First post: 3D printing the Milwaukee Road's Skytop sleeper-lounges

it looks great, wow! I wonder how could you achieve a flush glass fit. Looking forward to your progress.

Looks like the future to me !! Fantastic . . . . keep us informed

Spectacular!

Probably the most difficult passenger car model to fabricate.

Bob

Gorgeous!  As with all who have gone before you, the glass is going to be your greatest challenge.

Your hard work is paying off.  Keep at it!

Amazing

I've been trying to do simple things in Sketchup and just can't grasp the concept, yet.  I was a draftsman back in the 1970s so I can draw, but with a pencil and straight edge.

All the talk is about  what the latest printer can do but without something to feed into the printer, well....you're SOL.

It looks great and if you've gotten this far the windows will be a piece-o-cake!

This may bring me a step closer to finishing my Hiawatha Milwaukee cars! The observation car is the hardest part.

I now use Rhino instead of Sketchup.  These are the  TT controller light covers

SANTIAGOP23 posted:

it looks great, wow! I wonder how could you achieve a flush glass fit. Looking forward to your progress.

You can print in clear plastic for flush windows.  Looks like a great project for this application!

I'm an old school AutoCAD jockey, but really need to learn Revit since I have it on my computer.  Very precise, but very complex to learn.

Thanks for the feedback and words of encouragement, everyone! Yes, the windows are what's next on my list. Then floor/base, rear diaphragm area, roof detailing, and then the interior. Final step: joinery/kit assembly details.

J Daddy posted:

This may bring me a step closer to finishing my Hiawatha Milwaukee cars! The observation car is the hardest part.

Are those scratch-built or vintage Walthers kits? I saw a set of those for sale in the Twin Cities a few weeks back–they're timeless!

GG1 4877 posted:

SANTIAGOP23 posted:

it looks great, wow! I wonder how could you achieve a flush glass fit. Looking forward to your progress.

You can print in clear plastic for flush windows.  Looks like a great project for this application!

I'm an old school AutoCAD jockey, but really need to learn Revit since I have it on my computer.  Very precise, but very complex to learn.

This is exactly what I'm going to do. Print with transparent material, sand/polish to get as clear as possible. Will post photos of the window solution later tonight or tomorrow, once I get around to finalizing it.

Progress update: 

After trying multiple techniques to achieve the best (and most reliable) window fit, I've created the geometry and merged it with the body. The intent is to print a relatively inexpensive, non-transparent version to use as the master model for a resin mold. Final piece will be clear resin. Clear resin 3D printing is available, but quite expensive at the moment (hoping this will change in the near future!).

The idea for this came after seeing the following photos on the 2-rail forum (Walthers kit and custom-built):

Here are two photos of the model during CAD construction. The windows are generally .05 inches thick, with slight variation in the solarium area:

And a shiny render of the solarium in clear resin:

After living with the clear version for a while, it might be cool to have one unpainted version that can show off the interior: a window into life on the rails.

Excellent! Keep us posted!

Cool idea. I love the Skytops. Be they the sleepers or the parlor cars!!

I think I actually read that article about the dome car when it first came out.  Want to say he "cast" the thing over a wooden mould in the oven.  Sound about right?

Fred

 Not to diminish your super craftmanship but we have all the detail parts for the Hiawatha cars as well as the buck to form the Skytop end as the Nystrom trucks. So this may save you some time and effort.

Fred Brenek posted:

I think I actually read that article about the dome car when it first came out.  Want to say he "cast" the thing over a wooden mould in the oven.  Sound about right?

Fred

Yeah, I think that's exactly what happened. Then automotive detailing/striping to make the window frames on the dome.

Scale City Designs posted:

 Not to diminish your super craftmanship but we have all the detail parts for the Hiawatha cars as well as the buck to form the Skytop end as the Nystrom trucks. So this may save you some time and effort.

I was planning on buying the Nystrom trucks when the time came! However, I'm not seeing anything related to the Skytops when searching your site for "Milwaukee Road." Is there a link you could provide?

pixelpushing posted:

 

Scale City Designs posted:

 Not to diminish your super craftmanship but we have all the detail parts for the Hiawatha cars as well as the buck to form the Skytop end as the Nystrom trucks. So this may save you some time and effort.

I was planning on buying the Nystrom trucks when the time came! However, I'm not seeing anything related to the Skytops when searching your site for "Milwaukee Road." Is there a link you could provide?

I did a search for "Nystrom" and the trucks came up as the only result.

I have a Walthers Skytop that I paid too much for ten years ago and still haven't grasped how to paint the rear window piece. I have had a lot of coaching but still no nerve. Can your window section fit the Walther's car? if so I'll buy one. Thank you. Please contact. cbqer@aol.com.

