Help, please: Gravermeister/915 handpiece running HOT(SOLVED)

[Imageraj]

Hello, I am a beginner in engraving and recently acquired an (un)used Gravermeister with less than 100 hours use on it. It’s probably 35 years old (800-1200 SPM) and was stored in dry California climate so looks almost new (see picture). After talking with GRS, I purchased a new 915 handpiece that came with a new air hose. The handpiece tends to get very hot only after 30 minutes of use. I tuned the handpiece per instructions and running the Gravermeister around 1000 SPM. The oil level is little below the level mark. Is there a way to fix this overheating problem? Thanks in advance for your help and suggestions. I am enjoying learning engraving and the air assist is very helpful in reducing my learning curve.

 

[John B.]

First thing to do is check with GRS customer service when you can give them some input.
To give them some help with their diagnosis you might do the following checks.
Make sure the machine is out in the open where it can get plenty of room temp. air.
When the handpiece gets hot check the temperature of the casting that contains the pump end of the Gravermeister where the pressure is produced.
If it is excessively hot the problem may be originating in that area and may be a cooling fan
or compressor blade problem.
If it is just normally warm from use , then it would indicate that the problem is in the handpiece itself.
Best of luck with the problem. You have a first rate machine and I'm sure that GRS will help you find a cure.

 

[Imageraj]

First thing to do is check with GRS customer service when you can give them some input.
To give them some help with their diagnosis you might do the following checks.
Make sure the machine is out in the open where it can get plenty of room temp. air.
When the handpiece gets hot check the temperature of the casting that contains the pump end of the Gravermeister where the pressure is produced.
If it is excessively hot the problem may be originating in that area and may be a cooling fan
or compressor blade problem.
If it is just normally warm from use , then it would indicate that the problem is in the handpiece itself.
Best of luck with the problem. You have a first rate machine and I'm sure that GRS will help you find a cure.

John B. Thanks for your reply. I talked with a couple of tech support people from GRS and learned that overheating 915 handpiece is a known problem and there is not a lot one can do to fix it. They suggested a couple of things and I am going to try it to see if it helps (and will report back). I am a bit disappointed with this issue without any solution. Thanks

 

[mitch]

It depends on how you're using it, but 30 minutes of steady use can definitely heat up a Gravermeister handpiece. Many years ago I did some production industrial purpose engraving for a tool & die company (way back before 5-axis CNCs were common) and I'd wrap the handpiece with stretchy fabric athletic tape, both for grip and insulation. It was literally 'pedal to the metal' hogging out steel. I hated the work, but loved the $$$.

 

[Imageraj]

It depends on how you're using it, but 30 minutes of steady use can definitely heat up a Gravermeister handpiece. Many years ago I did some production industrial purpose engraving for a tool & die company (way back before 5-axis CNCs were common) and I'd wrap the handpiece with stretchy fabric athletic tape, both for grip and insulation. It was literally 'pedal to the metal' hogging out steel. I hated the work, but loved the $$$.

Thanks Mitch - I read elsewhere to wrap surgical tape and it is helping. I don’t intend to do long marathon engraving sessions so hopefully It will work.

 

[monk]

i bought mine when john rohner answered the phone at grs. i've also never had a problem with the two handpieces on mine. till you find a fix, if there is one, do as mitch did. that should help somewhat. good luck.

 

[Marrinan]

I used "Vet Wrap" after adding the 2400 speed kit, before I added that it was not an issue.

 

[sam]

I haven 't used a Gravermeister in over 40 years, but I do remember the handpiece being pretty warm. Try using a slower speed. You don't have to run a 2400spm. Maybe that'll help.

 

[Imageraj]

Thanks Sam! I have the original model up to 1200 SPM and running around 1000.. after talking with the GM experts at GRS (great support) and a hydraulic mechanic friend of mine, I figured out and fixed the problem. It also noticeably increased the stroke power! In my opinion GM is a very robust machine and so far I am loving it (I have no experience with other machines to compare). Very pleased with GRS tech support for this 40 years old machine. Thanks

 

[Imageraj]

Looks like I have Successfully solved the Gravermeister 915 handpiece overheating problem. I wanted to share what worked for me hoping it may help others. Of course, the technical support folks at GRS helped me a lot. The primary issue seemed to be with the sliding vane plates - when I opened the housing and checked them only one was freely sliding while manually rotating the shaft. I thoroughly cleaned all the vane plates and lightly oiled them and checked them for freely sliding before closing the housing. I also thoroughly cleaned the oil intake and canister, refilled it with Dexron III ATF and it completely eliminated the handpiece overheating problem. Now I am building a soundproofing box with a couple of muffin fans for air intake and exhaust to reduce the noise and get the stinky oil smell out of my garage workshop. Any suggestions on soundproof box building? Thanks

 

[Imageraj]

Thanks everyone for their help and guidance.

 

[John B.]

A plastic milk crate, lined with convoluted foam and turned upside down over the machine.
Add corner posts to the crate so that it stands about an inch from the ground when it is upside down over the machine.
Muffin fan that extract the heat will also draw in fresh air from below the enclosure.
Corner posts can be 1/2inch dowels fixed in the corners with twisted bailing wire.
Used one for years when I had a Gravermiester.

 

[Imageraj]

Great idea! Thanks

 

[John B.]

Imageraj.
PS to the Gravemiester enclosure. Heavy extension cord with a lighted switch.
I used a multi-outlet extension cord with a switch outside of the enclosure.
Both the Gravermiester and the muffin fan were plugged into this extension.
Drilled the strokes lever, brass rod through the top of the enclosure to adjust strokes.

 

[Imageraj]

Mine is plugged into an extension cord with foot on/off switch and I was wondering what to do for the stroke lever and oil canister (mine seems to use up a lot of oil since I reassembled everything). Liked the brass rod idea - thx. I am also thinking of adding a temp sensor with lcd display.

 

[mitch]

However you enclose it, make sure it has some flow through ventilation or you'll have another overheating problem. you might want to search for solutions on covering/muffling air compressors for more ideas. i think John's suggestion sounds pretty workable.

 

[Imageraj]

Yes - proper ventilation is a must to avoid overheating- I am researching different air compressor box designs online but like John’s idea of a crate lifted up from the bottom. Fortunately the Gravermeister is small enough for building an enclosure around it using off the shelf crates/boxes. If I can reduce the sound somewhat and get the oil smell out my wife will be happy!

 

[John B.]

Never had an oil smell with my Gravermiester because it did not burn much oil/trans fluid.
I replaced the carbon vanes in a regular basis over the 20 odd years I used it.
Cuts down on oil use and burning/smell.
Also never had an overheating problem with the enclosure and muffin fan air flow extractor.
Used a vacuum cleaner on both the inside and outside of the the enclosure about every month to remove any accumulated dust in the convoluted foam.
The convoluted foam helps with air filtration and also noise.

 

[Imageraj]

Mine had less than 100 hours of use on it When I got it and the carbon vanes look like new - the oil I am using is dexron III very stinky- someone in this forum said 10W non detergent so may be I should try that. I don’t see any adjustments for oil use so may be after some regular use the consumption will reduce? I ordered some sound proofing foam (2 inch pyramid tops) from Amazon after watching some videos on soundproofing air compressors so let’s see how it goes. I don’t intend to run this machine all day/every day so overheating inside the box may not be an issue. I am an Enamelist and will be engraving background texture (Phil Barnes style) on jewelry scale fine silver so it will be a few hours here and there! Here are couple of photos of my trial run (before I started learning engraving through an online class) Thanks

 

[John B.]

The adjustment for oil use is how far and how much of the wick is in contact with the oil.