Author Topic: Getting a shell to stay put on IM SD40-2s  (Read 3717 times)

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Steveruger45

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #15 on: January 26, 2022, 10:07:58 AM »
+1
What about glueing a couple of latches of flat styrene on the bottom of the shell at each end such that they latch over the bottom of the frame?
You could still get the shell off and on using tooth picks or similar to spread the shell.
Steve

Ed Kapuscinski

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #16 on: January 26, 2022, 10:19:47 AM »
0
What about glueing a couple of latches of flat styrene on the bottom of the shell at each end such that they latch over the bottom of the frame?
You could still get the shell off and on using tooth picks or similar to spread the shell.

That's a good thought.

I had thought about using tabs and then a bar across the bottom too.

Angus Shops

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #17 on: January 26, 2022, 08:32:53 PM »
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Their F units have the same problems. At least mine do. It seems that one end of the body is always sitting higher that the other end. Otherwise these a fabulous engines.

w neal

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #18 on: January 27, 2022, 11:02:07 AM »
0
A bit off topic, apologies. What is the preferred method for gluing on the sunshades etc? Please educate me.

Also, what's the best solution for reducing that coupler arm length on the front? I.E. Any suggested replacements? Ta.
« Last Edit: January 27, 2022, 11:19:19 AM by w neal »
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Ed Kapuscinski

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #19 on: January 27, 2022, 12:41:35 PM »
0
Also, what's the best solution for reducing that coupler arm length on the front? I.E. Any suggested replacements? Ta.

I just picked up a 10 pack of 1015s yesterday to solve this exact problem on my quartet.
The existing couplers are 1016s (the extended ones). Unscrew them, do the swap, and put the 1016s into your stockpile.

It's another frustrating example of "ugh, so close".


w neal

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #20 on: January 27, 2022, 01:46:03 PM »
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Ta.

Gluing hints?
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Ed Kapuscinski

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #21 on: January 27, 2022, 03:41:27 PM »
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Ta.

Gluing hints?

I squirt CA into a medicine cup, then get a drop on the end of some steel wire. Touch it where I need it, then insert.

w neal

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #22 on: January 27, 2022, 08:35:01 PM »
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Ta very much Ed.
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squirrelhunter

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #23 on: October 06, 2022, 01:14:12 AM »
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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.

So, I bought a pair of Fort Worth and Western SD40-2's, and the sill unit on the snoot nosed one was warped down pretty noticeably because the cab was improperly seated on the main shell casting. Figured it was useless as it was, so why not tear into it?

Well, my efforts on the shell were less than successful (getting it apart was tricky, reassembling it appears to be impossible) my work on the frame looks to be a resounding success. Basically if you file off the nubs that support the bottom of the shell and make sure the top of the fuel tank area is flush you can really reduce the ride height! I had to tweak the bends in the contact strips, but my modified unit no longer towers above my Atlas GP38/40 units.

I'll take some photos this weekend, but this turned out to be a relatively easy mod that made a big improvement in the ride height.

cgw

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #24 on: October 06, 2022, 06:47:02 AM »
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The insert for the dynamic brake/non dynamic on top causes an interference fit with the decoder.    I had to file the inside of the shell and glue the insert on.   that  allowed the shell to fit  The interference was about 1/2 mm with causes the shell not sit properly.     I also removed the black foam on top of the decoders and used black fingernail polish on the unused LED  ontop of the decoder.   I had to do that with about 10 of these units.   they all now sit and snuggle the Frame with no issues.

ednadolski

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #25 on: October 06, 2022, 09:57:43 AM »
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Sometimes that is indicative of a fit problem with wires or other parts (say from a decoder) that are sticking up and preventing the shell from seating properly.  However with a warped/distorted shell then you are fighting the shape and trying to force it into a position that it does not want to go.

Ed

squirrelhunter

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #26 on: October 06, 2022, 10:40:12 AM »
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The insert for the dynamic brake/non dynamic on top causes an interference fit with the decoder.    I had to file the inside of the shell and glue the insert on.   that  allowed the shell to fit  The interference was about 1/2 mm with causes the shell not sit properly.     I also removed the black foam on top of the decoders and used black fingernail polish on the unused LED  ontop of the decoder.   I had to do that with about 10 of these units.   they all now sit and snuggle the Frame with no issues.

I'm glad you posted this- I'd forgotten that when I tried one of my other SD40-2 shells on the modified frame, it had flash on the underside of the dymanic brake area that kept it from sitting properly on the frame. I had another shell that didn't have flash and it fit right.

I pretty much always take the black foam tape off the ESU decoders on my SD40-2's as soon as I got them. My understanding is the tape is meant to keep the auxiliary LED's from showing if you accidentally turn them on. Although, I think the base of the rear headlight lens holder is what actually holds up the back of the shell, but I need to measure to make sure.

I'm planning to post photos and a more detailed write up in the next couple of days.

squirrelhunter

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #27 on: October 07, 2022, 12:42:47 AM »
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A few quick photos, I'll try to take some better ones this weekend.

Here is a nose to nose of my lowered SD40-2 on the left and at Atlas GP 38:


Here is a nose to nose of a stock SD40-2 on the left and an Atlas GP38 on the right:


As you can see, even the modified SD40-2 still rides high, but not nearly as bad as the stock unit.

Here is a shot of the modified frame, where the forward nubs the shell rests on have been filed off along with the little nubs on the thin shelf of metal that is over the middle of the contact strips. I also bent the contact strips so they would not bow up so much on either side of the fuel tank:


For reference an unmodified frame:

wazzou

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #28 on: October 07, 2022, 01:40:17 AM »
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I’d never noticed how marshmallowy the tooling of the trucks was until now.
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oakcreekco

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Re: Getting a shell to stay put on IM SD40-2s
« Reply #29 on: October 07, 2022, 02:54:39 AM »
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I’d never noticed how marshmallowy the tooling of the trucks was until now.

Is IM still using Atlas trucks?
A "western modeler" that also runs NS.