Model Engine Maker

The Showcase => Vehicles & Models => Topic started by: Zephyrin on February 21, 2022, 10:08:10 AM

Title: A gearbox for a little locomotive
Post by: Zephyrin on February 21, 2022, 10:08:10 AM

This is about a little gear box for a next project, another small gauge locomotive powered with a 4 st engine...

this gearbox looked quite simple, simple enough to be made very close to the original, and if the rail gauge is 45mm, the spur gears are between 38 & 15 mm, easy to cut with a module between 0.5 and 0.75.

it is something that I thought to be fairly simple, but I underestimated the loss of gray cells when getting older,
and I can't get the succession of gear wheels involved in each position of the 2 selector forks...
how to obtain low and high gear together with for and backward run, as moving either of the lever leads to engage the clutch ?
between idle and leading wheels, i'm out of touch in fact !
Title: Re: A gearbox for a little locomotive
Post by: Roger B on February 21, 2022, 11:18:15 AM
As I see it the engine drives the large gear on the first shaft which then drives the small gear on the second shaft. The shafts will then turn in opposite directions at different speeds.
The speed is selected by engaging one of the shafts with one of the equal size gears in the middle. These are free running on the shafts.
The direction is then selected by engaging one of the smaller pinions with one of the equal size gears (which will be turning in opposite directions) which engage with the large gear below.

I think that I have seen a model similar to this in Maschinen im Modellbau  :thinking:
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on February 21, 2022, 11:30:20 AM
I see Roger just beat me to the answer.

The important thing to understand is that the two equal sized gears in line with the center crank line are freewheeling on the shafts (like the two smaller ones just below), until one of them are locked to the shaft with the two moving gearless wheels on top of the draving (connected to the High/Low selector handle). And the shafts are locked to the gear wheels on the bottom.

Funny - I can't find any clutch on the drawing.

Per
Title: Re: A gearbox for a little locomotive
Post by: Roger B on February 21, 2022, 11:38:38 AM
I believe that the clutches are the fast and slow gear selectors. I have driven some German narrow gauge locomotives with this system. In the cab picture the hand wheel operates a screw mechanism to engage either clutch. The hand lever in the gear diagram is not correct.
Title: Re: A gearbox for a little locomotive
Post by: Roger B on February 21, 2022, 11:48:45 AM
This was the build I was think of:

https://www.vth.de/maschinen-im-modellbau/unsere-beitraege/minenlok-mit-verbrennungsmotor

If I remember correctly the ignition System was in the log wagon.
Title: Re: A gearbox for a little locomotive
Post by: Vixen on February 21, 2022, 11:50:18 AM
Hello Zephyrin.

My take is similar to Roger B's. However I think both levers are shown in the mid position, ie, with neither fwd/rev or fast slow selected. You can see the fwd/ rev gears shown partially overlaping the lower gear. When one of the levers is moved, it moves two of the dog clutch gears ; one move inwards and engages the drive dog clutch while moving the gear central, the other moves outwards disengaging that gear.             Each lever moves two gears and their dog clutches.

The full size engine with it's big flywheel should have been able to tick over quite slowly and the loco would move off slowly when the levers engaged the drive. Model engines tend to run at a much higher speed so engaging the dog clutches could be interesting.

Did you see I recently posted the drawings for my two speed/ rev gearbox on the Westbury Seal topic?

Cheers :cheers:

Mike
Title: Re: A gearbox for a little locomotive
Post by: Roger B on February 21, 2022, 12:34:04 PM
Hello Mike,

If you closely at the gear diagram forward and reverse are dog clutches, fast and slow are cone clutches. Selecting the speed ratio via a clutch was quite common narrow gauge loco practice. The Ruston and Hornsby gearbox selected the three speeds with individual clutches via a lever. O&K used a system similar to that above.
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on February 21, 2022, 03:10:08 PM
Hi,
Thanks for these answers, very helpful!
I had to admit that I can't figure out how to make this gearbox design by myself, this is somewhat frustrating, as I can't see these gears running just by thinking.
I can't upgrade my brain.
Fortunately, skills here are fabulous, and that at first glance experienced modelers know and understand how it works, this is so helpful.

on my previous loco, I simply did a friction drive, with continuously variable speed in both direction, the principle being much simpler...and my "diesel" shunter is a pleasure to  run on the track at the club, and I like to open the bonnet to see and show its inards.
https://www.youtube.com/watch?v=VwDeO6ktf7A

But a geared speed box is a step ahead, mechanically more interesting to do, as far as I understand the functioning !

