Hey all, as promised in my introduction post, I'm starting a thread for my Queensland Rail (Australia) inspired Nn3 layout. The size and scale is determined by the fact I have very little room for a layout, along with our local rail operator Queensland Rail running narrow gauge tracks, hence the decision to make things complicated by modeling in Nn3. Add to that the fact there is nothing local ready to run in Nn3, and very little available in N scale for Queensland Rail locomotives or rolling stock, and you'll realise I've made quite the challenge for myself! Nevertheless, I enjoy a good challenge The layout is on 1080 x 820mm benchwork on castors in the garage (the only space available), and the aim is to represent the 70s/80s era I grew up in, focused on the freight and passenger services around the area. This is the current layout, and the track is in place on some foam, but the turntable and roundhouse are yet to be installed (still working on those as you'll soon see). I've revised the design since doing this in XTrackCAD, and there'll only be four roundhouse stalls to give me a little more room as down the track I may choose to install a single tram line down the roadway in the centre of the layout. As you can see, it's going to be a busy and cramped little layout, and going by my current rate of progress is going to take quite some time to get fully operational! For locomotives and rolling stock, I aim to have a passenger service based on two Queensland Rail 2000 class rail motors running in a consist. This is what they look like: I also plan on having a couple of diesel hydraulic shunters which were the DH class: For hauling, I'll likely go with a 2100 class diesel electric: Here's a bit of a dodgy run with a Rokuhan Shorty based power chassis on the layout as it stands: I've also built a mimic panel to control it: I've cut the foam out for the turntable and have started installing the stepper motor and so forth, but need to make some adjustments as I managed to drill the mounting holes a few mm off centre unfortunately. I'll follow up with more posts/photos as I get time, but where I'm at currently is finalising the design and installation of the turntable as you can see, and also the prototype of my QR2000 class rail motor, which I hope to have running in the next week or so. As an aside, part of the reason this will be slow going is that I'm also on the DCC-EX team, so spend a bit of time working on that, and you'll notice along the way that all my electronics are based on various DCC-EX projects.
Yesterday I was able to figure out the lighting for the QR2000 class rail motor finally. Note this is 3D printed on my Creality Ender 3 V2 printer which is doing pretty well with the 0.3mm nozzle and the finest 0.08mm layer height I can do, but it's just not quite good enough for an end result I don't think. I'm using a 3mm warm white and pair of red LEDs for the lighting, and 1mm and 0.5mm plastic "fibre" optic up to the holes in the shell for the headlights and marker lights. Obviously it's in prototype/test mode so very messy right now, and I need to cut all the LED and resistor legs down and attach the DCC decoder yet. For some reason these photos are not uploading in the orientation I've set them, so apologies if you need to stand on your head to see them properly! Here's the front and rear unlit: When running forward, the headlight and marker lights will be on, with red marker lights on the rear. When running in reverse, just the red marker lights up front will be lit. I also started figuring out how to realign my turntable stepper mount so it aligns correctly with the pit rail, but I didn't get very far so no photos of that just yet. I also cleaned up my shed a fair bit as all things being equal I should be picking up a second hand Anycubic resin 3D printer and wash station this evening which should let me print things in a good level of detail now.
New distraction this week as I picked up a second hand Anycubic Photon M3 resin printer along with a wash station and a few other bits and bobs. It needs a good clean and came with a bit of resin so I need to get that sorted and setup in the shed, and hopefully on the weekend I can do some test prints and get it going. Providing it all works, this will let me get some good shells for the locos and rolling stock I need to make, and let me print more detailed things like my QR buffer stops which are ok on the FDM printer, but extremely fiddly to post process. This is an early prototype print of my QR buffer stop I designed, which clips neatly into the Rokuhan track bed I'm using. This will be so much nicer in resin I think.
As expected, I got completely distracted on layout progress as such by my new to me printer and getting it up and running. I'm going to need to replace some bits and pieces as I expected to get it running well, and then spend some time calibrating the settings, but for now I'm happy it works after a lot of time over the weekend testing things after getting the printer and wash station set up in the shed. If anyone's wondering about the mess and smell, then yes, it can be messy, and yes it does smell. However, it only smells when you have the resin or cleaning fluid uncovered, so it's temporary. I'm using methylated spirits to clean with FYI. The mess can easily be contained, just be careful and don't spill resin everywhere! I've been using pieces of newspaper between the printer and wash/cure station for getting the prints off the build plate which so far has proven effective. I'll likely take a tip from Sumner and get a silicon mat to put there as well. After all that, I got one item printed successfully, which is my Qld Rail style buffer stop. It's not a perfect print as the rear corners curved up, but it's good enough for me to see how good prints will be when I get all the settings dialed in and some new resin and parts I've ordered. Here it is after washing and curing with the supports still attached: Compared with what I printed on my Ender 3 V2 with an 0.3mm nozzle and at the highest quality 0.08mm layer height, it's light years better quality as expected: It seems to still be dimensionally accurate too as it still clips neatly into the Rokuhan track bed as designed: Oh, if you're wondering, no that's not a complete buffer stop. There are two items missing I haven't printed yet which need to be glued on. These are the stop itself which is timber in the real deal, and a pair of rails that is bolted too, which is then welded to the top of the curved rails. You can see these in my previous post. Now, fingers crossed the parts I ordered don't take too long to get posted because I'm itching to get some printing done, especially of my rail motor body! In the meantime, I really need to get back to sorting out the turntable mounting so I can get the base and pit installed.
