3D printing

ModelRailroadForums.com is a free Model Railroad Discussion Forum and photo gallery. We cover all scales and sizes of model railroads. Online since 2002, it's one of the oldest and largest model railroad forums on the web. Whether you're a master model railroader or just getting started, you'll find something of interest here.


I have not tried this idea, but it occurred to me last night, when thinking about printing trucks or even couplers that it might be necessary to hold them in place if the back side (or any other) required flat machining/milling. That could be awkward, but why not print a female "negative" (almost a mold) to hold the male-positive casting in place firmly enough to machine those cast parts?

I'm sure someone has long-since done this, but I haven't. If you do try it, let us know how well it works...or not.
 
Talking a printed car and trucks does have one place where some machine is necessary, a car printed on an incline will not have perfectly horizontal bolsters. In this case I place an end milling bit in my drill press and adjust the height with the end stops and place the car floor on the plate and mill the bolster hubs flat. Eliminates tilted trucks. Trucks so far don't seem to need machining. The arch Bar tracks need a little beefing up as their e is some flex in the small arms.
 


---------------- Arc Welder ---------------

Saw this last week, but forgot to post a link until I just saw it again:


"Arc Welder" is a free app and library intended only (as far as I can tell) for additive (filament) printers rather than for resin printers. As I have use for one myself, and nearly bought one last week as well, I keep an eye out on additive printing/printers/methods/tools too.

The video is about 15m long.
 
Just got the ship notice for my Anycubic M5 :eek: This is exciting, but I think I need to button up a few wood-based projects before I dive into the 3D printing deep end.
 
Have fun! I expect there will be a learning curve, if your experience is anywhere typical. The resin and printer need to be tuned and it's common to take a while to learn how to design fro the vagaries of 3D, and to place and remove supports.

Good luck! Tom
 
@Tom, and pretty much anyone else:


^ A short 2m video about casting bismuth metals in 3D printed silicone molds.

Silicone female molds taken off male 3D printed masters will pretty much keep their shapes, although there may be some dimensional creep too, so calibrate if necessary if precise sizing of your finished products are required.

Low temperature bismuth metals will go liquid at temperatures much lower than will silicone molds, as seen in the video, where he melts the metal on a simple hotplate. Moreover, "bismuth alloys" are quite heavy for a given volume--right up there with lead, and only a bit less than tungsten.

I WOULD consider carefully melt temperature on your bismuth castings. If you select a melt temp which is very low, and accidently leave them in a place where the temp is way too high--on the dashboard of your SUV in Tucson...in August--you might find all your hard 3D work has puddled up on your floor carpet.

I had a link to a good US source (which I can't find ATM) which listed various alloys and melting temps--they also sold small 1-2 lb. ingots IIRC. A better search than mine should find it.

But failing that, ebay is a good starting place, perhaps:


I don't have any details about these ingots, or shot pellets, bars...or whatever other shapes they come as, but a basic going quantity seems to run around $14/lb. for a two pound ingot. At a recommended NMRA N-scale weight of 3/4 an ounce, that should cover forty-odd cars or so, provided you model and mold accurate shapes and volumes for your metal weight castings.

Which brings me to my next question(s): Calculating volumes on 3D software modeled shapes...and hopefully calculating them automatically, and even on the fly in real time, rather than doing it the harder way, by adding volume shapes together, piece by piece.

AutoCad has done this for twenty years or more, but I'm not sure about other programs like Shapr3D or DSM. Or Blender.

I DID buy a program for specifically this reason about thirty years ago: Turbo Cad...but it seems to me this is a feature which should long since have been copied or improved upon. But I'm having trouble getting answers as to which programs do and which don't. I guess it's a niche issue.
 
Aaaaand now I have a bottle of resin and a wash/cure station, but no actual 3D printer
I received a reply from AnyCubic last night, which said they expect to generate shipping info for mine in the next 24 hours. If it happens this week, it'll be fine with me.

[tracking says Saturday afternoon, and the only reason it really matters is so I can (hopefully) be here to snag it before the porch pirates do].

They did also say my printer is ready for shipment, and I take it that means ready to go at a warehouse here in the US. They said about a month back that enough printers to fill all the US pre-orders were on their way from China (no mention of how large the order was, but I'll guess a 20'-40' container or so).

I'll guess it's the same for the UK and EU, although the schedule was running about a month later over there.

-------
Further updates as events warrant. Film at eleven... :p.
 
Last edited:
I got my printer today! They did not generate a tracking notification, but when I emailed customer service they were able to provide me with one. Now to clean up enough crap in my office to find a good place to set it up 😅
 


V good. They just sent my shipping notices (2) a couple of minutes ago.

