A Tag-Team Four-Motor Vacuum Setup

      A shop owner describes how he ganged four 240-volt motors onto one vacuum system to get the suction he needed within the power limitations at his shop. January 5, 2010

Reprinted with permission from ShopBot CNC Tools.

By Gary Campbell, Islamorada Woodworks, October 2nd, 2008

While waiting for our shipping date to arrive, my son and I, like most new users, agonized over all the details of electrical, vacuum, placement and layout of all the items necessary to running our Bot. We probably read every post on the TalkShopBot Forum concerning vacuum going back to 2005. After asking a few questions, we decided we wanted a 15 HP regen blower, or ring compressor. After a quick call to our electrician, we found that it would cost over $10,000 to get 3 phase power to our building and install a new panel. Add that to the cost of the blower and it didn’t take long to put that decision aside. What we decided to do was install every other component of that system that we could, and use a less expensive vacuum source.

We used 4 Ametek vacuum replacement motors, purchased from Grainger. We selected a 240v model that had 7.5” Hg and 110 cfm. All the motors that were 240v and higher numbers were much more money. We probably could have saved a few bucks by going to 120v motors, but these motors only draw 4.2 amps and the 120v versions drew 10 or above. This way all 4 vac motors can run on one 240v 20A circuit. The motors were installed by drilling and recessing carriage bolts down thru the table, similar to the way that the table board is installed to the machine frame. Long 1/4" bolts were used and they had a washer and nut installed at the bottom of the table board to keep from turning. A mounting plate made from PVC holds the motor up in place by using nyloc nuts and washers. A strip of 1/8" by 1/4" wide AllStar adhesive back gasket was placed around the mounting face of the motor to seal it to the table.

The control system uses 4 DPST switches, 1 for each motor. Since it is all one circuit, I was able to use a #12awg pigtail and plug into a 240v 20A receptacle. It is my intent to use these switches to control either air or electric operated valves when we can get the large blower. I also drilled and tapped a hole in each zone, near the vac inlet, and installed a fitting and tubing that runs to a vacuum gauge in the control box. This allows us to monitor each zone for vacuum while cutting, which, I feel is a very good feature.

After using this system for 7 or 8 months here are my thoughts, both for and against:

For:

* Price... OK... under what a couple Feins cost with higher flow numbers

* You save on all that plumbing cost and work also... no ball valves to replace

* Easy to control and eye level gauges are a plus

* Using thin Plexi for a zone mask keeps cutting vacuum around 5-6’Hg, anything below 3” smaller parts will start to move.

* With a couple relays, it could easily be controlled by the SB control box using unused outputs if available.

* Gives a relatively simple, neat clean installation; doesn’t use room under the table.

Against:

* If I were to use this as a permanent system, I would work on sound deadening. Even though it is not as noisy as a regen, 4 unmuffled shop vac motors are NOISY!!

* There is no filtration in the system. We have not found this to be a problem yet, but I should mention it. The motors have a steel housing and impeller it may never be a problem.

Vacuum gauges and controls. Detail of vacuum motor mount: 4 motors mounted under table.

Reprinted with permission from ShopBot CNC Tools.



Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?


Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Knowledge Base

  • KnowledgeBase: Dust Collection, Safety, Plant Management

  • KnowledgeBase: Dust Collection, Safety, Plant Management: General


    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.



    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2016 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB











  • WOODWEB - the leading resource for professional woodworkers


      Home » Knowledge Base » Knowledge Base Article