I have some Athearn Blue Box locos that the motor mounts ( Plastic ) are questionable. Can anyone tell me what size machine screws to use to replace them.
Thanks. Kay.Div.
Blue box Athearns never used screws. (?)
Mark.
I have a couple of old Atheard BBs that did use screws to hold the motor to the frame, back from the Eisenhower administration. I replaced them with 2-56 screws. I used nylon screws so the motor would remain isolated from the frame.
After that, I removed the motors and gears and ran the engines as dummies.
What are these screws you speak of?
LION would use a glob of silcone caulk and call it finished.
ROAR
Do some more research, but I think that all BB locos can be converted to screw mount, but you can’t really just screw into the existing mounts very well, IMO.
Replace the existing plastic “push through” mounts with replacement mounts that Athearn sells, which are also designed to accept replacement screws that fit inot the holes in the underside of the fuel tank. Athearn’s website probably has the part numbers listed.
Those older mounts do dry out and get loose.
Or do what LION does and just fill the gap between the frame and motor with caulk, being careful not to get too much underneatrh as to compromise the connectivity between the underside of the motor and the frame.
LION wires all of the Atheran motors of him, so frame conductivity is moot.
ROAR
Regardless of how you fasten the motor, I would suggest that you do so that will isolate the motor from the frame. even if you are running DC, now, RTV/ silicone install or relying on the bottom clip to frame for conductivity, will make it far difficult in the future if you decide to run DCC .
Athearn sells modified motor mounts that use screws instead of just pushing into place. Check their web site.
EBay is full of listings for motor mounts and screws. Many online Athearn parts retailers also carry them. ATH 84028 is a package of 4 mounting pads and 8 screws
Len S