Black Box Vac Source

[beacon14]

i'm using two of Gary's original 220V motors mounted to a simple "temporary" plywood box manifold which is connected to my PVC plumbing system (ever since my last Fein gave up). I have the other two motors on the shelf but haven't had time to set up the fancy new four-motor manifold so they are just sitting there as backups right now.

I cut full sheets of melamine and plywood with few problems as long as I take a few steps, like ensuring that no small parts near the edges of the sheet get cut last. I keep small parts away from the edges, make sure the small parts get cut first when there are a mix of small and large parts on the sheet, and try to separate small parts to leave a web of waste around them when necessary.

I also use the two motors to cut solid wood parts down to just a few inches square on a single 24 x 24 zone by nesting them against an "L" shaped fence which is butted to the table stops, covering the rest of the zone with 1/4" one-sided MDF (or anything non-porous), and taping all the seams with blue masking tape. Rigid masking boards work better than plastic sheet to cover the rest of the zone because they provide great resistance to sideways movement of the workpiece. Taping it all together (with the vacuum running) makes the whole thing act as a single workpiece, giving you effectively the surface area of the whole zone to prevent sideways movement.

Using a down-cut bit leaves enough chips packed in the kerf to keep most wood parts from moving or losing too much vacuum, plus it applies downward pressure as it cuts. I can count the number of times I've had to use tabs in the last five years on one hand.

[michael_schwartz]

i'm using two of Gary's original 220V motors mounted to a simple "temporary" plywood box manifold which is connected to my PVC plumbing system (ever since my last Fein gave up).

I can count the number of times I've had to use tabs in the last five years on one hand.

This is really good to hear.

[michael_schwartz]

I also use the two motors to cut solid wood parts down to just a few inches square on a single 24 x 24 zone by nesting them against an "L" shaped fence which is butted to the table stops, covering the rest of the zone with 1/4" one-sided MDF (or anything non-porous), and taping all the seams with blue masking tape..

Thanks. Based on this recommendation, I am going with a 5 zone plenum, rather than 4. I am glad that for whatever reason I bought an extra knife valve. I will add a 24x24 zone.

[beacon14]

Glad to be able to help. Sounds like a good plan.

[sbd1]

Hello everybody. My name is Daren & I'm posting this - my very first post - from my home in western Canada.

First of all, let me say thank you very much to Brady, Gary, David & many others for all the fabulous info you have shared with the rest of us clawing our way up the learning curve. I really admire your commitment to sharing your wisdom, as well as your creativeness & workmanship. I have learned more than just SB stuff from you guys here.

About me. I've had a used, dual-Z, 4x8, PRTalpha for a couple of years, but until recently I haven't been able to spend any real 'quality' time with her. After reading (and re-reading) through this forum for many months (I'm a slow learner) I have started working on my first (and very much desired) vacuum table. I always planned on posting something on the forum someday, it's just that until recently I didn't feel like I understood enough SB terminology to say anything relevant. A few weeks ago I was further inspired by the sense of helpfulness you guys provide in a short Q & A phone call to David about his table design. Now that I've broken the ice here, I hope to be able to do the same as you some day.

I currently have two, 240V, LH7123 vac motors that I'd like to build into a black box like Gary's. I'm not sure yet whether to build the box big enough to possibly expand it up to four motors later, and if I should include a series/parallel valve. I plan on cutting sheet goods in various sizes as well as solid wood parts & I'd appreciate your feedback.

My questions for Gary are:
1) Would you share (or sell me) your black vac box design? I have recently installed eCabs & the SB link trial version, but I have not purchased it. It looks good, but I'm waiting to get more fluent with the SB & eCabs before I invest any more money. I would however gladly accept it from you in eCabs file format (and decipher it from there) should you decide to share it with me.

2) I have read your previous vac motor setup (where you had 2 motors setup with a valve that would switch between series & parallel). But I'm not sure about this black box design. It seems to me like you are only running it in parallel mode. Is that correct?

3) I'm not clear how the integrated check valve works. Could you please explain to me how it operates?

Cheers from frosty Edmonton!
PS. A big thank you also goes out to the ShopBot staff & management who welcomed me with free support when I first called them with my question of "how the heck do I get this to connect with my computer?" This is definitely a business worth supporting.

[garyc]

Daren...
Thanks for the kind word on behalf of myself, David and Brady. Answers to your questions:

1) Yes, I have sent it to others. One note: it requires use of both eCabs and PartWorks to complete as the exact motor geometry was unknown at time of design.

2) This box is parallel only. My testing showed very high temps when connected in series.

3) It is simply a pivoted flapper valve made to mimic the check valve provided to our user group by Brady.

I would recommend using the 4 motors as it will allow you to hold most anything (that is reasonable). Getting the CFM over 400 is the single biggest advantage of this system over most others.

[sbd1]

Thank you for enlightening me Gary.

I think I'll be able to work with your eCabs design. My goal with your drawing is not so much to use it to cut from, but rather as a guide to show me how you directed the airflow. I assume once I see it I will better understand how the flapper valve works. Will you send it to me via email, or is there something I need to do?

I'm glad to hear you think parallel is the way to go, that helps reduce the complexity a little.

[garyc]

Daren..
Send an email to caseworxmfg (at) gmail (dot) com and I will send you the file(s) when I return to Durham.

There is no referrence to the check valve in the files. There is actually more info in the post via the pictures.

[sbd1]

Gary. After looking at your design in eCabs I now understand how the flapper valve separating the two pairs of motors works (doh!). I'm going to build a box like yours (with room for 4 motors) that will allow me to use the 2 motors I have now with a flapper valve & add 2 more later. But I've still got some questions if you're not tired of me yet.

1) I noticed there are a couple of small differences between the eCabs drawing you sent me & the drawing & pics you posted here. I assume the ones you posted here (ie: below) is your revised/preferred design? If so, what is the open cavity used for on the top of the other side? I saw that you used 1 side for the electrical switches.

2) How do you plan to access the motors for service/replacement? Remove an end, then top, then the upper-center fixed shelf above the motors?

3) Do you think it would be beneficial to seal around the vacuum exhaust pipes (through the melamine) with silicone to insure that all of the exhaust is sent out below the box & not coming back into the box? Would it help to keep the motor cooling intake & exhaust air completely separate from the vac exhaust? Perhaps with your open-bottom design this is not important, but I was even thinking that it might be worth adding a vertical, length-wise partition under the middle of the cabinet section to help keep the high-pressure (I assume) vac exhaust from pushing it's way up the lower-pressure (I assume) cooling exhaust.

4) I'm not sure how big of a breaker I need for 4 of theses motors. I believe that they draw up to 6 amps each. So does that mean I should get a 25 amp breaker?

Thanks

[mumeo]

Hello all,

I am also building a box right now, very similar to Gary's design, and thank you very much for all of the information on this forum!

I am putting together a 5 zone system, with a couple of tweaks that I'll detail in the thread I've put together for the build.

http://www.talkshopbot.com/forum/showthread.php?t=14940

For now though, I'm having a little confusion about these vacuum motors...

I see in the black box image that the cooling fans point upward... but where is the inlet for the cooling air? It seems from the picture that that part of the box is completely sealed... is it above? And, is that intake filtered? It seems like it would be a good idea, keep the dust off the cooling fan blades. Maybe with a shopvac filter or something to that effect?

Any help is very much appreciated! Thanks for everything already!