Kato Unitram trucks for tiny projects

[robwill84]

I know a lot of you guys here like to tinker with tiny power projects (as do I). Here is a relatively new power source I recently became aware of- self contained power trucks from Kato tram models. Here is a page showing how to get to the trucks-

http://www.rmweb.co.uk/community/index.php?/topic/23779-okwb-kato-portram-evolves-to-a-lister/page-2

And this page has a breakdown of whats inside. Pretty amazing little assemblies!

http://www.rmweb.co.uk/community/index.php?/topic/23779-okwb-kato-portram-evolves-to-a-lister/page-3

Street price is well under a hundred bucks for a tram, and each one comes with 2 power truck assemblies. Pretty cool!

[Philip H]

those are pretty hot little power trucks.

[robwill84]

Youtube videos mostly show them running pretty quick, here's a guy that made a narrow gauge critter out of one. Very nice speed control, and watch it go over that turnout. That's pretty impressive.

[Philip H]

from the photos they look like small pager motors with different gearing.  I assume if you dcc'ize them you can get better speed control.

Hum, makes me wonder if these would work for a RANDGUST climax or dunkirk . . . .

[robwill84]

Yeah! Or a GE 25 tonner! These would be ideal, just stack as much weight as possible on them and I bet it would really pull.

[robwill84]

Little more info, here is one compared to a L.G. Thek chassis (scroll to the bottom). Looks like the same diameter wheels, and maybe about a foot longer wheelbase...

http://www.hon30.org/l-g-thek-9mm-mechanism-first-impressions/

[peteski]

Good find Rob, but these threads are 3 and 4 years  old. We had a similar discussion on the A-board when Portrams first came out (around 4 years ago).

I have couple of these but I haven't had the time to do some serious reverse engineering or experimentation.  The biggest obstacle is the pager motor. It is probably designed to run at 1.5 or 3V max.  The circuit board houses components (it is not just a simple resistor) to lower the 0-12V to a range safe for the motor.

What also worries me about these is the fine-toothed gears.  These will be very prone to getting jammed with all sorts of debris found on the layout's right of way.

But I do have to agree that these tiny self-powered trucks show some serious potential.

[Chris333]

I'd be interested to play for around $50, but those trams are around $130. I do see some gear reduction so that is better then straight worm to axle 15:1.

[railnerd]

FWIW: My local hobby dealer noted that you'll burn up the UniTram if you run them on 12V DC.  Might want to add a limiting resistor in series somewhere in case you are going to run them on track with > 9V.

-Dave

[VonRyan]

Are both tram trucks powered?
And perhaps the whole truck assembly is available as a part from Kato?

-Cody F.

[TiVoPrince]

Portram
runs pretty darn quick at 6vDC.  There is a specific decoder for the Kato Portram out there but I never found a method to get one from Japan without resorting to smuggling. 

Digitrax has a neat bit UP6Z, reduces regular DCC to voltage levels required for 'delicate' decoders.  I would really like to DCC my Portram and similar motored green Kato tram...

[peteski]

The specifications on the box state Max. DC12V (not 6V). So, if it burns out on 12V, Kato should honor the warranty.  As I mentioned, there is a circuitry already built-into the model which reduces the 0-12V input voltage to a lower voltage the motor can handle.  If that circuit was removed then I can see the motor burning out from being powered directly by 12V!

Each truck is a self-contained power unit. SO there are 2 motors and 2 voltage reducing circuits in each model.  I have not found trucks offered as a separate spare part.  But I suspect that even if they were available, the price of 2 trucks would be higher than the price of the complete model (just look at the spare parts prices for US locos on the Kato USA website). 

EDIT: the instructions do show the truck along with the voltage converter as a part you can buy.  Part number is 14801D1G . Price 1890 Yen (that's around $20!) That is cheap! Good luck trying to get one though!

[robwill84]

Yeah, I'd really like to find a way to get these to play nice with DCC. They would be perfect trucks for something like this:

http://www.pacificelectric.org/wp-content/uploads/2010/03/DD00034.jpg

[randgust]

When I saw that photo of the truck disassembled, showing the gear train inside...

HOLY $#@@!  Now that's Kato engineering at its best.  Or for Peteski, the worst.  Depends on your perspective I guess.

There's no way I can pass on that one.   No way.  That's just an amazing design to drop the motor down in there.

My favorite Japanese supplier has them for $87, hmmm.  Probably still worth a shot.