Old Athearn blue-box frames were part of the electrical circuit from the track to the motor, and therefore we're always "hot" electrically. If you use a metal coupler like a Kadee in a metal box, it, too, will be hot. This could occasionally give you polarity issues and shorts between engines if connected.
For this reason, I always use plastic Kadee boxes fastened by drilling and tapping a small hole into the frame. With the plastic box, the coupler is isolated from the frame and causes no problems.
It takes an iron man to play with a toy iron horse.
Thanks for all of the replies & Help I had glued the metal coupler box with JB Weld,All is fine now working great cheers.
Back in the days when I was still using diesels, especialy ones from Athearn, I cut-off the portion of the metal frames meant for mounting couplers, then replaced them with a stack of .060" sheet styrene, cemented to the underside of the end-platforms. Once the cement had set, I drilled a hole in each stack, then tapped them to allow screw-mounting of the draught-gear boxes.
Not the best photo, but here's an Athearn U-Boat, with a stack-mounted Kadee coupler...
The three U-Boats each weighed-in at a little over 33oz. apiece, and with two motors each, exerted a drawbar pull of 8.3 oz. (or 25oz. when operating together).
Wayne
Tin Can II In past Kadee coupler installations, I was able to file down the coupler pad on the blue box frame, drill a hole, tap it for a 2-56 screw, and screw the coupler box to the frame.
In past Kadee coupler installations, I was able to file down the coupler pad on the blue box frame, drill a hole, tap it for a 2-56 screw, and screw the coupler box to the frame.
Just a little more information to go with the above Tin Can II's Quote. The 2-56 machine screw will use a 'tap drill' of #50 and a 'clear drill' of #42.
Mark EXACTY where you want the screw hole to be with a scribe and lightly center punch that mark. You may want to use a smaller diameter drill bit to make the first hole through the frame/chassie coupler pad then move up to the #50 drill bit. You should put a very small drop of oil on the mark, do not force the drill bit, let the drill bit do the work. Clamp the frame/chassie down before starting to drill.
EDIT: Wait a minute, am I seeing your Athearn Frame picture correctly? Is the coupler pad broke off of the frame/chassie?
As I look closer at the picture, the silver end of the 'short' coupler pad, the file.
Tin Can II In past Kadee coupler installations, I was able to file down the coupler pad on the blue box frame, drill a hole, tap it for a 2-56 screw, and screw the coupler box to the frame. If poissible that works very well. I like to add a very small dab of CA glue between frame and coupler box to keep the box from rotating. The screw does ensure the lid stays on. Charlie - Northern Colorado
If poissible that works very well. I like to add a very small dab of CA glue between frame and coupler box to keep the box from rotating. The screw does ensure the lid stays on.
Charlie - Northern Colorado
could also cut the pocket tab off the frame and glue the kadee plastic box to the shell. a possible last resort sice that would take a little planning and doing to make sure it is set to the right height
SHane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
I'm not so sure that the constant pulling on the coupler could be withstood by adhesives such as CA glue or 2-part epoxy, etc.
Rich
Alton Junction
I agree that the Zinc alloy frame will not accept solder . use 2part Epoxy or JB weld (a sound mechanical connection must be established while the adhesives cure.)
Two things: First, the loco frame material may not be solderable. Solder will not adhere to all metals. The loco frame is most likely a pot metal or zinc material which is extremely difficult to solder to. Second, it is extremely unlikely you are able to get the loco frame hot enough to solder without doing significant damage to its components. I wopuld recomment using an adhesive, maybe a cyanoacrylate "super glue". If possible I would use a Kadee #242 coupler box with a #148 coupler.
The solder you are using is fine for general model and electronic work. Some may suggest a more aggressive flux, such as active or acid, but this will result in long term corrosion and should be avoided. It will also not solve the frame heating issue.
Hello all I am trying to solder a small metal coupler box to my Athearn SD40T-2 frame,But the solder will not stick keeps falling off.Below are 2 photos 1 is a photo of the solder I am using,Other photo is the Athearn frame and the small metal coupler box.What solder do I use to make it stick to the frame and coupler box? Hope you all can help me out thnak you all.
https://ibb.co/3zMQMVW
https://ibb.co/87wmbcF