3" scale D&RG inspired boxcar

[Harlock]

Kudo's to your solidworks skills and for sharing the details of your findings.
I'm equally impressed with the advancements in photo-realism rendering - I thought your SW pic was the finished part!

Solidworks Premium includes PhotoView 360, which is a dedicated renderer. It comes with a lot of nice scene presets that use radiosity and a number of other tools that were computationally prohibitive to use casually a decade ago. Before I would have had to export the geometry to another software package that I used when I worked in visual effects. (I used to create photo-real 3D cars and things for TV commercials) Now I can render quickly and easily from inside SW, really nice to have for demos.

I think the most difficult part now is getting the RP parts to look as good as the render! the machines continue to get more accurate and the price continues to come down for that accuracy, so, all we have to do is wait...

-M

[Dick_Morris]

Very nice.

Another option would be to use your master to make an RTV mold and cast the part in polyurethane. It's tough, can be colored, and is available in a big hobby shop. The main drawback is that to do the best work you need a vaccuum pump.

[Harlock]

Very nice.

Another option would be to use your master to make an RTV mold and cast the part in polyurethane. It's tough, can be colored, and is available in a big hobby shop. The main drawback is that to do the best work you need a vaccuum pump.

Yup. You get into those sorts of thoughts when you start thinking about casting things yourself too. Too much money and time to get it right. I don't need another (aspect) to the hobby right now, machining and sheet metal fabrication are enough. The PA2200 (white material) is a nylon variant that you can actually paint. It should be strong enough for the job.

-M

[Kimball McGinley]

We have two Objet plastic RP machines here at work. (I just walked down the hall to check the name and found one running 4 parts that I up loaded from S/W just last night) The parts are quite strong. My expeience with them is yes, they end up rough as the software is essentially adding miniature "bricks" and so has to decide whether to use one or not on curved surfaces. We usually just make them a little "fat", about +.005" or +.010" to allow for filing and or sanding where needed. The naterial can be a little sticky too. A good coat of paint or polyurethane finish helps too, or a little silicone grease.

The missing letters on the one part are most likely damage from cleaning off the support material that is used to create any features that would otherwise be cantilevered as the build progressed. In other words, they sent you a damaged part, in my opinion.

Does nobody in the US offer a similar service? You had to go overseas?

[Curtis_F]

We usually just make them a little "fat", about +.005" or +.010" to allow for filing and or sanding where needed. The naterial can be a little sticky too. A good coat of paint or polyurethane finish helps too, or a little silicone grease.

Kimball,

Thanks for that note. It's goog to know quirks and tricks for working with this kind of stuff.

Does nobody in the US offer a similar service? You had to go overseas?

American Precision Prototype (www.APProto.com) and Solid Concepts (www.SolidConcepts.com) are both US domestic companies that have a wide variety of machines including Objet (PolyJet material) machines. A bit more expensive than ShapeWays, but the money pays for personal attention and higher quality. Both would have rejected the part with the incomplete lettering.

Both are very good at listeing to their customer's needs and helping them select the best material and process (machine) for the job.


Mike,

I'll be honest with you. You put all that work into the 3D models and you're spending money on test pieces. Why not make some master patterns and go through www.modelrailcastings.com to make metal (bronze or even Aluminum) castings? Yes it's more expensive up-front, but those pastic pieces will break and need to be replaced.

Cheers,

Curtis F.

[Harlock]

Curtis,

That's the site I went through for the quote above. It's very costly for a small run. I know Jack uses him but he's in a different price bracket, his customers can pay for this stuff. We don't have a ton of money to dump into jewelry on the boxcar...the locomotive and its dingalings consume the majority of the expenditures.

My position is to use the PA-2200 material, polished, and see how it holds up, after beefing up the design. If it then has a problem then have those pieces cast. The bottom door guides will certainly not break unless the car gets side-swiped in a crossover collision. (and I'd rather have those break than the pieces get ripped out and damage the wood)

Regarding the text output, I knew in advance that the text detail was likely too small to hold up in the white version. They are very upfront about how much detail each process will produce. It's definitely not their fault or a defect, the PA 2200 process is about half the resolution of the translucent stuff. But it's much stronger, so I have to go with that for now.

