Live diesel project: Polar-Deva

The roof will not help in heat removal. The cut does not goes through. It is just for bending ease. It has been donne with laser. I plan to cover it with a thin sheet of metal (either tin or zinc).

Yes the fan is supposed to extract hot air from the engine compartment. There is also a smaller one directly flushing the engine head.
My only concern is their feeding from the electrical generator: they are 12 volts model and my generator will only deliver around 7V at idle. Maybe I will have to replace them with 5V model; but I chose 12V so that the regulator circuit does not overheat too much at higher engine rpm.

I thought it must be laser, it's a lovely intricate pattern.

Do the fans turn on 7V ?  If so they may be OK on idle.  If not you could use 5V models with a simple 7805 chip circuit.

I'm using castor oil in the fuel, this provides ultimate protection against overheating.

Best wishes,
Dave.

I first thought of this solution (I even bought the 7805 and small centrifugal fans that did not fit for plotting reasons), but I was afraid that at maximum voltage (if ever reached) the voltage drop in the 7805 will produce too much heat. So, when buying new fans, I finally chose 5V. I have some regret, but this not a big deal because those fans are not that expensive.
Let's wait and see...

I see you live in New Zealand! That is a country that has always facinated me (though I am not at all a rugby fan!). Unfortunately it is the farthest place on earth for us. So there is very very little chance I ever get there. This is the beauty of internet being able to exchange with people so far away.

dewintondave wrote:

I thought it must be laser, it's a lovely intricate pattern.

Do the fans turn on 7V ?  If so they may be OK on idle.  If not you could use 5V models with a simple 7805 chip circuit.

I'm using castor oil in the fuel, this provides ultimate protection against overheating.

Best wishes,
Dave.

Castor oil? Seriously?

En français pour éviter les confusions: castor oil ne veut pas dire huile de castor (beaver en anglais!) mais huile de ricin. Celle-ci est encore couramment employée avec les petits moteurs thermiques.

k&nwlr wrote:

dewintondave wrote:

I thought it must be laser, it's a lovely intricate pattern.

Do the fans turn on 7V ?  If so they may be OK on idle.  If not you could use 5V models with a simple 7805 chip circuit.

I'm using castor oil in the fuel, this provides ultimate protection against overheating.

Best wishes,
Dave.

Castor oil? Seriously?

Mais oui  

I have been progressing on the body details (unfonctionnal, just decorative!)



I am rather satisfied of the result for a first try.

But assembling all elements on the chassis will ne a nightmare the bolts and nuts being hardly accessible. I will be probably obliged to replace the nice hexagonal headed bolts by more common ones more easily manageable.

Some news about my project, getting along very slowly! The main issue is still building a small efficient exhaust system.
So I progress on the loc body.



I dare not taking off the windows protection until all gluing is through. So ,it looks rather ugly. Next step is putting the brakes pipes and the connection platforms. And then the roof cover. I planned to glue a thin tin layer, but the price seems dissuasive and I must wait going to Paris to get it. May be zinc would work nearly as well, but it is stiffer to bend.

I nearly assembled all the existing modules. The engine compartment is full as an egg!



in the space on the front will stand a little 50mm fan.

on the other side:



I apologize for the notes in french!

That looks fantastic, some creative engineering! Interesting manifold from copper?
How did you couple the engine and motor exactly? It seems very precise.

I designed a specific exhaust system made of standard plumbing pipes and fittings:



but I am somewhat reluctant starting the realisation since I have never hard-welded.


As far as the coupling is concerned I just fit the BLDC on the OS engine axle (see on this message first page). The process was the following:

- Take off the BLDC axle (somewhat difficult as it is hard-mounted
- Put the rotor on the OS axle
- Drill a first hole in the OS waffle, using the rotor as a guide
- Thread to 2mm
- put a 2mm bolt for tightening the two parts
- drill and thread the three other holes
- fit the two parts securely with headless bolts and Loctite
- Put the group on the chassis
- drill the BLDC side plate and fix the BLDC stator on the chassis
- drill the holes on the OS engine side using the OS fixing holes as guides

This result in a very compact group: 90mm long and 50mm wide including the gas servo on the rear side.

