Re: Another Shapeways report

midrly <midrly@...>

Not just we STMFC modellers interested in RP work and Shapeways. Here is a piece from UK author George Dent on a depressed flat car using rapid prototyping.


WW2 Warwell produced by automated 3D printing

Is this the way forward for model railway kit production? After browsing the website of Shapeways, I found the range of Wild Boar Models, a specialist in 4mm scale military railway vehicle kits, previewed a few months back in Model Rail magazine. After choosing the wagon I wanted, the transaction is made and then the CAD files are sent to an automated factory in Eindhoven where the model is 'printed' in 3D and dispatched by first class mail.

It's a bit rough and ready, with the acrylic needing quite a bit of work to smooth-out the marks from the laser cutting process. Extra details like builders plates, load shackle loops, brake gear and bogies have to be sourced separately and I doubt the plastic buffers will last long, so they'll have to go. Would it have been easier to scratchbuild? And is it superior to the (rather nice) Genesis Kits whitemetal kit of the same wagon? Well, I'll have to finish this 'kit' off before I make up my mind.

It's worth a look at the Shapeways site. It's certainly an interesting concept and quite a few MR readers have mentioned it in the past. As long as you can design it, they can make it. So it opens up a lot of possibilities to modellers..."

Some images are at--


Steve Lucas.

--- In STMFC@..., "soolinehistory" <destorzek@...> wrote:

--- In STMFC@..., "pullmanboss" <pullmanboss@> wrote:

Time to clear up some misconceptions. There are two inkjet-type heads mounted back to back. One contains body material, the other contains support material, in this case wax. Each head is capable of dispensing its material onto any pixel in a layer in the same pass. Same resolution, same layer thickness... But where there was wax, those tiny marbles that were in contact with the wax will have oozed out from the surface, leaving a rough patch...
Thanks for the more detailed explanation, Tom. So, while the resolution is the same, the effect on surface finish is certainly detrimental. Which leads me to conclude that Fused Deposition Modeling (FDM) isn't the right process for mechanical parts like brake cylinders and valves which by their very nature are going to have overhangs somewhere.

I wonder about SLA? From photos of parts like dental crowns it appears that can build an overhang, so long as it is continuous with all the fused material on a given layer, to a point... the Asiga web page makes a claim that their software automatically calculates where "support structures" are needed. The problem is, these support structures are then one with the finished part, and have to be cut away by hand, maybe just a sprue nipper job, maybe much worse.

As to the surface finish on the part in my photo relative to everyone else's, keep in mind my triple valve is but a fraction of the size of what anyone else has posted photos of, so the magnification is much higher.


Join { to automatically receive all group messages.