original 1987-88 Kato GP38-2

[scaro]

Hi

I am wondering if the original 1980s Kato GP38-2 use the same wheelbase truck as the RS3 they did for Atlas ?

Tend to like to check, as sometimes they're a bit out, like their RSD4/5 which was shorter than it ought have been.

And whether the axles are the same as the Atlas-Kato RS3 / ConCor PA 'sleeved' design.

Regards, Ben

[jagged ben]

I can tell you that those two mechs have next to nothing in common. See:
http://www.spookshow.net/loco/kators3.html
and
http://www.spookshow.net/loco/katogp38.html

[peteski]

I can tell you that those two mechs have next to nothing in common. See:
http://www.spookshow.net/loco/kators3.html
and
http://www.spookshow.net/loco/katogp38.html

While that is correct about the mechanisms, but I do think that they use the same wheelsets (plastic axle with integral gear, and wheels with sleeve half-axles).  But I'm not 100% sure as I don't have those locos handy for comparison.

[nkalanaga]

They LOOK like the same wheelsets, and the truck design is the same, although I doubt that they're the same trucks. 

[peteski]

They LOOK like the same wheelsets, and the truck design is the same, although I doubt that they're the same trucks.

That is correct.
Kato RS 3 and GP38-2 use different trucks, with different wheelbases. I was addressing the question about whether the wheelsets used in both truck are the same.

[scaro]

Thanks guys. Useful.  What is the wheelbase of the GP38-2 truck?  I don't care about the mech being similar, provided it can be lengthened.

[u18b]

The trucks are interchangeable as I recall.

But as for stretching a Kato GP38-2..... wow... that would be a nightmare.

What is it you are wanting to do/make?

If you need to stretch a mechanism to a custom length, the Atlas GP38/40/38-2/40-2 mechanism would be better.  And low friction.

[randgust]

The Kato GP38 and GP50 are evolutionary Platypus in our world.   Not that they can't exist, but God never tried that again either.

I can't imagine a project that would use those as a starting point, not even another GP38.  I've got two of them, and they are the darndest oddball mechanism assemblies I've ever seen, and the electrical pickup isn't that great either without any frame pickup wipers.  They'll pull nails out of the wall, but that's the redeeming value of the design.

If you wanted something to chop up and mess with, try a plastic frame LL GP38 with a five-pole.
http://www.spookshow.net/loco/llgp38.html

[peteski]

I think scaro uses oddball N scale mechanisms to built TT-gauge models.  So he needs to re-gauge them from 9 to 12mm.  He needs trucks with inside bearings to do that.  But I agree that the design Kato used on these trucks (and especially on the entire GP38-2 mechanism) is really odd and not really suited for being stretched.  The electric pickup is also not ideal.

[scaro]

Pete's right, it's the arrangement with integral gear/axle and half-sleeve axles which lets me use brass tube, tapped into NWSL code 72 wheelsets, to make new, wider half-sleeve axles. The lack of wired pickup with these old Katos is an enticement too.

However if the GP38/GP50 mech is not able to be stretched, does not sound ideal.  Pity as I'd rather stick with Kato as they're so reliable.

The wheelbase I'm looking for is 16.5 - 17mm. It could be some old Kato Japanese electric or diesel has this wheelbase, or possibly some other manufacturer used the integral gear/axle and half-sleeve axle design?

Tomix or some other Japanese N manufacturer?  Unsure of that.

Or even the 1987 GP7/9 Kato did for Atlas?  If the trucks are shorter than the RS3 (I do not know whether they re-used the RS3 truck with a different sideframe.)

Ben

[nkalanaga]

As far as I know the RS3 and GP used the same trucks, with only the sideframes changed.  After all, they used the same mechanism.

And, since you want them for TT models, they wouldn't be hard to stretch, with a little careful work.  Cut one end between the truck and motor, splice the joint with brass bar, screwed on, and splice the driveshaft.  The TT body should be wide enough to allow for 1/32 inch brass on both sides, which would be plenty strong enough.

[scaro]

Does anyone know truck wheelbases for 'sleeved axle era' Kato Japanese N stuff?  Looking at the DE10 Co-Bo and the range of electrics that ConCor painted up as US prototype.