Mechanical Music Digest  Archives
You Are Not Logged In Login/Get New Account
Please Log In. Accounts are free!
Logged In users are granted additional features including a more current version of the Archives and a simplified process for submitting articles.
Home Archives Calendar Gallery Store Links Info
MMD > Archives > February 2009 > 2009.02.11 > 05Prev  Next


Adjustable Vacuum Source for Testing
By Pat DeWitt

Hi All,  For a steady, dependable vacuum source I use a tank-type
vacuum cleaner with about twenty feet of hose so I can minimize the
noise by "hiding" it far enough away in a nearby room for which I can
close the door.  (I used to use a spare Ampico pump but I found the
sweeper to be much better.)  I bought a piece of corrugated plastic
sump pump hose to make up the long length, but spare vacuum cleaner
hoses are sometimes available at Goodwill or Salvation Army stores
and they can be spliced together.

The most important feature of this arrangement is an in-line port for
varying the vacuum.  To make this I took a 1-foot piece of 1-1/2" PVC
pipe (size it so your hose fits tightly inside) and cut a 4" long,
narrow, tapered hole in the side, similar in principle to the hole
used on a typical tempo slide valve.  The hole is about 1/8" wide at
the small end and about 1" wide at the large end, and runs parallel to
the length of the pipe.  I covered this hole with an adjustable slider
made from a small piece of PVC cut out from the next larger size pipe.
This piece was made just large enough to cover the hole and was held in
place with a piece of 12 gage copper wire wrapped around the pipe.

In use, I hook up the device to be tested, turn on the sweeper, and
move the slider along the pipe, exposing some of the hole, until my
water manometer reads the correct vacuum that I need for the test.
(Note: The air rushing into the slider hole is noisy so this pipe
also needs to be located as far away from your testing site as is
practical.)  I also plug my sweeper into an extension cord with a foot
operated switch so I can turn the vacuum source on and off from my
workbench.

Pat DeWitt
Fort Wayne, Indiana


(Message sent Thu 12 Feb 2009, 02:33:49 GMT, from time zone GMT-0500.)

Key Words in Subject:  Adjustable, Source, Testing, Vacuum

Home    Archives    Calendar    Gallery    Store    Links    Info   


Enter text below to search the MMD Website with Google



CONTACT FORM: Click HERE to write to the editor, or to post a message about Mechanical Musical Instruments to the MMD

Unless otherwise noted, all opinions are those of the individual authors and may not represent those of the editors. Compilation copyright 1995-2024 by Jody Kravitz.

Please read our Republication Policy before copying information from or creating links to this web site.

Click HERE to contact the webmaster regarding problems with the website.

Please support publication of the MMD by donating online

Please Support Publication of the MMD with your Generous Donation

Pay via PayPal

No PayPal account required

                                     
Translate This Page