Upgrading the Sculptor: Bondtech BMG gearing, Silent fans, and Thermistor replacement

Sculptor ready to print

    Time for some 3D printer upgrades! This time it's the Sculptor i3MK2.3 under revision, specifically the print-head assembly. After refitting my Ender 3 with Bondtech gears during the early fall. I was quite impressed with how reliable they after a couple hundred hours of printing. So when a decent quality clone of the BMG turned up on Amazon, it was time for a much needed upgrade and overhaul for my second oldest printer.

E3D Thermistor and Capricorn XS PTFE tubing.

New (top) and old (bottom) E3D thermistors

   First step of the upgrade process was to strip down the existing tool-head and check the electrical parts for any issues that may have come up over the last year or two of use. One issue that I'd been aware of going into this refit was a bad bearing in the hot-end fan, but as soon as I removed the part fan it became clear that there was a major safety issue with the thermistor cartridge, specifically that part of the insulation had frayed away from the wires it was supposed to protect, that could cause a fire if the control board glitched at the same time, so getting a replacement became the top priority for this upgrade cycle. Fortunately it turns out that E3D had already fixed the manufacturing fault that caused the issue, so I ordered a couple of the updated version, one as a replacement and one spare for future repairs.

Secondary extruder gear installed on idler arm

    Bondtech actually has a specific kit of the BMG that is meant for refitting an i3MK2, so there are SLS optimized source files to work from for the printed parts, fortunately I found an FDM optimized remix on Thingiverse (thing:3347150), so it was just loading the parts into a batch on one of the other printers, cleaning off supports and starting assembly using the online instructions from the official kit as a guide on what goes where.

Gearing system half installed on motor

Assembled Tool-head bolted onto gantry

    Once the mechanical assembly was done, it was time to sort out the electrical issues that had cropped up. Since I had the tool-head apart anyway, the hot-end got stripped down to components and refitted with new parts, Capricorn XS PTFE for the barrel lining, a fresh nozzle and the replacement thermistor, all fairly simple refits but you do have to dismantle the lite6 hot-end to do them. With that side of things done, it was time to deal with the worn out fan.

Fractal Designs Silent Series R3 4010 12V fan

     My local computer store turned out to have some nice 4010 fans from Fractal Designs in stock, so I picked one up to test it out and see how it compared to the Noctua model on the Mega Kossel. Visually, they're quite different, the Noctua has a smaller core with larger blades whereas the Fractal looks more standard, but sound-wise they're about the same when powered up, so I'm fairly happy with the Fractal Designs model and I'll probably be using them in future refits.

Fractal Designs fan installed and ready

     Once all the fans were mounted, it was time to calibrate the extruder and do a test print. Instead of the usual 3DBenchy, I decided to try the Lattice Cube by Lazerlord (thing:1850320) and see how it turned out. 6 hours of overnight printing later, I was greeted by a nearly perfect print when I came into the workshop to check on it. Overall I'm expecting this upgrade to keep the Sculptor running reliably for several years to come.

Lattice Cube freshly printed

3D Printer Kit review: Creality Ender 3

Mystery Box

     New year, new printer in the workshop. Over the 2018 holiday season, I purchased a Creality Ender 3, so this is my mini-review of what's in the box and my experience using it to date. On first getting the box, it comes with just the shipping label stuck to the outside of the printer's box, so it's clearly marked as to the contents, it weighs about 6 kg at a rough guess, so be ready for a large and heavy package.

Interior of shipping box with top foam removed

    Opening the box reveals that much of the interior is packed with this grey plastic 'foam', quiet dense and sturdy. Unpacking revealed that all parts were securely nested in fitted holes, wrapped in cling film for the extrusions, and in multiple bags for the smaller parts.

Gantry parts fresh out of the box

Ender 3 base and Power supply freshly unpacked

     The printer is about half built straight out of the box, all the electrical systems are pre-installed and it's mostly just a matter of following the instruction sheet that's at the top of the box to get it fully assembled. I would recommend plugging the included microSD card into a computer, there's an animated video clip on it that goes through the entire build process step by step, it helps clarify a couple of points in the printed instructions. I did make a couple minor changes to the printer during assembly, mostly optimizations that the user community has come up with over the past year or so. 