Correction:
I just tried to move the OS with the BLDC (as for a start). It does not work! I am surpised because I already tried it but with a different ESC (30amps instead of 10A). I am quite a bit disapointed, because if I have to change, it will be quite a job since everything is welded and very tight.

Very interesting. And a very room saving arrangement. I'm curious to see your exhaust system.

I finally identified the problem: the ESC was defective: one phase did not give any power resulting in an oscillation of the motor instead of turning. I shall put back the other ESC. I will do the first tests using the regular exhaust and when I am a bit more familiar with this engine try a more efficient exhaust system.

Thanks for your support!

END OF THE PROJECT: A COMPLETE FAILURE

I must admit I started the wrong way assuming that the BLDC motor would start the OS engine, without a real try. It is only when all was finished that I realize it does not have the torque to start the engine!
The power is much too heavy forthis small engine: I have burned out two ESC and I do, not know if the engine is burned outor not.

My Polar-Deva will just be reduced to a trivial battery powered model. What a shame! Unless I switch to a pull-start engine, but I guess I will not have room enough to put it in my engine compartment.

Sorry for the disapointment!

Hey, don't give up so quickly. There's another way to start a glow engine via rod and external starter motor. And the pull starter wouldn't need that much room too.

As a relief, I am going to finish the body soon and have it run battery operated. By the way I found that a 14.7 V battery results in a high speed of the Playmobil motor-gears assemby. Sure my 24 V project was a bit high. Maybe I should have aimed something lower such as 18V.
As anyone any idea about the subject?

On the other end I start looking for a solution based on a Kyosho GX12 engine with pull start. Those engines usually run at higher speed than plane engines. Therefore, may be I shall change my 360KV BLDC for something higher such as 500 or 600 KV?

Don't give up with this as Lorenz said. Just put it away for a bit while you do some more to that great body!

That's a shame about the ESCs burning out. Are you using a powerful enough model?
Have you tried turning the OS engine with the glo plug removed? Also preheating the engine (carefully).
Then replacing the gloplug. Also only give it a quick spin for a second or so if it will turn at all rather than turning for a long time.

A 970KV motor from RC Timer will turn a Kyosho GX12 no problem using a 30amp ESC. I have tried that a few times now.

Thanks Carl for your support!

I have converted my Loco to battery operated for a while, just not to be completely discouraged. It works. They should be some adjustments to make speed control more progressive. This can be done both in the RC and the ESC programing; but I have to learn how to do it, since it is my first RC and of course ESC module.A view of the converted chassis:



The Château Margaux box in the luggage room contains the RC battery. Transposed in reality it would have cost the same amount of money as the loco!!!

Just to put an end to my unsuccessful experience, I used a RCtimer 30amp ESC with the RCtimer 5010/14 360kV motor. It could not start the OS15LA even with a 14.7V battery.
To be more correct I succeeded starting it the way you says above:
- remove the glowplug
- put the glowplug on the glowplug lighter
-put the power on the ESC: the engine turning freely
-rescrew the glowing glowplug in
the engine starts

But this is really not a normal starting procedure! Furthermore i am not sure what burned out the esc. Maytbe it is in this case the power generated by the turning brushless

For all these reasons, I prefer to turn to a pull start device. I contacted Brian who had quite a lot of GX12 to sale. I will try to keep the compact direct mounting on th engine shaft.
I discovered an other minor problem: the model speed is very high even with the low voltage of the liPo battery. I may have to turn to a higher kv motor, which is not much of a problem since RCtimer make the same motor with higher kV. But maybe also the Kyosho would be powerful enough at low rpm. Wait and see.
As far as available space is concerned, happily enough the space taken by the pull start will be balanced by the one recovered by taking off the the ESC and  the connector. The only new issue is: I will have to build a custom made fuel tank, longer and thiner that the standard Kyosho I used before.
As a matter of fact, starting could be even easier, since anyhow I have to take off the body to start the engine. No battery to connect, no RC chanel needed.

The body is nearly finished (probably the next week-end). It is not perfect since it is my first model and I made many mistakes in the building scheedule, spoiling sometimes what I had done before. But anyway I think as it is a single unit model it is difficult to forecast everything since the beginning.

