Diesel traction for the Seychelles Government Railways

quote]
Van, Clearly your Doctorate in Electro-Mechanical Engineering from the University of Seychelles has finally paid off![/quote]

With honours I may add

The MIL is still firmly resident chez moi with no visible sign of departure so some more progress despite the snow and freezing temperatures.

I found some fine brass mesh to use for grills but wasn't too happy with just soldering straight to the body so made some tedious surrounding frames from nickel silver.

Also some Seychellesque sugar plantation type lamps from 12mm brass plumbing end-caps and LEDs. These will be powered by a small separate battery in the cab somewhere.

And seeing as this machine is going to a (former) diesel truck driver it just had to have one of those natty little hats that flips up and down with the exhaust. That took a day to make and get right....try telling that to the 'domestic staff'...they just don't understand....
There is a choice of a conventional exhaust stack too.















The problem (for me) is that the details can start to get a bit obsessive and you have to stop somewhere.
I really do need to think about painting and some testing, both of which are difficult here with the cold.
However Monsieur Méteo says it will be a balmy 8° degrees this Sunday.

Supurb detailing Carl! If it took you a day to make that flip-up exhaust hat than it was a day spend well!

Excellent Carl.

I had a lesson cancelled today and most of the snow has cleared plus spurred on by progress in Kent...

A short test, it breathes life!




1. Getting the mixture right was a little tedious, started at 3 turns out but far too rich although this engine had been previously run with about 30 cc ok on that setting. Eventually ended up at about 1 3/4 turns out and still just a tad rich. but after that it started on the first pull.

2. Plus points, fuel tank and exhaust worked fine, no air and no oil at all back into the tank. Maybe the close proximity of the tank to the engine contributed to it running richer.
Throttle operation was perfect with the slight drag on the spring sufficient. The second servo and switch worked fine and enabled the engine to be run in neutral. Tickover speed was enough to generate electricity to slowly turn the traction motor for a realistic crawl.

3. Minus points, gear meshing was a little sloppy and I may have to shim up the engine mountings to compensate. This contributed to a lot of gear noise which as you can hear almost drowned out the engine noise although I didn't use any grease. This will be amplified and resonated with the body on.
It's not going to be loco for a surburban garden railway!

The biggest but solvable problem was that the engine gear came loose and I will have to drill the crankshaft spigot to stop this. The problem was caused by me filing down the end of the locating grub screw because it was too long and fouled the other gear but then after it didn't grip correctly.

I may also have to remake the diode rectifier which became soaked with oil although for starting and testing a simple tube connected to the exhaust to pipe it away would do.

Carl, I have started to use Loctite retainer to fix pulleys to shafts just to save drilling, tapping filing flats on crankshafts. I have not had any problems with it coming loose on the two occasions I have tried it. Different versions are recommended for different air gaps so maybe I just have been lucky. It can easily be removed by applying heat with a gas iron.

http://www.youtube.com/watch?v=riTo3zwyIaU

Have you ever used this stuff ?

Yes David I have used Loctite and its different versions and it is a good option.

However...I have now made some as yet untested improvements including drilling just a small dimple on the crankshaft spigot. I have greased the gears and made a simple easily removable gearbox cover to avoid the grease being spun all over the place and as an extra safety measure although the gears cannot slide off the shafts anyway as there is no room.
Fuel tank is now black with an improved mounting fixing.
A simple dab of protective tape over the rectifier to avoid shorts and fuel/oil splatter.
Plus a simple lighting battery box that bolts to the cab bulkhead, PP3 9v battery, 400 ohm resistor and switch, lights are negative earth so only one positive wire feed required.







A few first impressions in black - still more coats to do yet. Brass is difficult to paint successfully and a good initial key is required. I soaked the body in a salt and vinegar solution for a day before using a bare metal spray primer.
The exhaust pipe though is chemically etched black and won't come off!

I hope you take it to Paris before you let Van get his sticky hands on it ??????

