Using Google SketchUp and printapart.com

[finescalerr]

Fred, Derrell and I are old pals. Next time you talk to him say, "Hey, 'South Park', Uncle Russ says hello!" He will know immediately that you and I have been in touch. You also should give him a hard time about not being on this forum. And about not sending me any articles since about 1995. -- Russ

[Fred H.]

Russ - I'll say hey when I visit with Derrell. I need to send him a dimensioned sketch before I proceed any further.

Marc - I just LOVE inside jokes that don't include me. For full disclosure I should say that my interests include: C&S, Gilpin Tram, Swayne Lumber Co., Feather River Rwy., and the 8th US Army Air Force!

[DaKra]

Very interesting thread, I've always been an advocate of using high tech in model-making to push the envelope.  I do all my design work in 2d in Adobe Illustrator, but would like to learn 3d software like SU or Rhino.

Questions--

The rungs on the 1/1 ladder look like they were manufactured from cylinders with squashed ends.   But the drawing seems to indicate separate cylinders and end pieces.  Is this because its difficult to make fillets and smooth transitions in the software?  Or am I missing something in the photo?

I understand sending the the horizontals to Printapart-- you get the advantage of saving a lot of repetitive labor, and ensure that every one is identical.  But why have you chosen to make the entire ladder as a single piece?   Seems to me if you made only the horizontal rungs, it would be more cost effective, and much sturdier too, if you made the vertical bars by hand out of brass. 

Dave

[Fred H.]

Dave, you really got me thinking...

Working on this project, like a lot of modelling, requires research/knowledge about manufacturing methods/techniques or guesstimates. I probably SHOULD find out how a part like the rungs (horizontals) was/is made. That would guide how I approach drawing it. But I also need to be thinking about: (1) how it will come out in printapart; (2) how much clean-up will be required before it goes off to the foundry for casting; (3) the look and "robustness" of the finished casting; and (4) how the ladders eventually get attached to the model. (To be 100% honest, a lot of those thoughts didn't go through my head when I started this exercise.)

So, I'm thinking that I have two choices for the end result:

• Uprights and rungs as separate elements.
• Uprights and rungs as a unified part.

I'm definitely leaning towards the second choice, but I might be making a mistake in that the rungs could end up being too delicate. Brass wire with flattened ends might be more robust, either to make the rungs for the casting or else at the very end when I'm building up the finished models. The considerations here also include how do I get that great little rounded end (on the flattened portion) which will definitely show up in 1:24 or 1:20.3?

In addition, assuming 10 reefers = 40 ladders = 200 rungs. Ick! (Maybe even double ick!) Well, why decide now anyway? Let's do it both ways and see what comes back from printapart.

On another matter... I really like the fact that scale hardware makes miniature rivets! (See: http://www.scalehardware.com/miniature-rivets-c-10 And I think that attaching each finished ladder to the car side using four brass rivets would be really cool/smart. So, for both the "separate elements" and "unified part" runs I'm going to leave four holes all the way through.

[Fred H.]

Here is the dimensioned sketch being verified. Project on hold until dimensions finalized. (Backwards from how I SHOULD have done it, I know!)

[Chuck Doan]

Very interesting SBS here! I'm considering SU too, as I would love to be able to make use of printapart.com

Marc, regarding the gaps between rungs and uprights... is there any reason you couldn't simply draw the rungs long enough to extend _into_ the uprights a little bit?

Ray, you might want to find out how well this material will stand up to outdoor exposure. Even if used inside a structure, they may see temperature extremes that indoor models do not.

[marc_reusser]

Fred,
The inside joke/backstory is, that I basically have a huge dislike (to put it kindly) for anything related to Colorado railroads.

One more thing re. the SU model came to mind. A while back when I once looked into exporting SU into .STL, I recalled that the convertor I was reading about/looking at (name I cannot now recall) required the removal of duplicated hidden surfaces....areas where two parts came into contact with eachother ....in your case the the rung and the 2x2....the small contacting surface areas on both parts had to be deleted, so the parts became a unified whole....(hope this makes sense)......the program at the time would run through the SU model and let you know where these areas were, so you could fix them.  Don't know if the convertor you will be using has that issue/requirement, but thought I would give you a heads up.


Ray,
You would not want to draw the part "longer", as this would not solve the problem, and would likely only cause you more problems down the line. There really is little to no room for those kind of variables when working in CAD,....it is a pretty "absolute" form...and any variances/vagaries/dicrepancies will very quickly become cumulative and begin causing more and more problems down the line.  The whole purpose of using a program as exacting as CAD, is to be accurate. I'ts every anal Swiss guys dream



Marc

[Fred H.]

Well, Marc, I sure have knocked up the pooch, haven't I?

What's my penance?

[JohnP]

Fred, if you need to add extra material such as sprues across the back of the ladder uprights for strength. They would be clipped off before installation. The ladder will be stronger when it is attached so you just need to manage it in the meantime.

Marc, I am not Swiss, but I guess the anal part makes me enjoy using CAD. I draw almost every project I do in CAD so the thinking is done at the computer and the assembly or modeling is fun. Layouts, bridges, 7/8ths railway stuff, mechanical stuff for casting equipment, house plot for our gardens- it's in my computer.
John

[marc_reusser]

Well, Marc, I sure have knocked up the pooch, haven't I?

What's my penance?

No worries.....I didn't want to mention it........but since you felt left out and asked 

I look at this project like Freud would ....sometimes a ladder is just a ladder.  .....and in the end, it's the modeling that matters.


Marc

[Fred H.]

Well, as long as we don't get into a my ladder is bigger than yours kinda thing, I can live with that! I originally planned to model the Gilmore & Pittsburgh RR, which was an NP subsidiary that ran over the Divide from Armstead, Montana, to Leadore-Salmon-Gilmore, Idaho. Talk about obscure! (I grew up about 60 miles from Leadore.) It was affectionately known as G&P = Get Out And Push. Most beautiful river rock and timber depots. Truly stunning. When I was a kid we used to stop for an ice cream cone at the Depot Cafe. Some mindless/thoughtless asshole burned it down.

[lab-dad]

Fred,
I know this is an "experiment"  but I know I could have made a brass master by now and sent it off to the caster.
I like the idea of the rivets to pin the ladder to the car, using the right size will give the look of carriage bolts.
-Marty

[Fred H.]

Marty -- Thanks for the encouragement. (That WAS encouragement, right?). There's a LOT of program learnin' built into those time logs. Hope I can talk the scale hardware folks into sending me a sample pack of their stuff. But, I think using rivets probably IS a good way to proceed.

[lab-dad]

Yes Fred it was encouragement!
The owner at Scale Hardware is a nice guy and a great vendor.
I have bought from him for years.
I have quite an assortment of nuts & bolts but no rivets.
-Marty

[Fred H.]

Update 7. Elapsed Time = 14.00 Hours.

Well, guys, I'm stuck. I've just spent the last 1.5 hours rebuilding the ladder rungs and I've got two identical "halves" that for the life of me I can't join together. I'm sure there's some completely easy way to do this. Help!!

I'd be HAPPY to send someone (hint, hint) the .skp file...