Dick

So can a 3D printer make a thinner one that can be used to cast one in brass?  If K-Line had made the Skytop in brass, I would have bought a string to match that die cast Bipolar I am going to buy and 2-rail some day. 

You can bet I would have repainted the K-Line brown to Milwaukee maroon.

looks great...........

CBQer posted:

I have a Walthers Skytop that I paid too much for ten years ago and still haven't grasped how to paint the rear window piece. I have had a lot of coaching but still no nerve. Can your window section fit the Walther's car? if so I'll buy one. Thank you. Please contact. cbqer@aol.com.

Dick

Unfortunately, I don't have a Walthers model on hand to compare, but I don't think they're compatible. When the time comes, I might offer up a kit...

bob2 posted:

So can a 3D printer make a thinner one that can be used to cast one in brass?  If K-Line had made the Skytop in brass, I would have bought a string to match that die cast Bipolar I am going to buy and 2-rail some day. 

You can bet I would have repainted the K-Line brown to Milwaukee maroon.

I don't think that is possible, since the only materials that currently support large enough prints are plastics, and making a mold from a plastic print that can sustain hot brass casting doesn't seem like it would work. You can print in brass, but the sizes are very small and the cost is prohibitive.

Mike Slater posted:

looks great...........

 

Thanks, Mike!

I would take a clear shell and put it on a MTH chassis.  That would be cool

Lost wax and lost plastic are terms of art.  One can make a part out of either, encase it in plaster, burn the wax or plastic out, and pour brass in.  The part would exactly duplicate the plastic, but would be much stronger.

I am having an Atlas Erie-Built nose done that way as we speak.  Success is never guaranteed, but I am in an anticipatory mode.

So the question: could a thinner one be made that could be turned in to brass? Or is the one you are making strong enough to withstand some thinning where the glass goes?

Any chance to buy a copy of your CAD drawing so I can scale it up and build me a car in G scale??

bob2 posted:

Lost wax and lost plastic are terms of art.  One can make a part out of either, encase it in plaster, burn the wax or plastic out, and pour brass in.  The part would exactly duplicate the plastic, but would be much stronger.

I am having an Atlas Erie-Built nose done that way as we speak.  Success is never guaranteed, but I am in an anticipatory mode.

So the question: could a thinner one be made that could be turned in to brass? Or is the one you are making strong enough to withstand some thinning where the glass goes?

Bob2    dont you have shrinkage involved to contend with, I worked in lost wax castings and we always used 4% . In other words pattern is 4% larger. Dennis Mashburn told me that as well.

Bob Harris

Yes.  You make a metal part, then a vulcanized rubber mold, then pour wax in there.  The wax is around 4% smaller than your original part.  The additional 1/2% is due to the metal shrinking as it cools.

Going directly from plastic to metal loses only that 1/2% due to metal chilling.  We can generally handle that.

Dentists have special rubber that eliminates the 4% shrink.  That is why your gold teeth fit darn near perfectly.  We did that trick on some UP truck sideframes for which we could find no other provenance.  You couldn't tell the difference.

Very interesting discussion re: brass casting! 

Casey Jones2 posted:

Any chance to buy a copy of your CAD drawing so I can scale it up and build me a car in G scale??

I plan to offer it for sale sometime in the future, so I don't think sharing the source file is an option right now, my apologies!

Now, for some progress updates...

Most of my time these past few weeks has been spent (1) adding roof, diaphragm, and other secondary details, (2) installing insertion points for grab irons, and (3) figuring out an assembly scheme.

Here's the model overall:

Close-up of the vestibule/diaphragm attachment area and some roof ventilation + ribbing details:

Solarium with skirting/coupler modifications:

Cantilevers (six total in the model) mounted to the underbody, with hexagonal guides (six total as well) for the attachment of an interior (still to be designed):

Mounting receptacles on the body (where the cantilever snaps into, with small indents below that allow the modeler to insert a tool and more easily disassemble the components):

At first, I had created mounts attached to the body that would receive a heat-set threaded insert. The underbody then had a clearance hole and countersink for a Philips screw (highly recommend McMaster-Carr for sourcing specs for such joinery).

However, I recently saw a lighting installation tutorial by KATO for their N scale passenger cars (KATO is truly awesome, IMO... great trains, great design, great value!). This changed everything! Their use of snap fit components is masterfully simple and robust. So, the assembly of my model is now snap-fit. Much simpler production-wise and very user-friendly.

As another note for any prospective 3D printers, I have .005 inches of clearance between parts that will be joined/touching in final production. Since the material has some slight sizing variance, others online recommended such clearance to allow for a snug fit out of the box. We'll see how it goes!

