Baldwin-Westinghouse Class B

[timwatson]

With this setup the worms would turn opposite directions. You could remove one of the worm bevel gears and run a common shaft with both worms on it to get them to run the same.

Great point Jim this is much simpler/reliable. I fixed it. I did make a version with the worm and gears reversed on the opposite side as well.
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[bbunge]

https://d24rugpqfx7kpb.cloudfront.net/SCM/26AD0E1B8C66D0656FFE5EA5B014A996/0018_0020instr.pdf

The shift in units made my head spin for a second as I zoomed in to make sure those were inches on one view and mm on the other view!

Bob

[Chris333]

The shift in units made my head spin for a second as I zoomed in to make sure those were inches on one view and mm on the other view!

Bob

Yeah I deal with that all day at work.

[nkalanaga]

NASA lost a Mars probe by doing that.  One part was programmed in American, the other in Metric.  Missed Mars completely.

[randgust]

The Kato 11-105 trucks have somewhat of a fatal flaw in that the center gear tower places the shaft and universal inboard quite a distance, the center of the trucks swings that universal left and right, leaving very little room in the middle for a motor and driveshaft.

But if you take a look at the solution Kato came up with in the NW2, you should get an idea; that's more or less the same design, but the driveshaft connecting the trucks has a vertical spur gear and the motor is above the driveshaft.  Don't get all hung up on the split gear thing, just look at the concept.  The 11-105 trucks should work, the Kato approach of putting the motor above the driveshaft with a spur 'might work', and also get you reduction and torque you need.

Note on the NW2 also how LOW the truck driveshaft ended up, another point.  Vertical clearance for the motor.

On the 11-105's, look at the driveshaft.  It can be cut, shortened, and spliced with a tiny bit of brass square tubing drilled out to .040 and reset with ACC.  I have to do that on all my Climax models with the 25:1 gearhead drives to fit, it's REALLY a tight squeeze.  That gets me one truck drive and 25:1 reduction, about 15mph top speed, and yes, the motor can be shucked over to one side.  I'm using the Solarbotics GM15A, that's my go-to gearhead and motor, dirt cheap.

I was seriously looking at this NW2 approach to do my Heisler as I have to have two-truck drive, and I might do it yet.   If Kato had made those NW2 motor/gearboxes available, I might have even done a kit, but despite directly reaching out with a proposal, no such luck.   But that's how you get a short wheelbase truck system to work on both trucks powered if you have some vertical carbody distance.

[peteski]

Yes, Kato NW2 and also RDC trucks use a low profile design, but the wheelbases are too long for this model (those trucks look like they have a freight truck's wheelbase).



I've been thinking if this rather short vehicle really needs swiveling trucks?  Why not make it solid 4-axle wheelbase and just add separate trucks sideframes to make it appear like it has 2 swiveling trucks?

Also, only the end hoods are off-center the main body is full width and centered.

[randgust]

The conceptual design I used for my Heisler was lucky in that I could fit the motor high up in the cab and clear the driveshafts off the 11-105 trucks instead of the NW2 trucks.   Don't know if that might help here, but an alternate approach if you really want two-truck drive.

But a 6mm 3V gearhead (with a 100 ohm dropping resistor) on the 11-105 single truck drive will undoubtedly work even if you have to shuck the little motor/gearhead over to one side.   I've built dozens of Climax models that way, and my 25-ton Shay had to deal with the sideways offset issue.

Normally you'd never get away with a series resistor; the original Kato 11-105's used those and they were a complete turkey, the resistors would heat up on full slip, difficult to control under load.  But in a gearhead, the draw is greatly reduced and torque is higher, so the series resistor is stable rather than either overheating or fluctuating motor voltage under load.  Now the Kato 11-105's use a 12v motor, but that legacy circuit board is there because it used to have the resistor on it.

The other oddball mechanism that probably won't work for this application but deserved mention as Tomytec is rerunning it is the ED01, that's an end-axle pickup, short truck, incredibly short 8x8 drive.  Plaza Japan is taking preorders again for like $26 each (instead of Ebay extortion), I got a couple, that's the only way I can get 8x8 in my Whitcomb kit, worked quite well.
https://www.plazajapan.com/4543736256663/?srsltid=AfmBOoo6QKy5nIhJLhpXu8zxYRNoJWW5m2eKAZyxEdEniZ5OkJMS-nNV

If I thought Tomytec would stick with this darn thing instead of discontinuing it periodically I'd go all out on my Whitcomb kits again.

As far as fixed four-axle, well, depends on your curves.  Atlas did their 4-4-0 tender that way, it's not crazy.

[InterurbanModels]

As expected, the Kato 11-105 (or 107) could not fit, even if it is not so far away. Once the white motor cover removed, there is a little more space. Perhaps relocating the motor to the center could bring some relief to make place for the gangway beside the off-center hood.
The off center hood means that in fact you must design the drive like there is nearly no hood at all.

Keep in mind that I would like to create a motorization that could be build with basic tools by everyone.

[InterurbanModels]

General dimensions (scale 1:1, grid spacing = 12"). Truck center distance is 192", Wheelbase 78"

[Chris333]

I started a 45T looooong ago and used the Kato worm enclosure as the blower motor. A bunch of us here have shortened those drive shafts.

[Chris333]

I started a 45T looooong ago and used the Kato worm enclosure as the blower motor. A bunch of us here have shortened those drive shafts.

Crap I still have it. Built this 15+ years ago. Sorry for the dust.



What it should look like:
https://resourcedrails.com/cdn/shop/files/DSC_5902_1024x1024@2x.jpg
https://resourcedrails.com/cdn/shop/files/DSC_5923_1024x1024@2x.jpg

[Jim Starbuck]

As expected, the Kato 11-105 (or 107) could not fit, even if it is not so far away. Once the white motor cover removed, there is a little more space. Perhaps relocating the motor to the center could bring some relief to make place for the gangway beside the off-center hood.
The off center hood means that in fact you must design the drive like there is nearly no hood at all.

Keep in mind that I would like to create a motorization that could be build with basic tools by everyone.

You can shorten the driveline by eliminating the couplings and driveshaft altogether and installing the worm directly to the motor shaft. This will move the motor more central where there’s room. Still retain the worm cover which keeps the truck attached to the chassis. The worm will reside inside the cover but won’t be attached at all. The truck can still pivot with the truck gear engaged with the worm.
With the chassis being so short the truck doesn’t need to pivot much if at all.
I’ve used this technique several times but also mounted the geared truck solid to the chassis and let the other truck pivot. Too much emphasis gets put on the truck needing to swivel with these short mechanisms.

[peteski]

Too much emphasis gets put on the truck needing to swivel with these short mechanisms.

Exactly!

[InterurbanModels]

No no no ! This is for Traction modeling !

[Chris333]

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