Has anyone converted 2 Rail Atlas O Gunderson stack cars to 3 Rail? I just bought a pair of andrews trucks and am about to tackle it but I can use some tips. I E-mailed bill from atlas and he responded "You have to mill the end platforms to go from 2 to 3 rail." but i am still unsure. Thanks for any help you can provide
No experience here, but I'd bet it depends on your curves.
The coupler swing is probably restricted by the end platforms he mentioned.
IF you use larger radius curves the problem is reduced or eliminated, depending on the curve.
I don't think its coupler swing. I think the issue is the ability to mount three-rail truck-mounted couplers at all.
My recollection is imperfect, but I think the Gunderson is one of the few Atlas cars that has different body-end components for two- and three-rail. The reasons have to do with mounting the two-rail couplers. Normally, there's no difference in the body between two- and three-rail, and one can see on the three-rail version of the car the place or pad where two-rail couplers would mount. There is no place on the three-rail Gundersons to mount two-rail couplers, probably because of clearance issues with the truck-mounted three-rail coupler. (I know this from having done the opposite conversion).
So my guess is that Bill is telling you that after you remove the two-rail coupler draft gear boxes from the car, you have to get rid of the mounting pad for the two rail couplers in order that the three-rail coupler won't foul on them when you mount three-rail trucks.
To test this, remove the two-rail trucks and then the couplers. Once the draft gear boxes are off, try fitting a three-rail coupler on the car. You should pretty quickly get an idea of what's in the way and needs to be removed. I think you will find that it is the mounting pad for the two-rail couplers that is in the way. Whether the conversion actually is feasible or worthwhile, I just don't know. (You might consider keeping the body-mount couplers and thereby dip your toe into "Three Rail Scale").
Also, while it's your railroad and you can do whatever you want, and all that sort of thing, Andrews trucks are not correct for these cars. Roller bearing trucks are correct.
Rich, That is one of the most detailed replies i have ever heard, Thank you for your insight. Now i can't wait to get home from work, put those puppies on my bench and get cracking, thankfully i have a complete 3 rail TTX set to use as a guide. I was the stupid one who bought a NOKL 3 rail C-D-E and a 2 Rail A-B set. Hope this works. I will keep this updated and thanks again!
Ok so far I have taken the trucks and the coupler off and now I see what bill was talking about, there is a small metal lip (1/32") that extends the whole side of the coupler box and half way on either side of the front. This is missing on my 3 rail version. I put the 3 rail trucks on and the coupler only swings a few degrees left or right. If I had all 072 curves I think i'de be ok but I don't. Seems easy enough to grind out and it gave me an excuse to pickup a Dremel. Now I just have to wait for amazon to deliver it and i'll be golden