-M

[Adirondack]

Curtis,

That's the site I went through for the quote above. It's very costly for a small run. I know Jack uses him but he's in a different price bracket, his customers can pay for this stuff. We don't have a ton of money to dump into jewelry on the boxcar...the locomotive and its dingalings consume the majority of the expenditures.

-M

Hi Mike. I know Brad does some nice work for the money he charges. I've always been of the mindset "build it, and they will come". If you made a run of 10 pieces and used 4, you would find someone to buy the other 6. Brad also will add the piece to his inventory and only charge you for the castings if the deal is agreeable.

You should know that Shapeways is dialing back the resolution of their machines to keep production rates high. This is why you saw the poor quality parts you saw. A year ago, they would have been much better. Once again, high demand reduces the quality of the service the demand is for, eventually reducing demand and allowing higher quality. Go figure!

I use John Vegner at www.moddler.com for my RP parts and his machine goes down to 16 microns for amazing parts. The material the Objet printer uses is much more durable than you would expect.

But hey, you've already decided.

Cheers,

ADK

[Harlock]

You should know that Shapeways is dialing back the resolution of their machines to keep production rates high. This is why you saw the poor quality parts you saw. A year ago, they would have been much better. Once again, high demand reduces the quality of the service the demand is for, eventually reducing demand and allowing higher quality. Go figure!

I can't imagine that they would do that and and then not offer a premium service where they would run the same material at higher resolution (like with the high detail translucent material that is offered at fine and very fine detail levels for a slightly higher price, likely from the same machine.)

If the machine that does the PA2200 material is capable at running at a higher resolution, it would be nice. But they are very up-front about the level of detail in each different material. I got exactly what I expected, there was no deception involved.

I use John Vegner at http://www.moddler.com for my RP parts and his machine goes down to 16 microns for amazing parts. The material the Objet printer uses is much more durable than you would expect.

But hey, you've already decided.

I'll look at it for other projects down the road.

[Greg_Lewis]

Say, what about casting the parts in resin or white metal? The HO and O scale guys have been doing that for a long time. Would the resin they use be strong enough?

[Harlock]

Say, what about casting the parts in resin or white metal? The HO and O scale guys have been doing that for a long time. Would the resin they use be strong enough?

I'm not sure that would be strong enough for the door hangars but everything else probably.

[Fender]

now you probably notice another problem with these parts in terms of direct use. They are not particularly smooth, especially the white parts. Good news, Shapeways offers a post-polishing process that involves a drum polisher. When used with the white strong flexible material, it comes out looking like molded plastic. In a part made to look like metal and then painted over with a primer and then several top coats, you would not be able to tell the difference. The white material is also the most paintable out of all the materials they offer.

Harlock, thanks for posting all this RP info. I have question about Shapeways that you might be able to answer. I have a model of a truck sideframe that was created by my good friend Bill Shields (see the thread on "Tender Truck Doodad") that I sent off to Shapeways for a quote. It came in at about $84 for the WFS material. My plan was to use this as a pattern to make sand castings. Unfortunately the polishing service is not available for large parts like this.
My question is, do you think the WFS part could be sanded or painted with a filler to allow it to be used as a pattern? My only other good options from Shapeways are to have it done in "sandstone" or "ceramic" but I'm afraid either of these would lose too much detail.
Thanks,

[Harlock]

Yes the white material can be sanded and the filler will probably work as well.

now you probably notice another problem with these parts in terms of direct use. They are not particularly smooth, especially the white parts. Good news, Shapeways offers a post-polishing process that involves a drum polisher. When used with the white strong flexible material, it comes out looking like molded plastic. In a part made to look like metal and then painted over with a primer and then several top coats, you would not be able to tell the difference. The white material is also the most paintable out of all the materials they offer.

Harlock, thanks for posting all this RP info. I have question about Shapeways that you might be able to answer. I have a model of a truck sideframe that was created by my good friend Bill Shields (see the thread on "Tender Truck Doodad") that I sent off to Shapeways for a quote. It came in at about $84 for the WFS material. My plan was to use this as a pattern to make sand castings. Unfortunately the polishing service is not available for large parts like this.
My question is, do you think the WFS part could be sanded or painted with a filler to allow it to be used as a pattern? My only other good options from Shapeways are to have it done in "sandstone" or "ceramic" but I'm afraid either of these would lose too much detail.
Thanks,