Yes Roger, this is exactly the type of loco I plan to make. The model published in "Maschinen im Modelbau" is beautiful, I do have a copy of the full paper, very inspirating.
Yes, Vixen, I followed the seal build, and its gearbox too, I hope it will make me clever, it may works at the end !

In fact, I'm still in the project stage, but already if I understand how to make a simple 2 speed gearbox plus reverse, I'll be relieved!
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on February 21, 2022, 06:59:49 PM
That is almost cheating Rodger .... having read the original build article - the link is a dead give-away :Lol: 

I must admit that I can't deduct the Cone-Clutches in the drawing - I can see that they aren't Dog-Clutches as  Forward and Reverse .... But it makes perfect sense that they are clutches and works as you describe.

I also agree that both "Levers" are in "Neutral" in the bottom drawing.

Interesting Shunt Loco - I will certainly follow  :cheers:

Yes - I remember the build of the one in the video Zephyrin  :ThumbsUp:
Title: Re: A gearbox for a little locomotive
Post by: steamer on February 21, 2022, 07:48:37 PM
GailNM built a small loco powered by a "tiny" engine.    It wasn't that long ago.   

Dave
Title: Re: A gearbox for a little locomotive
Post by: Dan Rowe on February 21, 2022, 08:05:00 PM
Dave the gas loco Gail built was a model of the Hornsby-Akroyd oil engine 0-4-0 Lachesis which was supplied to the Woolwich Arsenal in 1896. This was an 18" gauge line the model is 7/8" scale on 32mm track.

Cheers Dan
Title: Re: A gearbox for a little locomotive
Post by: steamer on February 21, 2022, 08:19:34 PM
Dave the gas loco Gail built was a model of the Hornsby-Akroyd oil engine 0-4-0 Lachesis which was supplied to the Woolwich Arsenal in 1896. This was an 18" gauge line the model is 7/8" scale on 32mm track.

Cheers Dan

That may be, but I know he made one with  Tiny hit and miss engine in it....maybe O or G gage....
Title: Re: A gearbox for a little locomotive
Post by: Dan Rowe on February 21, 2022, 08:35:19 PM
Yes Dave we are talking about the same loco with a Tiny hit and miss engine. Gail made a small batch of these and I missed out.... :facepalm:

Cheers Dan
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on February 22, 2022, 08:58:56 AM
Yes Gail Graham (GailNM)  built 2 different loco for 7/8 scale, both powered by the "Tiny" H& M engine, the Woolwich and a Baldwin loco, visible on his Utube channel "nmsteam". He built more than a dozen of these models !
https://www.youtube.com/user/nmsteam/videos

The realistic point is that with an H&M engine, the tickover sound at idle is really close to the original loco, in spite of a larger rpm.

Thanks again for these explanations. I clearly understand now how this gearbox works...
I had completely missed the presence of a hidden second set of clutches the cone clutches unravelled by Roger in the upper set of wheels (langsam/schnell)
The wheels are free on the 2 rotating axles when not engaged by the dog or cone clutches.

I can also buy one of the cheap plastic gearbox for rc cars and trucks, simply to look inside...if it is simpler before cutting gears, there is a lot of teeth to carve !
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on March 07, 2022, 10:10:39 AM
Hi,
I found on the Net a page about the restoration of one of these small Deutz narrow gauge locos, with a description of their transmission!
thanks again for your explanations, the only point that differs is that the clutches are not cone clutches, but wrap spring clutches (Schlingfederkupplung), not that simple to get them working in model, I think to be satisfied with a simple soft friction drive with an O-ring…

http://gillbachbahn.bahnwiki.org/index.php5/FWM_Lok_35
http://gillbachbahn.bahnwiki.org/images/b/b7/C14getrb.PNG (http://gillbachbahn.bahnwiki.org/images/b/b7/C14getrb.PNG)
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on April 10, 2022, 03:24:59 PM
Hi,
Here are the first parts of my next model, a small Deutz 4-stroke field loco for narrow gauge (600mm), at 1/13.5 scale, for 45 mm rails, from the images above.
I especially liked the transmission, and thanks to the help I received here on how the gearbox works, I was able to reproduce it faithfully enough, with the dog clutch system for both directions and the clutch on both shafts, fast and slow; the latter is done here by friction and cone instead of the spiral spring (Schlingfederkupplung), a bit too complex to miniaturize.
and I added a reducing stage because my engine will not be able to run at the speed of the original, 300-400 rpm !

