Building a GP9 in Proto:48

[ednadolski]

My etched parts have arrived!    So here are the frets for the steps and the grilles/louvers:











And here is what the steps look like when installed:










Next to do are the grilles and louvers.  The etched metal parts are replacing the cast-in grillwork on the model, and should add some depth to the appearance.   Cutting out these areas on the shell is going to take some work, as the plastic is pretty thick.   Stay tuned! 


Ed

[strummer]

Am enjoying this very much. Might have to pull out my "old" Geep 9 and do some upgrades myself...

Mark in Oregon

[basementcalling]

Holy staircases, Ed.

[6axlepwr]

Ed,

Really liking the radiator shutters and grills. Question for you. Is that grill work going to fit into a frame? Or did you leave teh frame on teh model and the grill work will fit into an opening you cut?

[ednadolski]

Brian, since the shutters have a bit of overlap, I did them as a two-piece etching with a top and a bottom.  The shutters are bent into position, and then the two pieces are glued together around the 'frame'.   Note that one frame is half-etched from the front and the other is half-etched from the back. The cast-in grilles are cut out from the model and cleaned up (takes some effort since the plastic is rather thick).  The shutters are glued in place from the inside, and then the grilles are glued in place from the outside.

These pics are just a temporary install with the parts taped into place, as I plan to paint the parts separately.  I am pretty pleased with the look,  in-person there is also a 3D look with a depth that cannot be captured in photos.






Ed

[Scottl]

Nice effect Ed.  Trainworx did the same thing for the SD70M-2 etch kit in n scale and it was also very effective.

[GaryHinshaw]

Wow!  I'd say the 3-d look comes across just fine in photos. 

[6axlepwr]

Before you glue all that in place. Put the half round drain holes in the frame. They are located right at the bottom of grill on the flat frame portion.

If you are interested in doing this, let me know. I have detail photos of this area as well as dimensions for the holes and the spacing.

You did get a lot of good depth with your layering.

[ednadolski]

Wow!  I'd say the 3-d look comes across just fine in photos.

Trust me, in-person it really makes a difference.  Hopefully it draws attention from those awful black louvers... 

Before you glue all that in place. Put the half round drain holes in the frame. They are located right at the bottom of grill on the flat frame portion.

If you are interested in doing this, let me know. I have detail photos of this area as well as dimensions for the holes and the spacing.

So drill a regular hole & fill the bottom with half-round styrene?  Would love dimensions if you've got 'em.


Thanks,
Ed

[6axlepwr]

Ed,

I will send you photos.

PM me your address and I will make copies of the drawings I did. They are rough, but I think you can make them out. I do not have a scanner.

BTW, do you have Scott Chatfield's GP7/9/20 fuel tank detail information. has dimensions for the various tank sizes. If not, I will make copies of the sheets I have and send them along as well.

Another thing I can give you. I have made a 3D drawing of the air reservoir bracket in HO scale. The bracket that encases the air reservoirs. If you have a 3D program, I can send you the drawing and you can resize it to O-Scale. I also have the tank ends that you can resize. I use a program called Cubify. It used to be called Alibre. You could get these parts printed.

If you want, I PM you my mailing address and you can send me an SD card and I will put all the GP7 detail photos I have. I know you are building a GP9, but the underframe stuff is pretty much the same.

[ednadolski]

Thanks Brian (and sorry it took me this long to get back about this).  Turns out I have some GP9 pics on hand that show the drain hole locations.  Size-wise I'd guess they are about 1.25" diameter (larger than a grabiron, smaller than a handrail).   So I can probably go with 0.025" holes, and sand down styrene rod to a half-round.... what do you think?

Thanks for pointing these out. That part of MRL 132 is painted black, and my proto pics of that unit are not very good, so I otherwise would never have noticed them.

Ed

[ednadolski]

Just a quick (but overdue) update:  I finally have the speaker installed in the fuel tank:



This is a 1.5" high-bass speaker.  Fitting this in turned out to be a bit more of a trick than I anticipated.  I had originally thought that I could fit something larger, considering that this is O scale after all, so it must have tons of room in there somewhere, right?   Well, not so fast.  The shape of the fuel tank turned out to be pretty constraining, and the space inside the body shell is actually fairly well consumed by the internal components (motor, drive shafts/towers, and decoders).    My Atlas O SD40 actually has a lot more room in the fuel tank, but OTOH the prototype tank is a lot bigger, and Atlas O is no stranger to compromises for the sake of selling models (espcially to accommodate the 3-rail market, but I digress  )

Because of the curved bottom I had to cut a square opening in the tank and fill it with styrene sheet (two layers) cut with the circular opening for the speaker.  Cutting into the tank was one of those "point of no return"  moments, since getting a replacement is nearly impossible.  The insides are all caulked up to seal any gaps.  Note too the 'weld seam' made from a strip of 0.010" round styrene, glued in where the tank's top and bottom halves come together.  At least I hope it will look like a weld seam.... actually on this model it may end up being mostly hidden behind the side sill skirting, but in any event there it is 

I masked over the wires and speaker opening, and gave it a nice coat of flat black from the rattle can.  Since the smell is kinda unpleasant, this is going to sit in the garage for a few more days while the paint cures.

I'm also working on the installation for the decoders - one for the motor (an HO decoder that can handle 4 amps) and a Tsunami TSU-1000 for the sound and lights.  Hope to have some pics of that to show soon.

Ed

[railnerd]

Might want to consider adding a bit of mesh— you'll be surprised what the magnet inside that speaker element will pick up.

[ednadolski]

Thank you, that's a good point.   Since the P:48 track is hand-laid, likely it could pick up a number of spikes over time.

Ed

[peteski]

Ed, is the back pf the speaker enclosed in an air-tight enclosure (preferably made from some non-flexible material (like lead sheet)?  The enclosure shold be as voluminous as possible. That will dramatically improve low-frequency response which is so sorely lacking in N scale.  It would be nice to hear some low rumble in a larger-scale model.