Great topic !  Would love to do something like this myself, so I'll be "looking over your shoulder".

Alan, 

Please forgive my ignorance.  What is that green tool?  How does it work?

Ron

Ron,

It is called an Accu-Arc. Draftsman use it to draw a large radius. My background is drafting and I discovered this tool many years ago. In this case, I adjusted it to the inside radius of the track and backed it off by 1-1/8 inches to get the inside radius of the bridge. I added the appropriate inches to then get the outside bridge radius. It made things real simple for the layout of the roof deck.

I do not think this tool is made any longer but you may find one on e bay.

Hete are some more updated pictures. I would have put them on earlier but I decided to take my Challenger out and put the fan blade through the radiator. At least this project is going much better than the car

Nice work Alan as always! Ouch on the Challenger! Accu-Arc available on Amazon.

Al.....your work is amazing!

Peter

Looks really nice Alan. I like the angle of the arch under the bridge.  That accu arc is too cool. I'll have to check that out on ebay amazon. 

Great work Alan! Styrene is a wonderful building material isn’t it?

Another neat project in the offing. Al, just how do you put a fan blade through the radiator? Fan Clutch explosion???

Nice work Alan. I ordered an Accu-Arc -- that beats the daylights out of using plot points.

Sorry to hear about the Dodge.

@Ron045 posted:

Alan, 

Please forgive my ignorance.  What is that green tool?  How does it work?

Ron

 

Amazon.

ACU-ARC Ruler INCHES Drafting, Engineering, Art

Also, GS direct and a number of others

Not sure how I missed this thread Alan but glad I caught up with it. We'll have to talk about this Accu-Arc! The project is really looking good. Thanks for the progress pics.

Dave

@Alan Graziano posted:

Hete are some more updated pictures. 

Alan, wonderful project and terrific "in Progress" photos of the construction process.

Suggestion:  Please edit the thread's title to include today's date and mention the addition of new photos to the thread.  Without such a cue, I almost missed your excellent photos.

Thank you guys. I am glad some of you are buying an accu-arc. You can’t beat it when it comes to cutting a large radius. It sure made it easy to make a bridge on a curve.

The challenger will be fine. I think the clutch fan must have seized and did not like 5500 rpms. Nobody got hurt and the car will be back on line in a couple of days.

Mr. Love,

you are right. Styrene is a wonderful thing.

I had to hit a deer in SW Missouri photographing water mills to model, to put a fan through the radiator.

Great work  what thickness styrene do you use for your initial structure

Marty,

I use .040 and 060 thickness for this type of structure. No matter what thickness you use, reinforcing gussets prevent warpage.

@Alan Graziano posted:

I am starting a new project to construct a stone bridge. I understand that a flood created a new river on this layout and emergency construction of this bridge must take place. I will construct the bridge out of styrene covered with plastruct cut stone. Here is a sketch and the start of the cutting of the styrene. The bridge will be approx 32 inches long and 9 inches high.

Alan - great bridge modeling! I wish that I had the time.

By the way: I started out my career on a drafting table like that. Nowadays it's all CAD or Pro E.

Your usual excellent work on the bridge.  Glad to hear the Challenger will be up and running soon.  Must be a pricey repair.