Large Scale Central

STMA Rib Side Caboose

So I have two projects going at once. One is one of those pesky bucket list models. And its in conjunction with one of those finish what you started builds.

But in the grand scheme, one of my “finish what you started” projects is what will likely be my only modern train. I want to model the St Marie’s River Railroad. Part of that is one of their ex Milwaukee Road rib side cabooses. I have the entire thing designed in CAD asA 3D model. The smaller parts and ends will be resin printed and the main floor, walls, and roof will be filament printed.

I was very very pleased when the second attempt to print the caboose end off the printer. I am very pleased.

I have them both printed now. I just need to get the filament printer printing, its finly set up and I have my slicing program ready. Just need to get it going.

For the record this is a 1:29 scale build to match the USA trains GP9

Well I have decided filament printers are stupid. Or I did something wrong. After a 19 minute test cube for my print settings I set up the file for the caboose walls, roof, and floor. Three days. Not hours. . . Days. Ill be dead before its done.

Quite common. This Whale belly shell is a 13 hr print

EDIT: Referenced my notes - this print is 22 hours!

13 hours is not 3 days. . . But I get it. I am asking it to do basically an entire car. . . But still I had no idea.

What I knew but it never sank in until now is resin prints an entire layer at once. So it takes no more time to print one pixel in a layer than it does to print the entire build plate. To a resin printer it makes no difference the size of the object in each layer. . . It’s only concern is the number of layers . . . Which equals height.

But filament needs to lay all the plastic for a layer before moving to the next. So I do understand why. . . Just wasn’t prepared for a 3 day print.

What layer height are you using, Devon? That can make a big difference in print time. For large objects that will be painted and weathered, a layer height of 0.3mm works just fine.

I am not sure I set it all up with Mike’s help. But for some reason I want to say its in that neighborhood.

I checked on it this morning and I have parts growing and so far they look nice. I do have to say I like the open frame and the fact there is no vat of liquid so I can actually see the progress that is being made while impatiently wait.

Yes 22 hours for that one part. Also consider this, printing one piece at a time makes for a stronger part as each layer stays warmer for the next.

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Thanks for that advice. That makes a lot of sense and hadn’t thought about that. But that’s very logical. I will see how this one comes out and in the future remember that. Even though they are both 3D printing, the process are nothing alike between resin and filament.

And to follow up on Dan’s suggestion, printing one part at a time takes no longer than printing multiple parts at the same time other than the time required to remove one and start the next part. Also, if there is a failure, and there will be, eventually, you only lose one part, not multiple.

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That all makes perfect sense. And especially the failure part. And that just continues to further my need to understand that the processes are not the same. One head is laying down one thread at a time. Entire layers are not being processed at once. So the time to make all four parts would take just as long because the machine has to lay down so many passes and it can only do it so fast. So that really does make sense.

That is another difference I guess between resin and filament printing. Though I have gotten away from this practice, you can stick as much as you want on the build plate of a resin printer and all you waste is resin if you have a failure. And a failure in one part may not affect other parts. Build time has nothing to do with the number of pieces on the build plate it has to do with the height of the build and the number of layers.

I’ll learn. It all makes perfect sense, Just need to retrain the brain to think of it differently than resin.

It actually take a bit longer to print multiple pieces as there is travel time when jumping over empty space to each part for every layer.

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Well did it turn out? I’m impatiently waiting…

So I reprinted just one side. I started it and went on vacation to raise heck with Pete. When I got home I pulled a successful print off the printer.

My analysis is such. As my first successful FDM print i am both happy and disappointed. Its a very serviceable piece. But still has very prominent build lines. I haven’t worked with it to see if I can sand and/or fill to make it workable.

Strong part but the lack of detail and buod lines has me skeptical. It will definitely make great car frames and structural parts but detail will have to be left to the resin printerunless someone can advise what I am.doing wrong.

Is the rib detail a part of the FDM print or are you planning on resin printing that part?

FDM definitely has its perks like Dan’s whaleside hopper car where it has odd contours but for flat shapes like a boxcar, I think .125" styrene works just as good as a base.

I made the rib detail a part of the fdm print. Depending on what I can do with it, I am sorta on board with you. I think the filament printer will be awesome for the frame and floor. I love the resin printed ends. A styrene box for the main body would be great.

I am not at all asking one machine to don’t all. Its a matter of learning what machines do what best and what can still be done better old school.

If I went with what I have now. . .I’d print the details in resin, make the sides and roof in styrene, print the floor and frame with foment.

Very much a work in progress and learning here.

Yep. The railroad industry uses sheets of metal extensively. Far easier to replicate using sheet plastic.

I have a nice CNC router machine to make precision cuts but even if I didn’t, I’d just cut any large flat parts by hand. I’m certain just armed with a an Xacto, I could build the sides including bay window and ribs (strip stock) of that car 10x faster than 3d printing/smoothing.

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Thats where I am leaning Dan. Its how I was originally going to tackle this and I think I am back to it.

So that supply of .125" styrene is coming in handy again? :wink:

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The supply of styrene and a gallon of MEK