[tracking says Saturday afternoon, and the only reason it really matters is so I can (hopefully) be here to snag it before the porch pirates do].

I also bought the charcoal filter thing. Might need a big wash station too, but I already have the smaller one I bought with the Mono X, so I'll be good until/unless I start printing bigger. That won't happen for a while yet.
 
Last edited:

That link shows a step in resin casting I had not heard of before: curing prints while they are immersed in glycerin. VogMan lays out the theory behind it, and--on the surface of it (no joke intended)--it makes some sense.

What I'm much more interested in are casting parts in "tough (flexible) resins. Siraya Tech does offer that one ^, and it seems to be useful too just as an additive to other standard resins when used in smaller proportions, vs. pure and un-adulterated. There are other brands out there too. Auto-paint plasticizers might be useful too.

Ultrasonic cleaning is something I read about only last night, although it's been around for as long as the micro-wave oven. While perhaps useful for prints, if only due to cleaning speed, it has other applications, not the least of which is cleaning photo-etched parts.

If I can snag one as large as the others, it would make conventional wash-stations almost obsolete. But not the UV curing part, of course.

As far as basic resin process handling, and for anyone who might not have thought it through, I'll recommend Nerdtronic's video as a good place to start:


At the 1:30 mark, Michael recommends some splash mats. While useful, I contemplate worst case scenarios like spilling an entire bottle of resin, so I bought one these to contain a real disaster:


Mine only cost $12 or so a year back, so it's hard to see why the higher cost. In any case, I think you might want one that's undrilled for a drain. Why catch a spill only to drain it onto just one smaller spot on the floor or carpet?

As to whether or not any spilled resin might be salvaged...a turkey baster might be your friend. At least to find out if any of it CAN be salvaged or not:


Maybe one for conventional resins, and another for high-speed resins.... :D
 
Last edited:
The printer arrived, but the charcoal filters didn't make it onto the delivery truck, so tomorrow for those they say. No hurry--it's all gonna sit for a while yet.

An idea I had a couple years back for lift-the-lid type printers: There's the problem of lifting the lid with resin coated gloves, and one solution is to drill a hole (or holes) in the top for something like one or two lifting eyes. But this obviously voids your warranty, might crack or even destroy the lid and might even let too much in the way of fumes out if not thought through carefully. Using the right size drill bit, etc.

So...why not use something like a lift eye with a steel--magnetically attractive--base. Put one or two of those atop the lid, and hold them where you want them using one or two largish neodymium magnets under the bottom of the lid. Lift up and off with a rig as simple as found to raise and lower venetian blinds. Easy peasy, and the lid is still pristine (we hope).

You can always motorize your lift system too, just in case the gloves are sticky. Footswitch trigger etc.

Just don't start the lift using "The Clapper." Clap on/clap off, with messy gloves could spatter that resin everywhere...which defeats the point really.
 
Last edited:
I bought a box of something like 500 nitrile gloves at the hardware store, so a clean glove to lift the lid off. A very useful feature of the Anycubic is the pause and resume. One may for large pieces need to add resin, or if the power goes out, you can keep going. A previous printer, a power glitch and your print was done!

Tom
 
Dammit, I mangled the screen protector while setting up the printer :mad: It's like a cellphone screen protector except much larger and more hateful. Ugh, ordered a pack of them, maybe I can get one of them to go on without bubbles or crap under it.
 
As my antecedents would exclaim "Wha hail". The protector sheet doesn't have to be perfect, Mine has a few minor bubbles. Good thing to have as my previous printer I destroyed a couple of LCD plates without one.
 
Dammit, I mangled the screen protector while setting up the printer :mad: It's like a cellphone screen protector except much larger and more hateful. Ugh, ordered a pack of them, maybe I can get one of them to go on without bubbles or crap under it.
Dunno what instructions you might have been following (or not...or even none), but this is a basic guide:

However...and this a key, IMO, do NOT fold the protector back over onto the screen and start to push it down along one edge. Instead, and as you flip it back over into place, start fixing it down under thumb pressure starting in the CENTER of the screen. Then work your way along the vertical centerline from the center out in each direction toward the top and back toward you and the bottom edge as you peel the bottom protective layer further and further off. You MAY find, when you do this, that the protector bulges up a bit as you work it back toward you--between the center and the locating tape along the edge. When you work back down the vertical centerline toward that edge tape...that is the time to take the edge tape off. It has served its purpose.

Same goes for the horizontal centerline. Work it into place from the center gradually out to each edge if you can. This divides the whole area into four quadrants, rather than just one. Then once the vertical and horizontal center lines are in place, work from the screen center out toward each corner.

