Wutter's Dome

[Maletrain]

DRIFT ALERT!!!

Looking through Wutter's products, I found this: https://www.shapeways.com/product/W7ZNE5USL/chessie-low-profile-dome-n-1-160-1x?optionId=65601482&li=shops

It is the very asymmetrical dome for the cars that were built for the C&O's "Chessie" (that never ran) and ended up on the B&O's "Capitol Limited" and "Shenandoah".  I have been wondering how I could ever build one in N scale, as I drooled on the RTR HO versions of those cars.  That dome is so distinctive that stand-ins just don't make it for me.

Now that I see Wutter has prints for that part, I am wondering if those prints are strong enough for that service on a model.  Has anybody used them?  Are there alternatives that I have missed, too?

[Wutter]

DRIFT ALERT!!!

Looking through Wutter's products, I found this: https://www.shapeways.com/product/W7ZNE5USL/chessie-low-profile-dome-n-1-160-1x?optionId=65601482&li=shops

It is the very asymmetrical dome for the cars that were built for the C&O's "Chessie" (that never ran) and ended up on the B&O's "Capitol Limited" and "Shenandoah".  I have been wondering how I could ever build one in N scale, as I drooled on the RTR HO versions of those cars.  That dome is so distinctive that stand-ins just don't make it for me.

Now that I see Wutter has prints for that part, I am wondering if those prints are strong enough for that service on a model.  Has anybody used them?  Are there alternatives that I have missed, too?

To be honest, I personally haven't printed those domes, but I have had two different customers buy them without any rejection notices from Shapeways or any complaints after they were shipped out and received, so I can only guess that they were OK and strong enough.
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Albeit this is a little different since its printed on a Photon, this is what the geometry looks like, its designed to fit into the removable dome section for either the dome observation or the normal dome cars of the Kato CZ. There is a little warping since its not glued down or anything but being so light and thin,glue should easily keep it down.

[Maletrain]

I am curious whether there would be any way to print the glass insert for that frame shape, and have it look anything like glass.  It would definitely strengthen the finished model, and having it as a separate part would make painting a lot easier.  But, I have yet to see anybody print something that can look like clear glass.

I am thinking I might sacrifice one of the frames to make a mold to pour clear casting resin into to make a "glass" insert.  Haven't quite figured how to make the pane surfaces end up at the right places, especially considering the curved ones.

[Ed Kapuscinski]

I split this out so that it's easier to keep the other thread for reference.

[Maletrain]

Thanks, Ed.  I was about to start a new thread for the same reason, but this is better. 

[Ed Kapuscinski]

I do what I can!

[ns737]

I did something like that I made a mold of the part. and then filled the mold with a clear resin that you use to make water. I think it was called envirotex. and it remade the part and now has glass windows.

[Maletrain]

I am thinking about doing the same thing, except I would make an inner mold surface that makes the dome hollow.  It needs to provide a very clear and relatively undistorted view of the inside, where there will be seats and other details.  It is probably the most exposed interior possible.

So, making the "glass" clear and optically "flat" will probably be difficult.  I would probably need to do some serious polishing of both surfaces after it came out of the mold.  So, it would be best if the ribs were not cast onto the outside surface.  Which means that the mold would need to have a surface that includes the ribs on the dome structure part, so that there would be hollows for the printed part to fit into the cast part.

Still hoping there is a better way.  3D printing "glass" would be great, but I don't know if there is capability to do that, yet.

[Wutter]

I am thinking about doing the same thing, except I would make an inner mold surface that makes the dome hollow.  It needs to provide a very clear and relatively undistorted view of the inside, where there will be seats and other details.  It is probably the most exposed interior possible.

So, making the "glass" clear and optically "flat" will probably be difficult.  I would probably need to do some serious polishing of both surfaces after it came out of the mold.  So, it would be best if the ribs were not cast onto the outside surface.  Which means that the mold would need to have a surface that includes the ribs on the dome structure part, so that there would be hollows for the printed part to fit into the cast part.

Still hoping there is a better way.  3D printing "glass" would be great, but I don't know if there is capability to do that, yet.

Yeah I haven't though about this part too much yet, I could either make a plug that goes on the inside that allows glass to be cast in-between the dome frame and the plug. Or potentially a master model that is the glass shape itself but made out of a 3D printed material so that whole piece can just be cast. The geometry is pretty complicated though so I would need to think more about how to do all the compound curve windows properly.

[peteski]

I did something like that I made a mold of the part. and then filled the mold with a clear resin that you use to make water. I think it was called envirotex. and it remade the part and now has glass windows.

If you were to make a buck for the "glass" (maybe even have it 3D printed then sand it smooth), you could heat up some clear soda bottle plastic and once  soft,  stretch it over the buck and let it cool.  Sort of like vacu-forming without the vacuum.  Automotive modelers use this method to make new compound-curved model car windshields.,  I'm sure there are videos of the process on YouTube.

I get yourself a small vacu-forming  machine (ones used by dentists for mouth guards).  Micro-Mark sells one, but you can get them cheaper on eBay.  While not needed often, it is a very useful modeling tool.

[ns737]

or you can put the seats in after you pour the clear in the mold. that way the seats are the base.

[Nato]

           The Rio Grande purchased the three dome coach observation cars built for the C&O Chessie, and briefly operated by C&O on other trains. Rio Grande replaced the lounge seating in the rear with coach seats including single seats in the round end part of the car. A squared off extension was fitted to the rear that contained a diaphragm and a standard vestibule door. The old now out of production Con Cor Budd California Zephyr dome observation,which used the GN car floor and lower seating interior looked very much like these cars and was offered in the Grand's single stripe paint scheme. Only the dome shape was wrong , but it is cast in one piece with the roof and would have to be carefully cut out to fit Wutters Dome. One of these cars has been restored to a C&O car with the mid train end piece removed by I believe the C&O Historical Society. Another car operated as the "Big Ben" owned by Butterworth Tours on the Quad Cities Rocket when RI did not join Amtrak. A third car was rebuilt by Bill Kratville's Autoliner Corp. named "Silver Holly" it was reconfigured inside as a private car with bedrooms , lounge and small galley. It is now preserved under cover in Florida,(I forget the location). Nate Goodman. (Nato).

[peteski]

or you can put the seats in after you pour the clear in the mold. that way the seats are the base.

Solid brick of "glass" (resin) gives a lens-like fishbowl effect.  I don't care for that. "Glass" needs to be thin to look realistic.  But we all have different standards.

[Lemosteam]

@Wutter, if you designed a master to fit inside the printed dome minus some material thickness (very nice BTW) the windows could be vacuum formed over it like this:

RC guys use this technique for molding their "glass' cockpits

[ncbqguy]

Wouldn’t a Con-Cor dome observation be a better starting point?  The Kato has the correct CZ high rear roof after the dome and full truck skirts while the C-C has a low roof and no skirts.
Charlie Vlk