12VCompressor for a Brake Car

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, WJH, cbrew

User avatar
Pipescs
Posts: 1857
Joined: Wed Feb 03, 2010 10:16 pm
Location: Lester Alabama

12VCompressor for a Brake Car

Post by Pipescs » Sun Apr 14, 2019 9:18 am

Morning all,

My attempt at a brake car for the American worked great except when it did not work.

The first try was using a CO2 bottle from a paintball gun with a regulator set at 30PSI.

As I say it works great until the gas runs out.

Will now convert it to a battery driven compressor with resevoir tank and a auto shut off for the air supply.

I will keep the same 2 channel radio to activate it.

So,,, My question for anyone having done this is, What is a good 12 V compressor to buy, and what size 12 V battery is needed to power it in a days running?
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

User avatar
dwilloughby
Posts: 232
Joined: Fri Apr 18, 2008 8:39 pm
Location: North Las Vegas, NV

Re: 12VCompressor for a Brake Car

Post by dwilloughby » Sun Apr 14, 2019 9:49 am

I use a Viair compressor for my train brakes. After going through a number of Thomas and Cadillac air ride compressor, I found the Viair compressor very reliable. I use a Deep Cycle Interstate marine battery for power. You will need to have a relay between your pressure switch and the compressor as the starting amperage is in the 35 to 40 amp range.

User avatar
tornitore45
Posts: 1715
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: 12VCompressor for a Brake Car

Post by tornitore45 » Sun Apr 14, 2019 10:51 am

I have a Viair compressor to keep my travel trailer tires and recommend it for the way is built and works.
Do not skimp on the relay rating, braking 40A at 12V on an inductive load is a challenge. Place a 1N4002 or equivalent across the motor and one across the relay coil to provide a path for the inductive kick. The direction of the diode is such that does not conduct when the circuit is energized.
Mauro Gaetano
in Austin TX

User avatar
Marty_Knox
Posts: 1400
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: 12VCompressor for a Brake Car

Post by Marty_Knox » Sun Apr 14, 2019 10:56 am

dwilloughby wrote:
Sun Apr 14, 2019 9:49 am
I use a Viair compressor for my train brakes. After going through a number of Thomas and Cadillac air ride compressor, I found the Viair compressor very reliable. I use a Deep Cycle Interstate marine battery for power. You will need to have a relay between your pressure switch and the compressor as the starting amperage is in the 35 to 40 amp range.
I will second Dean's recommendation of a Viair compressor. I have used two of them now, and they never failed to work (except when the battery ran down). I make up a module with the battery, compressor, pressure switch and relay. With a union in the airline, I can disconnect the union and lift it out as one piece. I'll have to look and see if I took any pictures.
My hot rodding background shows - I buy them at Summit -www.summitracing.com.

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: 12VCompressor for a Brake Car

Post by Bill Shields » Sun Apr 14, 2019 11:23 am

maybe you can consider a 2000 PSI compressed air tank for paint ball...

a lot more punch in a tank of similar size....

or a SCUBA tank....one can fit in a car.....
Too many things going on to bother listing them.

User avatar
NP317
Posts: 1916
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

Re: 12VCompressor for a Brake Car

Post by NP317 » Sun Apr 14, 2019 1:11 pm

Bill Shields wrote:
Sun Apr 14, 2019 11:23 am
maybe you can consider a 2000 PSI compressed air tank for paint ball...

a lot more punch in a tank of similar size....

or a SCUBA tank....one can fit in a car.....
Then you need to spend big $$s for a high pressure output air compressor to fill your portable tank...
~RN

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: 12VCompressor for a Brake Car

Post by Bill Shields » Sun Apr 14, 2019 1:40 pm

nah...you go to a paintballl shop....or use a standard compressor with an amplifier...
Too many things going on to bother listing them.

