Diesel electric

This forum is dedicated to Riding Scale Railroading with propulsion using other than steam (Hydraulics, diesel engines, gas engines, electric motors, hybrid etc.)

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Lonnie
Posts: 14
Joined: Sun Apr 10, 2016 6:20 pm
Location: Halstead Kansas

Diesel electric

Post by Lonnie »

Has anyone done a small water cooled diesel engine coupled to a 48vdc forklift motor to drive there diesel locomotive? I am starting this. The power plant is a 12 hp Kubota. I can mount a motor cycle radiator horizontal on the ceiling of the locomotive with electric fan. The forklift motor is a 6kw . I should able to control the speed of the locomotive buy the speed of the engine. Reverse can be achieve buy a reversing contactor. I will have a low rpm cut out switch to disconnect the power when engine in slowed to an idle. Any feed back on this would be great. Lonnie
Bob D.
Posts: 381
Joined: Thu Jun 21, 2012 10:43 pm
Location: Saco, ME. USA

Re: Diesel electric

Post by Bob D. »

If I understand you correctly your using the 48vdc forktruck motor for a generator? What will you use for traction motor(s)? What is the 48vdc motor's rpm rating? Direct drive or gearing up?
I don't think varying the throttle will give good enough speed control. Might want to use the forktruck motor for the traction and something else for a genset. An alternator set up to control the field will give better speed control for the traction motor.
I'm off on the same endeavor myself with no plans set in stone. There are quite a few ways to go about it. I'm using an interesting vintage inline 4 cylinder air cooled gas engine that is 16hp with alot of low rpm torque. Currently thinking to direct drive a 400amp 28vdc alternator. Should be able to get 200amps at 1600rpm. Leave it regulated and tied to two 12v batteries and run a speed controller for two 24vdc winch motors. This would allow operation without the gas engine running, batteries would pick up any sag in genset output. Varying engine rpm would allow controlling amperage capacity. Batteries always charging and no chance of a open alternator output.
May skip the batteries and speed controller and go the alternator field control route. This would be cheaper to do. Really like the idea of limited operation without the engine running though.
Your idea may work. If you can turn the generator slow enough to get a creep speed but still fast enough for the voltage you need to get adequate loco speed.
Lots to figure out but others have done it. Hopefully others will chime in with ideas and suggestions.

Bob
3/4" Juliet II 0-4-0
3/4" Purinton Mogul "Pogo"
3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
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GM 12 Loco
Posts: 11
Joined: Wed Apr 30, 2014 6:31 am
Location: Adelaide, South Australia.

Re: Diesel electric

Post by GM 12 Loco »

Hi Lonnie and others. Have a read of the article under the heading - 'Baldwin RF-16's in South Australia'. There is some great information on building a gas/petrol electric drive using DC aircraft generators and how to control the output for the traction motors - also some photos of the power trucks and traction motor installation. I have built many locos using this system and the result is smooth and efficient operation.
Bob D.
Posts: 381
Joined: Thu Jun 21, 2012 10:43 pm
Location: Saco, ME. USA

Re: Diesel electric

Post by Bob D. »

Graham,
Yours is a very interesting post. I have done a bit of searching for the aircraft style generator. Not alot to be found online or documentation to support. I have found quite a bit on the Niehoff brushless high effiency alternators used on military vehicles like the HumVee. Plenty to be had surplus in various outputs. External regulator. Really robust unit.
I'd like to see a wiring diagram for your generator/traction control. I imagine an alternator setup would be nearly the same.

