Does anyone have experience designing stuff for 3D printing? I’ve already searched the shapeways site, but there’s nothing existing in N scale that would work for me. I’m still trying to find a solution to the complete lack of accurate balloon stacks for 4-4-0 Americans. I emailed Lowell Smith, who did those fantastic Great Locomotive Chase engines with accurate stacks, but as I expected they have no more parts for those engines. Bachmann, which makes he closest stack available, customer service never got back to me (I may try again). And I really don’t want to scratch build balloon stacks, because frankly they’ll look like crap. The other solution, waiting for junk engines to show up online, isn’t very cost-effective or easy to wait for.
There are a few of us around... if you have a set of calipers to provide very accurate dimensions and links to pics of what you want shoot me a PM!
If you can fine some real prints of the balloon stacks would be nice to I have seen a few at Shapeways and most shop owner can re scale any of there model so it can be in a different scale then re-scale! I guess you are looking for "N" 1:160 scale
MVP, I was wondering if there was any update in regards to your quest in finding these. I too, am looking for spare balloon stacks.
Have you look for this item in different scales on Shapeways? If some one has designed this item for another scale, they might be able to scale down the part for N scale use.
You could go onto Shapewats AOTRS Shipyards shops and contact Alex there and send him drawings Full size and the scale you want and how many. If its simple either he or I could draw it and then it would go on his shop. Normaly he charges for 3D models but if its simple, one way or another he may not charge for the creation of the model just the printed parts.
there are quite a few members with 3d printers .... all you need to do is provide the stl file ? a balloon stack for a N scale loco isn't a big deal ?
I've done two stacks in cast metal - one being my own design of a Radley-Hunter (which some people call a balloon stack) and the second is a cast-metal version of the Bachmann 4-4-0 funnel stack separate part. On any small steam you need as much weight as humanly possible, and depending on the printer and material, may run into some surfacing problems. Cast metal using an aluminum or plastic master works rather well. I made my master from turned aluminum. This is the Radley-Hunter stack I came up with as there wasn't anything out there even remotely close to this design: http://www.randgust.com/HVR5042 final 5.jpg The Bachmann one is the typical large funnel stack, I just replaced mine to get more weight on a chassis as it's a pretty big stack. I do sell that metal stack casting separately - see my contact information on randgust.com
Thanks all. I ended up getting in touch w Eric Cox. He apparently had the drawings ready to go a few years back, but hadn't put them into his shop. We're waiting on a test print and he'll let me know how they turn out.
This is slightly off topic but I always wondered what the benefit was to having the balloon stack. Did it have a functional purpose such as lifting the smoke higher or what? Okay, maybe its more than slightly off topic but inquiring minds want to know.
Balloon stacks were mostly found on wood burners but occasionally some low grade coal burners. The taller stacks increased draft and a series of screens or mesh inside the stack trapped large embers that could be pulled through by the draft.
"Early spark arrestors were simply iron wire screens installed within the stack. This screen reduced the rate at which smoke and steam could escape from the boiler. Embers caught upon the screen further reduced available space for passing steam and smoke and heat generated by these burning embers rapidly melted the restraining wire screen. Chimney top diameters enlarged to increase screen surface area and reduce smoke velocity through the screen so embers might fall away from the screen into collection hoppers."
