I wonder if one of the shapeway designers on the n scale forum would be interested in discussing a car load idea I have. I handled a move of manufactured frames for JLG lifts from North Dakota to Pennyslvania and have been wondering how to model the frames ever since. I have photos of the frames and can easily provide those. I don't have the computer skills to design them myself. Anyone game? Joe
I had seen rotary couplers discussed elsewhere..... would be difficult to keep 'em straight, and small stuff has more breakability Delrin is almost required to make a durable scale (or close to it) coupler.
Been hoping that a Krauss Maffei body/trucks would be done. My wish was answered late last night! Someone did do the Krauss Maffei in N Scale! With trucks! Using the Kato SD45 chassis. Have one of Marks telescoping boom kits. A very nicely done kit too. Just gotta paint and assemble mine one day.
Now that would be quite a challenge! I kinda doubt that it would be possible given the current technology though unfortunately... Neat, thanks for pointing that out! I might have to get me one of those eventually...
Shapeways can produce products in several different materials including a vinyl like product used for trucks and even a stainless steel. It's just a matter of designing for the material. It because it shows the fine details that the brittle plastic is used for most models. I think the rotary coupler could be done like the old T shank couplers. Instead of a flat T and a square shank, a disk and a round shaft. This should work in the old Rapido style coupler box. And of course a non operating knuckle. You don't do switching with a unit coal train.
The other key (and one of the reasons that the majority of us use FUD) are the tolerances - the stainless steel parts are only accurate to within +/-2mm of the design you submit, for example. That's around +/-1 scale foot in n-scale. With tolerances that big it would be nay impossible to make an intricate working part like a coupler. Other materials are better than stainless steel, but it's difficult to beat FUD's ±0.025-0.05mm (±[FONT=Helvetica Neue, Helvetica, Arial, sans-serif]0.16-0.31 N-scale inches). [/FONT]
The question is how long would the FUD last as a coupler. The coupler in not a working park, its a single solid piece like a Unimate. The cost of the steel would make the couplers too expensive for a 50 car train. The white or black vinyl would be the material to use. I know that Jim Lincoln of podcast fame has made O scale truck parts from it. As long as the coupler can match up with any of the commercial N scale ones, most people should be happy. The important part is that it functions. Anyone who does build my idea a common courtesy would be to send me a sprue or two. These should be set up with ten or 20 to a sprue.
The rotary coupler: Since it's a semi-working dummy and detail below .3 mm is not required it should be feasible in the more durable 3D materials. Some sort of detent with a Rapido spring mechanism could keep it centered as long as it's returned to center after rotating the car. Would have to make a coupler box for it too. FUD material can be brittle so strength might be an issue as the coupler faces bang around. Since the tough materials are heat fused there isn't any microscopic porosity like FUD, so they can handle stress and strain. My link and pin couplers are FUD, but they aren't used in trains longer than 5 cars either. The lift frames: I might be interested, but it will be awhile. Most likely need to be FUD, which is pricey, but if they're just skeletons they'll be economical. Send a plan or photo. Eric Cox http://www.shapeways.com/search?q=panamintmodels