Printed off five Qld Rail buffer stops today, not a great success. I can probably make three useable ones from those and the one I printed on the weekend. I may end up just scrapping them yet though as a learning exercise. Basically, I need to stop trying to print now until the parts and resin I ordered arrive, so I can start from a known good point, do proper calibration, and have a good chance of success. Continuing like this will just be frustrating. The parts and resin were posted today apparently, so hopefully they don't take too long to arrive!
I received my new FEP film and resin on Thursday, so yesterday I spent time cleaning up the screen protector on the printer. The old FEP film had a pin hole in it which is one of the reasons that last print was so bad, as it cured the resin to the screen protector underneath the vat rather than on the print bed. The screen protector is now about 90% better than it was, but I haven't received replacements yet so I replaced the FEP and tried calibration prints with the new resin yesterday, and had success immediately. Yay! I got the exposure time set pretty well so I gave a first proper print a try with four of my buffer stops, and again success! No warping, no missing bits, and very happy with the detailed end result. Today I hope to get my rail motor body printed, start cleaning up the buffer stops, and hopefully get back to mounting my turntable motor.
I ended up with mixed success yesterday. Firstly, while waiting for my Qld Rail 2000 class rail motor body to print, I got the buffer stops separated from the supports and assembled the first one, and I'm very happy with the results! I suspect I possibly should be painting before assembly, but I really wanted to see how well they assemble and be sure they still clip into the Rokuhan track bed, which they do. I have yet to cut the short piece of rail that will be glued onto each side to allow it to join to the Rokuhan track properly. I chose to scrap the others I had printed as they are nowhere near as good as these now that I've sorted the printing issues out. I got two prints of the rail motor body done, but both have issues with getting good support, most likely due to the fact the wide walls are relatively thin. This is the best of the two, but you can see clearly on each side where it's somewhat caved in. I'm very happy with the detail though! I realised after printing this that I can likely print it in one piece, including the doors and the lower front piece, so I've got that set ready to try when I get home today. I've tried adding extra supports on the inside of each side also. I'm not sure if that's enough to resolve the issues but I'll see tonight. I also did end up getting my turntable stepper centred properly and mounted up and took a quick video of it in action, using my mimic panel to control it. Happy with the operation, and especially the absolutely silent operation now I've switched over to a TMC2208 stepper driver. There are two things I'm not happy with though. Firstly, I need to make that rotary encoder software easier to use. Having to turn it all the way to the next position is tedious and annoying, and it should simply move to the next defined position. The other is the turntable bridge itself. The design is really quite bad as it turns out. I designed it to use Rokuhan Shorty wheels to run on the pit rail, but the friction is too much and overcomes the friction of the bridge against the metal rod, so that's a bust. I think I'll simply add fake wheels so it hovers just above the rail rather than run on it. The rod and stepper etc. is all sturdy enough that the weight of my tiny locos on the turntable won't cause any issues. You'll note in the video I've just left the wheels off, as that was the only way I could get it to rotate smoothly and reliably. Anyway, still happy with the weekend's work and really looking forward to getting my rail motor body sorted, as it will be fantastic to have a train to run!
I feel like I'm getting closer with supports for the resin printing, but not quite there yet. I held off doing more prints of my rail motor body until I finalised the design incorporating the QR logo on the front and the buffers on the rear given I now know I can just print the whole body in one go. I've ended up creating the support structure with Lychee slicer as the auto generated supports are laid out better, but I have also added a lot manually as well. I'm still slicing in Chitubox though as that's where my printer and resin profile is setup that works well. I'm definitely happy with the design and detail the printer can produce, it's just a matter of figuring out the best orientation and supports to get a final print that I can paint and fits neatly on the chassis.
I feel like I've had a win! The issues with the warping of the walls all seem to stem from the bottom of the walls being so thin, and they start at 0.7mm where they taper in at the bottom. I adjusted the chassis to be 0.6mm narrower, which allows the walls to start at 1mm thick at the bottom, and I also added some 0.4mm thick braces across the bottom of the walls that I cut out along with removing the supports. I also oriented the body so it's vertical, and just angled up at the front. I've let Chitubox do its auto supports, and then added a few extras where it seemed to need them, and the first print yesterday looks like it has solved all my warping issues after curing and letting it sit overnight. I realised after printing that my adjustment removed one side's recesses where the bogie centres are, so I'm printing again now, but you can see that when I post process the chassis and body properly, the chassis will fit in very neatly as it should, and there is no warping of the walls. One other issue I'm having is that the was station seems to cause the body to bump up against the basket it's in which is leaving defects, so the next print I'll wash by hand and see if that stops that happening. Starting to look good though, and it'll be great if I can get a rail motor up and running soon!