Bob
3/4" Juliet II 0-4-0
3/4" Purinton Mogul "Pogo"
3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
3/4" Hunslet 4-6-0
3/4" Kozo A3. Delayed construction project

1 1/2" A5 Camelback 0-4-0
Lonnie
Posts: 14
Joined: Sun Apr 10, 2016 6:20 pm
Location: Halstead Kansas

Re: Diesel electric

Post by Lonnie »

Thank you guys for replying.
My 48VDC fork truck motor is rated at 1400 RPM I will direct drive it to my engine that is set for a max of 2900RPM. There will be a 20% lost in the DC output but I should be able to make that up with RPMs. My traction motors are 48VDC 1000W (electric scooter motors) I plan on using 4 of these on two thee axle trucks. I will bench test all of this first before incorporating into a locomotive. Any and all feed back is welcome.
Lonnie
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cbrew
Posts: 3161
Joined: Sat Jan 04, 2003 12:17 pm
Location: Vancouver Wa

Re: Diesel electric

Post by cbrew »

Lonnie wrote:Thank you guys for replying.
My 48VDC fork truck motor is rated at 1400 RPM I will direct drive it to my engine that is set for a max of 2900RPM.
Lonnie
if i am reading that, (driving the motor as a generator) are you not worried doubling the rated RPM? the rotating mass may not handle that very well.. just a thought
If it is not live steam. its not worth it.
Lonnie
Posts: 14
Joined: Sun Apr 10, 2016 6:20 pm
Location: Halstead Kansas

Re: Diesel electric

Post by Lonnie »

I think I will not to need to run the engin rpm up over 20% of the motors rpm rating to get the voltage and amps I need. One I determine them max rpm I need to operate I will dial the governor down on the diesel. This being said the toque curve on this little engine is pretty good 1600 rpm.
Lonnie
Posts: 14
Joined: Sun Apr 10, 2016 6:20 pm
Location: Halstead Kansas

Re: Diesel electric

Post by Lonnie »

Ok I think I have enough other stuff caught up so I can start on this. I have taken the forklift motor apart for inspection and found a bad bearing. A little cleaning out and sanding the armature. This motor is series wound and I believe I will need to split that and excit the fields with a 48 vdc to produce 48vdc variable output. So I wil plan to couple a 1000watt 48V pm motor on to the tail of the forklift motor and wire it to the fields with a blocking diode.
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Franklin RR
Posts: 1
Joined: Sun Jun 05, 2016 7:56 pm
Location: Franklin, TN

Re: Diesel electric

Post by Franklin RR »

I just finished my "diesel" electric running with a similar design. I started out with a Hatz air cooled diesel, but it was too noisy and smelly for me to enjoy the ride so I swapped it out for a 9 hp Honda engine. Much quieter! The engine drives a 28 volt Leece Neville alternator, and I use this setup to charge a pair of Group 4D batteries. It will put out about 60 amps at 2000 rpm - well below its 90 amp rating. I then use a 400 amp heavy duty golf cart motor controller and a reversing relay to control the motors. The batteries are able to pick up the high current requirements for starting and going up grades, and over the course of the day the alternator can easily keep them charged up. Plus if I want to listen to the wheels on the rails I can always just shut the engine down.
Lonnie
Posts: 14
Joined: Sun Apr 10, 2016 6:20 pm
Location: Halstead Kansas

Re: Diesel electric

Post by Lonnie »

I am trying to go with the genrators speed to control the wheel speed somewhat like the full size do. I was working on it tonight. The Kubota is a 20 HP and I am hoping to get 100 amps out of the forklif motor. I am going to run the motor with my lath and see what I get before coupling it to my engine. I can turn it 2000rpm. I would like to see any pics you might have as this is a little off the regular path. Lonnie
Lonnie
Posts: 14
Joined: Sun Apr 10, 2016 6:20 pm
Location: Halstead Kansas

Re: Diesel electric

Post by Lonnie »

I am learning!!! After spinning this monster and putting a voltage to it I did make power but I burned out my power supply that I excited the fields with!!! So a couple of conversation with so welder , genrator repair guys I know and it was explained real plain that the winding on the field ate big and to much like way to much resistance!!! So it was suggested that I wind to of the fields with smaller wire and tie them into the builder wire on the other two fields. This will act as an exciter just like a welder! When I ran the motor/genrator I had it chucked in my lathe. I have mounted the Kubota diesel on a temporary mount and am working on getting it ready to run so I can couple the gen to it after another test with the lathe. I almost have my truck cad out for prints and a cut file. More to come soon.
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