Fein Vacuum

[neal_meyers_jr]

I am in the process of purchasing a ShopBot and I am reading/researching a lot about how to set up and use my new Bot.

My question is this: Will the Fein vac that ShopBot sells work as the vacuum source for the hold down table? I am going to make up an 8 zone (David Buchsbaum) table and from what I've been reading: I make up the base table out of MDF and then place a clean sheet of MDF on top, sealed with silicone.

I know that shop vacs will not work for the vacuum source, due to the vac needing air flow to cool the motor, and working from my garage I do not have access to 240v 3 phase. I know of phase converters, but the expense of this and the larger vacuum systems is just out of reach at this time. I really liked the system that Gary Campbell built and that may be an option in the future, but 4 vacuum motors and the required power is just not an option at this time.

So Thank ya'll for any and all help and suggestions.
Neal Meyers Jr
Euharlee Woodshop
White Ga.

[bleeth]

Neal: Some use 1 Fein and some use 2. I am sure a couple Fein users will chime in with their thoughts.
For the first layer of your table base I suggest as a minimum 3/4" plywood ( of a relatively decent flat grade and not mdf), and mine has a sheet of laminate on the bottom as air leakage "insurance". If the extra money is not an issue you may want to use 3/4 PVC. The vac plenum itself is usually regular mdf and you can glue it to the base with yellow glue, silicone, PVA adhesive, or whatever. After you cut your plenum seal it all very well. 2 coats of shellac is easy to apply, quick drying, and works well. Check the down limit of your router/spindle to make sure you are reaching where you will need to reach. since your spoilboard can easily end up as thin as 1/4" before you end up replacing or going over it with a new one you want to make sure that for the type of cutting you will do the bit will reach that low. I suggest using a small diameter shorter bit as your standard as no matter what you plan on cutting you may end up needing that at some point. On mine I have a double base under the plenum but my machine is customized and the base support is further from the spindle then the current PRS.

[Kworks]

Neil: I surfaced a 4' dia. cherry table top today. I attached the top to a 4x4 sheet of melamean(sp). The top was set back about 8" from the front of the shopbot to give room to run the bit past the edge, so about 80% of zones 1 &2 were covered, the Fein Vac pulled the top flat and I was able get a good clean cut (only .05 deep). Cutting sheet goods or attaching parts to a sheet has worked well for me with the 110v fein.

[knight_toolworks]

myself I would not make 8 zones it is overkill and costs too much and may lower your vac. What I started doing is cutting my spoilboard stock into 4 pieces say 48.25x24.25 and I will use yellow glue on the inside cuts to seal them then glue each piece down one at a time. it ie easier the dealing with a full sheet and it isolates the zones.
also if you have 220 getting separate 220 vac motors and making a box for them will give you quite a bit more suction for about 1/2 the price of one fein. but you will have more noise.

[waterwheelman]

I started out using two shopvacs for my shopbot hold-down. The best I could get was about 3-4 "Hg. I then went to a single Fein III vac and was able to get about 7 "Hg. I have installed two Central vac motors in parallel about a year ago. I can now hold matterial more reliably with an average vac of about 12-18 "Hg. I agree with Steve the noise is definitely greater, but I have the option of having the vac motors in a seperate room with the vac plumbed to the Shopbot table. The cost with plumbing was about $400.00

[tracys]

David,

What brand or model of central vac motor did you use?

[waterwheelman]

Tracy,

The two vacuum motors I used were model LH7123-13 from Lighthouse Industries. Mine are mounted on a wall in a room seperate from my ShopBot. They are not enclosed, because they develope heat. If they where enclosed in a box they would burn out like some have experienced.

[bob_s]

Some folks have mounted them in a box --WITH COOLING circulation- to cut down on the noise. I just decided to mount them ON a box to use the box as a manifold. Be sure to add some internal bracing, as I had built a nice box 12x22x6 with a 1/2 inch bottom that got sucked right in when I ran the pumps with very little inflow. It now has a 3/4 bottom and some internal supports - will hold up 2 elephants easily! It is the easiest way to combine the vacuums, I have now added a switch to cut out one if I am only using a small area of table surface. Gary Campbell put up some really nice designs for a "black box Vacuum system" that is really state of the art if you want to what is possible with these things.

[fredtoo]

I have two Feins and originally had plans for a multi-zone vacuum before Jimmy A suggested just 2 zones for my 8' x 5' table. I use PVC, coroplast, masonite, whatever to cover the open areas and I'm happy with the results (and the lack of plumbing!).