that you really don't need a lot of vacuum for most things - rather, you need to use the vacuum that you do have more efficiently. I have standardized a few removable grids that I use for about 90% of the cutting that requires vacuum. I've got a 4X8, 4X4, 2X3, 6" X 8' & 6" X 4'. These sizes let me direct all the vacuum I have to these specific areas - rather than going overkill with a big pump or asking the 4X8 grid to be a 'one size fits all' - it doesn't fit smaller sized material well at all.

Stay tuned....I've got a method up my sleeve to aid in holding down very small, tightly nested parts - even if you are using a single Fein or Lighthouse motor...It's one way I steal jobs away from the shops that run 'big iron' ;)

Great to see you are busy..."Big Iron" shops are many on the "dump it quick" sites... IRS,XFACTORY among others...tough to see these mails...
so small shop ideas are always welcome.

[dlcw]

I've had a 4-zone setup since day one using a Lighthouse motor for each zone. They can be turned on and off individually when needed. For doing smaller parts - carvings, etc. - I screw the material to a piece of MDO that is just a little bigger then one zone. I place the MDO on the board and turn on the one zone. The MDO's not going anywhere and the screwed down part isn't going anywhere. With this config I have no screw holes in my spoil board.

I did recently cut over 200 4.25" circles from 1/4" MDF and not one of the circles moved during cutting. MDF and a compression bit are great at packing chips and sawdust into the cut so nothing moves around.

In the future, I may get additional motors and figure out a way I can switch them into series or parallel "circuits" with the existing 4 zones to add more hold down capability (i.e. - lots of small parts). At 2500' altitude there is a drop in vacuum capability so I have to make it up in other ways.

I used the Lighthouse "mufflers" on my motors and it helped alot to reduce the noise. Quieter then my ShopVac brand vacuum cleaner but a lot noisier then the Fein vac.

All in all I've been very happy with my setup. The spoil board is glued to the plenum. As I surface it it gets to the point that I just grind it all off and put on a new spoil board. I get 5x10 sheets (my table is 96x60) of 1/2" Trupan and cut it to match the 4 plenum zones. I then edge band each board with melamine edgebanding to seal the edges.