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 Live diesel project: Polar-Deva

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Saint-Oblas




PostSubject: Re: Live diesel project: Polar-Deva   Thu Sep 10, 2015 7:56 pm

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.



Last edited by Saint-Oblas on Sun Sep 13, 2015 11:24 am; edited 1 time in total
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Tacbob



Location : Harz, Germany

PostSubject: Re: Live diesel project: Polar-Deva   Fri Sep 11, 2015 3:03 am

That's looking good. The drawing could be directly from a technical book.
Donít you need a drainage exit?

_________________
Lorenz
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Fri Sep 11, 2015 4:06 am

Yes! the hole on the right en side in the picture is intended for that. But I have not done it, because I need to see exactly how all this take place in my loc to orient it the best way. Same thing for the pressure nipple on the top to be connected to the methanol tank.
Furthermore, the top cover with the final exhaust pipe will not be welded, in order to be able to switch the material. I plan just to do a small silicon gasket.
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Fri Oct 02, 2015 11:07 am

Hello Brian! I am progressing very slowly in adapting the engine you sent me, but I am progressing. Here is the last picture:



Now I have to buils the support that will have several functions:
- maintain the stator static
- support the diodes rectifier
- support the PWM controller
- support also the RC receiver
and eventualy the glow ignitier
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sun Oct 11, 2015 2:08 pm

Even if it is still a long way to go, I have clearer ideas where to go! Here are two pictures showing the plot of the major elements of the power generator.


†and†


The diode rectifier and the pWM controller will be attached to the upper pert of the plate above the BLDC.


As you can see there is not much room left!!!
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Bearcastle



Location : Brie

PostSubject: Re: Live diesel project: Polar-Deva   Sun Oct 11, 2015 6:31 pm

Your nuts could get loose with the vibration !

Some locks nuts (Nylstops) or washer (Grower) could be use to make a stronger connection.
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Mon Oct 12, 2015 3:02 am

Sure! It is just a temporary assembly to check the plotting. For most nuts, i will use Nylstops or washer ( star ashers) and in some cases Loctite.

Thanks!
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sat Oct 17, 2015 8:31 am

Unfortunate but useful check: the fuel tank is unsuitable: right size but the fitting are absolutely in the wrong position. So I shall build an other tank, probably out of copper. I guess the muffler and the tank will be heavier than the engine!
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sat Oct 31, 2015 3:02 pm

Hello Carl, Brian and all others who were involved in this adventure so called "live diesel"!

Designing a device is something, but making it is an other story!!! Having never hard or soft soldered in my life, I really had a hard time building a copper tank, but when it came to my exhaust system as shown upwards, that became hell! It's done: it is ugly with plenty of defects but IT IS. I hope it will be somewhat efficient. But I think I will run in the engine without not to accumulate problems. Now I have to buid the diode rectifier. It will be directly located under the PWM controller. For space reasons it is not the Syren 10 from Dimensiion Engineering that I used previously but a Pololu 24V12. I hope it will work just as well. The Syren10 will be recycled to the BB BB.
I will put some pictures when all will fit together.
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Wed Dec 16, 2015 12:26 pm

In the last weeks I have been runing in the Kyosho Brian sent me. Now it is runing more and more smoothly. I tried this morning the exhaust system described above. It seems quite efficient as far as noise reducing is concerned. But the cyclonic separator that was intended to prevent spreading oil all over the place has an efficiency very close to zero! I still had a huge blue smoke from the exhaust and collected nothing in the separator. For my other models, I will build simpler exhaust system with the† same muffler but no separator, that was the most difficult part to buid ans is useless. What anoys me is that there will be a lot of oil on my carriages behind, and the materials they are build from, make them difficult to clean.

A short video of this first trial:



I am pretty satisfied of this engine: for not being completely runed in, starts very wel, runs quite smoothly and has quite a quiet idle. I replaced the glowplug by a hot one.
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dewintondave



Location : New Zealand

PostSubject: Re: Live diesel project: Polar-Deva   Sun Dec 27, 2015 3:40 am

Merry Christmas!

Do you have room in your loco for a large expansion chamber for the exhaust?† My loco has little oil passing through with the exhaust.† The oil is drained from the bottom of the exhaust chamber to the ballast below using back pressure to push it out.† The exhaust flow itself (out of the final exhaust pipe) is cool to the touch due to the expansion.

