hackin gup and old athearn

[ShaunCN]

hi everyone, got another question. I have an old athearn SDP40 that i bought at a train show for $8. it run fine and everything but i would like to make it into a SD20-2, i was originally was simply going to make it a SD40 but now i want to make it into t SD20-2 wich requires me to remove a good section of the long hood as the SD20-2 only had two rear fans and the one i'm doing will have no DB brakes either, anyways it is simple to modify the body and take the required sections out but what about the frame, i think i would have to remove portions of the fuel tank on either side of the motor but once i cut through the metal frame how do i re attah it together? also since it's an athearn the motor gets power from the metal frame. i'm just full of questions. O and it will hope fully look something like this one when i'm done http://www.trainweb.org/chessiephotos/photos/SD20-2/7702cs-b&o.jpg
o ya the drive shafts would have to be shortend up as well i think[?]

[raynbecky]

Your best bet would be getting an Atlas SD35 since that's what the real ones used. The SDP40 is too long for starters. You would have to do a lot less modification to a SD35 if you started with one of those instead of an SDP40. About all you would have to modify on an Atlas SD35 is the removal of the 36" fan as well as the db blister and fans. You could use an Athearn GP38-2 non-db hatch to replace the old SD35 hatch.

[ShaunCN]

one problem is i can't afford to buy any other locomotives. so all i got to work with is the SDP40, plus the body is alredy pretyy much junk so one way or another the body needs to be fixed

[jrbernier]

Shaun,

You have a real project on your hands. The SD20-2 was built out of an SD35. This is a lot shorter than the SDP40, so you will have to shorten the fuel tank/frame. For the body, you can get a Atlas SD35 shell, but you may have to also get a 'thin' Athearn motor if this is a real old Athearn(fat motors) so it will fit in the correct Atlas body.
The 'real' SDP40 was only purchased by GN and NdeM. The 6 GN units went to BN, and at least one of them wound up on MRL, IIRC.

Jim Bernier

[wp8thsub]

QUOTE: Originally posted by ShaunCN

...the body is alredy pretty much junk so one way or another the body needs to be fixed

If the body is that far gone you'd be better off trashing it. Athearn's SDP40 is from their old tooling which is very poor in comparison to newer models. The hoods are too wide, the door latch detail looks truly awful next to newer shells, the cab is a mess, etc. I once spent a lot of effort rebuilding an old shell Athearn GP35 (narrowing the hoods, new grills, Cannon parts everywhere, etc.) and it still looked like a dud when Kato's GP35 came out.

Assuming the mechanism runs, you may want to consider your $8.00 an investment in spare parts to use in other Athearn units. If you do decide to go ahead with the project and shorten the frame, even if the finished frame doesn't conduct electricity around the splice it's easy to re-establish electrical flow to the motor. Solder a jumper between the motor and the metal portion of the truck that contacts the frame (assuming you're not using a DCC decoder), bypassing the frame entirely (this works on any older Athearn unit and really helps maintain power pickup).