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Just another modeller
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QUOTE (steamrailuk @ 26 Jul 2008, 22:31) <{POST_SNAPBACK}>Thanks for the info. The reason why I'm using the double frame is because I have a bachman 08 diesel shunter with that wheel design and since having it I've always wanted to build a victorian styled loco with outside frames.

The reason for the tender motor is because i tried to fit it in the front but it was too big so I dicided to move it into the tender but kept it driven in the front to give the loco enough traction.

The locos you have suggested are very nice designs, I may look into building something like those in the future.

Regarding the motor and driveshaft design. I'm only using the motor from the hornby 0-4-0 and its worm gear, possibly also the cog if needed. I was planning to use a rubber sleeve/ tubing to connect the loco and tender drive shafts, a simplistic form of the universal joint and both shafts will be fixed in place to prevent them flexing except at the joint, in the bends.

I will take into consideration the idea of mounting the motor to the front end while its still in the tender but that may just complicate it. The idea of mounting the driveshaft below the footplate I will try if the gears can go low enough.

If i can find all the parts i need to make it work I'll post a more detailed drawing showing the layout of the motor design.

***It will work just fine - I'm close to completing several Midland 4F's with exactly that drive system - fine music wire as a driveshaft inset into pure silicone tube. Keep the centre of gravity low and the loco will work well and if you fill the body with lead, it'll pull well also.

Richard
DCCconcepts
 

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Just another modeller
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QUOTE (steamrailuk @ 28 Jul 2008, 02:42) <{POST_SNAPBACK}>Which one would work fine? the method I'm planning on using or the method you suggested?

Both - with conditions: Alistair covered it prety well.

The "rubber" part should not be too long or it will twist much a Alistair's spring - only a tiny bit of twist will be bad for drive smoothness. If the shaft is more than a few CM most should be rigid with flexible material only at the UJ positions. You will have to be sensible with radii - such drives are best on larger radii,

Richard
 

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Just another modeller
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QUOTE (34C @ 28 Jul 2008, 16:01) <{POST_SNAPBACK}>A small can motor mounted on a fold-up multi stage kit gearbox will fit out of sight within small, low boilered prototypes with none of the difficulties of engineering and concealing a driveshaft coupling. Likely to make for a much simpler job.

*** Yes, but its not always the right answer.

It is much easier to use an acceptable sized motor in EM or P4 as "between the frames" can be utilised better, but not so easy in 16.5mm. Motors get to be too small.

Experience shows that small can motors have little torque and less tolerance for hard work, especially current batch mashimas which run far too hot... space for weight is lost and pulling performance suffers. For harder working loco's not such a good idea...

Its only kitchen table engineering really... there's little difficulty in using a single or 2 stage box and tender driveshaft other than arranging front/rear bearings for the worm on the gearbox, and thats not so hard. Use an NWSL gearbox and its done for you.... Add a little pure silicone aircraft fuel line as the flexible part of the shaft/as replacement for universals and its smooth as silk....

I'd possibly sometimes stay with a loco mounted motor in a whitemetal loco but having built a large number of loco's such as Brasmasters 4F with the beautifully crafted milky bar boiler anything small that does not have a metal body now works better for me with tender drive - its effectively invisible with a close coupled tender anyway, and the ability to use the entire boiler and firebox filled with lead makes a big difference to pulling power on a 4F etc.... A well balanced 0-6-0 will do surprisingly well built this way. Add suspension and pickup improves & pulling power is exceptional!

Richard
 

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QUOTE (steamrailuk @ 29 Jul 2008, 22:13) <{POST_SNAPBACK}>I'll consider the gear step down method for the driveshaft if I can find enough gears to do so.

You brought up how I would collect power from the track to motor. The only methods I can think of will be using one of hornbys methods, running a wire from the loco to the tender. The other is from what I saw on my American Old Timer 4-4-0, collecting power from the tender wheels. The later seems the best option at moment.

I was informed to use silicon tubing for the connection between the two driveshafts, but I don't know where to find it. Does anyone know what type of stores sell silicon tubing small enough "about 1mm inner diameter"?

**Actually if you close couple engine and tender and use a music wire driveshaft its pretty well invisible anyway, so above the footplate is OK if thats a lot easier for you..

As stated earlier in this thread, the silicone tube is model aircraft fuel line - you should be able to buy it at any hobby shop that sells R/C aircraft I'd think...thats where I get mine anyway.

Richard
DCCconcepts
 
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