Best wishes,
Dave

_________________
All my garden railway videos on YouTube: https://www.youtube.com/user/dewintondave
I am now posting images on Instagram: #LiveDiesel
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sun Dec 27, 2015 8:09 am

Unfortunately I have very little room! My main concern is "how will I get it inside my loc! I expected to retain some oil in the first stage of the exhaust designed as a cyclon: unfortunately it did not act as such! I got barely no oil at the bottom.
I am fairly satisfied of the efficiency on the noise level. Of course you cannot realise on the video, but it is not really noisy. You must have in mind that the enfine is a 2 strokes for a car: these engines are designed to run at higher rpm than the four strokes and are much noisier.
I think I will replace the steel wool in the last stage by the previous one which was just slightly less efficient as far as noise, but did not quench the engine as the actual one.

Now my next problem: how will I fix this in my loco without unscewing (and spoiling) all what as been done before? Would I have build this mounting from the beginning, I surely would have operated differently!!
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Thu Jan 28, 2016 9:30 am

I put the engine on the chassis. I just need a connector and I will be able to make the first test. As you can see ther is not much room left in the engine compartment:




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Tacbob



Location : Harz, Germany

PostSubject: Re: Live diesel project: Polar-Deva   Thu Jan 28, 2016 11:25 am

A really tight fit. Were you able to do a test run yet?

_________________
Lorenz
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Thu Jan 28, 2016 1:25 pm

I just tested the engine running out of the loco. Must do a testrun soon.
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sun Jan 31, 2016 3:16 pm

I tried the whole set a few days ago. Unfortunately, as I am a very poor welder, my fuel tank leaked as a sieve! Today I tried with a replacement tank; that is the reason why I have not been able to put the body back.
My test circuit was just a bare two R5 LGB rails, so nothing very spectacular.



Anyway I am rather happy, because this first run proved that the whole concept was valid. The loco run smoothly (at least when I did not get mixed with my RC channels!).
The Pololu 24V12 ESC seems to allow very low speeds. Now I have to make some other real tests on a real circuit with some carriages behind.
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Tacbob



Location : Harz, Germany

PostSubject: Re: Live diesel project: Polar-Deva   Sun Jan 31, 2016 4:51 pm

Congratulations Smile. Thatís really a very smooth run also on low speed. Keep up the good work.

_________________
Lorenz
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sun Jan 31, 2016 4:54 pm

Thanks for your support, Tacbob!

A little hello to Bryan who sold me the engine. I hope he will be glad to see it running fine! By the way, it starts very easily.

Since, I have set all the rails I own that is to say around 2,5 or 3m, and try pulling one carriage with a more than 5kg lest on it, and it hauled it without any problem (on a level track, of course)
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Tacbob



Location : Harz, Germany

PostSubject: Re: Live diesel project: Polar-Deva   Sun Jan 31, 2016 6:07 pm

That sounds really good. Do you need much rpm till the produced voltage is enough to set the loco in motion?

_________________
Lorenz
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Sun Jan 31, 2016 6:58 pm

I have no way of measuring thr motor rpm. But I chose a brushless with a very low 350 or 370Kv. If assume reversal (which assume Joule losses to be negectable) 18 volts would correspond to 18x350 = 6300 rpm. I wanted the rpm to be as low as possible for noise and vibration reasons. For a while I thought I had aimed to low. But this first try denies it. One must remember† that the genuine Polar-Deva (built in Sweden in 1924) only had a 90hp engine! so the speed was probably very limited.
In my model the engine seems to be powerful enough not to be obliged to have high rpm. Of course it was only a small try. I must see on a real track with a real train how it moves.
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Saint-Oblas



Location : Lyon, France

PostSubject: Re: Live diesel project: Polar-Deva   Thu Apr 21, 2016 9:05 am

The second try on the floor with all the rail section I could gather (that should be a good 5m!!!) was equally successfull and the pulling force was not bad at all. I was very happy.
I was rejoicing too soon!
I changed the fuel tank because the plastic one I used did not fit into the body. A third try was catastrophic. The engine started several times and stopped after a few second running. I was a bit desperate and put trhe loc aside.
David Grantham has very kindly sent me documents about the magnificent moidel by Ken Toone. I don't know the exact effect it had on me, but it sure awoke me!
Would I have had this paper a few years ago, I probably would not have started my project: I must have had a serious dose of unconsciousness to start such a project as a first model when I see how many problems an experienced modeller has had to overhelm before having it go!!
Any way: Alea jacta est! I have crossed the Rubicon and I will try to take advantage of Ken's experience. It may be a bad fuel feeding to the engine. May be there was some dirt or water dropplets in the new fuel tank. I must try again with fresh fuel as mine may be spoiled by water condensation after more than one year storage. I don't see why the pressure from the exhaust would have worked before and not now. On the other hand, maybe the pipe is closer to the exaust pipe and that I come across the evaporating problem than Ken encountered?

I tell you more afterwards!
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