I picked up a used MDC/roundhouse RS-3 at a swap meet a little while ago. It was complete except for the couplers. the couplers seem to be attached to the frame with small screws that would go through the draft boxes, frame and then into the shell. They also seem to be what keeps the shell on. Does anyone know the size of screws that are required?
Mdc Rs-3
- Thread starter Glen Haasdyk
- Start date
Glen, I don't know for sure, but it seems that a 2-56 screw would be a logical size, as that's the proper size for mounting Kadee draft gear boxes. My second choice would be a self-tapping screw, not because it's a particularily good choice, but rather because MDC did use them on a lot of their rolling stock kits. 
Wayne
Wayne
I'd have to hunt for the extra shell I have to be sure (it's never been used), But I do believe Wayne is correct.
(Edit) I just looked up the part sheet and it states they are #90008 #2x1/4 screws.
Then I looked at the other part sheets I have and found #90008 listed as a #2x1/4 self tapping screw.
(Edit) I just looked up the part sheet and it states they are #90008 #2x1/4 screws.
Then I looked at the other part sheets I have and found #90008 listed as a #2x1/4 self tapping screw.
It does indeed use 2/56 screws. These only hold the coupler and cover plate, not the loco shell. I have two of these unit and on both the body shell snaps on.
Now I'm a little confused here. there are no snaops that hold my body shell on. the sell slips over the motor and geartrain and sits on the top of the frame. there are cast and threaded holes in the shell directly in line with the holes on the coupler mounts on the frame.
I assumed that this was an MDC RS-3 since it's using a complete Athearn drivetrian including a gold motor.
I assumed that this was an MDC RS-3 since it's using a complete Athearn drivetrian including a gold motor.
Glen,
Is there one or 2 screws to hold each coupler pocket? If there is only one, you may have a Stewart RS-3. The MDC has 2 for each.
Is there one or 2 screws to hold each coupler pocket? If there is only one, you may have a Stewart RS-3. The MDC has 2 for each.
There is one. as I said it goes through the coupler pocket (which isn't there) the coupler pad on the frame and into the cast-in hole on the body.
maybe it is a stewart unit. I hadn't even considered that. I supose they used Athearn componts as well? If so, to get back to my original question, what is the size of the coupler/ body mount screw?
maybe it is a stewart unit. I hadn't even considered that. I supose they used Athearn componts as well? If so, to get back to my original question, what is the size of the coupler/ body mount screw?
Are the air tanks cast onto the sides of the fuel tank? if so it is a Stewart.
I used #2x56x5/16 screws on mine.
The MDC RS3 has plastic add on air tanks.
I used #2x56x5/16 screws on mine.
The MDC RS3 has plastic add on air tanks.