Building the Canyon Diablo Bridge

ModelRailroadForums.com is a free Model Railroad Discussion Forum and photo gallery. We cover all scales and sizes of model railroads. Online since 2002, it's one of the oldest and largest model railroad forums on the web. Whether you're a master model railroader or just getting started, you'll find something of interest here.




I tried cutting along a straight edge but that turned out to be very uneven, i.e. not straight. I tried scissors but they distorted the plastic edge. I think I'll try a belt sander with very fine sand paper to finish the edges.
 
Here is a foot that i built. I still need to drill the hole larger and make a pin.
 

Attachments

  • Screenshot_2017-01-16-22-53-59.jpg
    Screenshot_2017-01-16-22-53-59.jpg
    194.7 KB · Views: 347
D&J RailRoad said:
I tried cutting along a straight edge but that turned out to be very uneven, i.e. not straight. I tried scissors but they distorted the plastic edge. I think I'll try a belt sander with very fine sand paper to finish the edges.
Click to expand...

Ken - Far be it from me to teach you a thing or two, but the belt sander may be too aggressive and you may not get a flat straight edge. I have a series of sanding sticks that I made using, for example, 1-1/2 x 3/8 x 8 wood and clamped/glued fine and med sandpaper to each side. I use them as I would a file. A little manual labor is required, but Works good for me.
 
Sirfoldalot said:
Ken - Far be it from me to teach you a thing or two, but the belt sander may be too aggressive and you may not get a flat straight edge. I have a series of sanding sticks that I made using, for example, 1-1/2 x 3/8 x 8 wood and clamped/glued fine and med sandpaper to each side. I use them as I would a file. A little manual labor is required, but Works good for me.
Click to expand...

I would use the belt sander with a very fine belt to bring the excess down to near finished edge. Then I would use sand paper or blade by hand for the final.
 
I agree with Sherrel about the belt sander, even with a very fine sandpaper. O have done lot of work with sheet styrene scratchbuilding structures and other projects, I would suggest using a fine cut mill file, running it down the edge lightly. Easier to control. I tried a sander ONE time years ago. Didn't work well.

Don't want to stomp on your post, but I would hate to see you possibly ruin such a project. I do have some experience working with styrene. Here is a scratchbuilt building made entirely from Evergreen styrene.

Picture%20295[1].jpg It doesn't take very much heat do do damage to styrene,

The foot looks really good. Impressive. Waiting for further updates.
 
Go slow with the belt sander so it keeps from melting the plastic past the point you want to remove. I'm sure you thought of this but I just wanted to say. You never know when just saying saves one hours of work.

Dave
 


Here's a thought, KEN. I have a Dremel Belt Sander which also has a disk sander on the side. As I am not currently using it for any modeling projects - I could mail it to you if you can wait for a few days?
 
The finished width is 5" thats the arches side to side. With the wood deck walkways it will add 1/2" on each side for a total of 6".

Ken- i havent had a chance to get out to the bridge, work and weather, but i will get out there as soon as i can.
 

Attachments

  • 20170117_110214.jpg
    20170117_110214.jpg
    560.3 KB · Views: 371


2869ral said:
Ken, how much were the open trusses from Plastruct? I need 20 more packs and knowbody on ebay has the quantity i need.
Click to expand...

Those were 12.20 a pack of 2. Dimensions are 5/8" tall X 12" long.
Right now, the bridge strength may be compromised because the feet aren't anchored and the center will be able to bow down as the feet slide backward. With it setup on the carpet, I think the feet won't slip on that. Once you secure the feet the bridge will be more ridged.
Looking at the pictures of the real bridge, it looked like it might be closer to about 7" wide.
As you have installed the uprights and the arch, its' going to be more difficult to install the lattice between the uprights.
It's a very impressive bridge.
What thickness of polystyrene did you use for the plates that cover the joints were the beams come together?
For the top deck I am planning on using wood beams. Not sure what dimension yet.
Also, I am using 3/4" I-beams across the top that will support the 5/8" I-beams that will run the length of the bridge. The 3/4" I-beams tie the tops of the uprights together. Right below that is where the X lattice is attached.
The real bridge has an X pattern in the open web trusses. I couldn't find anything that would come close to looking like that short of using the Plastruct open web truss, shaving off one side of each truss then joining them together.
 
Last edited by a moderator:
You must log in or register to reply here.




Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website (Learn More Here)

Back
Top