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GP9 Project

Posted: Sat Aug 15, 2026 11:32 am
by up148
I've always been drawn to 1950's diesels and especially F units and GP9's. I bought a bunch of Red Caboose decorated shells and brass frames from Des Plaines Hobbies back in the 90's for this project, along with one stock RC powered kit. The plan was to build up a 3-4 units consist and now I finally gathered enough parts and interest to get started.

Besides the decorated DPH RC shells, I recently purchased a decorated Atlas shell with chassis, which is the same as the RC model, but has metal walkway/chassis and metal stanchions and handrails....parts that were always the achilles heels on the RC model. And except for some obvious changes to the chassis for the Atlas drive, everything measures out dimensionally and you can even interchange shells and cabs between them.

I also picked up a RC GP9 conversion chassis from John Wubble at AN. It's for converting the RC models to his drives and he did a great job. I plan on using this conglomeration of parts to built up several dummies and pull/push them with a built up power chassis that Jay built for me 15 years ago.

So, we'll see how this goes and I'll post photos.

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Re: GP9 Project

Posted: Sun Aug 16, 2026 12:57 pm
by Jay Criswell
Butch,

Only vague memory of that one. Of all the frames you show I much prefer the brass version that used to be available from Des Plaines Hobbies. As far as I know they are no longer stocked. Why do I prefer them? Because I can solder things to them. I have seen a few that were warped...and that's a bad thing. Looks like one of the old sway backs from back in the '50s. Yours looks to be warped also.

Actually, backing up slightly, the very best frames I have are the machined brass frames done by Lou @CLW for these models. Absolute brutes and beautiful.

I recently repaired one from DPH that I'd done quite some time ago and that frame was warped. Was it like that when I first got it? I dunno. I might have missed it. I stripped the frame and soldered brass inner frame rails. The originals were plastic and not shown in the photos. I will attempt to attach a Photobucket album that shows photos of the rebuild/repair.

https://photobucket.com/share/c6756609- ... 0dc7005c32

We may have to install the larger 2842 Faulhaber gear head motor if the loco can't pull what you want with the existing Faulhaber gear head motor.

We may want to go with a larger Tang Band speaker too.

Jay

Re: GP9 Project

Posted: Sun Aug 16, 2026 1:50 pm
by bob turner
I too was intrigued by the computer-machined billet brass frames. That's the modern version of a sand-cast frame.

Re: GP9 Project

Posted: Sun Aug 16, 2026 2:04 pm
by Jay Criswell
Trying to stick with the subject of Red Caboose/Atlas GPs. This is one I did for Nev (from Perth). No DCC straight DC.

https://photobucket.com/share/d27177de- ... 00efa35723

Experimented with rotating bearing caps too.

Bottom line, Nev, and his gang, loved it.

Jay

Re: GP9 Project

Posted: Sun Aug 16, 2026 2:35 pm
by up148
You almost hate to see a shell go on that beauty........it's a moving work of art.

Re: GP9 Project

Posted: Sun Aug 16, 2026 10:16 pm
by R.K. Maroon
Thanks for all the photos and accompanying narrative, Jay. I always enjoy (and admire) the "solid quailty" of your installations. I know from my own piddling around what an investment in time and material it takes to be able to do that kind of custom work.

Jim

Re: GP9 Project

Posted: Sun Aug 16, 2026 11:19 pm
by Jay Criswell
Thanks Jim,

...and then there was the Abilene Flyer!

Jay

Re: GP9 Project

Posted: Mon Aug 17, 2026 2:25 pm
by sleepmac
Jay, that GP sure is a work of art/craftsmanship. One question please: Why did you choose a chain drive over a belt or gearing?

thank you,
Dan Weinhold

Re: GP9 Project

Posted: Mon Aug 17, 2026 3:06 pm
by Jay Criswell
Dan,

I use both. Biggest reason, the pulleys come in IDs that aren't always easy to deal with. Sometimes you have to bore them out, other times you have to install bushings. Once bored, or bushed, to the right ID I have to turn down the flanges on the pulleys. This can be tricky and if I get to aggressive the flange will break off the hub. A rather expensive issue.

I have the Delrin sprockets cast in brass and I can easily bore them to whatever ID I need and install a set screw that mates up with a flat spot on the shaft. By the way, I've never had a brass sprocket split on me :D .

Because I use gear head motors all my chains, sprockets, pulleys, and belts operate far slower than drives with just a motor.

Sometimes people ask for one or the other and I try to accommodate them.

In the end both work just fine.


Jay

Re: GP9 Project

Posted: Tue Aug 18, 2026 12:32 pm
by sleepmac
Jay, thank you!

Dan Weinhold