Pullman-Standard Mini-Hy Cube boxcar in 1:29

[Burl]

I don't know how many of you here will be familiar with the name Brian Briggs, but several years ago, he built a Pullman-Standard Mini-Hy Cube boxcar in 1:29 scale.  As far as I know, he only built one.  I tried to get him to offer it as a kit, but he never would give me a definite answer.



Unfortunately, he passed away about a year ago. To my surprise, his wife, Margaret offered me patterns, molds & extra castings he had made for various projects.  Among them were the patterns for his PS Mini-Hy Cube boxcar.  He made it as a flat kit, with no patterns for the underframe.  It was my intention when I acquired it (with Margaret's blessing) to produce a kit from it.   Lately, I spent a little time working out the design of the underframe.  I think I can make an operating cushioned underframe, with sliding center sill.

I am working primarily in Sketchup:



Since Brian cut up USAT boxcar ends & used them as his pattern, I felt it best to re-make this part.  I am learning Autodesk Fusion 360 to draw these, since it has a filet function that I like better than Sketchup.





I drew the end ladders in Sketchup. Old habits die hard. Here's my first attempt at marrying them in Fusion 360. I needed to do this to get the mounting holes aligned.

[finescalerr]

Most impressive and inspirational. -- Russ

[Bill Gill]

Burl, That looks like it's going to be a good kit. And the operating cushioned underframe will be a unique feature. Good luck with the project !

[Ray Dunakin]

Very cool!

I remember seeing that on one of the forums when he first built it.

[Burl]

A little closer to having all the parts worked out for the underframe:

[finescalerr]

Well, that probably took a few hours .... -- Russ

[Burl]

If I'm not careful, I get bogged down in details here.  I borrowed some of the components from prior projects, so that sped it up a little.   These are low-poly stand-ins of details I had already made.

This might have been a better candidate for Fusion 360, since it supports collision detection, but I'm not comfortable enough with it yet to attempt anything very complex. 

[Burl]

My inexperience in F360, coming to light, I ended up redrawing the end from scratch.   Watching their tutorials, they put an emphasis on making everything components.

When I started cutting the mounting holes for the ladders, I realized making each rib a component was not going to work.  Making a hole in one, resulted in a hole in every rib.

When it was time to scale it down to 1:29, I also encountered odd behavior in how it handled what they call "patterns".  Where I had distributed rivets every 2 inches, it maintained the 2 inch spacing after the scale operation.

Redrawing it also allowed me to correct something I missed the first time.  The ribs are not completely straight, but slope gently from the middle to the end.

[Bill Gill]

Impressive attention to detail. Sounds like you're figuring out Fusion 360 in the process.

[Ray Dunakin]

Nice work.

All these different apps each have their own quirks.

[Burl]

Got everything broken down & arranged for a Shapeways order.

I'm taking a different approach on the ladders this time.

In the past, I have had them 3d printed in SLS nylon. The texture was a little rough that way, but I could live with it. However, Shapeways has a habit of revising their printing guidelines. I guess they're still going through growing pains. I have sometimes found things I printed 6 months ago, they say are no longer printable. Occasionally, things have also arrived broken (I assume they were handled too rough during cleaning).

This time around, I'm going to try making the ladders in brass. I'll use the acrylic prints (below) to make a mold for waxes. These waxes will be sent off for investment casting. The rungs (with NBW) will be one piece, and the rails will be a separate piece. I made them with locating pins to make assembly easier. I will find out in a few weeks if this is a better approach.




These parts will be used as patterns for resin casting:

[Burl]

Laser cut parts came in today.  I had these made at http://ponoko.com/
Kind of like Shapeways, but for laser cutting.  I have not taken the paper off yet.

[finescalerr]

Laser cut Plexiglas? -- Russ

[Burl]

Acrylic

[Burl]

My prints came in last week: