I had Shapeways run two more parts with much finer detail and/or more complexity than the bolster pan reported previously. But first, this note - I know these are not freight car parts, but the STMFC is where the most intelligent discussion of Shapeways' processes is taking place. Also, I fear that if I take this to the Passenger Car List the discussion will focus on the parts and not on the process. Thanks for your forbearance.

The first part is a truck-mounted lighting generator used extensively by the Santa Fe, and on heavyweight Pullmans assigned to the Santa Fe. When a car was air conditioned, a second such generator was usually added. The second part is a steam control box applied to Santa Fe cars and Santa Fe assigned Pullmans air conditioned in 1934. It came in both left- and right-handed versions. Both were made with Shapeways' MultiJet Frosted Ultra Detail (FUD) process. This photo shows the parts (sprayed with gray primer for visibility) next to an HO scale rule:
http://www.pullmanproject.com/Shapeways6.jpg

Another view of the two parts:
http://www.pullmanproject.com/Shapeways7.jpg

The generator from above:
http://www.pullmanproject.com/Shapeways8.jpg

The generator from below:
http://www.pullmanproject.com/Shapeways9.jpg

The generator has been offered in lost wax brass by The Coach Yard and Pecos River Brass, but as far as I know is no longer available. The design I submitted to Shapeways was an assembly of six individual parts intended for injection molding, a still-born project of Branchline's. It replaces the rear brake beam on Branchline Pullman trucks. There should be a cylindrical spring tensioner extending off the back of the vertical plate to the right of the generator (pulley side), but I felt it was asking for trouble to include it. Easy enough for the modeler to add.

The steam control box has never been offered in HO, and I wanted to see how the motor controlled valve came out. I designed the left-handed version, then mirrored it to create the right-handed version on the same backing plate.

First the good things. I had few hopes that the hasps, pins and chains on the steam control box face would build properly. The "chains" were just rows of little rectangular blocks in a hi-lo-hi-lo pattern, and they look pretty clunky on the computer screen. But they look pretty good on the parts, and you can even see the pins in the hasps. Shapeways claims the FUD material is brittle, and I feared the support rods on the generator would shatter during cleaning. They survived whatever Shapeways does, and also the ultrasonic cleaning in warm water & detergent I used. In fact, there is quite a bit of resilience to the assembly. Will they survive heavy duty impacts? Probably not. But ordinary derailments shouldn't be a problem. I was also concerned about the integrity of the generator assembly, since the six individual parts (front, two sides, two support rails, generator) were designed with clearances where they interlocked. The generator body was also a loose fit on the support rails, but it all built very nicely as one monolithic part.

Now the not so good. Rob Kirkham mentioned that the quality of the parts depended on the build orientation. Here's what he's talking about:
http://www.pullmanproject.com/Shapeways10.jpg

The painted part was built with the box faces facing up. The unpainted part was built standing up, and those tracks are where wax support material was laid down in line with the cleats at the bottom of each box. There are similar tracks on the gray part, but they're on the sides of the box in line with the hinge hasps, and are of little visual consequence. Shapeways places as many parts as possible on their build tray, so unless you specify otherwise orientation is something of a crapshoot.

If you blow the generator photos up to max resolution, you can see the surfaces are quite rough. You can also see tracks on the top of the \generator body like those on the unpainted steam control box. Considering these are located well under the car and seen only in profile, and that they are difficult to impossible to produce (economically) by other methods, I think they meet the "good enough" standard. They pass not only the "three foot test", but the "six inch" one as well. The steam control boxes will serve very nicely as masters for resin casting as-is.

I had uploaded a design for four HW Pullman half sides but will not order them. As indicated with the bolster pan, my take is the process is great for shapes but the FUD surfaces are too rough for large and highly visible things like car sides and roofs. Stereolithography is still the way to go for those, and Shapeways doesn't offer that. I also don't think it has the resolution for free-standing things like Dennis' LN brake valve, but must say I am very pleased with how the surface details on the steam control boxes came out. (The rivets in the cleats are 1/2" diameter in the design, but that is intentionally undersized because Multi-Jet, like PolyJet, overbuilds small details.)

Next step is to gang a bunch of generators into one assembly and have those run. Shapeways considers assemblages of many objects as one part as long as the objects are connected by runners. We'll see how that goes.

Tom Madden

Tom,

Very nice! Do you, perchance, have the lost-wax brass castings as well? I wonder how the grain of the Shapeways parts compares with the grain of a brass casting.

Regards,

-Jeff


From: STMFC@... [mailto:STMFC@...] On Behalf Of pullmanboss
Sent: Friday, October 05, 2012 3:52 PM
To: STMFC@...
Subject: [STMFC] Another Shapeways report



I had Shapeways run two more parts with much finer detail and/or more complexity than the bolster pan reported previously. But first, this note - I know these are not freight car parts, but the STMFC is where the most intelligent discussion of Shapeways' processes is taking place. Also, I fear that if I take this to the Passenger Car List the discussion will focus on the parts and not on the process. Thanks for your forbearance.

The first part is a truck-mounted lighting generator used extensively by the Santa Fe, and on heavyweight Pullmans assigned to the Santa Fe. When a car was air conditioned, a second such generator was usually added. The second part is a steam control box applied to Santa Fe cars and Santa Fe assigned Pullmans air conditioned in 1934. It came in both left- and right-handed versions. Both were made with Shapeways' MultiJet Frosted Ultra Detail (FUD) process. This photo shows the parts (sprayed with gray primer for visibility) next to an HO scale rule:
http://www.pullmanproject.com/Shapeways6.jpg

Another view of the two parts:
http://www.pullmanproject.com/Shapeways7.jpg

The generator from above:
http://www.pullmanproject.com/Shapeways8.jpg

The generator from below:
http://www.pullmanproject.com/Shapeways9.jpg

The generator has been offered in lost wax brass by The Coach Yard and Pecos River Brass, but as far as I know is no longer available. The design I submitted to Shapeways was an assembly of six individual parts intended for injection molding, a still-born project of Branchline's. It replaces the rear brake beam on Branchline Pullman trucks. There should be a cylindrical spring tensioner extending off the back of the vertical plate to the right of the generator (pulley side), but I felt it was asking for trouble to include it. Easy enough for the modeler to add.

The steam control box has never been offered in HO, and I wanted to see how the motor controlled valve came out. I designed the left-handed version, then mirrored it to create the right-handed version on the same backing plate.

First the good things. I had few hopes that the hasps, pins and chains on the steam control box face would build properly. The "chains" were just rows of little rectangular blocks in a hi-lo-hi-lo pattern, and they look pretty clunky on the computer screen. But they look pretty good on the parts, and you can even see the pins in the hasps. Shapeways claims the FUD material is brittle, and I feared the support rods on the generator would shatter during cleaning. They survived whatever Shapeways does, and also the ultrasonic cleaning in warm water & detergent I used. In fact, there is quite a bit of resilience to the assembly. Will they survive heavy duty impacts? Probably not. But ordinary derailments shouldn't be a problem. I was also concerned about the integrity of the generator assembly, since the six individual parts (front, two sides, two support rails, generator) were designed with clearances where they interlocked. The generator body was also a loose fit on the support rails, but it all built very nicely as one monolithic part.

Now the not so good. Rob Kirkham mentioned that the quality of the parts depended on the build orientation. Here's what he's talking about:
http://www.pullmanproject.com/Shapeways10.jpg

The painted part was built with the box faces facing up. The unpainted part was built standing up, and those tracks are where wax support material was laid down in line with the cleats at the bottom of each box. There are similar tracks on the gray part, but they're on the sides of the box in line with the hinge hasps, and are of little visual consequence. Shapeways places as many parts as possible on their build tray, so unless you specify otherwise orientation is something of a crapshoot.

If you blow the generator photos up to max resolution, you can see the surfaces are quite rough. You can also see tracks on the top of the \generator body like those on the unpainted steam control box. Considering these are located well under the car and seen only in profile, and that they are difficult to impossible to produce (economically) by other methods, I think they meet the "good enough" standard. They pass not only the "three foot test", but the "six inch" one as well. The steam control boxes will serve very nicely as masters for resin casting as-is.

I had uploaded a design for four HW Pullman half sides but will not order them. As indicated with the bolster pan, my take is the process is great for shapes but the FUD surfaces are too rough for large and highly visible things like car sides and roofs. Stereolithography is still the way to go for those, and Shapeways doesn't offer that. I also don't think it has the resolution for free-standing things like Dennis' LN brake valve, but must say I am very pleased with how the surface details on the steam control boxes came out. (The rivets in the cleats are 1/2" diameter in the design, but that is intentionally undersized because Multi-Jet, like PolyJet, overbuilds small details.)

Next step is to gang a bunch of generators into one assembly and have those run. Shapeways considers assemblages of many objects as one part as long as the objects are connected by runners. We'll see how that goes.

Tom Madden

Jeff Aley asked:

Tom,

Very nice! Do you, perchance, have the lost-wax brass castings as well? I wonder how the grain of the Shapeways parts compares with the grain of a brass casting.

I do have them, both TCY and PRB, and the brass castings are much smoother. The Shapeways FUD process is essentially a 750 x 750 DPI printer, and that generator assembly is only 3/4" across. The grain is much more apparent on curved surfaces than on flat, horizontal (to the build direction) ones, and it wasn't much of a visual issue on any surfaces on the much larger (1 1/4" x 2") bolster pan. In fact, if you put the bolster pan and generator in the palm of your hand and look at them together, the generator looks just great.

Tom Madden

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

I had Shapeways run two more parts with much finer detail and/or more complexity than the bolster pan reported previously. But first, this note - I know these are not freight car parts, but the STMFC is where the most intelligent discussion of Shapeways' processes is taking place. Also, I fear that if I take this to the Passenger Car List the discussion will focus on the parts and not on the process. Thanks for your forbearance.

Tom's recent round of test projects prompted me to send my L-2 passenger car triple valve out again...

Tom and I seem to be taking opposite tacks on this... Tom is looking to learn the limitations, so as to be able to design usable parts/patterns within those limitations. I think with Shapeways, he's found that build orientation is important, and if you can connive to have them use your preferred orientation, you can get usable flat parts. The problem is, there's lots of ways to get flat parts, photo etching, for one, and photo etching brings the added advantage of doing some creative folding to produce 3-D objects. Of course, Shapeways can be considerably cheaper than etching, especially for one-off parts.

I, on the other hand, want to test the usefulness of the process as a sort of "universal modeling medium" to produce those needed parts that just can't be made easily by any process... that's essentially why they aren't made. My triple valve fits this description; it's small, no, downright tiny, has almost no flat surfaces, and has mechanical features in multiple orientations, which would preclude simple injection molding even if I wanted to cut a simple cavity. This is not a simple part, but it shares these restraints with a variety of hardware parts; door hardware, hand brake housings, truck journals and spring packages... all the little details, many of which we would like to combine with a larger object, such as the door hardware integral with the door, or carside.

Anyway, here's a link to a set of photos of the project to this point; a photo of the prototype, some screen shots of my solid model, and photos of the part I had printed a couple years ago, and now from Shapeways.

http://www.flickr.com/photos/25967611@N04/sets/72157623125645997/

This result is better than last time, to the point where I'll probably use them if nothing better comes along before I get back to the project they're intended for. I'm not happy with the surface, but have seen enough dirt caked underbody equipment to justify the lack of precise surfaces in this application. The problem is, once you start working with computer modeling, you realize how simplified the other parts are. I would love to model a better detailed, correctly sized brake cylinder to go along with this valve, and it occurs to me that it would be really cool to also include the branch pipe with its dirt collector and cut-out cock. Problem is, I'm not willing to build models that look like they were done by Georges Seurat, where solid surfaces dissolve into thousands of little dots.

Several people have been a bit down on Shapeways, mentioning broken parts. Meanwhile, Shapeways has apparently just revised their minimum cross section requirements upward, obviously in an attempt not be responsible for failures when designers attempt to push the envelope. The problem I'm seeing, however, doesn't relate to minimum cross section (OK, so I can't include the brake pipe) but rather to layer thickness and surface resolution. The various machines I've researched that have a build envelope the size that Shapeways offers have a minimum layer thickness of 50 microns... essentially .002". Some systems are now claiming 27 microns, a bit over .001", but have build envelopes of only about one cubic inch. The problem is, .002" is clearly visible on an HO scale part; I've used that dimension for lap seems (although I prefer .003", to be sure it doesn't get filled with paint). I'm not sure that .001" is going to be much of an improvement. When the systems get down to 10 micron layers, I think we'll have something. I don't see why it isn't possible; I doubt 2-D printers lay down much more ink than that, but build time, and cost, is going to go up by a corresponding amount.

It will be interesting to see what the next couple of years brings.

Dennis

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

Tom's recent round of test projects prompted me to send my L-2 passenger car triple valve out again...

Tom and I seem to be taking opposite tacks on this... Tom is looking to learn the limitations, so as to be able to design usable parts/patterns within those limitations. I think with Shapeways, he's found that build orientation is important, and if you can connive to have them use your preferred orientation, you can get usable flat parts. The problem is, there's lots of ways to get flat parts, photo etching, for one, and photo etching brings the added advantage of doing some creative folding to produce 3-D objects. Of course, Shapeways can be considerably cheaper than etching, especially for one-off parts.

I, on the other hand, want to test the usefulness of the process as a sort of "universal modeling medium" to produce those needed parts that just can't be made easily by any process... that's essentially why they aren't made. My triple valve fits this description; it's small, no, downright tiny, has almost no flat surfaces, and has mechanical features in multiple orientations, which would preclude simple injection molding even if I wanted to cut a simple cavity. This is not a simple part, but it shares these restraints with a variety of hardware parts; door hardware, hand brake housings, truck journals and spring packages... all the little details, many of which we would like to combine with a larger object, such as the door hardware integral with the door, or carside.

Anyway, here's a link to a set of photos of the project to this point; a photo of the prototype, some screen shots of my solid model, and photos of the part I had printed a couple years ago, and now from Shapeways.

http://www.flickr.com/photos/25967611@N04/sets/72157623125645997/

This result is better than last time, to the point where I'll probably use them if nothing better comes along before I get back to the project they're intended for. I'm not happy with the surface, but have seen enough dirt caked underbody equipment to justify the lack of precise surfaces in this application. The problem is, once you start working with computer modeling, you realize how simplified the other parts are. I would love to model a better detailed, correctly sized brake cylinder to go along with this valve, and it occurs to me that it would be really cool to also include the branch pipe with its dirt collector and cut-out cock. Problem is, I'm not willing to build models that look like they were done by Georges Seurat, where solid surfaces dissolve into thousands of little dots.

Several people have been a bit down on Shapeways, mentioning broken parts. Meanwhile, Shapeways has apparently just revised their minimum cross section requirements upward, obviously in an attempt not be responsible for failures when designers attempt to push the envelope. The problem I'm seeing, however, doesn't relate to minimum cross section (OK, so I can't include the brake pipe) but rather to layer thickness and surface resolution. The various machines I've researched that have a build envelope the size that Shapeways offers have a minimum layer thickness of 50 microns... essentially .002". Some systems are now claiming 27 microns, a bit over .001", but have build envelopes of only about one cubic inch. The problem is, .002" is clearly visible on an HO scale part; I've used that dimension for lap seems (although I prefer .003", to be sure it doesn't get filled with paint). I'm not sure that .001" is going to be much of an improvement. When the systems get down to 10 micron layers, I think we'll have something. I don't see why it isn't possible; I doubt 2-D printers lay down much more ink than that, but build time, and cost, is going to go up by a corresponding amount.

It will be interesting to see what the next couple of years brings.

Dennis

Dennis,

Many thanks for the easy to understand report!

Looking at the shapeway part on flikr, I confess to being a little confused. On Tom's parts, I felt one could detect the orientation of the build layers. But on your triple valve, I can not spot a layering effect, instead the surface just seems to be "noisy".

I am wondering if a barrel tumbler/polisher technique might help smooth the surfaces of a three dimensional part? Start out with surface features a little oversized, and let the polishing medium remove the "noisy" surface features. In place of a tumbler, I wonder if a medium-thick paste of baking soda and water, in a small tight container with the part, might be effective if it was immersed in an ultrasonic cleaner? Kind of a mini-polisher.

Probably a crazy idea, but for 3D parts with all of the detail, it may not be vitally important that the desired features be perfectly replicated - as you noted about underbody grime. Outside of very close examination, what is more important - the suggestion of six hex nuts on the valve cap with the adjacent surfaces looking relatively smooth, or six perfectly formed hex nuts with the adjacent surface covered in warts?

But a very impressive effort and improvement over the old part - looks like a little more patience may be in order.

Dave Evans

Curious about the preparation you did on this part before priming Dennis? Just wondering whether any of the distortion might be the waxy support material they use? Not that I'm getting completely clean surfaces either, but thought I'd ask.


