Shapeways FM switchers: Cleaning FUD

[Dave Schneider]

Looking for some guidance on my newly acquired Shapeways FUD FM switcher shells. I soaked the shells in Bestine overnight and they mostly came out fine. I did run into an odd issue with the back cab wall of the H10-44. It had a very different texture than the rest of the model, with a very rough appearance. I thought that perhaps this was due to precipitation of the wax out of solution as the Bestine evaporated. It tried scrubbing it with a brush soaked in Bestine, but it didn't do much. So, it went back into the Bestine overnight and here is the result.  Really, no change. Note the difference in texture between the cab wall vs. the roof. The front of the shell (printed in the same orientation?) is much "cleaner".  There are other parts of the shell were it looks like the wax redeposited (a chalky white deposit), but that brushes off easily. The H12-44 shell looks better, but has similar issues on the pilot. door and sand hatches.

Question: Any opinions on whether this is a cleaning issue or a printing issue? I also noted that the cab handrails on the H10-44 are missing. They are not in the original bag or the Bestine bath, which suggests that this may be a printing issue? Should I try soaking them again in "clean" Bestine?





Best wishes, Dave

[daniel_leavitt2000]

My guess is that the model was produced cab end down. There is always some major issues with the bottom face of Shapeways models.

[Dave Schneider]

Thanks Daniel. Any ideas why the H12-44 (without the overhang roof) looks better?

Best wishes, Dave

[Chris333]

Your photos look exactly like items I have received from Shapeways... and thrown in the trash.

[Dave Schneider]

Chris,

I get your point! However, the rest of the shell looks pretty good. The main problem is with this one area.

Here is a link to a finished model by Randy Stahl on Trainboard. The shell isn't perfect but it is much better than the non-existent alternatives.
http://www.trainboard.com/grapevine/attachment.php?attachmentid=48528&d=1350678453

Best wishes, Dave

[Chris333]

Yeah I have found the same thing. Totally random surface changes.  Like the 2nd photo how there seams to be streaks running down after the details, like it was left out in the rain.

The thing is if they somehow rotated the model when printing you would get those same errors somewhere else on the model.

[wcfn100]

Your photos look exactly like items I have received from Shapeways... and thrown in the trash.

Yes.

Shapeways is more suited for proof of concept than prototyping.  And for that it does a great job (read - great price).

Jason

[Chris333]

On the other hand, wooden items don't look too bad:
http://www.shapeways.com/model/694469/r15-n-scale-coal-jimmy-wood-truck-x3.html?li=productBox-search

[bbussey]

My guess is that the model was produced cab end down. There is always some major issues with the bottom face of Shapeways models.

That is correct.  Flat portions of a model that are "face down" - i.e. buttressed against the wax support structure - tend to come out with a rough finish.  That appears to be true regardless of the level of ProJet3000 being utilized.  So models have to be designed and rendered accordingly, which is a major reason why it is good to have control over the build orientation.

Actually, what's better is to use the strengths of the FUD material, which is the rendering of smaller details, and leave the larger areas to another medium such as brass, styrene or wood.  Or, use the FUD as a core with details poking through other materials that have a better finish, such as this early version pilot sample from last April of the casting master for the upcoming ESM Keyser Valley caboose kit:



The body core is rendered in two halves lengthwise underneath the brass overlays, so the rough areas are inside.  The floor master is rendered with a "built-in" flash frame that raises it off the surface to reduce the roughness effect.

[Dave Schneider]

Thanks Daniel and Bryan. Any thoughts on whether Shapeways will agree to reprint, or is this within spec?

Best wishes, Dave

[bbussey]

Tough to say, since they have control over the build orientation, which is how they keep the cost down (by stuffing the build area with multiple models).  The way you will get the best result is if the part is built upright and probably perpendicular to the print head, which nothing being built above it.  The print head travels on the Y axis, so if you are looking at the build tray from above, you would see the roof of the model and it would be facing north/south.

Most people don't see that by the way, because they don't fully remove all of the wax.

That's why the 1930-era White Towers are rendered upside-down (so that the rough area is just the roof top and it looks like gravel) and the 1950-era White Towers are rendered as flat sides (so the rough areas are inside out of view).

[Dave Schneider]

I will go ahead and ask. It's free. I completely understand and agree with your point Bryan about maximizing the strengths of any particular technique. I went into this with my eyes wide open and still think I can produce a good model. If I end up with problems with the cab end I may look into a thin styrene overlay produced with my Silhouette cutter. Likewise, if the stepping on the side doors is too extreme I can use brass or styrene.

Best wishes, Dave

[Hornwrecker]

I was just going to order a couple of 10-44 shells.  I think I'll wait awhile.

Now to figure out what to do with the Milw Rd VO-1000 that I bought for it, and what it is doing in 1960s NE PA.

[daniel_leavitt2000]

I think this is also partially the fault of the artist. They should be making flat models that will only orient tray style. That would leave the chassis facing (inside) rougher and the outside with much smoother, better detail.

Sure, it would take a little extra effort. Not much as you can simply splice and paste sections of a model.

One problem I have had with the 3D software is it really is designed for a mouse or digitizer. My laptop trackpad just won't cut it.

[Dave Schneider]

I was just going to order a couple of 10-44 shells.  I think I'll wait awhile.

Now to figure out what to do with the Milw Rd VO-1000 that I bought for it, and what it is doing in 1960s NE PA.

I still think that this can be a decent model. Here is a shot of the rear cab from Randy Stahl over on the Trainboard thread. It looks like he dealt with the roughness pretty well.

http://www.trainboard.com/grapevine/attachment.php?attachmentid=49881&d=1355431118

Best wishes, Dave