Part cooling fan ducts, stock on the left, thing:3079610 on the right

     Probably the single most crucial change I made was to replace the stock part-fan ducting with thing:3079610, a 360 printed duct that puts the air where it's needed and not into the side of the heater block like the original will. I've been down the road of part-fans blasting the heater block on the Sculptor i3MK3 variant ducting, once is quite enough for that issue. This silly piece of plastic is probably why early versions of the Ender 3 shipped with the firmware thermal watchdog disabled, a problem that's apparently been solved on the one I received since a cold snap a couple of days after assembly set off the 'Min-Temp' error code.

thing:3303879 installed backwards

thing:2934313 installed

     Other than the part duct, the other changes were mostly minor optimizations, a cover for the milled slot in the base that the electrical bundle runs through (thing:2934313), and one of the many side-mount adapters for the stock spool holder (thing:3303879). But aside from those, I assembled the printer as designed and set about testing it.

Assembled Ender 3 almost ready to print

     After a bit of research turned up that Cura was the best slicer option for the Ender 3, I loaded up Cura 3.6 and discovered that it has a perfectly tuned profile for the Ender 3 baked right into the default preset package. Overall print quality is quite good, I've still got some slight nozzle drool issue, but I'm fairly sure that's just the PLA that I'm using. One issue that I found with the default 'Fiberboard' bed surface plate is that it warps under the stress of large surface prints, this lead to a couple of layer shift incidents during a long print, so I sourced the magnetic bed that's included on the 'Pro' version to try instead.

Early test print with default 'fiberboard' showing bending issue.

Ender 3 Magnetic Bed Sheet freshly installed.

     Once switched over to the magnetic version of the build plate, it's been fantastic performance all the way. I'd definitely recommend this printer to anyone who is just getting started with 3D printing, the quality and performance can't be beat at this price point.

Ender 3

Household 3D printing round 3: Lampshades and Gardening

Greenhouse over planter box

     Been busy with helping wind-down the garden and cleaning up for the winter over the past couple of weeks, this included converting one of the beds into a mini-greenhouse. The core materials are 25-30 square meters of transparent plastic sheeting for the shell, a couple of 12 foot lengths of 1 inch plastic tubing and some 1/2 inch electrical conduit (EMT) off-cuts from the old Proteus build. Obviously this collection of components needs some way to connect everything, that's where 3D printing comes in with custom adapters and clamps.

Frame hoop anchor bracket with EMT  connector and plastic tubing.

      The frame is formed from the 1" plastic tubing with the EMT conduit used as corner posts that are anchored with connectors that I'd made for another project over the summer, basically a corner anchor to connect EMT to wood or other sheet material. Installation is fairly simple, two screws hold the bracket down to the planter box, then the EMT gets inserted the bracket and the plastic tube is slipped over the top to form the main arches. Cross bracing is provided by both the outer plastic sheeting and a cross-beam formed from some spare 1" tubing with more custom brackets.

Cross-beam connector in white PLA

     The outer plastic shell is held down by custom clips that clamp onto the 1" tubing in a 270° arc. So far it's stood up to a fairly intense rainstorm with minimal issues, a couple of the clips were overwhelmed by the wind and their position on the frame but it's easy to fix by printing slightly tighter ones for those spots.

Plastic sheet clamping clip in use

     The other project I've been working on is spiral lampshades using parametric design in Fusion 360, mainly as a way to learn more about the program and to replace a couple of ancient dust-trap shades that had gotten impossible to clean.

Twisty Lampshade fresh off the printer

    The form I settled on is a 7-sided cylinder, 25 cm tall and 19 cm in diameter. I started with a lofted form to create the slight curve to the sides and then hollowed it out to have 1.2mm thick sides for optimum light refraction. The material is basic white PLA without any heat-treatments or other modification after printing, and it's held up perfectly fine with an old incandescent bulb in the lamp.

Lamp with incandescent bulb and PLA shade.

Designing Custom Lens Adaptors for Vintage Lenses and Modern Digital Cameras

Vintage Lenses with 3D printed adaptors

    Recently I was commissioned to examine a collection of vintage lenses to see if it was possible to make adaptors to mount them on a FujiFilm X-E2 digital camera. The lenses were quite varied, a pair of 16mm film camera lenses, a microscope lens, and Meyer-Optik 400mm telephoto lens.

Lens adaptor for Meyer-Optik 400mm lens

Meyer-Optik 400mm lens with adaptor attached

   The 16mm lenses were a bit different and required custom adaptor plates to link them directly to the camera's mounting ring, so I set about figuring out the dimensions and best way to print them.

Wide-angle 16mm lens with 3D printed adaptor

     The 16mm lens set consisted of a wide-angle lens and a more general telephoto lens that had a damaged mounting ring, so I designed its mounting plate to include some M3 set-screws to secure it.

16mm telephoto lens with 3D printed adaptor plate and set-screws

     Lastly, the microscope lens was the trickiest since it has no focusing mechanism at all, so it's adaptor plate had to serve that function instead by incorporating a screw thread between the inner and outer sections.

