SP NG Diesel #1 (GE 50T) - Triennial or Bust

[0351]

Looks good! At least you’ve go a good start, I’m still working on paper and looking online at the different options for parts.
Came across few more photos of GE 50 ton trucks. The last two photos are not quite the same as SP#1 but close.

[senorgilamonster]

Despite my goal to have the trucks done this month, I am taking a couple of days off to build a 1.6" scale electric. I will have to force myself not to get bogged down in that project, but I felt very strongly that I needed to get that done since I think I can whip it out in a couple of days. http://www.chaski.org/homemachinist/vie ... 5&t=106400

Here is how I did the first equalizing bar for the GE 50T: I took in the best side view of the truck I could find and loaded it into a graphics program. Although I have Photoshop and at least 2 other high end programs, I used (free) Paint.Net. I added a layer on top of the photo and carefully traced out one half of the equalizing bar, then duplicated the layer and flipped it so that I knew it was symmetrical. I put a grid on another layer that represents 1 foot. Finally I printed out the flattened image on heavy card stock so that 1 grid square equaled 2.5". Since I didn't have long enough card stock on hand, I printed each half on a separate sheet (with some overlap) then taped them together.

I then carefully cut out the card stock template. I layed the template down on my aluminum stock and traced around it with a thin permanent marker.

Cut along the lines. No careful measuring and transferring required. I then used the first bar as a pattern for drilling the holes in the rest of the pieces. Connect the dots with a straight edge and they will look better than the first piece.

[rkcarguy]

That's a great truck to model, the 4 bolt pillow blocks on the plates will look very prototypical.

[makinsmoke]

What thickness is your aluminum and how did you cut it out? Rough cut on a bandsaw?

[senorgilamonster]

The aluminum equalizing bars are 1/4" thick. I originally thought about going thicker, but I knew I was going to have to do a lot of shaping, so decided to try 1/4". It does seem sufficiently stiff.

All of the cuts so far, except the top of the journal pocket were but with a Harbor Freight Portable Band Saw. I marked the cut lines in white in the pic

[makinsmoke]

Thanks!

[senorgilamonster]

The Stretch Husky build has been a test bed/classroom for the SP1. I originally planned on putting a flat radiator cover on the Husky, but thought it would be a good time to try shaping a hood cover like the GE instead. IF it came out OK, it would make the Husky more distinctive.

I started out trying to make the radius top corner on a piece of scrap metal. This took a lot longer than I expected and I had the same problem that made me give up on milling - I couldn't get the work piece secured enough to prevent movement under the forces at work. However, I DID get the test corner formed.

Once formed I decided that I would just cut a flat plate for the Husky and save the effort for the GE. I had been planning on a larger radius to the curves for the GE and this sealed the deal. The test radius for the Husky was 1/2" Forming the 3 corners at a larger radius will be much easier...3/4" or 1".

I had a piece of leftover metal from the Husky hood that I cut down into the rough dimension of an access door. I placed one of the louvered doors from the Husky on top of it for a size comparison. This thing is going to be a beast.

I also tried out a couple of 1" hobby hinges for size. They are about right. I would like for them to be functional, but they barely open as it is and they won't after painting. I'll have to search for a hinge that will work. I am considering spot welding them to the door panels.

[Pontiacguy1]

JB weld works great for this. Bill Koster showed me how he made his doors and such on his locomotives, if they were non-functioning doors, he just cut them out of some 0.015" thick steel and JB welded them on the outside of the sheet steel. They looked great when painted. If it were me, i would make most of those doors non-functioning. Less headache, easier fab, stronger body, and a whole lot less rattling. Of course you may want to make one or two functional if you have something behind there that you need to get to regularly, like a fuel cutoff or something.

[Pontiacguy1]

Actually, I think he cut his doors out of aluminum and JB welded them on. Either way, just enough thickness to give them that 3-D effect.

[senorgilamonster]

thanks. I was trying to figure out how to attache the doors to the husky. I just need to make sure I don't ooze the epoxy out the sides or vents.

[senorgilamonster]

Today I cut the 3 remaining equalizer bars for the first truck, Next I cut out the journal slots for one sideframe.

I wanted to make my journals in a way that minimized milling. What I came up with was to drill 1/2" dia. holes through the aluminum block first, then slice the block on the center of the holes such that each block had a semi-circular groove down the side of it.

I will fit the edges of the sideframe journal slot with a 3/8" ID bronze sleeve bearing (OD 1/2"). The journal's semicircular groove will ride up and down on the OD of the bronze bearing. In the pix, I am using nylon spacer of the same dimension as the bronze for proof of concept. The bronze will NOT be cut down the center but close to one edge so that its opening is 1/4" (the thickness of the sideframe). Any ideas on how to do this will be appreciated.

Looks like the concept will work. Everything is a bit tight right now (that's good). I will still have to finish fit all of the parts of course.

[rkcarguy]

So the block with the nylon bushings is going to be your bearing block that will slide up and down in the side frame?
How will you secure the bronze bushing into the block?
As far as cutting them, if you are working with minimal tools I would scribe a line on them, clamp them by their ends and grind them down close, then hand file to finish. Or if you are looking to cut a long notch out of the bushing it could be done with a hacksaw or a cut-off wheel on a grinder or dremel. Are you going to radius the edges of your side frames to match the inside diameter of the bronze bushings? Being they are aluminum, you could router them with a carbide radius bit and lots of oil and they will come out really nice.