3D Corner 1

3D Printing

Warning, this post isn’t at all about trains. If you are just here for the trains I totally understand if you skip this one. I won’t name names (so nobody will know I’m talking about¬†you Kris ūüėČ ), but someone was giving me a hard time about my printer review not having any pictures of the cool stuff I’d made. The simple answer to that is I hadn’t finished anything cool yet. One of the biggest surprises to me was just how long it takes to print things, that’s why when you see a video of something being printed it’s almost certainly a timelapse loop. So I’ll be posting updates every once in a while with some of the neat stuff I’ve printed even if it’s not train related. In another note I do have a camera so I can take time lapse video of things being printed but need to get some focus and lighting issues worked out before they are worth uploading.

One of the first projects to finish was a golden snitch (from Harry Potter for anyone wondering what that means).

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I got this model off Thingiverse – Golden Snitch with Screw lid, and while this one didn’t turn out perfect do to some printer configuration issues (which I think I’ve got worked out, might try re-printing it) it still is pretty cool. The bottom screws off and there is a little place to hide something (like a stone…). I printed this in part because we are big Harry Potter nerds and because my oldest is turning 11 this month and thought it’d make a cool decoration.

It’s printed in white PLA and primed with Vallejo Gloss Black primer with the idea that the dark base would give it more depth (learned this trick from the Metal Colors I did last summer). Then I painted it with some Gold Vallejo paint and got a nice result.

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Next up a neat paint brush stand, which can be found on Thingaverse – ¬†Cubistand, since this one is a mostly functional piece I probably won’t paint it… unless I get bored.

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Finally hot of the press printer bed (as I type this) a Deathly Hallows pendant (also Harry Potter… I said we were nerds) which can be found on Thingaverse – Deathly Hallows Rotating Pendant. This one I particularly wanted to try as it’s printed as a single piece but the circle can move freely once you cleanup the supports. I’m not sure how painting this one is going to go while keeping it moveable.

Mixing 3D Printing With Scratch Building

3D Printing, Trains

I’ve been trying to learn CAD for a while now with a couple purposes in mind, first as a way to create drawings of what I’m trying to create to make it easier to convey. As an example of this drawing of a Thrall side beam.

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The other would be to use 3D printed parts, or printed tools and jigs to simplify construction. In the example of the thrall side beam I’ve used a scribing tool with some success but it’s still time consuming and easy to make a very visible mistake as this contour is very distinctive. I figured I could go two ways with this, 1) print the piece directly and use it as if I’d cut it or were using a Details Associate or similar piece 2) print a jig to simplify cutting the piece.

Idea one in this case is the simplest so I started with that. Once I got the wheels on my first scratch built flat car it was clear to me just how much weight was needed. Fortunately for that one I had already planned on a load but what if I wanted to run one empty? I need a way to put on some pounds. I’m willing to sacrifice underbody details for the weight, I just need to put it somewhere. I happen to have a collection of steel plates that were salvaged from various lost causes in the past and while they’ll be a little underweight by NMRA standards they should still track a lot better empty.

thrall-beams

The solution was to nibble a bit out of the the inside frames as shown on top in the diagram also with the space for the coupler box, bottom shows the profile of an outer frame.

The picture on the left is how the outer beams came off the printer (it’s hard to see ¬†but trust me they are both there), and the right after I’ve removed the brim. The brim is used to give the print a bit more purchase on the print bed so it doesn’t get knocked out of place during printing. Trust me it’s a good idea (nothing like 5 hours into a larger print and having it all lost because one of the pieces came lose).

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Here is a comparison of a beam I’ve cut and a printed one. Obviously the printed one has a bit of a stair step look on the angles which could be sanded down, and also obviously I’m not very good with an xacto blade.

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The printed version is not without it’s faults either with some cavities that will likely have to be filled in, which for the record is much easier to see in person than to photograph. There are also layer lines, it’ll be interesting to see how noticeable ¬†they are on a finished and painted model. I might also use some filler to smooth it out.

The inner beams I specifically left an area for the weight which is demonstrated on the right. In the left top beam some of the support material is left in place. because of the orientation of the print the center section needed to be supported while printing which just adds a little more cleanup to the part.

So far I’m pretty happy with how these parts came out, it will be interesting to see how they play with the rest of the build.

3D Printer: Anet A8 Review

3D Printing

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This was the state of my desk monday when a package from Hong Kong arrived, when I took this picture I hadn’t found any instructions either. It’s an Anet A8 3D printer, the same one Luke Towan has. Unlike Luke I got mine through Amazon but due to a bit of good luck it actually didn’t cost me anything. I won an Occulus Rift through a software developer survey, they fulfilled the prize through Amazon and included a gift receipt so I was able to return it for an Amazon gift card (I actually never opened the Occulus, the day it arrived I gave it back to UPS to head back to Amazon).