This is not the chassis of my future loco, but just a first test "to see" if everything works well with recycled loco components...
I put a small dc electric motor and a battery to animate the whole stuff, the power varied from 0.5 W when idling to 0.8 W, for fast forward.

https://www.youtube.com/watch?v=6UVJZqS2TNQ

The whole thing is quite satisfactory, except the PLA 3D printed dogs, fried after these tests...
I still have to put a steering wheel for the speed clutch and a lever for selecting the direction gear to keep these couplings well engaged during the ride.

Then the engine, a small 4 stoke (about 2cm3) with long stroke, will be also quite interesting to make, the rest of the model being more conventional modelling!
Title: Re: A gearbox for a little locomotive
Post by: Johnmcc69 on April 10, 2022, 04:40:21 PM
 :ThumbsUp:
EXCELLENT!
 :popcorn:

 John
Title: Re: A gearbox for a little locomotive
Post by: RReid on April 10, 2022, 05:11:24 PM
What a great little gearbox! I'm looking forward to watching this project develop. :ThumbsUp:
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on April 11, 2022, 08:35:15 AM
 thanks for the appreciations!
and thanks again for unravelling the mechanism of this transmission !

some pictures of the components.
I did first a set of 3d printed dog clutches, to see if they easily engage, but obviously they didn't last for long ! I hope the brass ones would last longer...I still have to make a new set with a slopped or staggered part in the dogs, as in the original drawings.
all the axles are mounted with roller bearing, to minimize drag in all these gears. I'm confident that my engine will cope with it.
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on April 11, 2022, 11:10:37 AM
A very convincing demonstration of the whole system  :praise2:

+ thank you very much for having the Deutch drawing in the background of the second to last picture - as it helped me to understand how the original clutch worked  :cheers:

Per
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on April 11, 2022, 06:40:24 PM
 Ha ha, the clutch with the spiral spring, I replaced it by a friction drive... as I didn't understand the arrangement..

but recently I have found on the net the instructions for use for these little loco, with the setting of the spiral clutch, with 0.5mm of clearance between the drum and the spring, with the proper documentation the mechanism in now cristal clear even for me...
pressure on the disk push the little lever and reduces the diameter of the spiral spring which bind to the drum and drive the gear wheel...
It is very clever, but alas too difficult to miniaturize...but if everything goes, maybe I will have a go.



Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on April 11, 2022, 10:30:47 PM
Nice to see it in even bigger format - but you can actually se it in the picture I mention  ;)

Per
Title: Re: A gearbox for a little locomotive
Post by: Roger B on April 12, 2022, 05:10:20 PM
Excellent  :ThumbsUp:  :ThumbsUp:  :wine1:

Some similar gearboxes were made with cone clutches, I think O&K may have been one of them. The spring type clutch, under the name Scroll Clutch was used in some early Mercedes Benz cars.

https://www.practicalmachinist.com/vb/antique-machinery-and-history/scroll-clutches-wrapped-spring-type-152483/
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on April 13, 2022, 10:57:17 AM
Thanks Roger,
the level of knowledge here is amazing !


Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on October 15, 2022, 08:39:40 AM
Some progress in this project, after a break and a visit to the hospital, I resumed the built of my loco, phew!.

I dit a short test on rails in the club of the little gearbox...

https://www.youtube.com/watch?v=JmsvwhXA32E

and continued on the loco, with its final chassis almost finished, somewhat bigger than the one in the video test.

and I also did some work on the 4 stroke engine too, I machined most of the parts from aluminium stock by turning the handwheels by hand while reading dials...
In spite of spending hours (and having fun) to model the engine in 3D with Solvespace, and 3D printed main parts, I didn't manage to get any good aluminium casting from the PLA 3D printed parts except the cylinder head.

