Older GraverMax - Air or Internal Component Issue?

Bob A · Oct 6, 2014

Hi, all - Among my equipment is a smaller compressor (similar to SilentAir) and an older (tan face) Gravermax with 801 hand piece.

When the compressor kicks in, the hand piece behaves strangely. Yesterday I wasn't fast enough and saw it on the microscope.

When the compressor kicks in, the handpiece stops for a second, and when it starts again it throws out 2 or 3 really violent, hard strokes (actually saw them on the scope - shook the stand). It then returns to normal frequency.

I tried adding 25' of hose to try to create an air cushion against what I thought was a compressor air lag problem, but that had no effect.

Is there a component in the older GRS Gravermax units that could cause this? When I inspected it upon receipt, I noticed that the glass inside the interior of the filter was murky, so I'm wondering if past [oil or other] contamination could be the culprit.

Thanks - learning lots from everyone's posts, and I appreciate your sharing. Bob

Marrinan · Oct 6, 2014

I may be mistaken but I think not. The gauge should never allow more air to pass through it than it is set at regardless of on off of compressor. I think either the gauge on the compressor or on the gravermax is misbehaving. Hook it to a friends compressor and see what happens. Or a valve in the max is letting full air in at the kick on and then wrongly reducing airflow afterwards. Fred

dlilazteca · Oct 6, 2014

My graversmith does something similar only once when powering on for the first time

Saludos,

Carlos

fegarex · Oct 6, 2014

What pressure going into the Gravermax do you have? Also what is the pressure at the gauge on the Gravermax itself?

Bob A · Oct 6, 2014

Hi - So, the compressor is at 80, the Gmax at 1.5. In response to another question, however, I noticed something that I'd never noticed before: When I step on the pedal, the needle on the Gmax guage vibrates between 1.5 and 1.0. It happens so fast you have to be looking for it to see it (or perhaps have younger eyes). When the compressor kicks on it drops about another .4 below 1.0 and then surges back. One source would indicate that it was rebuilt in the past (badly) and is missing a small valve. Bob

fegarex · Oct 6, 2014

The small reducer "valve" in the hose is to keep the gauge from fluctuating. It really doesn't affect the operation. It almost sounds like you are losing air somewhere or the compressor is just too small. The gauge should remain the same when the pedal is depressed. Of course this is hard to determine if the reducer wasn't installed.
My advice would be to make sure the hand piece is clean. (don't just check it, clean it) Then check all the hose connections inside and outside of the machine. Perhaps bump the Max gauge pressure up to 1.6 as well.
Rex

Bob A · Oct 7, 2014

Air.... So, the hose connections are dead on air-tight to the Gravermax, but once connected to the Gmax I begin to lose pressure - about 2 lbs per three minute period with no graver activity. There doesn't seem to be anything major coming out of the foot pedal. My (ill advised) assumption to this point was that this was how it was supposed to function. Perhaps that kind of loss is deadly when combined with the smaller compressor?

I'll clean the handpiece and check the piston and sleeve for roundness and wear; if that doesn't do it, it's time for a rebuild. I seem to remember there's a kit somewhere for this that replaces the older fittings, but I can't locate it just yet... Any clues would be appreciated.

Marrinan · Oct 7, 2014

The kit is available through Mitch.

golden forge · Oct 7, 2014

It may be way off base but, is your G-Max and Compressor plugged into the same outlet, or are they on the same circuit breaker?
"When the compressor kicks in, the handpiece stops for a second, and when it starts again it throws out 2 or 3 really violent, hard strokes." When this happens does the motor or even the light on your on off button on your G-Max falter for a split second, or even your bench lights?
Just a thought.:thinking:

Bob A · Oct 13, 2014

Good points by all, and my thanks to all who were able to help. The solution turned out to be:

1. Ordering reducer valve to get rid of irritating needle vibration.
2. Cleaned hand piece, replaced one faulty hose. Improvement in air retention.
3. Moved compressor to different breaker than Gmax. Some improvement during transition.
4. Readjusted the hand piece/foot pedal according to manual. Maybe some improvement in performance.
5. RTFM and emptied tank of water, just like it says on the maintenance schedule. Huge improvement in a variety of ways (air retention, power, etc.) Turns out that this was probably the major culprit.

So, if you have one of the Werther Panther compressors, watch out for any water buildup.

I'm sorta embarrassed to post this, but....

Thanks to all, Bob

mitch · Oct 13, 2014

Bob A said:
So, if you have one of the Werther Panther compressors, watch out for any water buildup.

Werther Panthers are very high quality Italian clones of the vaunted Danish Jun-Airs, right down to many interchangeable parts. iirc, they're actually the top-of-the-line models from the company that mfrs Sil-Air or Silentaire compressors? ANY air compressor needs checked/drained regularly for water in the tank, tho some may be more sensitive to excessive moisture. another reason to have good filtration on your lines, no matter what compressor you're using...

Bob A · Oct 13, 2014

Amen to that, Mitch. Fortunately I have the GRS filter set (water and oil) placed in line additional to the Werther filter and the filters on the GRS and Enset systems so I'm thinking my equipment is ok, but... I felt pretty stupid when when I popped that valve and it started spouting water (no mist!) like a faucet under pressure. I actually had to mop it up, there was so much. I've been amazed at how much water gets removed - I now do it at the beginning and end of every session. Bob

_________________________________________________________________________________________________________________________
To paraphrase Seve Ballesteros response when asked how he four putted at the Masters: "I miss, I miss, I miss, I make".

mitch · Oct 13, 2014

years ago my wife was helping me drain my big general use shop compressor (5hp/30gal Sears Craftsman) and i opened the valve too quickly, she lost her grip on the hose, it slipped out of the milk jug and blasted me in the face with rusty water. she said "I'm really sorry!" and i said, "No, you're not- you're trying not to laugh!" and we both cracked up...

Marrinan · Oct 13, 2014

I have had a lot of compressors in my life. They all had drain plugs in the bottom except 2. One was a home mad compressor put together after the war using a surplus tank off a tank. the other is my Silent Air 50. How does it drain with the relief tube in the top. In fact it has 2. one for auto blow off the other to drain the tank. I live in high humidity and drain about every week. Fred

golden forge · Oct 13, 2014

I have gotten into the habit of draining my compressors at the end of the work day, even with that it still amazes me how much water and rust particles can build up in a relatively short time.

Andrew Biggs · Oct 13, 2014

Hi Bob

Yes......rule number one with all compressors. Drain daily.

Especially small compressors that work harder than larger ones.

Cheers
Andrew

Older GraverMax - Air or Internal Component Issue?

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