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The lack of instructions wasn’t really a problem though, I’d found a few good build guides on youtube that were very helpful but if you find your self getting one there are instructions and parts lists on the included MicroSD card.

So why the Anet A8? I picked it for a number of reasons including the price, as a kit it’s fairly affordable (comparatively) for the build volume. It’s also based on a Prusa I3 printer (which is entirely open source) and seems to be one of the best hobby printers you can get. It’s also a kit, so once you get it working you have a pretty good idea how it works and how to fix or upgrade things (true story: most of the things on my backlog to print are parts for the printer).¬†Finally it appears to be a fairly common printer, I was able to find a ton of part models for the A8 on Thingiverse both as replacements (if needed) and as design upgrades liked the Z Endstop Fine Adjustment that I’d highly recommend as it’s super fiddly to get right out of the box (which paradoxically you will still have to do in order to print those parts unless you have a friend that will do it for you).

The build is pretty straight forward, if you are mechanically inclined you probably won’t find it to be difficult.¬†None of the things you need to do are difficult, but the scope of things that needs to be done is a challenge in itself. It comes with all the tools you need… except a 5.5mm wrench, you can do without it’d be a little easier with one for all the M3 nuts. In all it took me about 8 hours from unboxing to fully assembled, that includes keeping an eye on the kids, having supper, and keeping an eye on severe weather (side bar we had >60F on Monday when it arrived and severe thunderstorms, tomorrow it’s supposed to snow… all in a 7 day period). What helped me is doing the research before hand and watching youtube build guides ahead of time so I had a general idea of what I was doing and then referencing those same build guides as I went.

I don’t feel like I’m qualified to comment on 3D print quality as a 3D printing newbie, it’s so far been good for me and it’s important to keep perspective on what 3D printers are good at (which isn’t everything) and focus on using it to it’s strengths.

I don’t really fancy myself as much of a reviewer, and in evaluating this review you should keep in mind that I’ve been 3D printing less than a week but I would say this is a pretty good printer for the money, though it does take an investment of time to assemble and keep it running well.

Raspberry PI and OctoPrint

3D Printing, Electronics

Note: I had originally planned on posting this one after I had assembled my 3D printer but as it appears it’s going to be a while (FedEx has been¬†waiting for it to be dropped off for a week in Hong Kong, don’t think it’s gonna make it to the US by it’s scheduled delivery Monday)

One of the things I wanted to do right away with my 3D printer is to make it a little bit smarter which is where OctoPrint comes in which is a nice piece of software that gives your 3D printer a web interface for management. With Raspberry Pi’s as cheap as they are it makes the OctoPi version a no-brainer.

In addition to a web-cam via the Raspberry Pi Camera Module the Pi’s GPIO pins for a filament run-out sensor and a relay to cut the power to be able to cut power to the printer through the Pi, even remotely.

Filament Sensor

For the filament sensor I found an inexpensive optical endstop sensor (can be found many places, just included Amazon link as an example) and then printed a housing for it. I went with this one as it includes mounts for my printer, but this one is much simpler if you don’t need a mount or want to design your own mount.

OctoPrint has an plugin called Filament Sensor which has instructions for configuring it.¬†The sensor I got came with three pins labeled V, S, and G and absolutely no documentation so I guessed that G was ground, S was signal, and V voltage in. With that highly scientific deduction done I plugged V into one of the 3.3v pins, G into one of the ground points, and S to one of the GPIO pins. I chose GPIO24 as it was near both a 3.3v pin and a ground. Some testing found this appears to work so now I just need the printer so I can print the housing… and use it.

Power Relay

I got a dual relay board (getting the module instead of just two relays for cleaner wiring and mounting. One relay is for turning power on and off to the printer power supply and the other will be used later as a switch for some lighting for the print bed. I used this as a guide for wiring up the relays and configuring them in OctoPrint.

For wiring there were two sets of pins on my relay board. I relied on the internet on this one as I didn’t fully understand it but it seems to work. On the left side was JD-VCC which I wired to 5V, VCC which was wired to 3.3V and GND to ground. The other set of pins had GND (which had a trace to other GND so we don’t need to bother with it), IN1 which I wired to GPIO17, IN2 wired to GPIO18, and finally VCC I wired to another 5V pin.

I’ll defer to this documentation on configuring OctoPrint to have options to flip these relays. Make sure you change¬†/etc/init.d/octoprint and¬†~/.octoprint/config.yaml. Also make sure you use a relay that can handle the power as for this purpose I’ll be running straight mains power through it.

Nice Hat

So I got it all working and even wired up an RGB LED that I have some ideas for future work but it’s kind of a mess and if anything gets unplugged it’s gonna be a hassle to make sure I have the right pins. ¬†What I need is a hat… no seriously that’s what they are called (no I don’t know why). Basically it’s a board that can stack on a Raspberry Pi and provider an expanded interface for the GPIO pins. I picked a cheap one that came with support standoffs (I got¬†this one) and wired it up so it was a little easier to hookup and disconnect as needed. I used some multicolored jumper wires to create cables for each of my purposes and used coloring to make sure I know where things plug in later.

