Thread: 12v compressors.

That would probably result in the compressor being too high geared. Also, belts are very good at accomodating minor mis-alignment.

Aaron.

Just about all single unit compressors run the pump directly off the electric motor shaft. Probably end up being faster pumping at low pressures and slower at high pressures - I guess up to 50psi roughly is where you would want it to be fast rather than 140psi. It's probably belt driven to test the concept though, especially if Fozzy is to have the pump engine driven.

What ratio you use in any application is all about torque matching. The starter motor may power the compressor in direct drive, but this will use far more electricity, in a less efficient manner. As it was stated as getting warm to the touch in the geared down mode, it will get hot in the direct drive mode. The proprietry brand air compressors that operate in direct drive mode have a much lower swept volume, so needing less torque. They then increase the speed to get any discernable amount of compressed air. This home made compressor is no toy. It will be able to provide a serious amout of air at a decent duty cycle.

dave you being a go for it kinda guy in the metalology dept can you make a tig/mig welder utilising the power on a truck without compromising your ability to move after ie will it blow your sparks, might be a question more for the reme (oops wrong country) raeme boys, i seem to remember seeing an article on such a feat of diy engineering

with ref to compressors and for the hard of thinking er ...that's me, if the compressor produces say 100 psi(just a figure) would that convert to 100 psi into the holding tank or do you get loss in conversion at all just i never have had a compressor.

Originally Posted by Randylandy

did you considder coupling the motor directley to the pump or was it just too much a hassel?

Yes and Yes

Originally Posted by Aaron IIA

That would probably result in the compressor being too high geared. Also, belts are very good at accomodating minor mis-alignment.

Aaron.

Correct in both cases as well as DOR of the statermotor was the wrong way for the compressor if it was direct drive (not that it really matters for a york recipricator)

Originally Posted by lardy

with ref to compressors and for the hard of thinking er ...that's me, if the compressor produces say 100 psi(just a figure) would that convert to 100 psi into the holding tank or do you get loss in conversion at all just i never have had a compressor.

Without getting all rocket surgeon on you.

Technically pumps dont make pressure, they make flow. Pressure is the result of a resistance to that flow.

Ignoring all that crud. Yep in that particular setup because I have no check valves or pressure regulators whatever turns up on the output side of the compressor in theory (which means ignoring the losses caused by flow and restrictions within the system) turns up at the end of the hose I plug into the QD on the bottle.

Originally Posted by lardy

dave you being a go for it kinda guy in the metalology dept can you make a tig/mig welder utilising the power on a truck without compromising your ability to move after ie will it blow your sparks, might be a question more for the reme (oops wrong country) raeme boys, i seem to remember seeing an article on such a feat of diy engineering

its very easy to setup a welder off of a vehicle, in particular 24v vehicles and now fozzy since I have 2 700CCA batteries with some "Im not messing around here" interconnect cables in parallel with each other.

In my case I just hook the batteries up in series (which means rerouting one cable and disconnecting another) and using my jumper leads Im good to go for stick welding and IF i could get my hands on a wire feeder Mig welding (It could in theory do tig but I cant tig, yet.) If I ever get my hands on one of the alternators I really really want I'll convert fozzy to 24v and air start with the ability to throw about 120A at 30v.

as for blowing the electronics up.....

its Fozzy, what electronics? ATM the radio isnt even wired up.



Just by the by and don't tell anyone but Technically speaking I am one of the RAEME boys.

Originally Posted by Aaron IIA

What ratio you use in any application is all about torque matching. The starter motor may power the compressor in direct drive, but this will use far more electricity, in a less efficient manner. As it was stated as getting warm to the touch in the geared down mode, it will get hot in the direct drive mode. The proprietry brand air compressors that operate in direct drive mode have a much lower swept volume, so needing less torque. They then increase the speed to get any discernable amount of compressed air. This home made compressor is no toy. It will be able to provide a serious amout of air at a decent duty cycle.

Hot to touch isn't a guide though. The old ARB would get hot enough to melt the hoses and burn you, the new ARB compressor gets even hotter, flows more air and uses half the amps and will air up a couple of cars without a break. Don't get me wrong, and I think Kudos to Dave and its not about anything - I'm always a fan off getting stuff done and innovation such as this. If its a prototype, then its probably not all that relevant how hot the starter gets anyway if its going to be engine driven.