Equipment Question(s)

[thekoabenchgoldsmith]

Help me...help me....

I have a GraverMach with a Sil Air compressor. I would like to keep the compressor from cycling so often. The small bleed of air from the GraverMach forces the compressor to cycle even when I am turned away from my block to, say, sharpen a graver, refill my coffee cup, or, whatever. Does anyone know of a solenoid, or other, "air switch" that would block the air flow from the compressor to the gravermach when I don't actually have the pedal depressed? Or does this cause another problem I am not aware of?

When I am using the inside ring holder the tapered insert seems to jam into the plastic holder and its a bear to get the things separated. Does anyone have a solution to this?

Thanks everyone.

Aloha,
reb

 

[Sam]

Reb: You don't want to run your GraverMach with the air supply turned off. Most of us have done this accidentally...in fact I've left mine run all weekend with the compressor turned off and never had any problems, but I'm told the rotary valve system in the GraverMach can experience premature wear if left running for prolonged periods without air. I have the same setup as yours (Sil-Air). / ~Sam

 

[fegarex]

Reb,
I don't have a Sil Air but a large compressor to run my whole shop. I installed a 1/4 turn shut off valve right by my bench to shut off the air when I'm not using my machine. I've thought about looking into a solenoid too but I've got used to just turning the valve.

 

[Yves Halliburton]

Reb, I have the same problem you have with my Sil Air. The problem is that most compressors have an adjustable cut-in and cut-out adjustment. You can adjust at what pressure you want the machine to cut-in or start and cut-out to stop. My sil air does not have an adjustable pressure switch so it is fixed at a cut-in at around 80lbs and goes to 110lbs. The pressure swith is a black square box with the power wires going into it. Yours might be adjustable. I have the super silent DR 500. I have been working on finding another pressure swith that is ajustable so I can lower the cut-in to about 40lbs.

 

[msar24]

I'm not sure about the connectionson the Sil air compressors but Grainger has a large seletion of air compressor switches. Some of them are under $30.

 

[Yves Halliburton]

Thanks Kevin. I found one that is has a wide adjustment, 40-200lbs. It's $50.00 but I think that will work.

 

[Peter E]

I have a Gravermax (just prior to the Gravermach) release. From GRS, I had bought the "remote" air adjustment switch. GRS may still have them available as an option.

Peter

 

[John B.]

Like Rex, I have a 1/4" brass ball valve turn-off that I added where the line from my Sil-Air enters my GraverMax.
When not using the machine such as phone calls or sharpening I just flip the power switch and the ball valve handle off.
Any plumbing supply or home building supply outfit has them for $3-4.00.
Just a thought, John B.

 

[thekoabenchgoldsmith]

John B is the third person who uses a turn off valve. Does anyone know if there are problems along the lines that Sam mentions? That the rotary valve in the GraverMach/Max/Mate needs an air supply? Maybe someone from GRS could address this? Aaron...are you out there?

Thanks for the responses, everyone

Aloha,
robert e booth

 

[Yves Halliburton]

Robert, use the brass ball air turn off valve and have it mounted right next to your Gravermach. When you walk away just turn the valve to cut the air off and turn the Gravermach off. I, as others, have found this to be the most efficient way.

 

[Sam]

You can use any valve you wish. Just turn off the GraverMax or GraverMach when you shut off the air going to it.

 

[fegarex]

Robert,
You need to shut off the GraverMach/GraverMax as well. The valve requires air to lubricate it.

 

[fegarex]

Another thing to help this is to reduce the incoming air pressure to 40 PSI. This will keep the precision regulator in the Mach from working so hard maintaining a constant pressure and bleeding off the excess.

 

[John B.]

Robert.
I think we are all trying to remind you that you must also shut of the electric power while no air is being fed to your machine.

Make sure the light is off on your machine if the air is OFF.

Best regards and I hope you enjoy your new toy. John B.

 

[FL-Flinter]

Well, I don't know anything about the engraving equipment y'all are talking about but I do know controls & compressors.

First off, short cycling on a compressor will subject it to rapid wear on all the moving parts and it becomes costly on the utility side because on every start cycle you have a high electrical in-rush current - since the electric bill is calculated by the amount of current you use, every start cycle is costing you additional money.