Cheers Kurt, me too! I've ended up with two "good" prints of the shell that I trimmed all the supports from yesterday, along with two chassis' ready to post process. I haven't taken more photos yet but if I can get some time in the garage tonight hopefully I can start the clean up as I'd love to get a first prototype up and running soon.
Oh I also neglected to add I printed another set of buffer stops, so I believe I now have all I need printed ready for assembly and paint as well.
Just realised I've not put any updates on here but I have made progress! After sorting out the bracing to resolve the warping issues, I thought I was doing great, until assembly showed that the rear bogie couldn't rotate enough and the bogie sides were fouling on the inside of the rear steps, meaning it was derailing as soon as I rolled it into a curve. In addition, the rear bogie was too low as well. So, some modifications of the body design to the steps and lifting the rear bogie 0.5mm on the chassis has that problem solved, and the initial assembly test has it sitting at the right height and rolling around curves with no derailments. Excellent! Hopefully on the weekend I can figure out mounting some weights in there and wiring up the motor, lights, and decoder to get the prototype functional enough to test.
G'day, was searching for Qld buffers stops and found another crazy modeller, I did Nn3 decades ago trying and failing to do Puffing Billy in 2nn scale/1:152. Got back into the hobby last year, found this new scale TT120, grabbed calculator - QR TT120 is N gauge, VR NG is Z gauge, found my new scale. Got and broke Xmas Anycubic Mono2, second came today. Inglenook track was cut today, fits on 600mm floating shelf but I needed buffer stops. QLD steam era in TT is same size as N scale. Interesting to read about your 3D printing issues, about to try that for 7ft wagons. Messed up supports on my first and only attempt using PhilQR Thingiverse wagon STLs. I had decide on practice more with QR 4 wheel wagons before trying VR NG again. I only had Tough translucent green and it was too flexible for flat NQ bogie chassis.
Well I'm happy to report that I achieved my weekend goal of getting my rail motor prototype assembled and functional! I've been a bit slow getting back to post on it given it's almost another weekend... ooops! Pretty happy with it, and the lights are generally all good although the rear fibres don't seem to have quite enough support to align neatly, so I need to add a deeper hole for them to sit in to keep them straight. It runs, but not as well as it should, as I seem to have ended up with the worm gear a little close to the bogie's spur gear and you can hear that in the video. A small adjustment is required there. I can't seem to embed this unfortunately, but the YouTube video is here: https://youtube.com/shorts/idoSidJ7k94 Overall I'm stoked that it's up and running! Sounds like you're having some fun Gavin! Definitely interested to hear how you get on, I haven't started tackling rolling stock at all yet. My next step after the rail motor is functional is a DH Class shunter. For the rail motor chassis, I've stuck with my Ender 3 V2 FDM printer as it's a bit more forgiving, but definitely glad I got the Photon M3 for the body as it's so much nicer in resin.
Got a new printer this week, spare part for old one is months away. The Anycubic Mono 2 is getting cheaper each month. Have issues with stl files in FreeCAD when I printed some bufferstops, so I am trying out OpenSCAD. Posting my trials and tribulations on my Facebook page Babbage Brass Works. Trying to find Copper Tungsten bar so I can machine that for chassis. In the meantime I will try brass. Some guys have tried Tungsten filament, it breaks. Jazza tried Iron powder in resin? There is a way to rust it, Dulax stuff from Bunnings.
Ah cool, I'm glad I've not had to replace anything significant on the Photon M3, the FEP was pretty straight forward and easy to get. I still do need to replace the screen protector though, and they finally arrived, just haven't gotten to it yet. I'm a bit concerned about the mounting the rear coupler in a plastic chassis that it won't be strong enough, but for the rail motor it might not be an issue as it will only ever couple to a second rail motor in a consist. For the DH class, I'm contemplating how I might be able to use brass in the chassis somehow, but not given that a lot of thought just yet. I'm not on Facebook at all so will miss your updates there unfortunately, but good luck with it!
Got spare FEP and protectors, just not spare LCD. Getting into adding more details now using OpenSCAD , adding bolts n metalwork, but so tiny they may not print, may need to make them a bit bigger so the rivet counters can see them. 2mm Scale guy did a magnetic hook n loop coupler, I want to try that, got plenty of Microtrains Kadees for VR NG. A10 Class were 2-4-0 or 0-4-2, helped build the railway but not powerful so ended up on shunting duties. Weight for locos in these scales is hard to get, Lead alloy frame, lost wax(3D resin) casting? Still have a few Nn3 whitemetal locos I have not assembled.
Ah yes, those tiny details can get lost quite easily. I tried looking to add some more detail such as the rivets on the rail motor body, but they're just so small I would have to exaggerate them too much just to be visible and it would just look wrong. I've chosen just to leave them off and if it looks wrong when painting, I'll see if I can fudge them in somehow at that point. Sumner on here, however, has figured out some good minimum sizes for detail he's had good success with, and he has a girder bridge with larger rivets that looks pretty good even though they're probably technically too large for the scale.
