# Centerbeam, revisited



## Burl (Jan 2, 2008)

While I'm waiting on parts from Shapeways for my boxcar, I drew this up:










Here's the prototype:










It still lacks ladders, end walks & the roof detail, but the file is getting too big and I need to part out some of the detailed stuff so I can continue.

I did the opera-bay type several years ago as a kit, but it was pushing the limits of my mold making skills at the time and I discontinued it after a while because of the high failure rate. I always wanted to do this car, but I felt it was too complicated at the time.

So here’s where the monkey wrench comes in: when I started in large scale, I was more or less forced into 1:29 because of the availability of parts – mainly, trucks. Now that I’m making my own trucks & couplers (and almost everything else too), there’s nothing to keep me in 1:29. I can’t make wheels, but there are readily available sources for 1:32 wheels... so I’m strongly considering this car for my next kit, in 1:32 scale.


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## Burl (Jan 2, 2008)

I'll look at these for a couple days to make sure I didn't miss anything, but I think I'm about done with the drawings:


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## SD90WLMT (Feb 16, 2010)

..... the incredibly shrinking center beam flat...

Are you leaving us Burl....?

SD


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## Burl (Jan 2, 2008)

Its only shrinking by 9.375%... where would I go?


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## CliffyJ (Apr 29, 2009)

Always impressed by your work Burl. 

I'm amazed that you can get such detailed parts out of Sketchup, it always looks so... well... sketchy. I guess the presentation is just meant to look artsy, but the CAD data is precise and up to the job. 

Best wishes on your new model,
Cliff


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## jokensa (Dec 4, 2014)

wow!!

i would love to get my hands on one of these!

(in 1/29)

JKS


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## KCmike2013 (Jul 19, 2013)

Wow that is impressive! i guess since you can increase and decrease size on Sketchup relatively no problem, then doing a 1:32 or 1:29 shouldn't be too much of a problem since you wouldn't have to redraw for each scale, correct?


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## Burl (Jan 2, 2008)

Its drawn in 1:1 scale, with 1:32 minimums in mind. In other words, if its going to be printed in SLS nylon, and the minimum thickness is 1mm, then its drawn to a minimum of 32mm in Sketchup. 

I learned (the hard way) that Sketchup doesn’t do well with small numbers. When you start getting below 1/8”, it starts having problems. That’s why I draw everything actual size first, then resize it when I’m done. Sometimes, if I need both sizes in the same drawing, I’ll make it a component and scale one down to model size so I can work back & forth to get what I want. But I try not to do that unless I have to, because large numbers of components also slows it down.

Anyway, scaling it to 1:29 shouldn’t affect anything, if I decide to go that way.


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## SD90WLMT (Feb 16, 2010)

Burl - regarding your comments about the minimum thickness of 1mm, compared to being below 1/8",... 
1 mm = .039",... far below 1/8"....

Where are the limits here, can you better explain your thoughts please!?


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## KCmike2013 (Jul 19, 2013)

Can't wait to see your kit done in 1:32. I'd like to try and pick one up for a fall winter project if you have them ready by then.


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## Burl (Jan 2, 2008)

When you start trying to get Sketchup to do curves smaller than 1/8", it starts having problems. It also gives it fits with solid tools at that level. Even for 1:1 rivets sometimes I'll draw them at 10x and scale them down when I have it the way I want it.


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## Burl (Jan 2, 2008)

Can't say I'll have it done by winter... don't know if I can handle the pressure. This is a "spare time" project right now.


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## ewarhol (Mar 3, 2014)

I see requests for both 1:29 and 1:32. Will it be available in both scale?


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## Burl (Jan 2, 2008)

I guess that would be the best test, to offer it in both scales & see which one has the most demand. I'm having a hard time seeing how I would keep all the parts separate when there would only be about a 9% difference in size.


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