Getting alum. castings was the main goal of all this 3D modelling work...that seems useless now !

https://www.youtube.com/watch?v=E-RMN9a095M

I will continue on a new topic, owing to the warning that it is a old thread...
Title: Re: A gearbox for a little locomotive
Post by: Roger B on October 15, 2022, 10:20:49 AM
Glad to see you back on this and some wheels turning  :ThumbsUp:  :ThumbsUp:  :wine1:

There's no need to start a new thread, it's better to keep it all in one place.
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on October 15, 2022, 06:29:50 PM
You have made a lot of progress since your previous post - thank you for showing  :ThumbsUp:

The Test-Mock-Up ran nicely  :cartwheel:  - but I did not see how you switched from High to Low Gear ?

You have installed some nice handles - is this also how you plan to opperate it on track later ?

I hope that whatever put you in Hospital is a closed chapter behind you   :LittleAngel:  :cheers:

Per
Title: Re: A gearbox for a little locomotive
Post by: cnr6400 on October 15, 2022, 06:51:58 PM
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on October 17, 2022, 09:08:39 AM
Hi,

Here's the continuation of the build, with some pictures of the loco itself, plain model making, 2 mm steel sheets cut and assembled by riveting and screwing on commercial brass angles, a not at all square stuff !
turned wheels in cast iron, held on the axles by cylindrical embedded nuts.

I didn't bother to make the suspension, as I'll need the space between the frames.
On the other hand I had to made the brake controls, a very visible element on a model of this scale (1/13.5). The brakes are fully functional, but you have to be on board...

https://photos.app.goo.gl/3VSvxSn7pVwXpShA6

I will probably add coupling rods on the wheels, much more attractive than hidden gears for coupling wheels, and present on some these machines...

the fast/slow switch uses the little wheel which moves a small lever against one or the other of the 2 coned
clutches. this more visible on the last picture.

"
Quote
I hope that whatever put you in Hospital is a closed chapter behind you
yes Per, far much better after than before the surgery...with some 5.5 x 40 screws in my lumbar spine, self tapping screws, but they use tap on some occasions, yes, I did, I couldn't help asking.
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on November 04, 2022, 06:28:47 PM

Some more changes on the wheels, as I adopted external coupling rods, much more appealing on such a crude loco, and which leaves me plenty of space between the frames to house the ignition.

https://photos.app.goo.gl/oEopL2Rwagq23Ty48

Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on November 04, 2022, 06:36:09 PM

And now the engine...always my favorite point in model, even if I choosed this model owing to the gearbox !

the  plan of the engine is extracted from the same original picture, lot of infos, but really confused (the first picture of the thread)
it is a small 4 stroke engine with 12mm x 20mm bore & stroke, i.e. 2.2cm3, with spark ignition (coil and contact breaker) and carburetor.
the original engine had a magneto and a pump intake, (if I understood correctly), but I gave up the fuel pump at this scale.

the machining from bar stock is fairly conventional since I don't have any good aluminium castings with my 3D models...

https://www.youtube.com/watch?v=TtRIWxtQ6IQ


Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on November 04, 2022, 07:43:35 PM
Looks really old fashioned - and one German caption mentions that is was originally a Mine-Shunter - so do you plan to run it under ground  ;D

No matter - I really like the Looks and Apperance  :Love:   :cheers:

Per
Title: Re: A gearbox for a little locomotive
Post by: Roger B on November 04, 2022, 07:54:07 PM
Excellent  :praise2: The crank and camshaft look to run freely. I have done fuel injection down to 6 cm3 cylinders however 2.2 cm3 is another challenge. The pump would need to be 1.5mm bore and the injector needle 1mm  :headscratch:  :thinking:  ::)
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on November 05, 2022, 07:37:47 AM
You are right, Per, this shunter is pretty ugly, but not so ugly that she has to be hidden underground!
I chose her only for the engine and the transmission; and most of the pictures I gathered show the loco without the bonnet, fortunately !
(https://www.feldbahn-ffm.de/wp-content/uploads/2019/02/ffm_lok_b3.jpg)

Roger, with all that I learned by following all your experiments, testing a fuel injection system was my intention at the beginning of the project, this engine dates from right before the diesel and was a good model to have a go...
 But I had to leave this project this summer, and since I have lost its ambition and direction, and now, I'm trying simply to finish this small engine to the simplest and wishes that my model run like this stationary version of this 1905 Deutz engine.

https://www.youtube.com/watch?v=0-nAtXU8AO4




Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on November 05, 2022, 06:14:29 PM
I don't know about 'Hidding it Underground' .... as much as the fact, that it was presumeably meant to do almost all it's work underground -> not much point in 'Prettying it up' ....

