Getting a shell to stay put on IM SD40-2s

[Ed Kapuscinski]

I'm playing with my fleet again and realizing that some of my ride height issues are because the shells aren't fully seated.

The little nubs in the shells seem a bit worn and just aren't doing their job well.

Has anyone dealt with this type of thing? Any creative suggestions for holding the shell on and really keeping it there?

[mmagliaro]

Maybe just some short little strips of styrene glued to the inside of the shell with liquid styrene cement (so they are really fused on there and won't break off)  to build up the nubs?

[Ed Kapuscinski]

Maybe just some short little strips of styrene glued to the inside of the shell with liquid styrene cement (so they are really fused on there and won't break off)  to build up the nubs?

I thought about that but they're little "bumps". I'll try and get a photo next time I have it opened up.

These damn things have so much potential, but just continue to let me down in subtle ways (like this).

[Steveruger45]

Not had this issue on mine but maybe try a blob or two of Bluetack on the frame before nesting the shell on.
Never tried this myself so just an idea.

[jagged ben]

I've cut squares of electrical tape about 1/4" wide and put them over the nubs.  Maybe not the best but relatively effective f9r the effort involved.  I like the tacky putty idea too.

[squirrelhunter]

I use blue painters tape cut into tiny squares for hood units where the shell won't stay on. I put one on each end (on each side) and add more if necessary.

Speaking of IM SD40-2's, has anyone tried to lower one? I picked up one with ditch lights recently, and they way those are run makes me think there might be a enough space between the top of the decoder and the inside of the shell to grind off the nubs that support then shell and lightly file down the top lip of the fuel tank area of the frame so the shell will sit a little lower.

[tehachapifan]

The IM tunnel motors never struck me as riding too high in the least. As far as shell looseness, all of mine are quite a bit looser than I would like.

Edit: Sigh....I only just realized you guys are all talking about the SD40-2 and not the T-2.

[mecgp7]

Double sided carpet tape. Put it on the appropriate places on the frame and then put the shell on. A light squeeze and she is stuck until you want to change it. The tape is rugged, but it doesn't entirely stick to the loco frame. You can get the shell off if need be. One bonus is it may reduce noise as the shell won't vibrate. I've used the same to attach coupler boxes. Stuff will last forever or just use it to put the box in place then drill your hole for the screw. Perfect results everytime.

[Ed Kapuscinski]

These are all very good ideas.

I had personally thought of just a swipe of Walthers Goo too, but I was hoping for something a bit more mechanical.

Here are some photos that illustrate the issue. Note the differences in the distance between the bottom edge of the pilot and the desk.

Bad (normal):


Good (downward pressure applied):


Reference:

[John]

I have similar problems with some Kato shells ..

[Ed Kapuscinski]

Speaking of IM SD40-2's, has anyone tried to lower one? I picked up one with ditch lights recently, and they way those are run makes me think there might be a enough space between the top of the decoder and the inside of the shell to grind off the nubs that support then shell and lightly file down the top lip of the fuel tank area of the frame so the shell will sit a little lower.

I am VERY intrigued by this approach. I've been looking into it myself, but I'm afraid to start hacking up a difficult to replace frame. I just emailed them to see if replacements are available in case I mess one up.

[mmagliaro]

I thought about that but they're little "bumps". I'll try and get a photo next time I have it opened up.

These damn things have so much potential, but just continue to let me down in subtle ways (like this).

I think I know what you mean.  You might have to slice off circles from styrene rod, glue them in, and then fiddle the edges with the tip of a file to make it a good shape to go on and off the engine.

I know this is probably heresy... but if it were my engine, I'd be looking for two good places where I could hide tiny screwheads, and then just drill straight down through the top of that shell into the frame, tap some holes there, and be done with it.

[John]

I know this is probably heresy... but if it were my engine, I'd be looking for two good places where I could hide tiny screwheads, and then just drill straight down through the top of that shell into the frame, tap some holes there, and be done with it.

This

[peteski]

I know this is probably heresy... but if it were my engine, I'd be looking for two good places where I could hide tiny screwheads, and then just drill straight down through the top of that shell into the frame, tap some holes there, and be done with it.

There might be some areas on the bottom of the model to add couple of screws which will be totally hidden.

Another idea would be to use some very small rare-earth magnets to keep the shell down on the frame.  You know, kind of like those used for keeping N scale containers in place.  There are some really small magnets available on eBay. Even down to 1mm diameter (but those are a bit too weak to have a good hold). 2 or 3mm magnets would probably do the trick.

[squirrelhunter]

I'll chime on the screw idea- the big issue is that almost the entire top of the chassis from the cab back to the end of the long hood is taken up by the sound decoder, so there isn't much space to put a screw in the frame without also drilling through the decoder board.

I'm with Ed, these things are really nice in so many ways, but fall short in other obvious ones that are hard to fix. The ride height is clearly a design decision they didn't have to make if you look at the frame. Also gluing everything together, especially the details on top of the cabs. If you could get the shells apart it would be much easier to figure out how to lower them. It seems like they wanted the number boards and class lights to be illuminated, but they couldn't make it work so they went with glued on number boards and a lot of engines have weird silver patches over the class lights.