Model Railroader SP GP60 article : Feb '93?

Dear Craig,

My Go-to Model RR magazine Index sources seem to have gone AWOL,
but I seem to recall an article by Rick Selby in a 90's era Model Railroader
RE kitbashing an SP Speed Lettering GP60 from an Ath GP50,
which included lowering the ride-height of the trucks (EDIT: Check Feb '93 issue)

Seem to recall there wasn't any frame grinding, but rather trimming of the truck halves,
and re-bending the metal tab "bearing surface" which connects with the "frame side" wiper/contact/axle-bearing plate...
(NB this is using a "gold side can" era frame and trucks, where the frame was live,
and the trucks had an arm reaching up over the Uni-joints,
which passed power via a contact wiper bar to the top of the motor,
IE this is NOT a "Horizon Era" Ath mech article or mod...)

I hope this helps...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

stanced

Simple version, remove the rivet that holds the L shaped piece on the truck that goes under the frame.  Re solder it 6" scale inches lower.

Option two, mill the frame bolster 6 scale inches deeper using a trepanning end mill.

Paul

Mike Hopkin showed me how he milled an Athearn frame to

lower an Athearn locomotive he had kitbashed & detailed.  This was when he worked at a local hobby shop before he went to work for Athearn and later Scale Trains.  Since the Athearn had always had a problem with coupler height being too low, he cut off the Athearn coupler mount from the frame and body mounted the couplers.  If I remember correctly, he did not have a milling machine, so he put a Dremel milling bit in a drill press set the plunge stop so that the drill press stopped at the right point to mill the frame exactly as he wanted it.

You would have to mill the frame.

 The rest of the truck is the same height, so changing the height of the bearing plate ,won't solve anything , you would have to cut the top of the truck off otherwise the frame would just rest on the side plates and top of the truck.

Option 1

You need to mill around the king pin and all the recessed frame area on either side of the pin , so the trucks will swing properly.

You probably would want to raise the motor too in order to keep the drive line aligned.

Option 2

Remove most of the material in the recessed area but leave the crossmember , remove the center of the crossmember and build a new crossmember and kinpin out of brass and attach with 2-56 screws by drilling and tapping the frame.

Again,You probably would want to raise the motor too in order to keep the drive line aligned.

Option 3 

grind the top of the frame and shell  and lower the body. You may want to cut the sides of the tank off and make a new tank .

Personally I would take a hard look at Option 3 and see if it was feasible.

Either way its a considerable amount of work.

stanced

Here's a lousy photo of a modified truck next to a stock truck.  The rivet was cut off the bearing plate and the bearing plate soldered a little lower.  You can see the original height on the stock truck on the right, it is about 6 scale inches above the metal axle bushing holder.  On the modified truck the bearing plate is very nearly flush with the metal plate.  It is tricky to take a photo that shows the change but hopefully you get the idea.

Paul

There is a excellent article

There is a excellent article on lowering the truck bearing plate by Bill Nelson in the March 1990 issue of Mainline Modeler.

Thank You!

Thank you so much for the helpful input from you all. I did order the March 1990 issue of MM and will probably try this first. If I had access to a milling machine I would probably go with milling the frame but the best I have is a dremel in a drill press attachment and I don't think that's going to be accurate enough. I'll post my results.

Thanks again everyone

Craig