Rob Kirkham

--------------------------------------------------
From: "soolinehistory" <destorzek@...>
Sent: Friday, October 12, 2012 12:02 PM
To: <STMFC@...>
Subject: [STMFC] Re: Another Shapeways report

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

I had Shapeways run two more parts with much finer detail and/or more complexity than the bolster pan reported previously. But first, this note - I know these are not freight car parts, but the STMFC is where the most intelligent discussion of Shapeways' processes is taking place. Also, I fear that if I take this to the Passenger Car List the discussion will focus on the parts and not on the process. Thanks for your forbearance.

Tom's recent round of test projects prompted me to send my L-2 passenger car triple valve out again...

Tom and I seem to be taking opposite tacks on this... Tom is looking to learn the limitations, so as to be able to design usable parts/patterns within those limitations. I think with Shapeways, he's found that build orientation is important, and if you can connive to have them use your preferred orientation, you can get usable flat parts. The problem is, there's lots of ways to get flat parts, photo etching, for one, and photo etching brings the added advantage of doing some creative folding to produce 3-D objects. Of course, Shapeways can be considerably cheaper than etching, especially for one-off parts.

I, on the other hand, want to test the usefulness of the process as a sort of "universal modeling medium" to produce those needed parts that just can't be made easily by any process... that's essentially why they aren't made. My triple valve fits this description; it's small, no, downright tiny, has almost no flat surfaces, and has mechanical features in multiple orientations, which would preclude simple injection molding even if I wanted to cut a simple cavity. This is not a simple part, but it shares these restraints with a variety of hardware parts; door hardware, hand brake housings, truck journals and spring packages... all the little details, many of which we would like to combine with a larger object, such as the door hardware integral with the door, or carside.

Anyway, here's a link to a set of photos of the project to this point; a photo of the prototype, some screen shots of my solid model, and photos of the part I had printed a couple years ago, and now from Shapeways.

http://www.flickr.com/photos/25967611@N04/sets/72157623125645997/

This result is better than last time, to the point where I'll probably use them if nothing better comes along before I get back to the project they're intended for. I'm not happy with the surface, but have seen enough dirt caked underbody equipment to justify the lack of precise surfaces in this application. The problem is, once you start working with computer modeling, you realize how simplified the other parts are. I would love to model a better detailed, correctly sized brake cylinder to go along with this valve, and it occurs to me that it would be really cool to also include the branch pipe with its dirt collector and cut-out cock. Problem is, I'm not willing to build models that look like they were done by Georges Seurat, where solid surfaces dissolve into thousands of little dots.

Several people have been a bit down on Shapeways, mentioning broken parts. Meanwhile, Shapeways has apparently just revised their minimum cross section requirements upward, obviously in an attempt not be responsible for failures when designers attempt to push the envelope. The problem I'm seeing, however, doesn't relate to minimum cross section (OK, so I can't include the brake pipe) but rather to layer thickness and surface resolution. The various machines I've researched that have a build envelope the size that Shapeways offers have a minimum layer thickness of 50 microns... essentially .002". Some systems are now claiming 27 microns, a bit over .001", but have build envelopes of only about one cubic inch. The problem is, .002" is clearly visible on an HO scale part; I've used that dimension for lap seems (although I prefer .003", to be sure it doesn't get filled with paint). I'm not sure that .001" is going to be much of an improvement. When the systems get down to 10 micron layers, I think we'll have something. I don't see why it isn't possible; I doubt 2-D printers lay down much more ink than that, but build time, and cost, is going to go up by a corresponding amount.

It will be interesting to see what the next couple of years brings.

Dennis



------------------------------------

Yahoo! Groups Links

--- In STMFC@..., "Rob Kirkham" <rdkirkham@...> wrote:

Curious about the preparation you did on this part before priming Dennis?
Just wondering whether any of the distortion might be the waxy support
material they use? Not that I'm getting completely clean surfaces either,
but thought I'd ask.


Rob Kirkham

That's what I'm wondering, Rob. Hey, I don't have any inside track on this, I just submitted my part file through the automated front end of the web site, like anybody else. I would have thought they would have built the part with the flat disk surface that makes the end of the valve facing up, to give it the best quality, but apparently not. I actually submitted a dozen of these, joined together on a "runner", and I think they built it standing on end. It really doesn't matter, since the purpose of my test is to see what kind of quality can be had on ALL of the surfaces. This is the perfect part for a test, as far as I'm concerned, there is no "show face", they are ALL equally important.

Let me address Dave's comment about "noise". It appears that the best quality surface is the one that is "normal" to the print process, that is, flat and parallel, like a sheet of paper relative to the print head of a ink jet printer. These surfaces will be flat and smooth, as the face of Tom's boxes are. The next best quality will be on surfaces that are perpendicular to the normal, because each layer should end at the same point. The problem is they don't; there are minute differences in both the size and position of each dot of resin deposited, and the result is a certain amount of surface noise. The next worst surfaces are going to be those that are round, or at an angle to normal, because there is the possibility that the edges of the layers will actually show.

I am now realizing that the process used by Shapewys has another pitfall; the basic process can't build parts with overhangs, since there would be nothing to support the first layer of resin that hangs past the previous layer, so the process used by Shapeways builds a wax structure to support this first layer. Unfortunately, it appears that the wax construction is done at a considerably coarser resolution than the actual part, and any surface built against the wax picks up this coarser resolution. Tom pointed this out when discussing a unsuccessful earlier attempt of his, and If I can borrow a link to his photo:

http://www.pullmanproject.com/Shapeways10.jpg

You can clearly see the striations where the part was built against the wax supports that were needed to build the overhanging features. I believe I'm seeing this same effect on the bottom angular surface of the bowl on the bottom of my valve:

http://www.flickr.com/photos/25967611@N04/8077677749/in/set-72157623125645997

I have no idea why they would degrade the resolution of the process by using a coarser resolution for the support material, but it appears they have.

