Large Scale Central

Joe Douglass

VERY impressive Cliff.

Clearly, Cliff, you should live-stream your sanding/filling saga so we can see just how much goes into cleaning up one of these resin prints.

Viral! It will go viral, I tell you!

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Most kind, Jim! You’d see me in goggles and mask, covered with white powder after the Dremel-sanding, and hear me berating myself that I way overdid it on the supports, haha!

I just joined the 3d resin printer club and it seems like a 50/50 split on removing supports pre/post cure. Any specific reason why you do it post cure?

I suspect most of us will just be waiting for lessons on keeping our work spaces SO clean! :smiley:

Craig, good question. Main reason is probably my lethargy in learning about doing it pre-cure. The other reason is that when I did try it once, the support tips tended to take away little divots in the part; but when I clip and sand, I have better control.

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I have never worked with filament printers. But have used the parts. Resin is an entirely different beast. Other than the types of files they use there is nothing similar. The main issue with resin in large scale is the size. They have small print beds unless you plan to spend a fortune. But the detail in resin is unbeatable. So I like Dan Gilchrist’s methodology. He uses his filament printer for the large primary structures and then prints the detail parts in resin.

Resin is finicky. I am still fighting to get successful prints more often than failed ones. And since it is so slow it takes a long time before the plate is out of the vat enough to know you have a bad print and can cancel it. Unlike filament where you can see it going south almost immediately.

As Cliff mentioned height is what dictates print times. And I find with most things I want to print I have to stand them on end to get them on the bed so even though the part may not have a lot of volume it still takes a long time to print because of its height off the bed.

I am learning a few tricks and my success is going up. One of the biggest problems I was having was not getting my vat cleaned between prints. The resin needs to be mixed (shaken) before printing. I would finish one print and start another without emptying my vat. I thought I could just stir it up and then add more resin. What I found out is that in doing this an opaque layer was forming on the FEP (clear plastic on the bottom of the vat) and not allowing good curing. Now I dump my resin back into the bottle (use a filter) after each print and clean my vat with alcohol and then shake my resin and refill the vat. Doing this has greatly reduced my failed prints.

In my opinion resin is the way to go if i can only have one type. I can scratch out a large main body of something but the printed details have been awesome. And resin just gives such great clean parts.



On CAD. . .I was very intimidated. I was a knife and straight edge guy also. And i am not going to lie, learning the basics of Fusion 360 was very steep. But as steep as the hill is, its a short hill not a mountain. Once you understand a few basic things about how CAD works (and Dan Hilyer was awesome at walking me through it) then all of a sudden it clicks. Once you get over the first few hurdles it all sorta clicks and things just seem to happen. And you really don’t need to be “computer” savvy as the controls are for the most part specific to CAD. And then all of a sudden it seems easy and is actually quite addictive.

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Now that i have responded to Bruce,

Dang Cliff, this is great. One thing I am finding out between design and print is that resin doesn’t always play nice when there is big open voids. Almost any hollow cylinder will be warped. I had not gotten around to it needing it yet but wondered about designing in internal removable supports as you have done to eliminate it. Great idea and glad to see it work. All and all resin is pretty cheap and I don’t mind throwing away some support materiel.

Hey Devon, thanks!

Yeah, unsupported walls want to suck horizontally together. I don’t know why, but laterals (which the “supports” can’t do) really help sometimes.

The other thing you’d think I could remember is that printed lower horizontal surfaces should be avoided. I was dismayed at the stinky underside of my tender (where support plates will be fitted). So I tipped it 30 degrees in the slicer, redid the supports (with fewer), and it came out much better.

So now I’m doing the same with the cab. Too many auto-generated supports interfering with delicate features.

Speaking of your next printer, have you seen the Mono X 6K? Same price I paid a year ago for Mono X ($600), but 2x the light power, and up to an insane 3 inches per hour!

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I am patiently waiting for my friend Mike to upgrade and sell me one of his older elagoo mono printers cheap. I know I want a larger resin printer. But I am seriously considering a filament printer so I can print in ABS for both size and strength. Then use resin for the details. Hard to beat the size and strength for the larger basic structures. But having learned to appreciate the detail of resin not sure I can go that route.

One nice thing about having Mike close at hand is he is able and willing to print larger resin prints for me.

Understood, Devon. I really like ABS because you can bond it with pipe cement, and it plays better in the UV.

One thing about ABS is that it needs a hotter nozzle and bed than regular PLA, so just make sure your FDM printer is up to it.

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I am not sure I am happy with you Cliff, This build and watching you print this entire loco has me itching. I have a project in my bucket that is a perfect small loco (will be built off Lil Big Hauler motor block). And it will be the theme for my ceiling layout which I have been itcing to start. I have several buildings, some of which are MIk builds that were going to be a part of my G scale indoor before I abandon it for On30. So I have a few things I really want to display so need to get started on the ceiling layout. And this bucket list loco and consist are perfect small 3D print jobs.

I hear ya, Brotha! Yeah, the 3DP really opens up a whole world of possibilities, doesn’t? That and lasering… You could really use a laser too…
(sorry :grin:)

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I think I mentioned that I’d reprint the tender, but at a ~30 angle from horizontal. This tipping allows underslung horizontal surfaces to form better. I needed that on the tender underside, because some stiffening plates need to fit nicely up under there.

Here’s the reprint on the left, old print on the right.

I should have tipped it up even more (45 degree surfaces print fine), but this will work.

After I saw that, decided to reprint the cab, and this time with fewer supports, and more depth to the lettering. Ain’t perfect, but a long ways better than before. Neither of these have been worked on other than clipping away the (easier) supports.

So I’ve reprinted almost all the parts, for one reason or another… Maybe wasting ~$30 in resin. But WTH, this saves me a day or two of sanding and filling and sanding.



looking great. What a fun project that really show cases where the hobby has come and can go with 3D printing.

I which there was a decent source of motors and metal drivers of various styles. Or complete motor blocks with different driver sizes and arraignments. If we could get a reliable source for that then 3D printing makes our dreams come true. If you can imagine it you can build it.

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Thanks Devon. I agree; since I only used the motor block and part of the boiler, it might be nice to buy just those new (and not the whole Porter).

An alternative would be keeping an eye out for the appropriate used loco on Ebay or elsewhere, and just make sure it runs ok.

Either way, you’re right in saying you can print anything you want to go on top.

Daaaaaang, I just realized I forgot to add the lettering on the tender.

(photo by friend Andrew Brandon)

Oh well, so this will need to be decals. I’ll probably start with Cricut-cut vinyl, and when that fails, send an SOS to Stan C.

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Ahhh, it’s such details that make life special.