Building a MP GP-12 (1078) Phase III

[Charles Duckworth]

One item I didn’t notice until the crew cab was painted is the Phase III fireman’s window was narrower than the Phase I. I stripped the cab and added a piece of Evergreen 2” x 10” on the left side. [attachment=0:oo2rkaor]759D4B49-3D87-4F1A-B12A-58C044F18482.jpeg[/attachment:oo2rkaor][attachment=1:oo2rkaor]7872E7F9-06D6-446F-AAD1-EB8E26479490.jpeg[/attachment:oo2rkaor]

[Charles Duckworth]

[attachment=2:29s3v2ho]C299D70E-4BFB-4AE1-9E70-D3CFA7D37837.jpeg[/attachment:29s3v2ho][attachment=1:29s3v2ho]A8EA954C-A4A6-49BE-926B-1A845AEF2167.jpeg[/attachment:29s3v2ho][attachment=0:29s3v2ho]12492189-B9B3-4971-92B7-7A9498659780.jpeg[/attachment:29s3v2ho]Drawing and dimensions on number boards. [attachment=3:29s3v2ho]50B7DABB-B0FA-44E7-B06A-1D4B171F573B.jpeg[/attachment:29s3v2ho]

[Charles Duckworth]

More number board shots and other details I took today.

[Charles Duckworth]

They aren’t perfect but they look the part. Added wire attachments to the sides to hopefully keep them from getting knocked off during operating sessions. Will tackle the short hood tomorrow. I ended up cutting the Detail West Alco number boards down. As the came out of the package they were probably 30” HO and the MP version was 22”. Lots of filing and sanding to get the right length. The ‘L’ Evergreen plastic is almost 14” on either side so that was almost perfect for the bracket piece.

[attachment=1:3lzc1a0h]1409ED91-1C0E-449D-AC62-33185AF001F0.jpeg[/attachment:3lzc1a0h][attachment=0:3lzc1a0h]D918E532-1BBF-4BF7-8798-64CDE24F6D75.jpeg[/attachment:3lzc1a0h]

[Charles Duckworth]

Looking at the prototype photos and the model I went back and measured the number boards from Details West and found them to be both too short in height and too long in width. I added a piece of 2”x 10” to the top and reduced the width to match the dimensions from the museums RS-3. There’s not much surface for glue since the brackets sit on the curved areas so I’ll add a piece of brass wire to the front and side of each for strength. There were Phase III locomotives (see 1073 below) without these large number boards if you’d like to avoid making these but what fun would that be? [attachment=3:22l9uvyp]1F4BD401-447F-41AB-8CC8-BF093BFA8A85.jpeg[/attachment:22l9uvyp][attachment=2:22l9uvyp]5F59EEEC-58D1-48BF-8188-EE187EF17FDD.jpeg[/attachment:22l9uvyp][attachment=1:22l9uvyp]36723D53-D6B7-49C7-B3F8-0448E8D30CC4.jpeg[/attachment:22l9uvyp]
[attachment=0:22l9uvyp]9B4D8439-0649-48EE-9221-F80F79BA1430.jpeg[/attachment:22l9uvyp]

[Charles Duckworth]

I airbrushed the number boards this morning and sealed the paint and decals with a thin coat of Dullcote and let this dry for a few hours. I then started weathering the carbody with the water based oils similar to the Phase I locomotive starting with a light grayish brown on top on the walkways. I want to run these MU’d together and don’t plan to have this locomotive as heavily weathered as the first one with more of the Jenks Blue showing.

[attachment=0:1l7rzkmg]13E6C6C0-319D-42A1-B3AE-90FA28F2F035.jpeg[/attachment:1l7rzkmg]

[Charles Duckworth]

So layout shots; fuel tank next, decals in the number boards and glazing back in the cab. Air hoses, couplers, etc. Both sound great together. [attachment=2:1bg5hu8t]DBDCFE27-D0A6-4803-98FB-1B8A16502311.jpeg[/attachment:1bg5hu8t][attachment=1:1bg5hu8t]3C67F44C-49EB-4E0C-B223-2F4396C3EDCE.jpeg[/attachment:1bg5hu8t][attachment=0:1bg5hu8t]FCFB7854-07BA-4B3C-A888-9E04AF44847C.jpeg[/attachment:1bg5hu8t]

[mahcr450]

Hi Charlie,

I’ve been following for awhile, since your first GP12. Great job on the conversion.

Once I pickup the correct RS model, I hope to build my own. With some of the detail parts scratch built, I drew the exhaust modification and printed on my 3D resin printer.

Wondering if I could send you a couple and have you compare to your model. A lot of guesswork went into the measurements. One example is the spark arrestor mounts. They seem too wide, but could be an issue with the size of the metal castings.

Hoping the attached picture gives you an idea of the differences. One is prior to the spark arrestor installation and the other is setup for the Details West casting. Let me know your thoughts.

Thanks,

Mike

[Charles Duckworth]

Be happy to help, you also going to make up the radiator box and fans? That would save a lot of time.
Just send to
MPHS
16318 Valley St
Omaha, NE. 68138

[Charles Duckworth]

While not a great photo this gives you an idea of the width of the sheet metal supports for the spark arrestors. They should only be the width of the metal castings and should be open on either side of the exhaust stack. [attachment=0:21hmctul]7B5A29F6-105C-48B1-98FF-F6F6B9F883E6.jpeg[/attachment:21hmctul]

[mahcr450]

That image helps. I adjusted the size of the housing. I think it was too short before. It’s a scale 12″ tall now.

I moved the stack height to 28″. It looks like they should be the same height as the cab roof. Best I can tell, distance from the hood to roof is 24″, but that seems short.

Let me know thoughts and I’ll adjust the spark arrestor drawing based on this.

[mahcr450]

I think I’ve got it figured out. Image below with the spark arrestor mount. The mount is a little thick for scale, but printing less than 1 scale inch doesn’t work well. It’s like handling paper and just looking at it wrong causes it to crumple.

I have a few printed, and will mail you a sample next week.

Mike

[Charles Duckworth]

Mike
Do you want to add the small brackets around the lip to hold it in place? You can see them in the photo. You going to do the radiator fan box too?

[mahcr450]

One last post. Here’s the printed version with the SA castings.

[mahcr450]

I can probably add the mounting brackets to the flange.

The radiator fan box has quite a bit more detail. The housing should be no issue, but the fan detail might be tough.

Once you get a chance to look at the exhaust up close, let’s talk measurements on the radiator fans.

[Author]

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