Modeling a MoPac E-7

[lenaculbert50]

Hi guys. I always come across E-7 locomotives at swap meets and I picked up a couple cheap at the last one.

It seems the porthole window modification is not an easy one but doing it would mean to have a MoPac only model. Now with 3D printing and little risk involved with a model, I thought I would give it a shot.

This Southern E-7 was new in the box but had seen some rough handling.

A couple hours in isopropyl alcohol made it a clean slate.

[lenaculbert50]

I did some quick measurements based on photos and drawings. Unfortunately, no prototype around to get actual dimensions.

It only took about an hour to draw these out and off to the printer.

[lenaculbert50]

Some cutting, trimming and filing later, I have the openings ready to fit the printed parts.

I was able to go to the upright rivet strip at the front. The same at the rear. The only thing I hesitated on was at the center hood door. The door has a frame that slides into dovetailed slots on the interior. I had hoped to keep the slots intact, but am worried about a clean gap on the parts.

Anyway, this is my prototype so will see how it goes. Once I get the parts fitted, I’ll be back.

[lenaculbert50]

Latest progress:

The replacement panels were printed a little oversize so I could match the fit to the openings. I think they would have looked better if I had cut the opening all the way to the center door frame. It would cause the doors to be fixed, but I don’t expect them to be opened anyway.

The resin is a little softer than the plastic. Because of this, it sands easier and you can cut into it quicker when trying to fill the gap.

It also seems the details are a little too tall. I don’t think it will be noticed much in paint but I’m going to adjust the drawing.

[lenaculbert50]

I also had to fix the number boards to the correct 45 degree version. I would normally use Details West metal but of course I didn’t have a set.

I took some measurements from another model and drew my own. One definite advantage of 3D printing. The print came out better than expected with only three tries.

I also tend to get a bend in the metal number boards. I was able to add more angle to the resin prints so they look much better.

Since this is a test shell I’m not going to add a lot of detail parts. It will also be Jenks blue. Next post should be paint.

[Bud Moss]

Looking good. This is a tough conversion, but it will be worth the effort to have an E7 with portholes. Jerry Michels

[lenaculbert50]

As promised, here are images of the finished model.

The good:
It’s definitely MoPac’s version of the E-7. The conversion was fairly easy with minimal cuts needed using the printed parts.
The bad:
I should have gone to the center door frames on both sides with the cuts. Trying to save the opening center door made it more difficult to fill the gaps. Also, there is absolutely no spare space between the shell sides and the chassis. I revised the drawings to make the parts thinner.

Overall, I think it went well. I like the glossy blue look of fresher paint. The details were scaled back since it was really about testing the concept. This was a $20 swap meet model that would probably have ended up in a parts bin otherwise.

There are other variations in the MoPac E-7 locomotives. Some had additional vent grills around the portholes. Others had different filter mounts behind the cab doors. This number was the closest prototype I found to match the Proto 2000 shell.

[lenaculbert50]

One final item. I’m attaching the drawing files for anyone interested. This will give you the conversion parts if you have the capability to print, or send to a printing service.

[Bud Moss]

Gorgeous! Ready to roll the MoPac’s finest. Jerry Michels

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