Here’s what rooster was trying to share…
Might be good for the headlight, instead of antlers some loco’s sported.
Time for a model update, though I haven’t been able to put much time into it this weekend.
But about during the week, I want to share about a resin printing problem that I both caused and solved. Who knows but this information might save your life someday! Naah, prob not, but Devon might benefit from my mistakes here.
The first boiler I printed was pot-bellied, because the sides weren’t horizontally braced, and the stuff wanted to suck inward as it was being built. So I added bracing and reprinted, and was going to use that version (the lower one here).
But, two issues came up. There are flat steps on all the sides. And low and behold, it was a setting in Solidworks that was making the accuracy lower. So I wanted to reprint the thing just to see if that was so, as part of the learning curve. Also, I’d missed a couple fittings on the sand box where the tube comes out.
So I printed that, and on a diagonal to see if it would help. But here’s the new problem that came in: diagonal grooves (upper boiler). So I made it horizontal, re-did all the supports (as usual), and printed that. But then there was this big horizontal groove on both sides. Sure, I could have filled and sanded, but I wanted to understand what the cause was.
I finally realized what was happening. Remember the “sucking in” issue I mentioned at the beginning? Well, the print was still doing that. But the internal braces, once the print level got to them, brought an immediate correction – and bumped the sides back out, in that area. The horizontal groove in the lower boiler is where the bottom of where those internal braces start.
So, duh. Simple solution: make the bracing continuous, top to bottom, as it grows perpendicularly from the print bed. So, I redid the internal bracing (1/16" disks, with a .02 chamfer both sides, all around, to help break them free).
So that’s boiler #5. Maybe I’ll use the others in a boiler room or something…
Main thing today was sanding and fitting the pilot and tender to the chassis, and here’s how that’s going.
The main structural concern I’ve had is the joint between the (much reduced) LGB deck and the new resin tender. So there’s a screwed sandwich of deck on top, then resin, then a 2-layer acrylic panel on the underside as a stiffener. Seems good enough for this project.
I’ll probably recut the lowest acrylic panel with a little nub poking out the rear. Because guess who totally forgot to add a coupler?
Cheers,
888:> Cliffy
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Ah…the hazards of 3D printing! (Just in case you were wondering WHY someone would EVER purchase a part!). It’s NOT QUITE ready for prime time.
You’re referring to the rooster claw pipe?
I think guys who sell parts keep banging away at it like I’ve done, to get good prints to customers. But I’m very much on the learning curve, no where near the professional sellers like that g-gauge guy on etsy.
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Actually, I think THAT is the problem with 3D printing…(it sounds SO easy, but isn’t really). It’s tough, as it looks SO good in photos, but when you’re doing it, it isn’t easy at all.
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You’re right Bruce, in addition to design time, there might be lots of tweaking to orientation, supports, printer settings…
I’m finally happy with the parts, so I’m gradually pecking away at fit-up and sanding. That’s it for this weekend though, we’re gonna watch a Raven’s game for once!
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Great progress on the Douglass, Cliff. Thanks for the internal support lesson, too.
Bruce, Cliff makes it look easy but it’s much more complicated than it seems. Lots of trial and error. I have boxes and boxes of prints that have errors either from the design process (mostly) or printing issues similar to what Cliff is reporting. It’s no different than cutting a wood or styrene part just a tad to short, it happens.
Too true. I know exactly what you mean - but I think you have underestimated the trial and error component! (Especially for someone like Cliff!). I really do think that 3D printing will change the world, but not quite yet…
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Thanks Dan. Yep, lots of trial and error. Especially for guys like me who don’t have a tremendous amount of experience with the desktop resin printers.
And I think that’s a big part of what we’re all witnessing: the rapid evolution of these particular machines. If I’d ordered the parts from a print house like Shapeways, who has vastly better / more expensive machines, the part will come back pretty much exactly like I expect.
But there are nuances to these desktop units, since their methodology is much cheaper and sometimes trickier. But again, they’re evolving rapidly.
In the meantime I have filler and sandpaper. I could have used those on an earlier boiler, but I wanted to track down the nature of the grooves. And like I mentioned, the cause was an incorrect assumption on my part, which is now fixed.
Cheers,
Cliff
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Sure looks good! VERY nice work.
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Thats looking amazing Cliff. I love this project. Your issues with it sucking in have already effected two of my designs that I am working on that are out for print at my friend Mike’s. Instead of using the printing supports generated in the slicing program, I made (like your disks) elaborate and beefy internal supports. I created them as components in the design so I could add several easy. I tapered the edges where it will contact the part down to a fairly small point of contact, I added several that I then should be able to break out pretty easy. I am sure in addition that the regular bracing from the slicer will fill it in also. But I am hoping this will prevent this issue. I added them both in the boiler and the cab. As they are internal parts I am not worried about visual defects.
