Thoughts on a mechanism

[Iain]

I'm poking at potential future projects, and one I've wanted to do for a long time is to model Norfolk Southern's electric freight motors.

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(page from the Prince NS book)

These things are tiny, so I'm wondering if there is space to cram a drive in there.


@randgust what do you think?

[wcfn100]

You would need a drive like the Kato NW-2 where the worm drives the truck directly without the usual reduction gear tower.

I've got a couple traction locomotives I'd like to model some day that have a similar situation.

Jason

[pjm20]

Found this:



This guy used the classic Kato steeple cab and repowered it: http://www.teamsavage.com/ncat/Kato_shorty_B.html

[sd45elect2000]

I have a long list of little projects to power. These guys are even bigger than the motors you want to do !!

[u18b]

The Kato B chassis is idea for projects like this because the chassis is plastic and you can cut it to the length you need.   These are the same chassis, just different trucks.
https://www.amazon.com/Powered-Motorized-Chassis-11-105-japan/dp/B0003KCPGY
https://www.amazon.com/Kato-11-107-Driving-Shorty-Commuter/dp/B0003KCPHI

There is also room to move the motor if you need to.
Or.... design your own chassis as I did when I first proposed a GE44 tonner on the Atlas board years ago.   I just made my own frame out of styrene.

[bbunge]

I've recently used a Kato Shortly (11-105) chassis for a traction project.  This is a stand alone car, with the couplers chopped off, so no idea how they pull.   I have a 2nd chassis on the shelf with plans for a traction box motor. 

The mechanism is small, 9.5mm above the top of the deck and 44.6mm long, centered.  I haven't yet pried the plastic cover off, so I'm not sure how DCC friendly it is.  Do wish they had replaceable truck sides like the tomytec units. 

FYI, there is a nice adapter on thingiverse that drops over the 11-105, which then drops into a Bachmann Brill body.

Bob

[Jim Starbuck]

I agree with Ron and that’s exactly what I did on my recent Davenport 45 ton switcher project.

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I cut the frame up and glued the bolsters to the underside of the new styrene sill. This gave me the spacing I wanted while retaining the stock truck mount and pickup strips.

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I used a 7x16 mm coreless motor and extended the worm shafts with stainless capillary tubing.

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You could retain the stock worms and drive them like the stock Kato chassis does. Just a variation on a theme here.
I cut a slot in the styrene sill just wide enough to allow the motor to ride low enough for correct worm to worm gear spacing then glued the motor to the sill with Gallery Glass making a firm but soft mount. It worked great.
The caps that snap on over the worms are what secure the truck to the bolster. If you could come up with an alternate retaining ring below the worm it would gain a little room height wise since the hoods on the units you want to do don’t have much room there.

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I think something similar would work well for your application.
Keep in mind the Kato powered chassis have all wheel electrical pickup but only one truck powered. I used two powered chassis in order to have both trucks powered on my switcher. The little 45 tonner will pull 18 (that’s all I had) 33’ two bay hoppers.

Hope that gives you some ideas,

Jim

[u18b]

Jim, I used a similar coreless 7mm motor in my Shay.

I had my doubts about torque and heating.

But WOW.  Mine was a great motor.   Barely even gets warm.

I like your set up there.

[Jim Starbuck]

Jim, I used a similar coreless 7mm motor in my Shay.

I had my doubts about torque and heating.

But WOW.  Mine was a great motor.   Barely even gets warm.

I like your set up there.

Thanks Ron,

I’ve used several of these motors in various projects and absolutely love them.
No problems with power or or torque.
There’s one in my HH660 build and it’s perhaps the nicest running engine I own.

Jim

[randgust]

That double-ender Kato drive is a great idea.   I've always been defeated with an 8x8 drive on those trucks by trying to fit in universals.    Making it a pivot on the worm gear and eliminating the universals is a radical idea and something I never considered.

The Kato drives have what basically amounts to a 27" wheel on 5'6" wheelbase, very well made, excellent pickup if you don't mess with them.   You can also trade out half-axles if you really don't want that one traction tire the powered truck has.   That might really help an 8x8 drive.

Tomytec has a bunch of chassis out there, but to do it right I'd need to know some estimated dimensions of what you are building.   Their trucks come in 12mm and 14mm wheebases, basically a 33" wheel, end-axle pickups, swappable truck sideframes, easily modified plastic chassis, and driveshafts that can be shortened and spliced.    The "R" versions have a centered gear tower instead of the one at the far end - which would be what you would want for that freight motor.   The original versions have an end-truck gear tower that doesn't look like it would fit under the tapered ends.   The original motors aren't that great but it's certainly not impossible to swap them out if you have enough frame length to fit it in.  The trucks/gears are just as good as Kato.

The number of chassis listed on Plaza Japan can be mind-numbing, and not all Tomytec chassis are always available.  Seems like they run them in batches.   All the Tomytec chassis on Plaza Japan include a measured dimensional drawing of the mechanism, in millimeters.

There's a lot of other Japan/China chassis out there but the quality can be all over the map.   I've seen some really poor wheel profiles out there with no flange fillet and sharp flanges.   The Bandai Shorty-B doesn't even begin to be as good as the Kato.     

Nearly all these little guys are way, way, way too fast.   I've made putting 25:1 gearhead motors in Kato chassis standard for my Climax A models and it makes them an excellent low-speed performer, but you can't do 8x8 drive that way either.   Until Gizmoszone disappeared, their 5:1 gearheads on a Kato 12V motor was the best small motor combination I've seen and ideal for diesel switcher models - I recently took out a Faulhaber coreless and replaced it with that combination in my scratchbuilt 44-tonner.     

As far as for any standard diesel chassis, you'd be looking at a bunch of issues; most split metal frames are nearly impossible to change the truck centers wheelbase on; you would have to mill down the ends to fit, etc.   The Kato/Tomytec/others is the way to go for sure.

[Jim Starbuck]

That double-ender Kato drive is a great idea.   I've always been defeated with an 8x8 drive on those trucks by trying to fit in universals.    Making it a pivot on the worm gear and eliminating the universals is a radical idea and something I never considered.

Randy,

My 45 tonner is so short it requires very little truck pivoting and the worms seem to work just fine like this.

Jim

[peteski]

That double-ender Kato drive is a great idea.   I've always been defeated with an 8x8 drive on those trucks by trying to fit in universals.    Making it a pivot on the worm gear and eliminating the universals is a radical idea and something I never considered.

Radical?
Most N scale diesel models from Atlas and Kato (and others) use that exact design.
The worm is mounted in the chassis, while the worm gear swings with the truck. While not an ideal design from engineering standpoint, there are probably millions of N scale models of that design, and they seem to work just fine. I have never seen any appreciable or improper wear on the worm gear teeth, even in models which so much running time that the pointy axles of the wheelsets wore out holes in the axle cups!

That design goes back to the infancy of N scale (early Arnold and Minitrix N scale  locos were designed that way too).

[Iain]

I don't have any drawings or dimensions of these locomotives.  All I know about them is that they are GEs; I haven't even really started trying to track all that stuff down.

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[brokemoto]

Some of those things look like easy bashes from a caboose.  You even could leave the end platforms.

[wcfn100]

All I know about them is that they are GEs;

Are you sure?

I have a book that has the GE build numbers from 1893 to 1955 and there is no mention of any NS locomotives built or purchased second hand.

Jason