A Distressed Z Scale 52 foot Gondola

[Jesse6669]

My railroad handles a lot of gondola loads, much of them iron briquettes, aka pig iron.  The current Z scale offerings present some issues for me.  AZL has a nice modern 60' Thrall mill gon;  These are currently rather hard to come by.  And the I&O doesn't use much (any?) new equipment.  MicroTrains made an older 50-foot fish-belly style with the brake wheel (oddly) mounted on the side of the car instead of the end.  It also sits quite high on its trucks which would need modification.  And that's about it;  Armed with my new 3D printer I decided a Z scale gondola was a good first project.  A relatively simple (I hope) model to break the new machine in with.

The I&O has a rag-tag fleet of gons comprised mostly of leased and a few company owned 2nd/3rd/4th hand cars.  A lot of them came from Conrail or predecessor roads.  Also, Conrail used to be the tenant railroad at McCullough Yard (my model RR's home base) before the I&O.  So I figured a few Conrail prototype gondolas would be nice--I could model them during the Conrail era or modern I&O cars.  52-footers seem to be the car of choice for pig iron, which is very dense and generally doesn't fill more than 2/3 of the car before the weight limit is reached.   

I did a little browsing of some pics and came up with a couple prototypes that were good to start with.  Here's one I took of the leased gons on the I&O. I believe this is a former Conrail GX52 with new ends? 

 

To create the model, I started with the basic dimensions of Greenbrair's 52' mill gondola, which are available on Greenbriar's site.  I then adjusted the proportions by eye to match what I saw in the photos because it looks like Greenbriar's sides are higher than the G52's.  I ended up with this Z scale model: 

 

Note this above is a test print and not the final model which will have defects corrected and a few more details.

The ex-Reading GR52 series was also interesting to me and close enough to the original model design so that with a little swapping around of ribs, underbelly, and different ends this could be modeled as well.   

Looking at the test models I thought these cars just looks too new compared to the beaters in pig-iron service.  Or any mill gondola more than a year old.  Complicating matters--Z scale is just too small to be melting sides to poke them and distress them, not that I was every good at that technique..  so I got to thinking that I could "poke" them in the software Meshmixer using the sculpt tool, and just print them with bowed/distressed side panels.   Here's what the initial tests look like: 

 

Actually from arms length this looks good, but I'm going try a couple of things to improve them and smooth over those contour lines so they stand up to the close-up camera's scrutiny.  The good news is the proof of concept works and I think I can "distress" more models like this.
As for these two tests:  Still needed are installing trucks and couplers, some underbelly weight, and decals.  I'm planning to design artwork for of Conrail, Reading, NOKL and I&O cars.   I'll put up a Part 2 when I get further along. 

Jesse

[Scottl]

What orientation are you printing these?

[Chris333]

Since there are no rivets, you could lightly sand in-between each rib. Plus any scratches will just make it look more beat up.

[Lemosteam]

Wonder if it would be easier to print it without the bumps, press on the inner surface before curing, and hit the outside with a drop of acetone on the outside for a quick pre-cure of the panel (the acetone is cold).

[Jesse6669]

What orientation are you printing these?

61.19 degrees--40 micron layers.

[Jesse6669]

Since there are no rivets, you could lightly sand in-between each rib. Plus any scratches will just make it look more beat up.

That's what I'm thinking as well, increasing the number of triangles to recreate "random" dents makes the STL file huge.  A little sanding is easy  enough. 

Wonder if it would be easier to print it without the bumps, press on the inner surface before curing, and hit the outside with a drop of acetone on the outside for a quick pre-cure of the panel (the acetone is cold).

That's an option, but I think it'll push out the ribs as well; not to mention messing with acetone doesn't sound like much fun. Part of the reason I did it this way is because he ribs seem to hold up relatively well compared to the thin panels, which take a beating. 

[Chris333]

That's what I'm thinking as well, increasing the number of triangles to recreate "random" dents makes the STL file huge.

It looks like the blockiness of the dents is just the pixels on the screen. I assume they don't look like that when you draw them. This is Z scale after all. I don't think it looks bad.

[samusi01]

I don't think a little sidewall bowing is going to hurt all that much...



...or, for that matter, some sagging...

[Jesse6669]

Wonder if it would be easier to print it without the bumps, press on the inner surface before curing, and hit the outside with a drop of acetone on the outside for a quick pre-cure of the panel (the acetone is cold).

Just did a new test print without pre-distressed sides and I used a dental tool to press the panels.  It actually works just fine, holding your finger behind the panel to keep some back pressure on.  It's subtle but I like the effect.  I will need to see how much the panels smooth out as it cures, but there should be a way to get this done.  I used to have a small UV penlight that came with some UV-cured adhesive and used to use it to spot cure some of my T-scale stuff.  This could work but I lost it (off I go to Amazon to find one..)  (Excuse the curly grab irons, they shrink and straighten out with drying/curing.) 

Inside: 
 

Exterior:

  

[robert3985]

Looks like you've got the problem solved.

Additionally, hand-pressing the dents ensures that the sides will all be different, which is a good thing indeed!

However, on my N-scale detail prints, I'm running 30 micron layers since my machine is an 8K 10" printer with 28.5 micron screen resolution.

I use Lychee Slicer (subscription version) and turn my AA up to 5 pixels, and use Lychee's "Detail AA", which smooths out the layer lines, but still retains sharp corners.  I'm using Anycubic ABS-Like Pro II Gray & Clear resin for my N-scale beacon parts and the details are fabulous without a hint of layer lines.

Anyway, your gon is looking GOOD!

Cheerio!
Bob Gilmore

[Jesse6669]

The latest iteration.  Added stirrups, but it rides a bit high on the trucks.  I tested MT (right) and Bowser (L).  Gonna tweak that and re-print.  Getting closer though!   

[Jesse6669]

I think I have the ride height dialed in.  A few more minor tweaks.. I'm going to add temporary bracing on the inside so the sides don't warp during curing.   


 

[nkalanaga]

If you could get them to warp OUT that would be prototypical.

Knowing nothing about 3D printing, could you put a block of wood inside before curing it? 

[Jesse6669]

If you could get them to warp OUT that would be prototypical.

Knowing nothing about 3D printing, could you put a block of wood inside before curing it?

The appearance is a little deceiving--the bottom of the sides are actually flared out.  I added underbody bracing that I hope will alleviate this.   Another idea is to print the underbody/frame separately from the sides and have a bit of assembly required.  In T-scale I could get away with more one-piece models but this may need some concessions. 

Part of this exercise is using a new (to me) resin, the Phrozen RPG resin.  It's very tough--the stirrups and grabs are tough enough for use and they are thin as all get-out.  But if it's prone to warping I might try a different one.  Others have recommended Anycubic ABS-Like Pro II Gray, and Siraya Tech Build Sonic Gray resin.   

I think I'm up to about 17 revisions of the design, but each time gets a little closer to an acceptable model.  Many of the lessons will translate to other Z-scale cars as well, such as truck mounting, stirrups/grabs, etc.

[Sumner]

.... and Siraya Tech Build Sonic Gray resin. ............

That is what I use for everything.  Strong, somewhat flexible and great detail.  Very happy with it....

https://1fatgmc.com/RailRoad/UP%20Canyon%20Division/page-232.html

Nice work on the car.

Sumner