I'm wondering if these fused disposition process (FDM) is ever going to meet our needs. However, I see stereiolithography (SLA), where the part is grown from liquid polymer in a tank, has considerably finer layer resolution. Here's a video of the process. Scroll to the end to see the finished parts:

https://www.youtube.com/watch?feature=player_embedded&v=l2SCrahu2fo

Asiga is a new low cost (relatively) entrant into the field, here is some comments from their discussion forum:

====================================
Our system has two main factors that affect build quality of the parts, these are listed below:

1. Image Resolution
This refers to the size of the pixel in the exposed image. The Pico and Pico Plus39 have a 39 micron pixel size, the Plus33 has a 33 microns pixel and the Plus27 a 27 microns pixel. The smaller the pixel the sharper the exposed image and the higher quality surface finish and detail resolution.

2. Layer Thickness
The thinner the print layer, the less visible the stepping. Our range of printers have presets from 25 microns through to 150 microns and you can select which layer thickness you require depending on the part you are printing. The 25 microns layer thickness will achieve a much better part resolution compared to the 150 microns style. You can also customize this yourself and print in 1 micron increments if you wish.

A combination of these will determine the resolution of a printed part.

Please let us know if you require clarity. If you are unsure which machine suits your application then let us know what industry/product you are producing.

Asiga_Support
===================================

The build envelope on these machines is somewhat limited; 35 x 22 x 75mm for the finest resolution printers. That's 1 3/8 x 7/8 x 3 inches, approximately. Big enough for parts, not for complete carbodies.

Unfortunately, SLA is a single component system, so overhangs require support structures, as mentioned below:

===================================
Our Freeform Pico range of 3D printers are a single material system which means you do need to 'break-away' supports by hand after printing. Our Composer software automatically places these support points in the exact positions in which they are required so processing is quick and easy.

Asiga_Support
====================================

It's also unfortunate that I don't as yet know of any service bureau that offers to build parts on one of these machines. Perhaps Shapeways will see the need to offer a material/process that will reproduce finer detail?

I can see that this is definitely coming, but we're not quite there yet.

Dennis

I've posted a number of photos of my own recent experiments with 3d printing (waiting for them to be approved). These were done by ADC (Advanced Design Concepts) - but as far as I know they use the same machine and substance as Shapeways. Overall I am quite happy with the parts I received.

The first photos show tank car underframes for CPR 389xxx series tank cars. The cars looked a lot like the Athearn single dome tank (and also like an SP prototype Tony Thompson has written about modelling). I've been muddling my way through this project for a number of years, but this is the closest I've come to an acceptable frame model. At this point the issues are in my design errors - not the material or process used by ADC. that said, I can see some grain in the part that may show through the paint. And the particles that are fused to make the part do produce some "noise" when under magnification. But for frame parts that will be largely hidden beneath running boards and the tank itself, I think this is acceptable quality for now.

The other part is an inverted Murphy end used on the CPR's 2975xx series single sheathed automobile boxcars. The rest of the model is still in process. Again one can see some waviness in the flat surfaces, and some imperfections in the corrugations, but overall I think it is a satisfactory starting point for the model. My photography isn't good enough to show the rivets along the edges, but they are there too.

I've been using Bestine rubber cement thinner to clean the waxy stuff of the parts with success so far. A few minutes in that stuff cleans them and changes the parts from translucent to opaque white and cleans some of the wax away.

One thing about ADC - they focus on your job so the parts are oriented as you would like. The auto-box end was modelled laying on the interior side of the model. Interesting that the view of the back shows more of the printing texture. I assume that is the wax support - and "yes" it is far more grainy than any other surface of the model.

By the way this ties into the other thread re the UP boxcars - as, for example, I believe this process allows one to build the ends without hacking up Tichy parts. Of course some of you are skilled enough that you don't hack, but for those of us who do . . . .

Rob Kirkham

--------------------------------------------------
From: "soolinehistory" <destorzek@...>
Sent: Saturday, October 13, 2012 1:08 PM
To: <STMFC@...>
Subject: [STMFC] Re: Another Shapeways report

--- In STMFC@..., "Rob Kirkham" <rdkirkham@...> wrote:

Curious about the preparation you did on this part before priming Dennis?
Just wondering whether any of the distortion might be the waxy support
material they use? Not that I'm getting completely clean surfaces either,
but thought I'd ask.


Rob Kirkham

That's what I'm wondering, Rob. Hey, I don't have any inside track on this, I just submitted my part file through the automated front end of the web site, like anybody else. I would have thought they would have built the part with the flat disk surface that makes the end of the valve facing up, to give it the best quality, but apparently not. I actually submitted a dozen of these, joined together on a "runner", and I think they built it standing on end. It really doesn't matter, since the purpose of my test is to see what kind of quality can be had on ALL of the surfaces. This is the perfect part for a test, as far as I'm concerned, there is no "show face", they are ALL equally important.

Let me address Dave's comment about "noise". It appears that the best quality surface is the one that is "normal" to the print process, that is, flat and parallel, like a sheet of paper relative to the print head of a ink jet printer. These surfaces will be flat and smooth, as the face of Tom's boxes are. The next best quality will be on surfaces that are perpendicular to the normal, because each layer should end at the same point. The problem is they don't; there are minute differences in both the size and position of each dot of resin deposited, and the result is a certain amount of surface noise. The next worst surfaces are going to be those that are round, or at an angle to normal, because there is the possibility that the edges of the layers will actually show.

