shop-talk
[Top] [All Lists]

Re: Comperssor questions

To: shop-talk@autox.team.net
Subject: Re: Comperssor questions
From: "John T. Blair" <jblair1948@cox.net>
Date: Sun, 12 Sep 2004 10:28:40 -0400
At 06:29 PM 9/11/2004 -0700, Wayne Farrington wrote:

>Is a little squeal at start-up anything to be concerned with?

Not really, but it is an indication that something is a miss.  Check
the alignment of the pullies.  Are they on the same plane?  Check the
motor's mounting plate, try wiggling both the compressor and motor shaft.
One of them could have a little too much end play.  Finally you could try
putting some belt dressing on the belt to get a little better bite on the
pullies.

I'd say don't pry too hard on the motor to tighten the belt.  I'd rather
have a little squeal, then trash the bearings from it being over tightened.

My Craftsman compressor has the motor on a movable plate.  I guess to reduce
the shock on start up.  On day, the compressor threw the belt, and I put
it back on.  As soon as you turned on the compressor it would throw the 
belt again.  I finally started looking at things, and a couple of the spot 
welds where the motor was welded to the base had broken and allowed the
motor to twist so the pullies weren't in alignment.  I rewelded the motor
casing to the plate.  Several years later, the same thing happened.  None
of my welds gave, but some more of the original spot welds failed and the
case for the motor tore.  I disassembled the motor, and rewelded the case
and the case to the plate.  Haven't had any problems for several years now.


>There has been a little oil seepage around the base of the compressor
>for a couple years now. I can't determine for sure where it is coming
>from as it seems uniform around the base of the compressor, just below
>the lower gasket. The oil level is fine, and the oil still looks clean.

Mine does the same thing.  I keep checking the oil level, and it appears
full.  But a couple of months ago, I decided to try and add some oil, it
took quite a bit.  So even if it looks full, every time you check the oil,
try to add some.  You might be supprised how low the oil really is.

>How important is it to change the oil in these things?

Like any mechanical item that needs lubrication.  In fact it's recommended
that you change the oil in your compressor at least once a year.

I've gotten into this discussion about generators also.  Think about your
car.  I change the oil in my cars about every 3,000 mi.  So if I were to
put the car on cruse control at 60 mph it would take 3,000/60 or 50 hr
of running between oil changes.

Now think about your lawn mower.  You should change the oil in your lawn
mower once a year.  Most people mow their lawns once a week for about 6 mo, 
and it takes them about 1 hr to mow.  So that 1 hr /week * 4 wks/mo * 6 mo = 
24 hr of operation.

Based on those 2 examples it looks like oil should be changed about every
24 - 50 hours of operation.

Back to our compressors.  There are many weeks that it gets very little
use.  But there are other weeks that it gets a LOT of use.  So in an 8
hr day, it may run 4 to 6 hrs.  So I'd say that changing the oil at least
once a year is about right, unless you really use your compressor a lot.


John


John T. Blair  WA4OHZ     email:  jblair1948@cox.net
Va. Beach, Va             (eBay id: zebra48-1)
Phone:  (757) 495-8229

          48 TR1800    48 #4 Midget    65 Morgan 4/4 Series V (B1109)
     75 Bricklin SV1 (#0887)    77 Spitfire    71 Saab Sonett III
                       65 Rambler Classic

Morgan:    www.team.net/www/morgan
Bricklin:  www.bricklin.org






<Prev in Thread] Current Thread [Next in Thread>