swapping trucks around between atlas and kato chassis

[scaro]

hullo all

i'm wondering if atlas RSD trucks as used on their RSD4/5 and C628/C630 could be swapped into a kato SD40 or SD45.

probably a dangerous question, but i've heard that some you can swap, some you can't. 

it's about getting a correct wheelbase for a TT scale model ...

regards

ben

[nkalanaga]

The only RSD's I have are the original Atlas/Kato units, and those certainly aren't interchangeable with any of the newer units that have axle-end pickup.

[scaro]

hullo,

no, i'm thinking about the atlas china ones, not the atlas kato. 

they are 12'6" wb in N = 9'4" wb in TT (with a centre axle removed.)

cheers, ben

[u18b]

hullo all

i'm wondering if atlas RSD trucks as used on their RSD4/5 and C628/C630 could be swapped into a kato SD40 or SD45.

probably a dangerous question, but i've heard that some you can swap, some you can't. 

it's about getting a correct wheelbase for a TT scale model ...

regards

ben

If you want RSD trucks, your best bet is to get an Atlas/china RS1.  Cut the chassis and stretch it, and then place RSD trucks under it.

Here are two of my examples.

SD18




U25C

[scaro]

thanks ron ... is the rs1 mech particularly easy to stretch?

regards, ben

[johnh35]

Here is a thought. The Atlas 8-40B truck tower is the same as used in the RS3. Since the RS3 uses the same mechanism as the RSD4 (with the trucks being the difference), the RSD4 trucks should fit the 8-40B mechanism. Will that get you close on your wheelbase?

[AVR Mark]

You might want to keep in mind that the Atlas (China) "RSD-5" trucks are only powered on two of the three axles, unlike the older Atlas (Kato Japan) version which has all three powered.

Mark

[peteski]

You might want to keep in mind that the Atlas (China) "RSD-5" trucks are only powered on two of the three axles, unlike the older Atlas (Kato Japan) version which has all three powered.

Mark

It has been a long time but IIRC, the old Kato-made 3-axle trucks also only had 2 axles powered. But I'm not 100% sure.

[u18b]

The RS1 chassis is easy to stretch because of its low height.   It leave room to screw a square brass bar after you cut the pieces.

The following photo predates the Atlas China RS1, but the principle is still the same.  Make the cut in the middle of a low flat spot.
Then drill and tap 00-90 screws to mount K&S square brass tubing.
The worm shaft can be lengthened by gently beating it out of the worm and replacing it with a #53 drill bit (same diameter as Atlas/Kato shafts).  Do away with the inner bearing blocks.




Oh, I almost forgot I have made one more RS1 equipped loco.  A U28C.

[scaro]

You might want to keep in mind that the Atlas (China) "RSD-5" trucks are only powered on two of the three axles, unlike the older Atlas (Kato Japan) version which has all three powered.

Mark

oh? thanks for that. which two are they powered on?  sounds like it is wisest to use the C628/C630 - same wheelbase but IIRC powered on all three.

The RS1 chassis is easy to stretch because of its low height.   It leave room to screw a square brass bar after you cut the pieces.

The following photo predates the Atlas China RS1, but the principle is still the same.  Make the cut in the middle of a low flat spot.
Then drill and tap 00-90 screws to mount K&S square brass tubing.
The worm shaft can be lengthened by gently beating it out of the worm and replacing it with a #53 drill bit (same diameter as Atlas/Kato shafts).  Do away with the inner bearing blocks.




Oh, I almost forgot I have made one more RS1 equipped loco.  A U28C.

thank you for the shot!

[scaro]

Here is a thought. The Atlas 8-40B truck tower is the same as used in the RS3. Since the RS3 uses the same mechanism as the RSD4 (with the trucks being the difference), the RSD4 trucks should fit the 8-40B mechanism. Will that get you close on your wheelbase?

it may, but what is the 8-40B's length between axle centres?

cheers, ben

[scaro]

i am assuming the RSD has outer and centre axle powered and the rear is a dummy.  please tell me if this is not so, but it is the most common arrangement. 

converting to a B- truck by removing the centre axle, would, if this is true, mean only one axle per truck is powered, which doesn't sound great. 

i should focus then on the C628/C630 truck as it has all axles powered so a conversion to a B- truck would retain power on both remaining axles when the centre wheels are removed. 

now, the $64 question ... can this truck be installed in the RS1 chassis? 

regards

ben

[johnh35]

After checking some of my engines, the 628 truck will not work in the RS1 or the SD40. However, the SD40 truck is only 6 scale inches bigger than the AAR B truck to start with (from data I have read), so that would be even less in TT. If you are taking out the center axle, will that much difference be worth the grief? If you need the AAR B truck, cutting down a C628 would see to be the solution.

Another thought is the Trainmaster. It is almost spot on for the outer axle spacing and maybe the mechanism is close to what you can work with? Just some ideas

[u18b]

I'm pretty sure the RSD trucks from an Atlas/china RSD 4/5 will fit in an Atlas/china RS1.

[johnh35]

I'm pretty sure the RSD trucks from an Atlas/china RSD 4/5 will fit in an Atlas/china RS1.

They will, but he needs the outside axls driven and the RSD 4/5 China trucks aren't. I presume he is going to make a 2 axle truck in TT scale.