B&OBob
Posts: 348
Joined: Sun Jul 22, 2007 8:27 pm
Location: Blue Bell, PA

Re: 12VCompressor for a Brake Car

Post by B&OBob » Sun Apr 14, 2019 2:09 pm

Those compressors run at high speed, generarting considerable noise and some vibration. You might want to consider using a ventilated housing with moderate soundproofing and vibration isolation for the compressor. Also, the more air storage capacity in the system, the better to keep the compressor from cycling on and off too frequently. Compressor noise can be very annoying and it detracts from the realsim of a steam-hauled train.
Dave Sclavi has considerable experience with the kind of car you are considering.

B&OBob

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: 12VCompressor for a Brake Car

Post by Bill Shields » Sun Apr 14, 2019 7:34 pm

amen on the noise....
Too many things going on to bother listing them.

User avatar
ccvstmr
Posts: 1643
Joined: Sat Jan 04, 2003 10:37 am
Location: New Lenox, IL

Re: 12VCompressor for a Brake Car

Post by ccvstmr » Sun Apr 14, 2019 8:51 pm

Pipescs....have used (2) kinds of 12 volt compressors. For the remote brake system that goes in a caboose for card order switching operations...there are plenty of small 12 volt compressors on the market. Buyer beware...if the compressor looks cheap...it is cheap...like something you used to find at Kmart or Walmart now. Harbor Freight used to carry a compressor for like $25. That was reasonably quiet. Know one hobby supplier used to provide that for his brake systems.

For normal train ops, was able to get several Campbell Hausfeld compressors from heavy-duty tire portable tire inflators. Can buy the entire unit on line for $40-50. Might find something used on Ebay. This type of compressor has worked well for years (17 years?). Had to replace the extruded alum casting used to make an air reservoir due to "beer canning".

Larger compressors like auto air ride suspension compressors eat up battery life. Large air reservoirs...will take longer to pump up. Might exceed the duty cycle rating on the compressor. Small reservoirs...will need constant refilling. Actually, depends more on the type of railroad you're running as to how much gets used.

Noise...that's a crap shoot. Some compressors are just noisier than others. Usually, the quieter the compressor...the higher the price. Question is...how many compressors do you want to try until you find something that fits all your criteria: cost, noise, slow battery drawdown, etc.? Only you can answer that.

For power...my main train brake unit has a 75 amp-hour motorcycle battery. Reasonably small. Have built similar brake units and the remote brake units with an 18 amp-hour SLA battery (sealed-lead-acid). btw..."sealed" is a relative term. This is nothing more than a cover glued over rubber caps for each of the cells. The higher the amp-hour rating...the heavier the battery. Remember...EVERYTHING has trade-offs. Batteries typically last 5-6 years before replacement is needed.

All things taken into account...unless your loco has steam brakes...this is the cost of stopping the train (sometimes more important than getting the train to move!). Hope this helps. Carl B.
Life is like a sewer...what you get out of it depends on what you put into it!
I don't walk on water...I just learned where some of the stepping stones are!
I love mankind...it's some of the people I can't stand!

User avatar
Greg_Lewis
Posts: 1732
Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: 12VCompressor for a Brake Car

Post by Greg_Lewis » Sun Apr 14, 2019 9:07 pm

Here are the two currently on the Horrible Fright website. Remember that 20 percent off coupons are everywhere and on certain holidays they'll have 25 percent off. I have no idea as to how loud they are. I believe Ken Schroeder uses them for his brakes. They're cheap enough that you could buy two in order to have a spare at meets. Use a quick disconnect so if one blows you can just bin it and swap it out with another one.

$34.99 100psi
https://www.harborfreight.com/12v-100-p ... 69284.html

$62.99 150 psi
https://www.harborfreight.com/12volt-15 ... 69285.html
Greg Lewis, Prop.
Eyeball Engineering — Home of non-interchangeable parts.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

Wayne Davis
Posts: 97
Joined: Mon Sep 03, 2007 10:19 pm
Location: Creston Iowa

Re: 12VCompressor for a Brake Car

Post by Wayne Davis » Sun Apr 14, 2019 9:33 pm

Our club uses the Tom Bee compressor unit on our club cars with great results. It powers breaks for four cars.

Wayne

https://tombeeonline.com/collections/to ... essor-unit

Post Reply