I don't know how important it is to you, to make your models authentic - but if not (and you have a succesful roling chassis, w. Engine) - you could always put a more 'Atractive Top' over it  ;)

No matter what - I find your project very interesting  :cheers:

Per
Title: Re: A gearbox for a little locomotive
Post by: Roger B on November 07, 2022, 09:52:26 AM
I'm happy that you were thinking about trying a fuel injection system  :) however life dosen't always go the way we want  ::)

I look forward to seeing it running along the track  :ThumbsUp:  :wine1:
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on November 11, 2022, 09:37:43 AM
Thanks for your interest folks, a much appreciated nudge !

Here is the progress of the model, at this stage I still have the most difficult part to do; the cylinder head with the valves, the rocker arms and the cams...and then to make the engine alive!
I don't get tired of looking at all these little gears, in fact it's mostly for that reason that I'm making this model!

https://www.youtube.com/watch?v=n3JMKeJZ750
Title: Re: A gearbox for a little locomotive
Post by: Johnmcc69 on November 11, 2022, 07:11:04 PM
 :ThumbsUp:
 That really is some GREAT work. You're right about the gears, it's poetry in motion. I feel like a cat chasing a laser pointer when I see all those motions.  :Love:

 John
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on March 24, 2023, 05:26:12 PM
  warning says that there are more than 120 days since my last post , how quickly time flies when building models...

Here are the first tests of my little 4 stroke engine, in its final version for my 1910 Deutz loco...I even tested it in place on the loco!
Note that the original engine was not a true diesel, not yet common in those days, but a conventional 4 stroke engine, hence my choice for this model.
it respects the dimensions of the original, he also has a hopper for cooling water and a spark ignition through an electronic box. it uses plain car gasoline with 2% motor oil.
Break-in took about 2 hours of actual running to feel both a free rotation and a high compression, the best moment in the making…

It is a small engine (2.25 cm3) with a very long stroke, 20 mm for 12 mm bore and a volumetric ratio of only 4.3 owing to a large combustion chamber, it also has 2 "large" cast iron flywheels; then I was hoping for a slower running than my previous ones, but no, it isn’t, once again in the 4000 rpm idle, ie, about twice as expected. I will see how the speed changes upon different loads.


I have not yet been able to correct this surging running, an ignition failure at high rpm cannot be excluded, but it seems to me to come rather from a poor carburetion and atomisation, the air/petrol mixture is not stable with this small needle mixer...
A fuel injection at this scale is out of my competence, as well as the beautiful centrifugal speed governor present on the original...alas.

https://www.youtube.com/watch?v=sSqc76KTdtw

Once again it's going to be a struggle to fit everything on my loco… :hammerbash:

Title: Re: A gearbox for a little locomotive
Post by: Johnmcc69 on March 24, 2023, 06:21:42 PM
 A great running engine & a great project!

 John
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on March 24, 2023, 10:00:59 PM
Quote
A great running engine & a great project!

I agree completely  :praise2:

I do not think that you should expect to get it to run much slower .... it is a question of the combined friction and power loss, compared to the produced power ...!
All in All - Very good for such a small Engine  :ThumbsUp:     :cheers:

Per
Title: Re: A gearbox for a little locomotive
Post by: Kim on March 24, 2023, 10:28:00 PM
Congratulations!  That is very cool! She seems to run great! 

Kim
Title: Re: A gearbox for a little locomotive
Post by: Roger B on March 25, 2023, 07:47:09 AM
Excellent  :praise2:  :praise2:

My 3cc four stroke also tends to surge. I found that the carburettor temperature was quite critical and added a plastic insulator between it and the cylinder head.

The loco looks good, you seem to have the gearbox sorted  :)  :)  :wine1:
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on March 25, 2023, 03:00:19 PM


Thanks for the appreciations, much welcome !

