GP9 aluminum frame is designed specifically to replace the plastic frame delivered with Red Caboose GP9 locomotives.
Machined from 6061-T61 aluminum alloy as a drop-in fit, no modification is needed to the locomotive shell. Machined in prototype underframe detail (see below). Pre-drilled for speaker wiring under the fuel tank. Pre-drilled accessory tray post holes. The GP9 aluminum frame also replaces the flat brass frame sold by others.
Unlike the flat brass frame counterpart sold by some, the FineScale aluminum frame features machined relief pockets on the underside of the frame.
Why go to the extra effort?
The bolsters included with the original GP9 were designed to mount on the top side of the frame. The relief pockets I have machined into the frame allow space for the locomotive trucks to rotate without rubbing the frame. As a result, the trucks sit lower on the frame giving the locomotive a more prototypical stance.
In addition to the relief pockets for the trucks, I have added relief pockets along the sides of the frame. These side frame reliefs let the frame tuck under the locomotive shell and create the side profile of the steel beam that can be seen in the section drawing of a prototype GP9 underframe.
Some argue that the brass frame is a better solution because it adds additional weight. In reality, the brass frame raises the profile of the locomotive, and to me, that negates any benefit of additional weight gain. Add in the absorbent cost of quality brass and aluminum becomes a clear winner.
If you need the extra weight, stick-on lead weight can be added to my frame in any configuration needed to fit the many types of DCC decoder installations, battery onboard installations, and sound installations.
GP9 metal frame upgrade kit is intended to be used in conjunction with the P&D hobbies re-power kit #PDP2201K. This metal frame will work with both the plastic and cast brass truck conversion kits offered at P&D hobbies.