I have many athearn SP blue box locomotives that I have been superdetailing as time allows, and I keep running into issues with the couplers. 1st, if I try to use the stock snap on clip with kadee's, for some reason they almost always flop around and never center right. Also the copper spring piece protrudes from the end of the box and looks like crap, and the whole thing is really hard to install because I have to insert the coupler thru the plow and then try snapping on all the parts without it falling apart. 2nd, I've tried using the kadee boxes and drilling/tapping the coupler tang, but then it's too low and the shank hangs up on the plow. On top of that, on the tunnel motors, the kadee box extends too far back and restricts the turn radius of the trucks. 3rd, If I use another coupler like a bachman or mchenry, they fit well under the stock box and center nicely, but the shanks are too floppy and I have uncoupling problems when running multiple units and long trains. Note that all of my loco's are the older ones with the snap on plastic clips except my -9's which are all done up and work great.
The couplers on my Athearn Blue Box locomotives are in Kadee coupler boxes. I drill out and tap the hole for the plastic clip which goes in the trash. I file the coupler mount down the thickness of the Kadee box part with the centre post in it. This is a kind of try and fit as you go. Once the correct hight is achieved the Kadee box half with the centre post is ACC glued to the coupler mount. When the glue has set the hole is tapped again to clear any glue in the threads. The coupler is then assembled and the screw installed to hold everything in place..
I'll give that a shot, worst case if I file too much it can be shimmed back down with a washer. Do you have any clearance problems with the swivel on the trucks or do you trim the back of the box off? Another thing I may try is to epoxy a piece of flat stock into the body and body mount the coupler box to it, I'll have to see how much room I have though.
I cut the Athearn mounting plate off entirely, then build up the mounting pad from sheet styrene to mount the coupler pocket to. This way, the coupler pocket is part off the shell, and not the frame. You'll need a coupler hight gage before doing anything.
Hah just posted that I have a height guage mounted to a test track. It made an amazing difference when I spent a weekend weighing shimming and tweaking the "gladhands" as far as reducing derailments and uncoupling issues. I want to eliminate the plastic clip....had the in-laws over and after hours of flawless running alone, I hear a pop...and the entire string of cars went zooming backwards down the grade and shot into the tunnel to the garage at 200 smph, luckily all the switches were set and the raduis's were large enough it didn't take the plunge.... Then to top it off as I backed up the loco's to grab the string again I didn't realize the coupler had fallen off and I ran it over and derailed the loco:thumbs_down:
I don't modify the Kadee box at all. I use a coupler that will fit with no modification. On Athearn GP-9 and GP 35 I use a number 8 coupler. On Athearn F7 units I cut off the pounting pad at the hole for the plastic clip. Then drill a hole in the frame and use a number 7 coupler. I also cement the coupler box to the mounting pad. I recommend using Kadee shims or sheet styrene if you file too much.
Mr. SP, Have you done this to any six axle loco's? Reason I ask is that the rear of the kadee box doesn't clear the trucks on the front, and limits the pivoting action when in a turn. The inside of the trucks plastic side snags on the kadee box. On these I may end up having to body mount the couplers but I am trying to avoid it if possible because I don't want to hack up my chassis's. I couldn't figure out why on this one curve the very front axle kept coming off the track, but there is a hidden 22" radius in the back and then 28" radius out front, and I'm pretty sure the coupler wasn't letting it pivot anymore and the radius was too tight.
another reason not to use the metal clip on things is that if one engine shorts, the electrical short will run through the metal couplers all the way down the athearns. I had this happen once and it did some terrible damage to the power pack controlling it. so the plastic coupler boxes that kadee has with a styrene shim over it works great !
Actually, the Athearn BBs used a plastic clip. However, I've seen the Kadees short out. Rare, but I have seen it as you mention.
I've heard about that but never had it happen to me....and I have some BN geeps and an SD9 that are really old that I ran back to back front to front all the time. I guess it would take lots of run time to wear thru the black coating on the chassis...