[quote="Carl Hibbs"]No stupid question here not even from Anton.... joke!

Thanks for that!!!

What a great loco, beautifully crafted.

How do you form the curve in the single brass section between the two sides and the bonnet roof ?

It was just done in the jaws of a 'workmate' (the tool variety not a colleague....).
I bent the sides to about 120° angle to the roof and then curved the roof gently with fingers and a round steel bar. This then brought the sides perpendicular.

The key is to heat the brass first, and the wooden jaws of the workmate helped create the rounded corner.

Zinc is mush easier to bend than brass though!

Some testing this afternoon on the track:

First with the gear pinned on the engine but still a lot of screeching with gears despite improving the meshing and plenty of grease.



Then later after I modified the engine mounting and decreased the meshing gap again.



The gear screetching improved a little but still needs more work and modification. The gearbox cover made no difference so that was removed.

It was difficult starting outside today as the temperature was at 0°C. Getting the mixture right required a deal of patience!

Nice work Carl!

Just a curious question about the gears (because it has a very nice speed); are the gears ratio calculated or is it trail and error to see what works best?

Trial and error Paul but with respect to nitro engine speed at idle nominally 2,000 rpm and the BLDC motor generator capacity at the same speed or different depending on gear ratio!

Thus 910KV motor produces around 2.1 volts (allowing for slight loss) at an equal gear ratio at idle.

I have used (changed round from original post) 14 teeth on engine and 12 teeth on motor.
This gives a 16% increase in BLDC motor speed. So at idle it now produces about 2.5 volts.

This is without a clutch of course.

Thanks Carl!
Right, you have a diesel electric. I did forget that for a moment when I asked about it. I was somehow wrongly under the impression that the nitro engine was directly connected to the axles with gears... Although I know well that this is no the case!

Feeling kind of dumb now...
Probably thougt that because I was figuring out my gear ratio's on the Mamod...

Hi Van

Would you like me to look after your new loco for you

After all I might be seeing it at the weekend

After a number of mods the machine was duly tried and tested on track at Ferrovi'art to an intrigued crowd.

On Sunday(after a bench test on Saturday) it started with the first half pull of the starter which shows that if all the simple conditions are right these are sweet little engines indeed.

It ran for about 15 mins before getting a little too warm and air appeared in the fuel. Still some mods to do including increasing the ventilation in the body.

Otherwise a pleasing and successful debut.

For further info the final (I hope) configuration is as run at Ferrov'iart with a clutch and module 1 gears. This has eliminated all that screetching in the earlier tests.
Also starting the engine with a flywheel fitted is better too.

Next trial will be at the CFBS fête vapeur...or should that be fête diesel?

Maybe I'll let the owner take delivery after that.

[quote="Carl Hibbs )should I send it first to the Haute-Charente for further testing....???[/quote]

A sea sick diesel,now that would be a first

Great loco Carl .
There is one detail I like the most. That little rain cap on the exhaust stack. Do you have a pic of it
Ok, I found it.

Carl Hibbs wrote:

The MIL is still firmly resident chez moi with no visible sign of departure so some more progress despite the snow and freezing temperatures.

I found some fine brass mesh to use for grills but wasn't too happy with just soldering straight to the body so made some tedious surrounding frames from nickel silver.

Also some Seychellesque sugar plantation type lamps from 12mm brass plumbing end-caps and LEDs. These will be powered by a small separate battery in the cab somewhere.

And seeing as this machine is going to a (former) diesel truck driver it just had to have one of those natty little hats that flips up and down with the exhaust. That took a day to make and get right....try telling that to the 'domestic staff'...they just don't understand....
There is a choice of a conventional exhaust stack too.















The problem (for me) is that the details can start to get a bit obsessive and you have to stop somewhere.
I really do need to think about painting and some testing, both of which are difficult here with the cold.
However Monsieur Méteo says it will be a balmy 8° degrees this Sunday.