This page will follow the progress and build of a model locomotive using internal combustion as the
power source.
Real model diesel engines are very rare and difficult to operate.
Instead an aircraft type nitromethane fuelled 'glow-plug' engine will
be used.
This will be connected to a generator to produce electricity which in turn
will power 2 electric motored traction bogies.
Some initial tests and experiments have been carried out and
construction will follow very soon.
There are a number of technical issues still to resolve such
as type and choice of generator.
At the moment it is a high power brushed 12v DC motor used
in reverse as a dynamo.
This may change to an alternator system later.
If anyone wishes to add comment or advice then please e mail
me.
More details and photos to follow soon.
Live diesel project
Engine and motor set up
After an accident damaging my thumb I have now recommenced and have made a little more progress.
I originally tried mouting the glo plug engine on flexible rubber mountings and trying different types of flexible
coupling between it and the electric motor generator. None of these were any good and I ultimately bolted down hard engine
and used a rigid coupling but allowing the electric motor to float on the end of the engine crankshaft, but just limiting
it's movement.
This has worked so far on a continuous 30 minute test.
I was able to produce about 18 volts at full engine throttle but it is difficult at the moment keeping the idle
speed and consequently voltage low.
'Live diesel' project
Basic brass soldered chassis with Aristocraft bogies
Live diesel project
Glow-plug engine and 12v DC motor/generator. Shelves on chassis are for electronic equipment.
Live diesel project
Failed couplings
There is a short demonstration film on You Tube
Live Diesel Project
Basic locomotive chassis
Live Diesel Project
Engine and motor block loose fitted to chassis
More progress as at 19/07/07. Engine and motor unit bolted to chassis on rubber pads and a simple control panel and wiring
assemble. Radio control of engine throttle speed and forwards-stop-reverse of output to traction motors.
A further static running session carried out today to check vibration, stability and radio control functions.
Video film below.
Whilst waiting for the weather to clear so that we can make a trial on the track in the garden a start was made with
a simple body.
A 'boxcab' type style with some slight similarity perhaps to the Brissonneau et Lotz BoBo diesel electric
locomotives thta served on the French metre gauge.
3mm and 1mm birch ply were laminated to form the structure and using hardwood strip, sufficient cutouts
for cooling and maintenance were provided.
Live Diesel Project
Bodywork 3
The bodwork now finished off with three coats of white primer undercoat.
This will be next sanded down and prepared for top coat and a fuel proofer to protect against the stripping action
of Nitromethane fuel.
Live Diesel Project
First rail trials
Here's today's track trial video including showing the preparation for starting using at the moment an external 12 volt
battery.
The noise at idle speed is again acceptable and makes less noise than an average lawnmower. At more than half throttle
the noise is perhaps a nuisance.
Live Diesel Project
Now fitted with baffled silencer 'pot'.
Live Diesel Project
Fitted with electronic speed controller
Live Diesel Project
Finished body
Live Diesel Project
After a lot of work the body was finally finished in it's basic form.
The next trial will be with the machine wearing this body.
And here it is in action at my friend Troy's open day in England.
Live Diesel Project
Electronic speed controller in place with RC reciever below
Some more construction and assembly work.
The glo plug engine and electric motor were fitted to a new wooden block base which will fit as a sub assembly on the
loco chassis.
The motor is now rigidly mounted to the engine crankshaft which has proved successful so far but allowing some limited
play with motor housing now mounted on a thin flexible pad.
The chassis now has an underslung battery tray which will be filled with 12 sub C cells giving 14.4volts at 3.3ah;
The aim being to power the locomotive by battery in the event of engine failure and also to to provide starting power.
The radio controlled electronic speed controller is from RCS and will take either battery input or generator input.
Live Diesel Project
Engine/Motor unit bolted to chassis with simple wiring and R/C
Live Diesel Project
A start with the bodywork....in wood, 3mm birch ply.
Live Diesel Project
Bodywork 2
Live Diesel Project
Bodywork in primer undercoat
The weather cleared and the first primitive live track trials were held with reasonable success today 25th July
2007. That is under radio control it moves along the track generating it's own power.
There is still a lot of engineering to do but at least in principal I have achieved the main objective.
Now I will add electronic speed control instead of relying on the engine throttle to control electrical output and
thus traction motor speed.
At the moment the glo plug engine is still not getting too hot. If anything it is running to cold.
This is achieved because of the large brass engine mountings and the direct coupling to the motor generator which itself
acts as a large rotating heat sink.
More work carried out which included making and fitting a brass baffled silencer pot. This also incorporates a sump and
drain tube to help remove excess oil.
Using both channels, engine speed and electrical output are independently controlled.
The machine can be driven also without the engine using a large 12volt 3.3ah battery pack.
However this is not powerful enough to use to start the engine as hoped and an independent battery is still necessary
for that.