I am now realizing that the process used by Shapewys has another pitfall; the basic process can't build parts with overhangs, since there would be nothing to support the first layer of resin that hangs past the previous layer, so the process used by Shapeways builds a wax structure to support this first layer. Unfortunately, it appears that the wax construction is done at a considerably coarser resolution than the actual part, and any surface built against the wax picks up this coarser resolution. Tom pointed this out when discussing a unsuccessful earlier attempt of his, and If I can borrow a link to his photo:

http://www.pullmanproject.com/Shapeways10.jpg

You can clearly see the striations where the part was built against the wax supports that were needed to build the overhanging features. I believe I'm seeing this same effect on the bottom angular surface of the bowl on the bottom of my valve:

http://www.flickr.com/photos/25967611@N04/8077677749/in/set-72157623125645997

I have no idea why they would degrade the resolution of the process by using a coarser resolution for the support material, but it appears they have.

I'm wondering if these fused disposition process (FDM) is ever going to meet our needs. However, I see stereiolithography (SLA), where the part is grown from liquid polymer in a tank, has considerably finer layer resolution. Here's a video of the process. Scroll to the end to see the finished parts:

https://www.youtube.com/watch?feature=player_embedded&v=l2SCrahu2fo

Asiga is a new low cost (relatively) entrant into the field, here is some comments from their discussion forum:

====================================
Our system has two main factors that affect build quality of the parts, these are listed below:

1. Image Resolution
This refers to the size of the pixel in the exposed image. The Pico and Pico Plus39 have a 39 micron pixel size, the Plus33 has a 33 microns pixel and the Plus27 a 27 microns pixel. The smaller the pixel the sharper the exposed image and the higher quality surface finish and detail resolution.

2. Layer Thickness
The thinner the print layer, the less visible the stepping. Our range of printers have presets from 25 microns through to 150 microns and you can select which layer thickness you require depending on the part you are printing. The 25 microns layer thickness will achieve a much better part resolution compared to the 150 microns style. You can also customize this yourself and print in 1 micron increments if you wish.

A combination of these will determine the resolution of a printed part.

Please let us know if you require clarity. If you are unsure which machine suits your application then let us know what industry/product you are producing.

Asiga_Support
===================================

The build envelope on these machines is somewhat limited; 35 x 22 x 75mm for the finest resolution printers. That's 1 3/8 x 7/8 x 3 inches, approximately. Big enough for parts, not for complete carbodies.

Unfortunately, SLA is a single component system, so overhangs require support structures, as mentioned below:

===================================
Our Freeform Pico range of 3D printers are a single material system which means you do need to 'break-away' supports by hand after printing. Our Composer software automatically places these support points in the exact positions in which they are required so processing is quick and easy.

Asiga_Support
====================================

It's also unfortunate that I don't as yet know of any service bureau that offers to build parts on one of these machines. Perhaps Shapeways will see the need to offer a material/process that will reproduce finer detail?

I can see that this is definitely coming, but we're not quite there yet.

Dennis



------------------------------------

Yahoo! Groups Links

by the way, once approved the photos will be in the RP ladders folder in the photos section.


Rob Kirkham
--------------------------------------------------
From: "Rob Kirkham" <rdkirkham@...>
Sent: Saturday, October 13, 2012 5:35 PM
To: <STMFC@...>
Subject: [STMFC] Another Shapeways report

I've posted a number of photos of my own recent experiments with 3d printing
(waiting for them to be approved). These were done by ADC (Advanced Design
Concepts) - but as far as I know they use the same machine and substance as
Shapeways. Overall I am quite happy with the parts I received.

The first photos show tank car underframes for CPR 389xxx series tank cars.
The cars looked a lot like the Athearn single dome tank (and also like an SP
prototype Tony Thompson has written about modelling). I've been muddling my
way through this project for a number of years, but this is the closest I've
come to an acceptable frame model. At this point the issues are in my
design errors - not the material or process used by ADC. that said, I can
see some grain in the part that may show through the paint. And the
particles that are fused to make the part do produce some "noise" when under
magnification. But for frame parts that will be largely hidden beneath
running boards and the tank itself, I think this is acceptable quality for
now.

The other part is an inverted Murphy end used on the CPR's 2975xx series
single sheathed automobile boxcars. The rest of the model is still in
process. Again one can see some waviness in the flat surfaces, and some
imperfections in the corrugations, but overall I think it is a satisfactory
starting point for the model. My photography isn't good enough to show the
rivets along the edges, but they are there too.

I've been using Bestine rubber cement thinner to clean the waxy stuff of the
parts with success so far. A few minutes in that stuff cleans them and
changes the parts from translucent to opaque white and cleans some of the
wax away.

One thing about ADC - they focus on your job so the parts are oriented as
you would like. The auto-box end was modelled laying on the interior side
of the model. Interesting that the view of the back shows more of the
printing texture. I assume that is the wax support - and "yes" it is far
more grainy than any other surface of the model.

By the way this ties into the other thread re the UP boxcars - as, for
example, I believe this process allows one to build the ends without hacking
up Tichy parts. Of course some of you are skilled enough that you don't
hack, but for those of us who do . . . .

Rob Kirkham

--------------------------------------------------
From: "soolinehistory" <destorzek@...>
Sent: Saturday, October 13, 2012 1:08 PM
To: <STMFC@...>
Subject: [STMFC] Re: Another Shapeways report

--- In STMFC@..., "Rob Kirkham" <rdkirkham@...> wrote:

Curious about the preparation you did on this part before priming Dennis?
Just wondering whether any of the distortion might be the waxy support
material they use? Not that I'm getting completely clean surfaces
either,
but thought I'd ask.


Rob Kirkham

That's what I'm wondering, Rob. Hey, I don't have any inside track on
this, I just submitted my part file through the automated front end of the
web site, like anybody else. I would have thought they would have built
the part with the flat disk surface that makes the end of the valve facing
up, to give it the best quality, but apparently not. I actually submitted
a dozen of these, joined together on a "runner", and I think they built it
standing on end. It really doesn't matter, since the purpose of my test is
to see what kind of quality can be had on ALL of the surfaces. This is the
perfect part for a test, as far as I'm concerned, there is no "show face",
they are ALL equally important.