Microscope Lens with focusing adaptor

     After further refining my basic design ideas, I'm now offering some basic sizes for sale on Shapeways:

Filament Review: EconoFil PLA MasterSpool refills

Econofil PLA with MasterSpool from Filaments.ca

     I've been following the Master Spool concept with some interest since February, so when Filaments.ca announced that they were adopting it with the new EconoFil line, I decided to get a batch of 9 reloads to try out. On delivery I got 2 large boxes, one containing 8 of the refill coils and the other containing the 9th with an unexpected bonus of Filaments.ca's injection molded MasterSpool to get started with.

EconoFil loaded onto Mega Kossel for testing

    After loading one of the coils onto the included MasterSpool, loading and using the filament was the same as printing any regular PLA, albeit a fairly high quality one, the prints come out with a really nice silky finish that looks spectacular.

Fidget Cube, Dial Calipers and Carabiner printed in EconoFil Green PLA 

    All told, EconoFil PLA is a really nice material to use, not to mention cheaper than Amazon, so I'll be using it as my primary printing material for the future.

Household 3D Prints Roundup 2

LED candle shrouds

     Been a while since I covered prints that I've put around the house, so here's some of the stuff that's been made over the past year. Starting with the above, those are simple spiral vase prints that have a small LED tea light inside for decoration. Design wise, they're really simple, just a faceted cylinder with lots of extra horizontal rings twisted along it's vertical axis, I used Wings 3D 2.1.5 as my design program of choice here. Filament is MG Chemicals Gold PLA, prints look like natural beeswax in colour, really nice for making decorative shades and such.

Toothbrush Holders

     Not the kind of thing you'd expect to use transparent PLA vase-mode prints for, but the faceted spiraling makes them surprisingly sturdy for this kind of use. Again, custom designs done in Wings 3D, using 3D Solutech Natural PLA this time, all printed on the Mega Kossel.

Birdseed filter in use

Birdseed filter clean

Birdseed filtering funnel

     Next up is something bird related, I've got a couple of budgies that are rather picky eaters, they don't like large sunflower seeds and keep emptying the food dish onto the floor if the find them. My solution to the problem is to design a funnel with a removable filter grate that strains the largest seeds out but lets all of the smaller stuff through. It's a simple design, just a cone with a 2 cm cylinder stuck on the point and hollowed out to about 3mm thick walls, the real trick is that rather than modeling the final grill in the CAD software, I just modeled the outer dimensions for it and used the infill settings in my slicer software to create the grid. I'm using Slic3r for my slicing program and the filter grid is the result of using 10% rectangular infill with zero top and bottom layers.

Towel hook on bathroom door

    And finally, this is the current iteration of the Customisable U-Hook from Thingiverse that's being used as a towel hook on the bathroom door. It's printed in MG Chemicals PETG for strength, the previous ones were in PLA and both snapped after about 6-9 months of daily use, this one is currently at 5 months and counting, be interesting to see how it holds up after a year of use. And in closing, I redid the oven knob from last time, the original part wasn't thick enough on the walls for the adaptor plug and failed after about a year of use. the current one was made in one piece with a thicker walled plug and is still going strong after about 9 months of regular use.

Oven knob V2

Stress Testing the Mega Kossel: Building C. Laimer's Tourbillon Watch

Tourbillon Clock

     After the painting project from last time, I decided to try building a more mechanically complex project, Christoph Laimer's Tourbillon Watch (thing:1249221). It's a very complicated model with very tight printing tolerances, all the parts need to be as close to perfect as possible or the clock won't work properly. 

Printing the mainspring pinion gear on the Mega Kossel

     Obviously the first step in this project was lots of printing, about 100-120 hours in total, perfect for shaking out any glitches in the printer. Aside from a couple of spaghetti incidents caused by the print bed shifting on it's mounts, actually printing the parts was the easiest part of the project, tracking down compatible screws was the hardest part, I ended up reaming most of the screw holes to accept M2 screws since those were the closest that I could find.

Clock parts organized for assembly with mainspring being assembled

Mainspring clamped for assembly with printed machine vise

    Actually building the clock took a few days, the virtual walkthrough and assembly videos were invaluable for this stage, always making it clear what part was installed next at every step of the process.

Mainspring fully installed with outer casing in place

Clock parts set out for assembly

   I ended up using some 14-gauge wire cut to length for the gearing axles, long needle nose pliers are crucial for installing them in the upper center plate. Other tools I used were a 3/64-inch drill bit for reaming the gears mounting holes and a Philips screwdriver for the M2 screws. After a couple of days work I had it assembled and mostly working, one of the gears is a bit sticky on its axis, but it's mostly complete.

Test fitting Clock face components

Completed Tourbillon Clock