Upgrading an early 90s Athearn F7A&B

DragonFyreGT Jun 12, 2009

  1. DragonFyreGT

    DragonFyreGT TrainBoard Member

    Not really new to HO as I grew up with it, and even though G-Scale takes up my attention, I have a pair of old Athearn F7A&B Burlington Northern Units I've had since I was 5. A year ago I began to start purchasing parts to upgrade them, and detail them. Right now I have a close coupling kit installed with the diaphragms, passenger cooling pipes, winterization hatches, cab shades, metal handrails, Great Northern Snow Plow Pilot, new steam generator parts, new fans (I have been slicing into the shells and replacing them with these new parts as needed), handrails, orange strobe light, etc.

    Well today I picked up a detailed F-Unit cab for placing into the shells. But before I do that, I would like to know if anyone can recommend a chasis upgrade. Basically I need the cab to fit over the motors, I need a frame designed for DCC and Sound. I've been told by people I know that the new Athearn Genesis frames are a good choice. Other's have told me to go with Stewart Hobbies. I'm really confused at which direction to go in really. What other power trucks/chassis are compatable with Athearn's shells and are the most reliable?
  2. ctxm

    ctxm TrainBoard Member

    Hi, Do your Athearns have plastic sideframes or the older metal sideframes? The later plastic side frame drives run well with just a can motor conversion. You can mount it on sticky foam tape or caulking compound to make it DCC friendly. There's lots of room in F units so sound should be easy.....dave

    ALCOS4EVER TrainBoard Member

    If you are doing all the work to upgrade to DCC, sound and extra detailing why not just find a pair of Genesis units ready to go and save your old units for nostaliga? It will be cheaper and easier with the same results.
  4. James Fitch

    James Fitch TrainBoard Member

    I agree with the above. The old Athearn (now RTR) blue box F7A is very very crude by todays standards. It is generally accepted that the Stewart drives are the best overall, smoothest and most reliable of all the modern HO drives. Intermountain and Genesis are very good also but (with Genesis anyway) some have reported issues.
  5. JNXT 7707

    JNXT 7707 TrainBoard Member

    Can you (or anyone else) provide some info on this? The gap between my old Athearns is beyond the ability of my imagination to buy into :tb-ooh:
  6. YoHo

    YoHo TrainBoard Supporter

    I agree with the others, if you're going to spend the money on a new chassis, then you should just buy new shells too.

    Having said that, if it's an early 90s set, then it's the more modern drive and in that case, all you need to do to put DCC in it is Isolate the motor from the frame and wire in the DCC board. Once you get the motor isolated, it shouldn't be hard at all.
    The more recent Athearn BB mechanism is not bad at all. I wouldn't swap it at all.

    I'm curious though with all these upgrades, did you purchase a commercial window upgrade kit or are you doing your own?
  7. JNXT 7707

    JNXT 7707 TrainBoard Member

    Granted the Stewarts are superior but I'm trying to hijack this thread to find a way to close couple a couple of older Athearn F units. :tb-err: probably is a lot of trouble but the reference above to a "close coupling kit" snagged my search.
  8. river_eagle

    river_eagle TrainBoard Member

    American Limited, IIRC, is the company that makes the diaphgram and close coupling kit for Athearn f units, and others.
  9. JNXT 7707

    JNXT 7707 TrainBoard Member

    Thanks for the information! I'll take a look and see if they are still available. If not I came up with a brainstorm last night on doing a truck-mounted coupler that would bring those units a lot closer.
  10. JNXT 7707

    JNXT 7707 TrainBoard Member

    Well my brainstorm did work. And yes it was a bit of work too although not much more than an hour.
    I truck mounted a pair of 505 Kadees. Some "modifications" were involved, such as removing about 1/8" from the Kadees, along with removing the original frame mounts from the Athearn chassis. The inside of the shell had to be trimmed down some to clear the new couplers. But...it works...and it brings the coupling distance to where it looks right.

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