Hoping to order these two parts soon, just want to let them sit for a few more days in case I want to make any last-minute tweaks! 

how thick are the sides and roof? .030- .062 would be fine.

I've been gone for two weeks and I come back to this unbelievable work....WOW!!!   If you do a kit I'll take one.  If you do just the dome piece I will take several to go with the Walthers kits I have.

pixelpushing posted:

Hello everyone! I've been a lurker here for a little while, but decided to finally join the conversation. Recently, I've been working on a 1:48 model of the Milwaukee Road's Creek-series Skytops, with the intent of 3D printing a kit to assemble. 

I've attached some renders of the model's current state. It's my second time working with CAD software (Fusion 360), and my first making a rail model! Endless hours (a labor of love) have already been put into the solarium area.

Scale drawings were sourced from the Newberry Library's digital Pullman collection.

This look GREAT! I was wondering if you would help me out. I let my undecorated HO skytop and 5 other cars out to be painted professionally, but when I got my cars back, my beloved skytop was not there. Needless to say I was devastated. This was about 3 weeks ago and I have been searching all over to find another...no luck. My brainy idea was to have done what you have done, 3d printing but I have NO idea how to start or where. Any chance you would be willing to sell me a copy of your 3d file? It would be GREATLY appreciated!  Thanks much!

Tony G

Fantastic job!

I am looking to print the back end of the car for a Standard Gauge version - would you consider sharing just that part of the model? I have aluminum extrusions for the sides/rest of the roof. Because models are scalable, I should be able to scale up your model to build a significantly larger part.

I promise not to compete with you on your O scale version!

Jim

For those interested in a model, here's a link to the file (this model preview uses transparent material, slightly difficult to see all details):

http://a360.co/2wyDqED

I haven't been able to work on it much further (no interior or underbody), but the frame and body are complete.

Also attached are photos of a section that I had 3D printed to make sure the clearances and snap-fit joints work.

I am more than impresses with your achievement on the skytop observation. Patiently waiting for the opportunity to purchase one of these! By all means keep me informed and put me down on a list of purchase!  Thank you for what you are doing!!!

Hey Pixel - thanks for sharing your model. As I mentioned, I'm looking to build a Standard gauge version. Just got a CR-10 large format printer (print area is 12 by 12 by 15 inches), and starting a 30 hour print of just the end section.

See attached photo of the first half inch and a short video showing the printer in action. Printing in clear PLA. I will likely make a mold for it to get a nice clear part- I'm printing at 50% fill, so windows will not be very clear.

Thanks again

Jim Waterman

All of this was five years ago - any word on how this ended up?  Since then, I have completed my brass Erie-Built, acquired a Bipolar to 2-rail, and begun my passenger car string, which will have a Skytop on the back end.  Still thinking of a lost-plastic brass casting fitted to an aluminum extrusion.  I now have access to a printer, I think, through aviation buddies.

@bob2 posted:

All of this was five years ago - any word on how this ended up?  

It would be good to know this if anyone has a lead, but the OP is now listed as a "Former Member" so possibly he personally won't see this inquiry. Looking back, this was an outstanding piece of modelling using 3D printing, and it would be particularly interesting to see how the Skytop windows turned out. (By the OP's last post above from 2017 it seems he had got as far as finishing the body.)

Now, of course, GGD has made and is making aluminum Skytop cars, which I fully expect will be up to their usual high standards. I don't think I could ever contemplate trying to do a scratch built version; in fact, I am content with my old K-Line by Lionel version, which is aluminum and scale length.

@Hancock52 posted:

...snip... Now, of course, GGD has made and is making aluminum Skytop cars, which I fully expect will be up to their usual high standards. I don't think I could ever contemplate trying to do a scratch built version; in fact, I am content with my old K-Line by Lionel version, which is aluminum and scale length.

Unfortunately GGD is not releasing the tailcar as a separate sale item so I, too, will have to be content with my original K-Line version which is scheduled for two-railing this year. I do remember watching a Walthers version on ebay but there was there was just something about it that kept me from bidding on it. Oh, it was a very high quality build job but still ...................

@PRRMP54 posted:

Unfortunately GGD is not releasing the tailcar as a separate sale item so I, too, will have to be content with my original K-Line version which is scheduled for two-railing this year. I do remember watching a Walthers version on ebay but there was there was just something about it that kept me from bidding on it. Oh, it was a very high quality build job but still ...................

Ah, yes, that's right - I only looked at the GGD reservation form this morning and did not take that on board. I already have a couple of the additional UP color cars on order - Great Dome and Tap. I certainly could not go for the full set.