PDA

View Full Version : Compressor Grenaded



Bob La Londe
04-16-2018, 05:38 PM
I haven't taken it apart to see exactly what the problem is, but its four years old. A full year out of warranty.

An hour or so ago it started making an awful racket. It sounded suspiciously like it threw a rod. I shut it down along with all the machines dependent on it.

Diagnostic step one. I looked at the oil sight glass, and it showed just below center. Figuring to see how much of its guts poured out I cut the top off a soda can to catch the oil and pulled the plug. Nothing came out.

Blink!!! Blink!!!

I looked at the sight glass again. The oil level looked the same. I stuck an air nozzle in the drain hole (turned off the compressor, but left the valve open) and blew thinking maybe it was plugged. A very little oil came out and several chunks of metal.

I check the sight glass almost every day when I start up the air for the shop. It never changed. I wonder how long it was running with virtually no oil.

Well, I'm off to buy a new pump for it. I can't run without air.

A.K. Boomer
04-16-2018, 05:47 PM
Bogus adventure dude, that really sucks :(

CCWKen
04-16-2018, 06:11 PM
Bummer.

So is the sight glass stained? Why was it showing full of oil?

Bob La Londe
04-16-2018, 06:28 PM
The sight glass appears to "hold" a little oil in front of the sighting target.

Willy
04-16-2018, 06:35 PM
Bummer.

So is the sight glass stained? Why was it showing full of oil?

This plus where did the oil go. Was it leaking or did it blow past the rings?
When was the last oil change? I change mine once a year and it has never needed any between changes. Just wondering if it just started using a lot of oil recently that you weren't aware of.

chipmaker4130
04-16-2018, 07:11 PM
Chinese POS? A friend had a chicom lathe with oil sight glasses that were sealed, and filled to the 'proper' level with oil! Saw it myself. This was a '90s era lathe, don't know where he got it.

vpt
04-16-2018, 09:14 PM
Chinese POS? A friend had a chicom lathe with oil sight glasses that were sealed, and filled to the 'proper' level with oil! Saw it myself. This was a '90s era lathe, don't know where he got it.


That is funny.

Robin R
04-16-2018, 09:38 PM
That is funny.

Not if it was your lathe.

danlb
04-16-2018, 09:44 PM
Chinese POS? A friend had a chicom lathe with oil sight glasses that were sealed, and filled to the 'proper' level with oil! Saw it myself. This was a '90s era lathe, don't know where he got it.

It reminds me of a tale about a cheap, popular car of Indian manufacture that was cloned in china. The clone was a very good copy of everything that the engineers could observe and measure, right down to every design flaw.

In this case it sounds like someone observed, measured and documented " 1 round glass window showing oil level" on the drawings. Bet you the oil stuck in that window was always level.

:)

Dan

JoeLee
04-16-2018, 10:12 PM
Bummer.

So is the sight glass stained? Why was it showing full of oil? I've seen that before, but still it shouldn't have used all that oil.

JL...............

reggie_obe
04-16-2018, 10:12 PM
That is funny.


Not if it was your lathe.

Take heed dude. Time to change the compressor oil at the VPT shop.

vpt
04-17-2018, 07:20 AM
Take heed dude. Time to change the compressor oil at the VPT shop.


I just mentioned I haven't changed mine yet because it is full and clean. However mine has a dipstick not a sight glass. :D But yes it is time to change the oil!

wdtom44
04-17-2018, 09:24 AM
Are you getting the same compressor as you are replacing? If so what are you going to do to it to make sure the same thing doesn't happen again?

3 Phase Lightbulb
04-17-2018, 09:27 AM
That reminds me, I should change mine. I know it has enough oil but I think it's the same oil I put into her when I bought her back in 2005. She probably only has ~5 hours of actual on time (if that) but I'm sure after ~13 years the oil is probably ready for a change.

Bob La Londe
04-17-2018, 09:41 AM
Are you getting the same compressor as you are replacing? If so what are you going to do to it to make sure the same thing doesn't happen again?

Nope. Just bought a pump. Motor and tank are fine. Longer stroke slower turning bigger pulley different brand pump. Glass faces out and will definitely make sure it doesn't trap oil like the old one. I have to do a bit of work to use the new pump. It does not bolt right up. I'll need to make an extended mounting plate. Picked up the misc fittings to hook it up last night. When I finish my coffee I'll head out to the shop and get started. I would bet money I'll have it done before noon and be running jobs this afternoon.

The new pump is rated 10PSI lower. 145 instead of 155. I'll see if that is an issue. I never had an issue with air before. Typical cycle time with 3 or 4 machines running (3 have air seal spindles, one has an air brake, and the new one has an air operated tool changer) has been about 45 minutes. If it drops to 30 minutes I don't think that will be much of an issue. Lots of shops I've been in have compressors cycling on a lot more often than that. That and the noise is why they put them outside. In case it will give me a good reason to chase down my various air leaks I've been ignoring.

I really need to upgrade to a 2 stage 175psi compressor, but as with all things in life its a choice. New compressor or new carpet for my bass boat. New compressor or a new hunting rifle. New compressor or a new spindle for a machine. New compressor or a load of aluminum for the next round of jobs. New compressor or that AC/DC pulse TIG machine I've been lusting after.

enginuity
04-17-2018, 10:14 AM
I really need to upgrade to a 2 stage 175psi compressor, but as with all things in life its a choice. New compressor or new carpet for my bass boat. New compressor or a new hunting rifle. New compressor or a new spindle for a machine. New compressor or a load of aluminum for the next round of jobs. New compressor or that AC/DC pulse TIG machine I've been lusting after.

I hear you Bob.

If I was running a shop though I would seriously consider an oil injected rotary screw. Yes they are more money than a piston compressor but they are so quiet (like 65 dB) and are rated for 100% duty. The noise of an loud air compressor drives me bonkers. Here is a 5hp (16 scfm) single phase rotary injected screw that I'm told is reasonably priced:

http://www.dvcompressors.com/wp-content/uploads/2015/08/A5T-400px.png

http://www.dvcompressors.com/air-compressors/rotary-screw-air-compressors/a5t-apache/

You can get fancier ones with VFDs that modulate with the demand. But the simple on offs are still super nice.

Bob La Londe
04-17-2018, 10:46 PM
I finally got the new pump installed. Had to make a mounting plate, then drill and tap for the new pump, then chase down the fittings, and finally take the check valve out 4 times to try and repair it. Finally I did the stupid easy o-ring repair. I know it won't last, but it should last until I get a new check valve atleast. The plunger on the check valve looks like PEEK. Kind of overkill for only 155 PSI.

velocette
04-17-2018, 10:56 PM
Hi Bob
" In case it will give me a good reason to chase down my various air leaks I've been ignoring". This is one way to save on power wasted and save for your hobbies from being neglected. The results will tell the full story.