Frame Modifications for the GP40

Fortunately, I became friends with Brian Banna...Brian is an exceptional modeler who doesn't mind sharing his skills with other modelers in their pursuit of better models.  Brian got me interested in frame detailing at the 2007 Collinsville RPM meet where I saw his  EJ&E GP38-2.   The frame detailing was an eye-opener for me and I was hooked on it after that.  Brian has been very generous the past two years including me in his various pursuits...including frame modeling and tooling to accomplish it.  Brian designed the GP frame milling fixture shown here...as well as the custom fuel tanks I now use on my Atlas GP's...I also have been fortunate enough to be able to talk with Elizabeth Allen, another superior Diesel Modeler from time-to-time.  She has also provided expertise in regard to the ideas that are being used here.

I decided to apply Elizabeth's recommendation here of cutting the frame's lateral bracing down to the bolsters  to see if they would survive such drastic milling...if so...the detailing would be much easier...as I could use the Evergreen .125 styrene channel glued flush to the bottom of the Atlas frame!!

After milling the fuel tank area using Brian's special mill tooling for Atlas GP frames, I then modified the Milling Fixture to allow the entire frame to be milled repetitively while encased in the fixture...until I just touched the original Atlas frame webbing...this allowed the original thickness of the Atlas frame to be saved...with all lateral bracing removed.  With the .125 Channel secured to the frame with BARGE Cement, the added bracing really makes the frame a nice looking unit!!!    The structural integrity was retained despite the milling, and now we have a very nice frame to detail up the entire locomotive.

Here are some photos of the milling process on the frame:

frame locked in vise and milling fixture.	Frame after long cutting is almost complete	Milling fixture with Atlas GP frame encased.	Side view of milling fixture showing battery box weights.	Rear view showing the openings that allow the milling bit to cut the frame flush.
Notice the smooth looking milled frame...This one is being set up for another project...	Atlas GP40 frame with .125 channel glued on with BARGE...and an additional .020 x .020 styrene strip glued to top...Brian's custom fuel tank on the bottom (3600 gal).