Now all I need is a printer to finish this stuff off!

Goals Follow Up March

Trains

February was a slow month for me, for a number of reasons, but here is how I fared on my goals

  • Finish Speeder Shed track
    • I made some unplanned progress painting some of the wood features just because it was an easy and relaxing task on a couple of nights where a easy and relaxing task was needed. The track itself is almost ready to go, just waiting on a chance to apply some pliobond outside (because of the smell)
  • Figure out shelf layout operations
    • Just didn’t have the motivation for this
  • Finish DODX flat car construction
    • This I did, just needs paint, load, and couplers now
  • Upgrade SW1 drive shafts
    • This is close to being done, had a bit of a setback when one of the shafts bounced off my forehead and disappeared. I ended up cutting a new one just need to fine tune it for smooth operation

I’m optimistic about March though holding myself to a low standard as the weather getting nicer could easily¬†foil modeling plans.

  • Paint some models
    • I’ve got a backlog of things that need to be painted or weathered
  • Attempt to build a 3D printer
    • How hard could it be right? ūüôā
  • Mock up cardboard buildings on the shelf layout
    • I consider this to be a gateway to figuring out operations

Upgrading SW1 Drivelines

Trains

A while back my Soo 320 project SW1 broke a horned ball on it’s front truck drive, while searching for parts I found NWSL had instructions for upgrading the rear truck drive which was somewhat notorious on these models.

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It’s basically a rubberish straw, for a closer look:

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The NWSL solution is to create a cardan shaft between with the standard horned ball/cup arrangement on either end. You start by cutting a 0.250″ long section from a 2mm diameter shaft.

Press fit the cups onto the shaft making sure they are aligned

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And finally installing horned balls on the motor and truck shaft and you’ve go an improved drive (some fiddling about may be required)

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As I have two SW1 (which you ¬†might have guessed¬†from the pictures it was at this point I started working on the second one. I made it as far as pressing the cups on a shaft when it slipped out of my pliers bounced off my forehead and landed somewhere in the room… yet to be found. I don’t expect to find it until long after I’ve given up and cut another one.

Weekend Update 26

Trains, Weekend Update

It’s been a slow couple weeks for modeling, just a variety of other things taking up my time. I did get some time last night to work on some painting projects. I’ve been painting the Fairmont Speeder (again… long story) and that’s starting to come together but I’ve realized I lost the wheels. I imagine I’ll find them a week after I finally give up and order replacements.

I’ve also been painting some of the woodwork and pretty happy with how things turned out. I’ve also started working on the little track into the shed and starting to strategize how I want to paint the ties, tie plates, and rail.¬†Easiest option would be to rattle can spray it all brown and try to highlight bits of it later for more color variation. I might also try hand painting it, a lot more time intensive and fiddly but know I can get some pretty good aged wood effects if I do it that way.

Scribing Tool

Trains

I mentioned in my last tool post that I’d ordered a scriber (General Tools Etching Pen/Scriber) but it hadn’t arrived yet. Well it did arrive and I finally had a chance to use it last night. My hope in getting it would be that it would be easier/more comfortable to scribe starter lines in styrene pieces than an Xacto blade then using those scribe lines to guide the Xacto blade on subsequent cuts.

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So far it’s been working out like I’d expect. The problem I still have with pieces like this are that I don’t have a good way to hold rules in place precisely but a light pass makes it a little easier to stay steady¬†with the rule. What caught me off guard is just how well it works, it shouldn’t have been a surprise as this is marketed for use on “all metals, ceramics, and glass”. On a thin sheet of styrene this could probably be used to cut all the way through in just a few passes. I also found following the scribed path very slowly and lightly with the Xacto blade resulted in a much cleaner and precise cuts just taking longer, but that’s probably a work smarter not harder thing ūüôā

Modelling Reads

Trains

A while back a commentor suggested the book¬†Modelling Grassland and Landscape Detailing by Gordon Gravett (Was either Chris or Oly from The Model Railways of¬†Oly Turner and Chris Matthews which also is a good blog but I’m not sure which one was commenting).

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I managed to find a British retailer that would ship to the states for a good price as the prevailing Amazon price was kind of ridiculous. I’m not really the review type but I found it to be a very inspirational read. Enough so that I kinda wanted to replace my snowy city US based layout with a British country/grassland layout. I’ve resisted.. but future dioramas or projects may end up having a little more grass! (and by may I mean definitely will)

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Another book I’ve just started reading is by Rene Gourley of Prembroke:87, “Building an HO steam locomotive in brass and styrene”. So far it’s been a good read, looking forward to getting further into it.