There are a number of posts

There are a number of posts regarding Shapeways on the Yahoo Groups Nn3 board and also on the Railwire http://www.therailwire.net/forum/index.phpmainly in the N scale section..

The finish of the surface varies from smooth to small steps depending on the orientation in the printer.  The small steps may vary from unobtrusive to so large they make the product virtually unusable.  They can be easy or difficult to smooth out depending on the detail in and around them.

There have however been many successful models printed, particularly in smaller scales.  A number of nice products have been made and sold in N scale in general and Nn3 in particular.  

The knowledge and skill of the technician setting up the print run can make a big difference in the outcome with some previously successfully run models coming out trash in a later run.

Another problem is that Shapeways has apparently changed their requirements (probably because of complaints about the inconsistency in output) and had been refusing to print (claiming they are unprintable) products  they have successfully printed in the past. 

Price question

I have not bothered to do the math, so I apologize ahead of time if this is a stupid or obvious question.  How do the prices compare between HO scale detail parts (bells, whistles, stokers, pilots, stacks, and other steam locomotive parts interest me most) from Shapeways and investment cast in brass, as from Precision Scale or Cal-Scale?

My gut tells me that the prices might be pretty similar.  Assuming that such small parts can even be printed, it might be a good way to replace a dwindling supply of detail parts on the market and on the shelves of many shops.

how about what they have on their website?

Are things on their website likely to be fairly consistent and reliable in quality?  I see a few HOn30 items that would be nice.  I won't be designing anything--for my own scratchbuilding, I'll work in plastic, brass, wood, and cloth.

Shapeways?

I built a couple TT scale Shapeways cars designed by a guy called TTNut  and also a few pair of trucks. Mine are a few years old so the process might be better now. The cars I built had a rough finish like very fine sandpaper, not a problem on the truck moldings as real  trucks are kinda rough but could be a problem if one wanted to model a new shiny car. I wasn't concerned about it as the cars are cement hoppers and don't need to be smooth and shiny. IIRC the price for a TT scale hopper was about $20 delivered. I think Shapeways is a great way to get cars that are not available as kits or RTR but I'd go for brass detail parts instead of shapeways details if given the choice. The trucks do seem adequate in strength in TT scale and roll well enough.....DaveBranum

That's a nice looking Hopper

That's a nice looking Hopper (and overall scene) you've got there ctxmf74!

"That's a nice looking Hopper"

 Thanks, It's not as nice as an Atlas RTR hopper but in TT scale one takes what one can get. It's a pretty easy kit to build and makes a useful cement car. TT Nut also offers a three bay version from shapeways. As for the "scene" is was just an accidental construction. I didn't have any TT scale track so I split some code 55 N scale flextrack and glued the rails and tie halves to a piece of leftover bamboo flooring then set it in front of some TT cars on a shelf. It's funny how camera angle can change a scene. I took these two photos a while back of a TT scale yard I was designing .The high shot shows the overall plan and the low shot gives a more realistic view looking thru the yard. Even without track it reminds me of local yards I 've seen.DaveBranum 

Shapeways is not cheap, but

Shapeways is not cheap, but can be a timesaver on parts with a lot of features that would be hard to scratch together.  I have found that even their most detailed material cannot produce small details like you would see on an injection molded part. The material does usually need to be sanded...I use some squadron sanding sticks and water. The material is more brittle then styrene, so you need to take care when cutting it. It likes to be sawed more then it likes to be cut with an X-acto knife. On a HO locomotive cab, it takes about 10 minutes to clean one up. After that, you need to add all your own details, kind of like how Rail Power Products shells need to be done.

As for details- I had issues with things like louvers and door panels under .010 thick. You run into warpage issues when you get under .030" thick on wall panels also. Here are a couple pieces I printed recently.

HO scale Admiral cab replacement:

This one came out a bit better then my original crescent cab I did.

This is the cab with a primer coat and no sanding, to show the roughness from the manufacturer:

This is my first attempt at a NS Crescent cab....this one is kinda hard to see, but the louvers are messed up looking...the detail is just too small to be replicated well right now.

Thanks--tonight...

UPS shows my HOn30 locomotive cab and HOn30 passenger trucks as "Out for delivery."  So, I should have them today--and be able to look at them next week, after the family goes home.  It's based on so many replies that I decided to try an inexpensive (relatively) order, and I'll let people know how it comes in...

Thanks for all the replies--this place is great

Alternative

An alternative to try could be: http://i.materialise.com