One of the other issues you bring up is getting what I cal support lines in a build. I use Lychee Slicer for arraigning parts and adding supports. Its easy to roll the part around with the supports on it so I can look for supports that lay against my project and create these divots. Which to me is weird because I would think it would bond them and create a protrusion and not a divot, but that isn’t always what happens. On a side note, have you ever printed in a clear resin like Blu? Its weird because there are supports that the process sets up as it is printing but then completely fills in around it later in the process. When you look into the part you can see them. This is highly annoying if you are wanting a clear part because you can see them in there. I have not figured out how to remedy this one and haven’t much cared too.
Bruce, you are spot on. 3D printing has been both rewarding and a source of great frustration. Often times I could have made a part much faster out of wood or styrene. Not only does the print time take forever on large items but then there is the design time and often redesign time. For one off parts I would argue it isn’t worth it. But the beauty of it lies in that once you get a design and it prints right, then it is repeatable easily. So it can be a love hate relationship. Where it excels in my opinion is the ability to design and create parts as I need them with fairly complex design. I can design and print parts with much better detail than I can scratch build the, But that is also why I used to call it cheating (and in a lot of ways still do think it is).
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Cliff
You have made a great scrap pile for a new industry for your layout…
Great looking Loco…
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Thanks guys. And yep Sean, a big scrap pile!
You raise several interesting things Devon, I’ll get back to them after work.
Cheating? I sure don’t think so! Man, it sure takes a LOT of talent to learn and effectively use the CAD stuff. (It seems like about the same effort to learn to use an X-acto and straight edge. 
)
Hey Devon, thanks for the likes.
Sounds like you’re doing your internal bracing just like I did, and maybe for the same reason: auto-generated slicer supports can’t go horizontal!
About your divots vs. bulges. I’ve only used Lychee once (I need to learn it, but haven’t gotten round), so don’t have a solution. But, you could take the sliced file and look at it in both Lychee and Photon Workshop, and see if there’s a diff. And that might lead you to a cause, who knows.
FWIW, PW always makes the bulge, and I’ve had to sand many of them off.
You probably know, but an easy way to fill is dab on resin and cure it. I have a cheap handheld UV light that cures it almost immediately. After a few rounds of that, I sand it, and all looks fine.
Haven’t used the Blu, but I’ve done clears before. I can’t quite picture though how the printer would fill in around a support afterward, since everything at a particular .05 mm level prints at that same time. I’m probably misunderstanding your statement though? Does sound annoying though!
Bruce, I can attest to the frustration of the learning curve here. A year ago, Devon was telling Dan and I that he was just about to throw the printer down the hill (or words to that affect). Yet here he is, printing up a storm. And believe me, 5 months before him, I was right there too!
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Some of us are just “quicker”…
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I agree completely. 3D ends up being as much, possibly more work. Just as much talent required to get Cliff’s kind of results.
Those letters look great now Cliff 
I’m really glad y’all are sharing your trials and tribulations. Convinces me that It was a good decision not to go down this road. I still have modeling tools I’ve never used.
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Thanks Jon, I was thinking of your advice when I made that lettering more pronounced. Yeah, much better.
And I’m pleased to inspire you toward one direction or another. Reminds me of this classic (from Despair.com):
I guess I need to clarify my “cheating” comment. As a scratch building purest (before my LSC days even) I took great pride in scratch building in HO and then G Scale using wood, styrene, brass, and white metal. I considered commercially available detail parts to be a luxury. Many of you may remember my initiation to LSC being my now shelf queen ambituos 2-6-0 which was almost 100% scratch built off an 10 wheeler motor block. I am proud of some of the stuff I have cobbled together. I used to think that anyone can buy detail parts and glue them on and make a museum piece. Then 3D printing came along and the sky was the limit. Anything you wanted was there in instant hyper detail.
Then I bought a printer and began with Fusion 360. And as Cliff mentioned I hated it. Stupidest machine and stupidest technology ever. And YES Bruce the ability it takes to first model in a computer and then make the pieces into a model takes AS MUCH skill as scratch building. While it’s a different skill set, in many ways a harder one, it still takes vision and perseverance to.get what you want. And as Cliff has mentioned many a wasted part. And yes I wanted to chuck my machine out the window. Now look at me. I can design pretty much at will. The frustration has given way to pure satisfaction. As much if not more than the satisfaction I had with styrene and wood. And who says I have to give up styrene and wood. Its not gone, I just bought an entire 4X8 sheet of styrene. Of and I have not given up casting my own stuff either.
At the end of the day 3D printing is just another tool in the arsenal of available materials to build in.
I guess it’s only cheating because less blood is involved. I might have to slice a vein and bleed over a project as an offering to the scratch building gods.