1st Generation Geeps - Recommendations / What's best?

[bbussey]

I also suggested that he visit the Atlas site and look at the GP7/9 releases that have been offered since the beginning.  Since they are organized by release date, he should be able to identify the multiple dozens of models/schemes that be acceptable for his project.  He has four models to chose from in a myriad of schemes.  He actually has six models, because aren't the GP30 and 35 the same wheelbase?  Regardless, all of the information needed is on that page.

[Mark5]

The other complication is that around 2000 Atlas started using the slower (better) "scale speed" motor in their locos.

Mark

[daniel_leavitt2000]

Jess,
I would think twice about Big Dawg Origonals. They are no original at all. The GP7B shell you may be looking at is a casting of an Atlas shell with a Des Plains GPB kit added.

You will get a much better model by taking a real Atlas shell and a real Des Plains kit and doing it yourself. Resin always leaves defects, no matter how well cast.

Also, the shell has no provision to accept the Atlas handrails. I will tell you from experience that making handrails from scratch is a lot harder than minor surgery to a shell.

Third, you seldom get the shell pictured (the first copy usually), you may get the 10th or 15th. Take a look at one of his other shells:
http://www.ebay.com/itm/N-Scale-Trains-E3-6-A-Unit-Engine-Shell-Big-Dawg-Originals-New-Item-/281591143138?pt=LH_DefaultDomain_0&hash=item419023dae2

Look at how much rubber is left on the shell. His molds are not strong and you could be getting a very degraded model.

Forth, if you are interested in the GP9B, keep in mind that all GP9B were either phase III units with large fans on top, or the absence of the porthole window.

If still interested, I would purchase the shell then decide if its good enough to use as a model. Or just get the Des Plains GPB kit... I highly recommend it.

[Kentuckian]

The other complication is that around 2000 Atlas started using the slower (better) "scale speed" motor in their locos.

Mark

Is there a way to visually identify the slower motor?

[u18b]

Hold on gentlemen!

There are actually TWO versions of the Atlas China Geep mechanisms. The originals, which I wouldn't call "DCC friendly", and the newer ones which are.

Spookshow's write up shows you what you need to know about them:
http://www.spookshow.net/loco/atlasgp79.html

Ed,

You are of course correct.

When the day comes that I build a CSX GP7 (yes, they had a couple), I actually would prefer the older version.

The scale speed motor is obviously great (later)...

But there is a pretty good weight difference.
The decoder of choice for the earlier version is the TCS CN-GP.

Yes, it takes a little work to get it working.
But the weight difference is worth it to me.

http://www.tcsdcc.com/Customer_Content/Technical_Info/Tech_Manuals/TCS_Book_of_Classic_N_Installations.pdf

[Jesse6669]

Thanks to everyone for the great feedback-- one reason I really like this forum.  I was able to arrange for a couple of new GP9 mechanisms at a very good price, and decided to give the BigDawg a try-- If nothing else can provide some information for the group.  My project is a WM chopnose GP9, 6410, so even the casting will be modified.  And some other related side projects.

Jesse

[Ed Kapuscinski]

Whoa, if you're doing one of those, I think you might want to just keep the Atlas shell and go with the Lee Weldon / Chris333 collaboration for the cab:

[Jesse6669]

I checked with Lee first of all, he's still looking for one but they are all gone.  So I'll have two mechs, and I do have an old Atlas shell for one plus the resin one.. to compare/contrast?  Don't hold your breath at the rate I work it will be this fall before I'm anywhere near done!

[Mark5]

Is there a way to visually identify the slower motor?

Initially, the ("scale") motors were gray where the older (fast) motors were black.

I'm not sure if Atlas has been consistent all the years afterwards though.

If you know the stock # of the loco, you can find when it was released on the Atlas site - if after 2000 then it has the "scale" speed motor.

Mark

[jmlaboda]

I'm not familiar with BigDawgOriginal - is that someone doing custom shells?

There has been a thread over on Trainboard about these shells and a number of folks who have bought these shells have mentioned that the thickness of the sidewalls is so bad that you end up bowing the sides out when trying to put them on the shell they are suppose to be mounted on.  I have to say that they look good but if thickness is the issue you are going to waist money on them... if what is being reported is true.  Shame really... some of the shells would be of value to a number of folks... if only... B (

[PiperguyUMD]

While we're on the subject, does anyone know if the new Bachmann GP7 drive will fit in the any of the Atlas shells? Thanks!

[daniel_leavitt2000]

I think you only need to file the edges of the Bachman chassis to fit the atlas shell.

[peteski]

I think you only need to file the edges of the Bachman chassis to fit the atlas shell.

Why would anybody want to do that?  It is like installing a BMW body on a Yugo chassis. 

[chessie system fan]

A GP20 mechanism would be a good starting point.  You wouldn't have to shave the mechanism for the chopped hood (You'd have to do that with an Atlas mechanism because it's taller, right?).   The cab might prove useful too, and Atlas part fit everything.

[Missaberoad]

A GP20 mechanism would be a good starting point.  You wouldn't have to shave the mechanism for the chopped hood (You'd have to do that with an Atlas mechanism because it's taller, right?).   The cab might prove useful too, and Atlas part fit everything.

It would require a new fuel tank to match a GP9. an inexpensive part, if it is a direct swap?