In my next model, I will try to benefit from this very first experiment. It will be a much larger model, someting about 60cm long, with double boggies (BB BB). The prototype was built in the sixties by Alsthom for the Congo Ocean line.
I already bought them from Aristocraft, the only issue beeing that the wheeels are much too small and that if I change them the gear ratio may not be appropriate; but as there will be four motors, it may be powerful enough though. There will be a four stroke OS 26FS engine. I need to build a coupling what, as I read from this forum, is not that easy.
On this model I will try again starting the engine with the BLDC, but the later will be much more powerfull: a Pulso X4130_20.


Edited wednesday sept 3:

I found that Playmobil locs (though presumably built by LGB) operate with a strange 14V voltage. When choosing my BLDC Kv I assumed it was a more common 24V (or 18V). Oddly enough, I would probably have a too low Kv! I am amazed that Garden trains (even if in this cas it was a toy train) are using so different voltages : this could induce some bad issues in multi-locs running.

I may have two solutions:
- change the BLDC to a 600KV
- put the two electric motors in series

Have an idea of which is better?

By the way as anyone an idea of which voltage was used by Aristocraft?

Hi Lorenz
I've replied to your PM
Happy to help with GX12's and parts I still have them!

Not being able to usefully contribute to any discussion about the diesel black arts, I calculated the value of the wooden box containing Ch. Margaux. I can´t read the vintage, but for the sake of Argument let´s call it 1982, since that was a "good year".

Space, I think for around 36 half cases, making for 216 bottles and a total of €108K. Take care of the cargo, is the only advice I can give.

But if you could tell us how you built the crate with the Margaux stamp - now that would be equally valuable info.

I wanted to find something to hide my RC battery. I found that a wine box would be typically french. I looked for a vintage that I was sure to exist in the years 1924-25 when the Polar-Deva was operated on Chemin de Fer du Valmondois. The Margaux logo was not very difficult to redraw.


I engraved it on a Trotec laser. I printed the other marking on my Canon inkjet printer.

My loc body is nearly finished. Here are some pictures:



and



and




My main concern about this body is that it is very fragile. Manipulations have already resulted in scatches in the wood. Wood is flexible but not hard. PMMA is hard but easily breakable.

So it is easier to have in the lanscape in photo that in reality:

Now that´s very nice !

But very fragile. The wood i used (red cedar) is not hard at all, and a lot of smallscatches can already be seen on the body. On the other hand, the PMMA I used for suspension and brakes moke up is hard but breaks very easily. I shall be very carful in handling and running this model!

I am studying for an alternate solution for the diesel electric generator. I look forward using a Kyosho GX12 with pull-start as many people on this forum. Brian has been very kind sending me a bare engine for me to do measurements and all kind of things toward a solution.
I tried putting my BLDC on the engine shaft as I did before with the OS15LA. Just to bad! the  shaft is about an half centimeter too short and cannot get through the BLDC stator. Would I be a real mechanic, I would lengthen the shaft of this amount and it would be a nearly perfect (and tremendosuly compact ) solution. But I am not!
So I will probably go to the Brian's alternate, with two original or custom built (smaller) flywheels with two piggots beetween. One would possibly get a small turbine for engine cooling. 
The room getting free from side fan and ESc suppression would accomodate a custom built fuel tank, the longer engine-generator preventing using the Kyosho tank in line as before.

This is the point where I am.

I resume working on my loco. I started a device that I feared a lot: the exhaust system. I never hard soldered before so that was quite a challenge.

I do not know whether it will be efficient; just wishfull thinking for the moment. It will be made out of copper tubing (20--220mm) and the corresponding copper stops bought from industry. The small tubes are model brass tubes 0,45mm thich)

It will consist of three chambers:

- a cyclon separator with an exit through a perforated tube
- a second chamber through an other perforated tube
- a third chamber through an absorbing material (very likely inox wool)



After one or two horrible things (I burn a hole through the fine brass tubing), i finally made most of the elements to be assembled with soft soldering) when I am sure of the final plot.