Because of the in-rush current, every start cycle generates more heat within the electrical components shortening thier normal life span. You also have mechanical shock loading on moving parts on each start cycle shortening their life span as well. For these reasons, it is always best to have a compressed air system with as much storage volume as possible. You can increase storage by adding tank(s) but please keep in mind that each additional tank must be equipped with a properly sized and rated automatic safety pressure release valve and each tank must be rated at or above the maximum operating pressure of the system. If your compressor is short cycling, you may or may not have a control issue depending on the amount of system storage volume you have available. Generally, small recip compressors are set with about a 30 psig differential meaning that if it cut-out at say 120 psig, it should engage somewhere around 90 psig. If the unit is cycling with less than a 30 psig differential, then you have a control problem and most small units are equipped with a non-adjustable control switch and the entire unit must be replaced with an OEM spec unit because most are built brand-specific and you cannot obtain parts from anywhere other than the OEM. This is why I stress the point that when buying a compressor, make the initial investment for a high quality professional unit and it will save you more than the cost difference in the long run.

Air leaks are another major killer of compressed air systems. If you're system is loosing more than 10 psig over a 24 hour period, the leaks need to be stopped.

Moisture and heat within the compressed air are the two biggest enemies of air powered equipment. If you do not run an after-cooler/moisture separator system between the compressor head and storage tank, adding additional storage tank(s) will definitely help because the air will have more time to cool allowing more moisture to drop out in the tank rather than being pushed through the lines but this does not remove the need to use a high quality in-line moisture separator between the supply and tool(s). Fegarex also brings up an excellent point on using "multi-staged regulation" of the supply air pressure. Primary regulation should drop your main supply pressure to within 20% of the secondary regulation set point.

As for the secondary control system, you have several options and the least costly would be to install a "Start/Stop" station that will not require modifications to the plug & play equipment. - - Since I'm not familiar with the graver unit in question, I can only "assume" at this point and if my assumption is incorrect I hope someone will correct me - - I'm assuming the graver unit operates on standard 120Vac utility electrical power and has an "ON/OFF" switch so that if you leave that switch in the "ON" position and plug the unit in, it begins to operate. Provided this is the case, all you will need is a simple electrical enclosure that you can mount in a safe location within proximity of the graver unit that is large enough to house a properly sized SPST switch and a duplex outlet. The outlet will be controlled by the switch and the graver unit will plug into one side of the duplex. The you will need a solenoid valve rated for "gas" or "liquid/gas" with a 120Vac coil and the port sized correctly to the air supply line. (These are available at industrial suppliers like MSC, Granger, McMaster, ect. and always suggest getting Red Hat brand simply because they are quality proven in my experience) Properly and safely wired the solenoid valve will plug into the other side of the duplex outlet controlled by the switch. When you apply 120Vac power to the outlet via the switch, it will energize both the graver unit and the solenoid valve to turn on the air supply. Using a single switch control will prevent you from turning off either electrical or air supply to the unit independently helping to prevent damage to the unit. The solenoid valve will cost you around $25 and total cost for this set-up will likely be less than $40 in parts provided you can do the work correctly yourself - never guess when messing with electrical, it has no problem with killing you dead without remorse or warning! Same goes for compressed air systems, the entire thing is a potential bomb just waiting to explode and if you don't know what you're doing, please by all means hire a professional!! You can get as fancy as you want with control system by adding indicator lamps or using one control station to run not only the graver & air supply but also the compressor, air drier & oilers as well but it must all be done correctly and safely.

 

[Sam]

Excellent post! I have added it to the Tips archive. Thanks FL-Flinter

 

[FL-Flinter]

Thanks Sam.

BTW, I don't make it to the forum every day so if anyone has questions, please feel free to email me:
mark@fire-iron.biz

 

[Lee]

I use a power strip for the lights above my head and gravermach. When I leave the room and turn off the power strip everything goes off. If my compressor was hooked in it would be even better but it resides in another room.

 

[Swede]

Fl-Flinter is 'da man' in this scenario, and of all his suggestions, I think the easiest is to simply add another (or two) air tanks inline with the compressor. These are relatively cheap (maybe $30?) and should come pre-equipped with the necessary safety devices. A larger storage volume for your air equals less frequent cycling of the compressor system as a whole.