Let me address Dave's comment about "noise". It appears that the best
quality surface is the one that is "normal" to the print process, that is,
flat and parallel, like a sheet of paper relative to the print head of a
ink jet printer. These surfaces will be flat and smooth, as the face of
Tom's boxes are. The next best quality will be on surfaces that are
perpendicular to the normal, because each layer should end at the same
point. The problem is they don't; there are minute differences in both the
size and position of each dot of resin deposited, and the result is a
certain amount of surface noise. The next worst surfaces are going to be
those that are round, or at an angle to normal, because there is the
possibility that the edges of the layers will actually show.

I am now realizing that the process used by Shapewys has another pitfall;
the basic process can't build parts with overhangs, since there would be
nothing to support the first layer of resin that hangs past the previous
layer, so the process used by Shapeways builds a wax structure to support
this first layer. Unfortunately, it appears that the wax construction is
done at a considerably coarser resolution than the actual part, and any
surface built against the wax picks up this coarser resolution. Tom
pointed this out when discussing a unsuccessful earlier attempt of his,
and If I can borrow a link to his photo:

http://www.pullmanproject.com/Shapeways10.jpg

You can clearly see the striations where the part was built against the
wax supports that were needed to build the overhanging features. I believe
I'm seeing this same effect on the bottom angular surface of the bowl on
the bottom of my valve:

http://www.flickr.com/photos/25967611@N04/8077677749/in/set-72157623125645997

I have no idea why they would degrade the resolution of the process by
using a coarser resolution for the support material, but it appears they
have.

I'm wondering if these fused disposition process (FDM) is ever going to
meet our needs. However, I see stereiolithography (SLA), where the part is
grown from liquid polymer in a tank, has considerably finer layer
resolution. Here's a video of the process. Scroll to the end to see the
finished parts:

https://www.youtube.com/watch?feature=player_embedded&v=l2SCrahu2fo

Asiga is a new low cost (relatively) entrant into the field, here is some
comments from their discussion forum:

====================================
Our system has two main factors that affect build quality of the parts,
these are listed below:

1. Image Resolution
This refers to the size of the pixel in the exposed image. The Pico and
Pico Plus39 have a 39 micron pixel size, the Plus33 has a 33 microns pixel
and the Plus27 a 27 microns pixel. The smaller the pixel the sharper the
exposed image and the higher quality surface finish and detail resolution.

2. Layer Thickness
The thinner the print layer, the less visible the stepping. Our range of
printers have presets from 25 microns through to 150 microns and you can
select which layer thickness you require depending on the part you are
printing. The 25 microns layer thickness will achieve a much better part
resolution compared to the 150 microns style. You can also customize this
yourself and print in 1 micron increments if you wish.

A combination of these will determine the resolution of a printed part.

Please let us know if you require clarity. If you are unsure which
machine suits your application then let us know what industry/product you
are producing.

Asiga_Support
===================================

The build envelope on these machines is somewhat limited; 35 x 22 x 75mm
for the finest resolution printers. That's 1 3/8 x 7/8 x 3 inches,
approximately. Big enough for parts, not for complete carbodies.

Unfortunately, SLA is a single component system, so overhangs require
support structures, as mentioned below:

===================================
Our Freeform Pico range of 3D printers are a single material system which
means you do need to 'break-away' supports by hand after printing. Our
Composer software automatically places these support points in the exact
positions in which they are required so processing is quick and easy.

Asiga_Support
====================================

It's also unfortunate that I don't as yet know of any service bureau that
offers to build parts on one of these machines. Perhaps Shapeways will see
the need to offer a material/process that will reproduce finer detail?

I can see that this is definitely coming, but we're not quite there yet.

Dennis



------------------------------------

Yahoo! Groups Links

------------------------------------

Yahoo! Groups Links

Dennis wrote:

I am now realizing that the process used by Shapeways has another pitfall; the basic process can't build parts with overhangs, since there would be nothing to support the first layer of resin that hangs past the previous layer, so the process used by Shapeways builds a wax structure to support this first layer. Unfortunately, it appears that the wax construction is done at a considerably coarser resolution than the actual part, and any surface built against the wax picks up this coarser resolution.

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. On our PolyJet machine, a high-intensity UV light is mounted on the print head in the trailing position and cures the material almost as fast as it is deposited, "almost" being the key word. More on that shortly. I don't know if Shapeways' MultiJet FUD process uses a moving lamp or flashes each layer as it is completed, but the effect is the same - deposit first, then cure.

Think of your part suspended above the build platform and casting a shadow. A few layers of wax are laid down in the exact pattern of that shadow. This permits the part to be removed from the platform. If your part is, say, a cube, no more wax would be required - every layer from there on up would be body material only. If your part was a pyramid, built with the point up, that too would require no more wax. But if you built your pyramid with the point down, the first layer above the wax base would be all wax except one lonely spot of body material in the center. (Keep thinking of the shadow of the upside-down pyramid.) In the next layer the center spot would be larger and recognizably square, but the rest of the layer would be wax. And so on, until the top layer, which would be all body material. The point is, there has to be something underneath the body material on every layer. If it's not other body material, it has to be wax. If you were building a pyramid with a cube balanced on the tip, the pyramid would be completely encased in the wax that provides support for the bottom of the cube. Every overhanging portion of an object will have wax support material under the overhang.