Quote
I do not think that you should expect to get it to run much slower

yes Per a sort of cold shower, i was assuming, from what i have read and understood, (model engines are far from my academic degrees!) that with a longer stroke, my engine will give its peak torque at lower rpm, nearer from the wished "put put put put" and not the usual screaming note.

I will make soon tests with loads to check...(electric test would be the simplest)
 
Thanks for the tip Roger, a thermal insulator is easy to add...and test
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on May 16, 2023, 09:43:44 AM

the construction is going slowly...

I made a small muffler for the engine, placed under the floor of the loco, as on the original.

The exhaust pipe is simply cut in 2 and both parts connected through a expansion chamber, of about 5.5 times the displacement, I made a measurement with Audacity, (a free and powerful audio editing software)
and I note 9 dB of sound attenuation without even screwing the muffler in place, just put in front.
I show you the exhaust tests

https://www.youtube.com/watch?v=KIuTBrT-p6k


And still in the sound domain, the engine noise starts to have some realism when the engine is running at low speed while keeping enough power to move the loco!
the noise is low enough to allow the hearing of each of the put put put put... which was the secret goal!

I still have to fit and hide somewhere the ignition and all those ugly cables.

https://www.youtube.com/watch?v=_FlUNDl14cg

and by the way, I've dropped my personal electronic ignitions, definitively, very similar to the commercial ones, except for the way they work.
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on May 16, 2023, 11:44:10 AM
First - Congratulations for your new Sound from the Loco / Engine - it has a certain realism to it  :praise2:

Quote
i was assuming, from what i have read and understood, (model engines are far from my academic degrees!) that with a longer stroke, my engine will give its peak torque at lower rpm, nearer from the wished "put put put put" and not the usual screaming note.

This is one of those Urban Myths that are imposible to kill  :facepalm2:
You got the same pressure and if it is applied to a bigger surface, you have more power, but multiplied to a shorter stroke => same Crank output - and Vice Versa ...!
The true difference can be the Fuel/Steam consumption .... (but also other factors are in play here).

Per              :cheers:
Title: Re: A gearbox for a little locomotive
Post by: RReid on May 16, 2023, 03:16:07 PM
The engine runs very well, and sounds great! Congratulations, Zephyrin! :ThumbsUp: :ThumbsUp:
The muffler must work quite well, it would be interesting to hear "with" vs "without".
edit - Sorry, I overlooked the prior video that does just that. A significant difference!
Title: Re: A gearbox for a little locomotive
Post by: Kim on May 16, 2023, 05:25:56 PM
Very effective muffler!  And interesting experiments to measure the noise level. Thanks for sharing those with us.  :ThumbsUp: :popcorn:

She runs really nicely and makes a great put-put sound!

Kim
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on May 16, 2023, 08:26:12 PM
 thanks for the comments, much welcome !
yes I love the put put sound, at last i feel a progress in this direction...
I will not do this sound test again as the muffler becomes rapidly really hot, and I burn my fingers...

a well of science as always Per, thanks , great to have a clear view on so many topics, as my engine is not yet complete...
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on June 13, 2023, 09:27:16 AM

After putting the fuel tank in its final place, above the engine crankcase, as in the original model, I can no longer see the connecting rod turning alas, but above all new carburettor problems occur. It is harder to get the idle right, and the engine drowns quickly when starting... I did a lot more testing, (and even get some pops with the butane torch !) and finally rebuilt a new carburettor, with smaller passages from a small zamac casting: 
This new carburettor seems better, starting up is a lot easier... explosions from the first launches, and air fuel adjustments are possible very early on. The fuel inlet line is also more direct, with the fuel intake opposite the needle, well separated from the heat of the exhaust; I watch it running  with pleasure...
https://www.youtube.com/watch?v=mG7R_7boSOs
Title: Re: A gearbox for a little locomotive
Post by: MJM460 on June 13, 2023, 10:44:26 AM
Well Done Zephyrin, a great result for all your work.  Good to see it running so well. 

Now for the track?

MJM460

Title: Re: A gearbox for a little locomotive
Post by: cnr6400 on June 13, 2023, 12:16:27 PM
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:  Great job!
Title: Re: A gearbox for a little locomotive
Post by: Vixen on June 13, 2023, 12:28:13 PM
Well Done Zephyrin, :ThumbsUp: :ThumbsUp: :ThumbsUp:

I bet you are 'chuffed' with the result.

Mike
Title: Re: A gearbox for a little locomotive
Post by: Kim on June 13, 2023, 05:45:05 PM
Very nice, Zephyrin!  :ThumbsUp: :popcorn:

Kim
Title: Re: A gearbox for a little locomotive
Post by: RReid on June 13, 2023, 08:13:04 PM
Runs very well, and that is really a remarkable bit of packaging! :ThumbsUp: :ThumbsUp:
Title: Re: A gearbox for a little locomotive
Post by: Roger B on June 13, 2023, 08:19:31 PM
Excellent  :praise2:  :praise2: You must be happy with that  :)

Flexible carburation is a complicated subject which is one of the reasons I ended up working on fuel injection although I think at that cylinder size it would be beyond my skills  ::)
Title: Re: A gearbox for a little locomotive
Post by: Admiral_dk on June 13, 2023, 10:37:03 PM
Even better now - impressive  :praise2:

Waiting to see it back on track pulling a wagon or two  ;)   :cheers:

Per
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on June 14, 2023, 10:14:30 AM
thanks for the comments !

Yes, the next step is on the track at the club...
I'm doing a small wagon to carry the ignition box and the battery, as the loco is already too tightly crowded.
I also have to make the bonnet, probably only for the shelf, as the temperature inside while running would certainly be too high ...
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on August 26, 2023, 10:52:57 AM

Here's the first test of my little locomotive on the club track...
A successful test, I'm happy to say! The engine and transmission worked well together.

I finally had to build a small wagon, as I couldn't find anywhere else to put the ignition box. It was merely 4 wheels and 4 axle boxes cast in Zinc alloy, bolted on a brazed steel frame.

although the idling engine does drive the loco at a realistic very low speed, I don't really like this snail's pace, I prefer to step on the throttle and watch my loco move along the track at a faster speed...
The drawback is that the little 4-stroke gets very hot at the end of the run, when the 10 ml of petrol is over, about 10 minutes, the cooling water is almost boiling.

https://www.youtube.com/watch?v=8H-LTSykAkM


Title: Re: A gearbox for a little locomotive
Post by: cnr6400 on August 26, 2023, 01:06:46 PM
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :cheers:
Title: Re: A gearbox for a little locomotive
Post by: RReid on August 26, 2023, 02:57:53 PM
I'm just so impressed with what you've done, Zephyrin, and how well that little loco runs!  :praise2: :cheers:
Title: Re: A gearbox for a little locomotive
Post by: Kim on August 26, 2023, 04:06:18 PM
Congratulations Zephyrin!  She's quite a little runner!  You should feel really good about your loco!  Excellent run!   :ThumbsUp: :popcorn:

Kim
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on August 27, 2023, 08:52:16 AM
thanks for the kind comments, much appreciated !
you can easily imagine how pleased i am with the result !
a year and half working on it, and it's not completely finished; before the next project, I still have to put a hood on the engine, which probably will be constantly open, because of the engine heat, like on many pictures of the real machine I could see by the way...
Title: Re: A gearbox for a little locomotive
Post by: Roger B on August 27, 2023, 09:49:38 AM
Excellent  :praise2:  :praise2:

Successful model IC engine powered land vehicles are quite rare. You seem to have got the engine well matched to the load  :)
Title: Re: A gearbox for a little locomotive
Post by: Zephyrin on October 03, 2023, 03:01:01 PM
Hi,
here's my loco in its new blue livery, "bleu roi ou bleu de France" according to the french racing cars of the past years and of "our" french football and rugby teams.

Of course, the whole engine is impossible to cover, first the engine is a bit too big, or the chassis too small, although I'm not far from the true scale, but the small parts are largely out of proportion (spark plug or carb for example) and second because I need to keep access for starting, tuning, greasing and all the rest
She seems noisier with her hood, in fact it's mainly the rolling test bench that's heard (it doesn't have ball bearings).
All the controls still work well.
at the next overhaul with dismantling, i'll give the chassis a lick of paint - i can already see traces of rust!

https://www.youtube.com/watch?v=4PlWerbi_6g

here its first run in its final suit, on a track at the club, a fine run that makes me quite happy...and closing this project !
I hope I'll have the energy to start a new build....

https://www.youtube.com/watch?v=QAwBcnO0aYA




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