Sumpter250 EOY 2010 challenge

[ocalicreek]

I was thinking the same thing, only with SF 3751 or Maybe bringing some other steamers out of retirement like Cotton Belt 1522 pulling a mixed consist of excursion traffic. 3985'd work just fine, though. Better than fine, really.

Thanks for the reply. I've got a dinky little AHM 0-4-0 that'll get a boiler motor at some point, hopefully. I bought one from All Electronics, but the gearing was way too reduced and I was afraid I'd burn out the motor just getting the little guy to move. It'd creep, that's for sure, but I don't have that sort of time to switch cars!

Anyway, looking forward to seeing what you do with it. So far it's lookin real good.

Galen

[e-paw]

Very cool build. This challenge is full of steam power.

[Green_Elite_Cab]

Sumpter250
As Galen wrote before, i too see no need to place the motor in the tender. If the motor is in the tender you need to use a long drive shaft with two universal joints and with a telescoping member in the middle.

Galen wrote:
"You just might be able to get that dinky little motor in the boiler or firebox somehow. Is there a particular reason for putting it in the tender?"
That was tried, and is the reason why this project wasn't done a long time ago. I had intended on using a gear tower, so that the motor could sit on to of the drive gear box......it didn't work.
Leaving the boiler "empty", allows me to get the loco's weight balanced for better tractive effort.

Schraddel wrote:
" On the photo it seems to me there is a brass bushing over the Motor shaft. And it's outside diameter is equal as the diameter of the gearbox input shaft. "
The brass bushing was part of the above mentioned "gear tower modification". I may turn it down just a bit to accept a smaller universal fitting ( cup ).
the drive will be configured: [drive gear box shaft with cup...intermediate (through firebox/cab) shaft with ball, and cup in the cab area...connecting shaft with ball at both ends...and cup on the motor shaft.
The other consideration is that that intended motor, will not be strong enough to move the loco. The boiler area is not big enough to allow a larger motor, without removing all the backhead detail I've already built. There's room in the tender for a slightly larger motor if needed. ( I really didn't want to see "motor" inside the cab ).

Have you considered using Model Aircraft Neoprene fuel line? This may easily solve your drive problem. You only need to cut the fuel line the proper length between the Worm gear's shaft and the motor's shaft. It will pull apart easy enough if you have to, but when the motor turns on, It clinches down on the shaft, kinda like a Chinese Finger trap (you know the one, where you can't pull your fingers apart?). If the locomotive ever binds, the fuel line will twist off rather than let your motor burn out.

Its actually a very reliable technique, and i've used it to repair a couple P1K RDCs and an old Metroliner (pictured below), as well as tried it in an old Athearn locomotive. Again, its probably cheaper and easier than to try and make a solid drive shaft. it is flexible and will stretch and twist with the tender.

[Sumpter250]

Have you considered using Model Aircraft Neoprene fuel line? This may easily solve your drive problem. You only need to cut the fuel line the proper length between the Worm gear's shaft and the motor's shaft. It will pull apart easy enough if you have to, but when the motor turns on, It clinches down on the shaft, kinda like a Chinese Finger trap (you know the one, where you can't pull your fingers apart?). If the locomotive ever binds, the fuel line will twist off rather than let your motor burn out.
Its actually a very reliable technique, and i've used it to repair a couple P1K RDCs and an old Metroliner (pictured below), as well as tried it in an old Athearn locomotive. Again, its probably cheaper and easier than to try and make a solid drive shaft. it is flexible and will stretch and twist with the tender.

I tried that with my HOn3 2-4-4-2, and it was great until the first curve. with a curve in the neoprene tubing, it was just stiff enough to cause problems with the tender.
Because this is a standard gauge loco the tubing idea might just work. Once I have the drive ready to test, I'll try both the tubing, and the cup-and-ball universals, and see how they compare.

[Schraddel]

Sumpter250
These neoprene or silicone tubes have an bugbear.
They are manufactured by extruding, a continous process, and after some cooling down these tubes are rolled on a drum. For this reason they got a permanent bend. I have never seen exactly straight tubes all of them had an curvature or pre-bending as memory effect.
The photo of you show this pre bending curvature.
Used as an driveshaft it will work properly as long as the two shaft ends are exact in line.
Until the first curve. Then the tube is bend under rotation. The material has to be fulled on every rotation to equalize the not in line shafts.
And there is an pre-bend in the tube.
Rotating such an pre bend tube causes in unequal forces to bend it, depending if you bend it in the direction of the pre bend oor against it.
Thus can be resulting in an unequal running of the drive mechanism.

I have found this in the www:
<!-- m --><a class="postlink" href="http://www.clag.org.uk/cv-couplings.html">http://www.clag.org.uk/cv-couplings.html</a><!-- m -->
It may help you.

Pleas excuse my bad English

Lutz

[Green_Elite_Cab]

looks interesting. I can see why it didn't cause much trouble on the metroliner, since that part of the shaft doesn't move. good to know there are ways to improve the problem there.

[Sumpter250]

Sumpter250
These neoprene or silicone tubes have an bugbear.
They are manufactured by extruding, a continous process, and after some cooling down these tubes are rolled on a drum. For this reason they got a permanent bend. I have never seen exactly straight tubes all of them had an curvature or pre-bending as memory effect.
Used as an driveshaft it will work properly as long as the two shaft ends are exact in line.

Pleas excuse my bad English
Lutz

That manufacturing process is fine for fuel lines, but yes, the curve in the tubing can and does cause at least some vibration, if there is any misalignment of the two shafts.

Your English, is far better than my German !!

[Sumpter250]

Needless to say, the project hasn't seen any progress, and probably won't be anyway near ready by the end of the challenge.
But.......the basic frame is now built, and once the "Holiday madness" quiets down I'll be able to get this loco built and running.......which is what I wanted, to get started on finishing this.