Hon30 25’ boxcar

[Erock482]

That's an awesome suggestion - that's my next plan. Thanks for coming along.

No problem! I used it with some success when trying to print some D&RGW High Side Gondolas, the sides bowed out but I needed something to hold it square that was also easily removable. I may go back to it on boxcars but I find the permanent bulkheads I usually include do what I need it to and in less material.

[timwatson]

No problem! I used it with some success when trying to print some D&RGW High Side Gondolas, the sides bowed out but I needed something to hold it square that was also easily removable. I may go back to it on boxcars but I find the permanent bulkheads I usually include do what I need it to and in less material.

If you have a pre removal of the support lattice picture - that might be helpful to anyone doing the same here.

[Erock482]

Here are some shots from Sketchup, I'm afraid I don't have any of the printed version itself.

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How are you thinking of doing the sliding doors? I dabbled briefly in it but Didn't put much more development into it. Print doors separately and slip them into track printed on the body? That was my initial thought but the doors were so thin they warped quite badly.

[timwatson]

Thanks for those that's a really great model. I love the lattice work. I will try that next.

How are you thinking of doing the sliding doors? I dabbled briefly in it but Didn't put much more development into it. Print doors separately and slip them into track printed on the body? That was my initial thought but the doors were so thin they warped quite badly.

This was exactly my thought. Kind of like MT doors. Seems like warpage is the biggest concern and something i'm experiencing as well.

[timwatson]

I changed things up some to go with a “no suction force approach on the walls”. I used @Erock482 approach with the lattice and no roof or floor on the main shell. I left it curing in water and will check it tonight (after I get off work) for warping.

Floor is printed vertically, roof is printed on supports. I may tilt the roof 40 degrees and see how that works.
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[Chris333]

But how did it turn out?

[timwatson]

But how did it turn out?

So far so good but it's still in the water and I'm not home yet stay tuned!!

[timwatson]

But how did it turn out?

Ehh not great. Sadly. I feel like to go forward I have to keep moving backwards. This time there were undulations in the vertical surface where the lattice connected to the insides of the car. I should have made a solid breakaway sheet vertically. The sides mostly all stayed warp free however. So good news.

Pics or it didn’t happen.
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[Erock482]

you might want to go thinner on the horizontal lattices.

I have had good luck printing box car bodies with roofs included with a few bulkheads the same width as the car walls running across the car body.
If the underside of the roof is peaked as to not create a solid level, I can even print them flat with no issues.

I print the floors separate and upside down for the best detail possible on the underside, I'll have to give the on the side orientation a go

[timwatson]

I’m going to try this style breakaway support. I feel pretty good about it. I’m gonna call it the “ice cube tray support”.
I will put the roof back on and print with it on and sloped. For the record I have many successful prints of cars. I even have a successful print of this car but I want to take the design further.

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[Erock482]

Ice cube tray, Interesting! I'll be curious to see how it turns out!

[Chris333]

Now you see why I do some of the goofy crap I do to get a good print.

[timwatson]

Now you see why I do some of the goofy crap I do to get a good print.

Oh I totally do (always did really)! Hollow prints are hard!

[JeffB]

Now you see why I do some of the goofy crap I do to get a good print.

Yup...  When I'm actively printing stuff (which I haven't in long time), I have a lot more failed prints than successful ones due to trying out a lot of "goofy crap" to get good prints. 

But I'd say you've gotten to the point where you have a pretty good handle on what works.

Oh I totally do (always did really)! Hollow prints are hard!

Yeah, they certainly are!

One thing I have figured out...  When adding sacrificial supports to hollow structures, it's best to make these supports consistent in cross section for their entirety.  That is, don't use "lattice" structures.  Stick with vertical bulkheads that have very thin (0.02mm/0.008") connections to the parts you're trying to support.  This keeps the pull away force/tension or suction force on the FEP uniform.  Where you get ripples in the print is where that force changes abruptly.  You see this around window openings too. 

Chris333 has tried a lot of innovative/creative work arounds for this...  I'm sure he's got something that works.

Jeff

[timwatson]

Chris333 has tried a lot of innovative/creative work arounds for this...  I'm sure he's got something that works.

@JeffB how do you think I got here so fast!! Yes I am certainty riding @Chris333 's coat tails.
I'm just trying to give back some and record the good bad and ugly.

 ... AND I HAVE A SUCCESSFUL (NON WARPED NO LINES) PRINT!!!

I need to make the "ice cube tray" support more removable. BUT IT WORKS!

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Edit: I also need to sand the bottom.
Edit 2: I'm taking a close up image through a magnifier lens (thus the warp)