# Just when you thought it was safe...



## ralphbrades (Jan 3, 2008)

{2}

regards

ralph


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## Greg Elmassian (Jan 3, 2008)

I see the jackshaft that "appears" to bypass the fluid coupling... is that the reversing gear? but then it would be without the "clutch" as it were. 

Looks like a really fun project. You are using an oil bath to cool the motor, or just the fluid coupling? 

Oh, it's actually "worm" (longer skinny one) and "worm gear" (the gear that is driven by the worm)... weird... 

Regards, Greg


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## Michael Glavin (Jan 2, 2009)

Ralph, 

Interesting project... 

I haven't heard one of these glow conversion two stroke diesels run, what kind oif RPM are we talking? 

Michael


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## aceinspp (Jan 2, 2008)

I may be wrong but looks like it's close to what Pope built. Later RJD


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## Cougar Rock Rail (Jan 2, 2008)

Very interesting Ralph, but I also can't see why both the viscous coupling and the counter shaft are connected to the same input on the differential. 

Keith


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## Semper Vaporo (Jan 2, 2008)

The gear "around" the shaft from the engine is not connected to the shaft; it is just concentric to it and floats on it. The shaft drives the inner vanes of the fluid coupler which swirl the oil which drives the other vanes and they are connected to that outer gear. The shaft that goes next to the fluid coupler just transmits the power to the differential gears. The differential gears are NOT connected to the fluid coupler itself.


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## Michael Glavin (Jan 2, 2009)

I missed the re-circulated water cooling system at first gander. I noted the fan and oil cooling coil in the water tank. How are you cooling the water is that a coil in front of the fan or a water cascade much like an evaporative cooling tower? 

The spur gear is incorrectly identified and depicted as same it should be a WG or worm gear. Worm or worm gears are helical and or spherical cut. That said the Ws or worm depicted is disproportionate to what would be its actual physical size...


WG = worm gear (the gear that is driven by the worm); RWG = reverse worm gear (gear that mates with WG but not a worm

Ws = steel worm (the part that looks like a screw and is frequently miss-identified as a wormgear);

I liberated the definitions from nwsl.com

Michael


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## Cougar Rock Rail (Jan 2, 2008)

So are you saying that once the outer shell of the fluid coupling starts to rotate the whole counter shaft will also rotate with it? If so, wouldn't there be a major issue with vibration/balance? Sorry I'm so thick... 

Keith


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## Michael Glavin (Jan 2, 2009)

The fluid coupling shell is fixed in place. I believe the spur gear inline with the engines output shaft is taking a free ride until such time the fluid pressure builds engaging same and transmitting power to the jack shaft onto the “dog bevel gear interchange box” which provides FWD-REV. 

Michael


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## Mr Ron (Sep 23, 2009)

Have you checked out the Wada Works of Japan website? They make a diesel locomotive powered by a model airplane engine, driving a generator and electric motors all in 1:32 scale. You may get some ideas there.


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## ralphbrades (Jan 3, 2008)

From the Marine glow motor the torque is transmitted via the fluid coupling, there is no physical contact between the input discs and output discs. Oil is pumped into it to increase the amount of coupling and it drains away back to the oil reservoir by gravity i.e. it duplicates a *Mek Hydro* clutch system and the frictional heating is cooled by the water/oil intercooler in the water reservoir. The dog bevel system provides fwd/rev by capturing the rotating bearing block thus forcing the bevels to rotate. The central spur gear then takes the power off to the ends of the two bogies where the inner axles are powered via external conrods. Here in the UK we call this assembly a "Worm and Spur Gear" setup

The water tank (and added ice!) pumps water around the top of the cylinder and the hot water is cooled via the radiator which is of the twin row "square spiral" type and the system returns the water to the reservoir. The air from the fan vents through the length of the loco and out the other end.

This does actually duplicate in a very simple way the actual power chain of the original loco. Except for the fact that it only have one engine. The original had four power engines and two supercharger driving engines.

regards

ralph


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## ralphbrades (Jan 3, 2008)

Mr Glavin,

I checked my parts and measured them against the drawing... The worm gear is 1.0cm long (4.0cm including bosses at either end) and is 1.5cm wide. This is HPC part number ZW1-2 it has two starts and the spur gear is 3.0cm in diameter and is 0.8cm thick, and this is HPC part number ZM1-30. All gears are DIN 75441 Derin and are MOD1 and are rated at 1.32Nm. As such they *do* match the drawing. All the positions and sizes on it are to within 0.01cm -it is only a rough drawing...

I would also suggest you read my "bio"....

regards

ralph


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## Torby (Jan 2, 2008)

[No message]


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## Cougar Rock Rail (Jan 2, 2008)

Very cool Ralph--looking forward to seeing this one take shape! I really like the idea of a fluid coupling, and often thought all G scale trains should use a simplified version of one to prevent gear damage. Either that or some sort of a magnetic clutch. 

Keith


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## Michael Glavin (Jan 2, 2009)

Ralph, 

I wasn't trying to be critical; IMO your drawing makes the Ws or "worm gear" look disproportionate to what I have seen previously. Generally the worm or screw is twice as long as the diameter of the gear. 

Page 250 of HPC's catalog indicates the ZW1-2 bored gear overall length is 4cm with a working screw length of 3.2cm x 1.7cm diameter. 

I had not considered a working model radiator, neat stuff… 

Regards, 
Michael


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## Pete Thornton (Jan 2, 2008)

it duplicates a Mek Hydro clutch 
Ralph, 

Great project. I'm still confused about the 'output gear' that bypasses the fluid coupling. The latter I understand - my dinghy outboard has an automatic clutch that refuses to slip at higher revs but allows slip at idle. So what is the output gear and shaft feeding the bevel/differential for? 

_Scott McDonald was running his Wada Zephyr at ECLSTS - I posted a couple of pics and a v short video._


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## ralphbrades (Jan 3, 2008)

Peter, 

The motor shaft turns the Green discs. The Red discs are co-axially mounted on bearings to the input shaft. Friction between the fluid and the two sets of discs transmits the torque. The output gear is mounted on the end of the last Red plate and all the Red plates are linked together via a cage of 16 2mm steel bolts. The only connection between the Green and Red discs is the rotating oil. Thus the Red discs transmit the torque out of the Mek Hydro via the output gear. So, if there is no oil in the system -the clutch is "out" and the more oil you pump in the more torque the clutch supplies.

The Dog bevels provide the reversing system. *It is not a differential as such.* By using the servo to hold the Bearing block stationary, the bevels are thus forced to move and the whole system shifts into reverse. When the bearing block is free the whole system rotates as a whole and no reversing effect happens.

I hope this has helped.

regards

ralph


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## dawgnabbit (Jan 2, 2008)

Ralph,

One of these days you'll have to try building something a little more difficult than usual.


(Than usual for_ you,_ that is -- LOL)

Good stuff! I'll enjoy watching this one.

Dawg


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## ralphbrades (Jan 3, 2008)

Steven, 

You mean like this? 

 [url]http://www.cabbagepatchrailway.co.uk/gasturbine.html [/url] 

regards 

ralph


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## Cougar Rock Rail (Jan 2, 2008)

Very cool Ralph! 

For your ignition problem could you use a r/c plane glowplug? You might be able to take the head section of an old .049 and machine most of it off, leaving just enough to hook a clip to and the coil etc. 

Keith


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## dawgnabbit (Jan 2, 2008)

Nawh, Ralph.

I meant something REALLY difficult. Maybe something with a working onboard nuclear reactor. If anybody can, you can.


(Just kidding, just kidding)

Dawg


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