AirGraver uses 28 times less air volume (cfm)

[phil]

Hi everyone. I have heard those of you that use lindsay airtools saying that you can run them on small C02 cylinders. I use the grs system with a 17 litre compressor yet even with no cutting ( the gravermach left on but me not cutting) the compressor is firing up every 5 mins or so. I have checked for leaks with soapy water to see if any bubbles develop but cant find any problems.I realize this site is lindsay oriented but i know many of you will have used both tools.Can you please tell me if this is normal. Thanks in advance for your help.

[jlseymour]

Yes it's normal, I had the same question after I got my GRS Gravemax and it sounded like the foot control leaks but GRS rep say it was normal...
They said just turn the air pressure down to 0 on the Gravermax when not in use...
Jerry

[SVD]

The GRS tools get the pulses via a rotating bit. They require a constant stream of air going past to 'lubricate' the rotor. That's why it's very bad to leave a GRS unit on with no air.

Steve's units don't have that rotor (or the box it lives in) but do need to 'idle' so they also use some air all the time they're on - but not nearly as much.

There's a thread where the amount of air used by each system is dicussed. If I can find it I'll come back and drop a link.

Found it! It's in Post #12 in this thread

Here's the money quote:

Originally Posted by Steve Lindsay

I tested the air flow of the foot pedal Classic and PalmControl. The read out is in ml/minute and we need it in CFM (cubic feet/minute). I used this page to help convert the numbers.
http://www.iprocessmart.com/techsmart/conversions.htm

Here are the results:
PalmControl set at 35 PSI
Idle: 38.16 ml/min = .001348 CFM
Full throttle: 4333 ml/min = .153027 CFM

Foot pedal set at 35 PSI
Idle: 569 ml/min = .020095 CFM
Full throttle: 4333 ml/min = .153027 CFM

We can average the idle and full throttle together to discover normal usage.
PalmControl normal usage: 2185.58 ml/min = .077718 CFM
Foot Pedal normal usage: 2451 ml/min = .086561 CFM

The stroke adjustment effects the full throttle flow. The above readings were taken with the Classic stroke adjustment at the longest stroke. Both tools use around 2500 ml/min when set at the shortest stroke at full throttle (at 35 PSI). Therefore for average usage of the tools at a short to meduim stroke setting they are using approx .04 to .05 CFM .

With the PalmControl, the COS 16 gram cartridges get around 20 minutes. The 567gram (20oz) paintball co2 cylinders around 8 hours. How long they last is dependent what you are doing. i.e. if digging deep background cuts, not as long as shading or outlining.

Steve

Which was followed by this observation:

Originally Posted by Norsksea

The GraverMach requires a minimum of 1.4 cfm at 45 psi of compressed air. Thats almost 10 times more than Classic at full throttle and 28 times more air than the Classic at it's average usage speed. WOW
Frank

[mckeenh]

My GRS Graver Max doesn the same thing. Since I got Steve's tool, Classic with foot control my compressor hardly runs at all. There is a significant difference in the amount of air required,

Neil:yesnod:

[phil]

Thanks for all the info. That has put my mind at rest. This site is ace.

[Danny C]

The 20oz has a lot more 'air' in it then the compressor. So it takes less time before the compressor comes on - co2 and air both use "the same amount" of air, though.