That divides each quadrant in half again...and then you fan the air bubbles outward and away in a fan fashion. Not from side to side, but from the center outward in all directions.

Since the idea is to work air bubbles you have in the middle out, this will get it done.

Last: Clean the glass as well as you can just before flipping the protector over, and if you can (if you have an airbrush handy, for example) blow any dust out at the very last moment...before it circles back in. High air pressure is your friend here.

If you don't have forced air handy you can buy it in cans too. They are intended for airbrush propellant, oddly enough.
 
Last edited:
It actually looked reasonably good, but I just couldn't leave well enough alone. I peeled back a corner to see if there was a piece of crud under it - there was - and then before thinking about how dumb it was, tried to pick the piece of crud off the screen protector which of course installed about 20 more pieces of crud. I certainly know better, I have done the same thing with cell phone screen protectors before :p Ooh well, now I can watch videos and think about not being a dumbass next time while I wait for a replacement. The silver lining is that it could have been a lot worse in the "screwed up the new 3D printer" department, at least.
 
Got some replacement screen protectors today and got one installed more or less successfully.

Is it necessary/desirable to put a screen protector on the resin vat as well? This one came with a film over it that said "tear off the protective film and place the screen protector according to usage instruction" - however the instructions only say to put a protector over the LCD screen, and it only came with one. But I've got plenty of extras now, if it's worthwhile I could easily protect the vat too.
 


I may be misinformed, but I've never heard anything about screen protecting the vat. In fact, quite the opposite, particularly in the case of this new vat bottom. It's flexible, somewhat fogged in comparison to clear FET and that would defeat the purpose I think.


This video ^^^ explains, reasonably well, some of the particulars, albeit in a somewhat unfavorable light--"here's what Anycubic DIDN'T tell you," etc. But it also points out that this new printer can probably do everything any others can do, provided you fit the classic (stiff, but clear) FET vat bottom film, and provided you use classic (slow? Yeah, slow now, going by this new standard) resins.

The big advantage of the Anycubic m5s is that you can crank stuff out fast, if you like, and on a very large (by current SLA printer standards) printbed too.

So...let me pitch just one of my own ideas. What would make this particularly useful to me would be if Anycubic eventually offers a white colored version of the current grey fast resin. I will put in my vote for that one.

And then to why that would be really useful: Trees, and particularly in my case...aspen trees, or more exact: Aspen tree cores. Trunks.

If you take a second look at the supports you'll see on most angle printed 3D models (I have) they could look a LOT like a closely packed grove of aspen trees. But just because the slicers described them and automatically print them as "supports" doesn't mean similar shapes (groves) can't be modeled instead as sculpted trunks. The latter would take virtually the same length of time to print, once sculpted and taken off the build plate. I wouldn't want to just rip them off and discard them piecemeal, because I want the actual supports (sculpted of course).

And if they work they can be cranked off the build plate really fast.

My problem then becomes how to print the trunks to reflect the broken, torn off branches typical of such trees. I'm working on it. What I WON'T do is decal them.

[cue laugh track]

Another that might be cranked out far faster than I could plant them on the layout would be simple sagebrush cores. At the moment I'm harvesting bags and bags of local weeds with which I hope to cover my local terrain. So far, I've also been snipping the tops off actual sagebrush, and, simply because they are natural they do look...natural. The desert southwest I model is COVERED with sagebrush. Not saguaro cactus, but...weeds.
Once again, this printer should crank them out far faster than I can even paint them, let alone plant them.

Scenery application sequence: Paint with basic ground base paint, then plant sagebrush cores. Sprinkle with foam, leaves, whatever you favor...and then dust the open spaces with (in N-scale)...what is basically dust. Not even the smallest ballasts you can buy, but dust. Sifted, sorted, whatever filter screen size you favor, but basically dust. Drip rivuletes of thinned water (or other) with a pipette.

Viola. The (high) desert southwest, Colorado style.

To the build plate itself, I think I would--will--add a Wham-Bam magnetic flex release plate. Also, and it looks like it WILL be needed, I will probably add some portion of the Siraga tough resin as laid out above. What he's showing here makes it look extremely brittle, but he's also trying to remove thin prints with a spatula.

How a "tougher resin" like the Siraya tech would affect the print time, I would guess no one has yet fiddled with yet, or if they have, I can't find any results.
Which is why we often re-invent the wheel moving fast. It's slower and more tedious to find results, even on the web, than it is to just try ideas yourself.

That's why we experiment, or at least why I do. :D
 
Last edited:




Affiliate Disclosure: We may receive a commision from some of the links and ads shown on this website (Learn More Here)

Back
Top