12VCompressor for a Brake Car

[rkcarguy]

That doesn't run for very long does it?
I'm wanting to make a fake air tank for my riding car gondola that is open in the bottom and put my compressor in it. I'll line it with acoustic foam and hopefully it will be pretty quiet.

[cbrew]

That doesn't run for very long does it?
I'm wanting to make a fake air tank for my riding car gondola that is open in the bottom and put my compressor in it. I'll line it with acoustic foam and hopefully it will be pretty quiet.

no, less then a minute most of the time. also, keep in mind, the reason you hear it as much as you do in this video is because the gopro is hard clamped to the 11 gauge steel that the pump is also attached too.

[ccvstmr]

- the compressor will run as long it takes to satisfy the differential pressure setting on your cut-in/cut-out pressure switch. The closer those 2 set points are, the more the compressor will cycle.

- the compressor will cycle more depending on how much air you use...meaning the number of brake applications made. Going uphill...probably won't need brakes unless you stop and park. Going downhill...you'll probably be "riding the brake" and maybe feathering your brake applications if the grade isn't continuous.

While some people seem to be concerned about compressor noise (don't know why)...my compressor rides in a stock car (at the far end) behind the locomotive and tender. I welcome the "muffled" sound of the compressor kicking on/off...'cause I'd rather watch the track and other traffic as opposed to watching the air reservoir pressure gauge.

As a comparison...do you run a locomotive based on a throttle setting? ...or listening to the stack? Just sayin'....

Carl B.

[cbrew]

for me, the only gauge i watch is the train pipe pressure. I dont care what the main tank pressure is, if the pump fails and i deplete the air, i come to a stop, end of story.
I personally prefer to have short run times, it keeps the pump cooler.

like you, i dont care if i can hear the pump or not. the reality is, i feel the pump running more then i hear it

[NP317]

I've never heard a steam locomotive or diesel locomotive with a silent air compressor.
To me, audible compressor sound is prototypical, and just fine.
~RN

[rkcarguy]

NP317, don't the compressors spin full time similar to that of a bus or truck with air brakes?
I'm not wanting a "silent" compressor, but when I've used mine to inflate the kids stuff you have to yell over it and I'd like to not have to yell at people riding on my train.
Like cbrew, my brakes are setup so air pressure holds them off the wheels and no air = stopped.

[NP317]

The Diesels I have engineered have air compressors that do rotate with the prime mover engine. Their control valves are switched on and off as needed.
I would not be surprised to learn that new diesel locomotives now had compressors on separate motors.
Anyone care to educate me?
~RN

[cbrew]

NP317, don't the compressors spin full time similar to that of a bus or truck with air brakes?
I'm not wanting a "silent" compressor, but when I've used mine to inflate the kids stuff you have to yell over it and I'd like to not have to yell at people riding on my train.
Like cbrew, my brakes are setup so air pressure holds them off the wheels and no air = stopped.

the quality of the pump and the noise level go hand in hand.
I used some of the cheap pumps and they are very loud. the viair pumps have a mild tone. but you have to pay for that

[NP317]

One should not "cheap out" on brake systems. They are the most important system on any locomotive.
Literally anyone can make a locomotive or train go. Controlling and stopping them are where the real skills are required.
~RN

[rkcarguy]

NP317 and cbrew, I've actually engineered my brakes to be spring loaded "on", and the brake valves are venting versions that dump the air pressure downstream to stop. I've also drawn up a notched linkage that I can have laser cut that will allow me to quickly adjust the amount of leverage the spring has on the brakes. I figure I'll use the locomotive and riding car brakes when the train is empty or lightly loaded, and the full train brakes when loaded heavy or in an emergency. I'll have to play with spring rates a bit but it will be a good failsafe system in my opinion and not dependent on air to stop.

[cbrew]

NP317 and cbrew, I've actually engineered my brakes to be spring loaded "on", and the brake valves are venting versions that dump the air pressure downstream to stop. I've also drawn up a notched linkage that I can have laser cut that will allow me to quickly adjust the amount of leverage the spring has on the brakes. I figure I'll use the locomotive and riding car brakes when the train is empty or lightly loaded, and the full train brakes when loaded heavy or in an emergency. I'll have to play with spring rates a bit but it will be a good failsafe system in my opinion and not dependent on air to stop.

a friend of ours (Russ and i) have this setup on his cars. his and mine play nicely together.
i would have went this route, but my passenger car trucks have the cylinders mounted with in the truck. so this time of linkage would not work. but two air connects to double acting cylinders. works perfectly.

the beauty about our system, if the compressor fails. we simply come to a stop, no surprises at the bottom on the hill and you discover no or low air pressure when needed

[rkcarguy]

On my rolling stock, I'm going to be using a larger single air cylinder moving a lever arm centered in the frame. Then cables extend out to pairs of brake shoes mounted between the wheel sets with compression springs directly between the shoes. Kind of like bicycle hand brakes that work backwards and outwards if that makes sense.

Any idea what kind of spring pressures/rates to begin with? Not sure if It will be all that relevant because of my odd 2" scale and wheel sizes being larger, but I don't have a clue where to begin.