Back to that "almost" issue. Uncured body material is a gel. In the few milliseconds after a pixel of body material is laid down and before it is cured, it conforms to the underlying surface and to its neighbors. Curing the material bonds it to that underlying surface, if that surface is body material. The problems come at the interfaces. An uncured pixel of body material in the middle of a row will merge with its neighbors, while the end pixels in contact with air will pretty much hold their shapes. But if there's wax at the end of that row, the end pixel will merge with the wax pixel and lose its shape. Think of a vertical sidewall as a matrix of tiny marbles. In the absence of wax, under magnification the sidewall will appear uniformly granular. 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. You can see that in the faces of the double steam control box that was built standing on one end:
http://www.pullmanproject.com/Shapeways10.jpg

The three wax tracks go all the way up to the overhanging cleats on the mirrored component. Fortunately, I only needed one of each (left & right) to serve as resin casting masters, and the part that was built face up provided those.

Hope this all helps understand the process.

Tom Madden

I see the photos of my latest projects have been approved now. They are at: <http://groups.yahoo.com/group/STMFC/photos/album/219763914/pic/list?order=ordinal>

Rob Kirkham

Sent: Saturday, October 13, 2012 5:35 PM
To: <STMFC@...>
Subject: [STMFC] Another Shapeways report

I've posted a number of photos of my own recent experiments with 3d printing
(waiting for them to be approved). These were done by ADC (Advanced Design
Concepts) - but as far as I know they use the same machine and substance as
Shapeways. Overall I am quite happy with the parts I received.

The first photos show tank car underframes for CPR 389xxx series tank cars.
The cars looked a lot like the Athearn single dome tank (and also like an SP
prototype Tony Thompson has written about modelling). I've been muddling my
way through this project for a number of years, but this is the closest I've
come to an acceptable frame model. At this point the issues are in my
design errors - not the material or process used by ADC. that said, I can
see some grain in the part that may show through the paint. And the
particles that are fused to make the part do produce some "noise" when under
magnification. But for frame parts that will be largely hidden beneath
running boards and the tank itself, I think this is acceptable quality for
now.

The other part is an inverted Murphy end used on the CPR's 2975xx series
single sheathed automobile boxcars. The rest of the model is still in
process. Again one can see some waviness in the flat surfaces, and some
imperfections in the corrugations, but overall I think it is a satisfactory
starting point for the model. My photography isn't good enough to show the
rivets along the edges, but they are there too.

I've been using Bestine rubber cement thinner to clean the waxy stuff of the
parts with success so far. A few minutes in that stuff cleans them and
changes the parts from translucent to opaque white and cleans some of the
wax away.

One thing about ADC - they focus on your job so the parts are oriented as
you would like. The auto-box end was modelled laying on the interior side
of the model. Interesting that the view of the back shows more of the
printing texture. I assume that is the wax support - and "yes" it is far
more grainy than any other surface of the model.

By the way this ties into the other thread re the UP boxcars - as, for
example, I believe this process allows one to build the ends without hacking
up Tichy parts. Of course some of you are skilled enough that you don't
hack, but for those of us who do . . . .

Rob Kirkham

Rob,

      Please contact me off list.  Have questions about your parts that do not belong on this list.


Thanks,

Bob McCarthy




________________________________
From: Rob Kirkham <rdkirkham@...>
To: STMFC@...
Sent: Sunday, October 14, 2012 8:02 PM
Subject: Re: [STMFC] Another Shapeways report


 
I see the photos of my latest projects have been approved now. They are at:
<http://groups.yahoo.com/group/STMFC/photos/album/219763914/pic/list?order=ordinal>

Rob Kirkham

Sent: Saturday, October 13, 2012 5:35 PM
To: <STMFC@...>
Subject: [STMFC] Another Shapeways report

I've posted a number of photos of my own recent experiments with 3d printing
(waiting for them to be approved). These were done by ADC (Advanced Design
Concepts) - but as far as I know they use the same machine and substance as
Shapeways. Overall I am quite happy with the parts I received.

The first photos show tank car underframes for CPR 389xxx series tank cars.
The cars looked a lot like the Athearn single dome tank (and also like an SP
prototype Tony Thompson has written about modelling). I've been muddling my
way through this project for a number of years, but this is the closest I've
come to an acceptable frame model. At this point the issues are in my
design errors - not the material or process used by ADC. that said, I can
see some grain in the part that may show through the paint. And the
particles that are fused to make the part do produce some "noise" when under
magnification. But for frame parts that will be largely hidden beneath
running boards and the tank itself, I think this is acceptable quality for
now.

The other part is an inverted Murphy end used on the CPR's 2975xx series
single sheathed automobile boxcars. The rest of the model is still in
process. Again one can see some waviness in the flat surfaces, and some
imperfections in the corrugations, but overall I think it is a satisfactory
starting point for the model. My photography isn't good enough to show the
rivets along the edges, but they are there too.

I've been using Bestine rubber cement thinner to clean the waxy stuff of the
parts with success so far. A few minutes in that stuff cleans them and
changes the parts from translucent to opaque white and cleans some of the
wax away.

One thing about ADC - they focus on your job so the parts are oriented as
you would like. The auto-box end was modelled laying on the interior side
of the model. Interesting that the view of the back shows more of the
printing texture. I assume that is the wax support - and "yes" it is far
more grainy than any other surface of the model.

By the way this ties into the other thread re the UP boxcars - as, for
example, I believe this process allows one to build the ends without hacking
up Tichy parts. Of course some of you are skilled enough that you don't
hack, but for those of us who do . . . .

Rob Kirkham





[Non-text portions of this message have been removed]

--- 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.

Dennis

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.

<<http://georgedentmodelmaker.blogspot.ca/>>


"A GLIMPSE OF THE FUTURE?
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--

<<https://www.model-railways-live.co.uk/News/Wild_Boar_Models_announce_range_of_OO_gauge_wagon_kits/>>

Steve Lucas.