Sculptor i3 Upgrade: Magnetic Sheet Topped Heated Bed

Sculptor i3MK2.3

     This fall has been completely crazy for weather, November was partially frozen solid with heavy frost everywhere. I spent the month upgrading the Sculptor with a heated build plate on the y-axis, something I'd planned for since June 2018. I had been using a 65W laptop power brick for it's electrical harness, but that's only enough to power the hot-end and motors, not all that plus a heated bed, so my first step was to upgrade to the same 350W power module that I've been using on the Mega Kossel. Actually installing the power block was simple and straightforward, mostly just removing the old connecting wires and installing the new ones for the upgraded power supply.

Upgraded Y-axis bed support plate on Sculptor

     As for installing the heated bed, it was a bit more involved since I didn't have a standard i3 bed support plate installed already, so mounting one of those was the first step. I got mine from Spool3D here in Canada, it's made of 3mm aluminum with cut-outs for both 3 and 4 bearing setups, so I just had to install the appropriate printed connector for the drive belt and it was almost ready to mount the bed. For holding the bearings on I decided to take a page out of the old i3MK2 build manual and use zip-ties, one at each end of the bearings, it's surprisingly sturdy when the bearings are locked into their slots like that. Bonus is this form of mounting allows just enough flex to compensate for any slight misalignment that might get into the rails during re-installation.

Build Plate assembly with zip-ties

90W MK3 Heat-bed with Wanhao branding

       For the headed bed, I went with the classic MK3 PCB/Aluminum combo that most i3 variations are fitted with, in this case a pre-wired version that I'm fairly sure was meant as a spare part for Wanhao Duplicator i3 models, again from Spool3D. For my purposes, having the wiring pre-installed is one less step to sort out. I only needed to connect them to the control board and the electrical side of things is finished. For mounting screws I happened to have some countersunk head M3s in the parts bin, so the bed got reamed out to accept them.

M3 bolt with Countersink

Magnetic surface sheet kit

    For the actual working surface, I picked up the Wanhao Duplicator i3 Magnetic Sheet kit since I've been interested to see how one of the 'buildtak clone with magnet sheet backing' systems actually worked in practice. What's included is a sheet of thin, mirror polished steel with coated with adhesive on one side and a sheet of build surface material backed with what looks like an overgrown fridge magnet at first glance. Actually installing the system is fairly simple, just peel off the backing from the steel and stick it down to the build-plate like you would with regular sticker-sheet, then there's a protective blue film that needs to come off the front. And finally it's just align and drop on the magnet sheet to finish off installation.

Fully installed heat-bed with Magnetic surface kit

    After using it for 2 months, I can safely say that this kind of magnetic mount has become my absolute favourite, it has all the ease of removal that the spring-steel based ones are supposed to have with much simpler installation. I've tested it at upto 60C on a regular basis and it's held up nicely so far, I've only managed to put some minor cosmetic scratches on it from the nozzle during leveling, it's flexible enough that even the most stubbornly stuck bits of PLA can be removed without tools, just bend it at the right point and they come straight off, much safer than the sharp-edged scrapers conventional beds require.

Finished Sculptor i3MK2.3 with new heat-bed installed

     Overall, I'm happy with how the heated bed update has worked out, it's certainly proven perfect for running in cold weather, cranked up to 60°C it holds PLA  and TPE filaments down just fine even with the ambient temperature hovering around -5°C. 

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.

Prop Replica Build: N7 Helmet from Mass Effect Trilogy

N7 Helmet from Mass Effect games

     Back in January, I upgraded the Mega Kossel with an E3D Volcano, and I've been running it with a 0.4mm nozzle, so it was time to tryout the 0.8mm and see what all the fuss was about. I've been a fan of the Mass Effect saga for a long time, so when I found Killonious's N7 Breather Helmet (thing:2152838) model on Thingiverse, I decided use it as a test for printing large and detailed objects with the big nozzle.

N7 Helmet parts

     Now, not all of the parts were done with the 0.8, the green and red parts were done with a standard 0.4mm nozzle, but all the transparent parts are printed with the 0.8mm nozzle and 0.4mm layers. Surface quality on the transparent parts is comparable to the standard nozzles, just slightly more apparent ridging from the layer lines. It does allow for a drastic reduction in print times, one of the sections printed with a 0.4mm nozzle took 4+ hours to print on its own, a similar sized part took only an hour with the 0.8mm nozzle, so for making large prints the Volcano is clearly the best option.

Assembled helmet with Dremel tool for friction welding

    Since most of the parts for this build are large and thin, my usual method of using 5-minute epoxy to join the parts would clearly make a big mess, so I pulled out my old model 275 dremel tool and chucked some scrap filament to start friction welding the parts instead. Friction welding can be done with either a 3D printing pen or a dremel with a section of filament loaded as the tool head, I'm using one of the smaller collets to get a firm grip on the 1.75mm filament. Once the filament is loaded, the basic technique is fairly similar to conventional welding in metal, creating small joints to hold the parts together first and them doing a second pass to finish the joint. Once that step was finished, it was time to paint this monster of an object.

Base coat of paint being applied

    As with any large prop, painting is the key to making it look like it's an actual object and not just a model. Since most of the shell was done in transparent PLA, the first step in painting was to base-coat the entire model to look like metal, I've used some silver acrylic mixed 3 to 1 with black to create a nice grey metal look before, so that's what got used for the base colour. After that, it was time to pull out the masking tape and start detailing things.

Masking applied to N7 logo area and waiting for paint to dry

     As you can see, this helmet has a lot of different sections that each need a contrasting colour to bring out the details, so it got masked and painted in stages starting from the top and working towards the back. Now, I'm not following the in-game colour layout properly, that would just be lots of blacks and greys, so this is more my personal idea of how the colours should look and I'm fairly happy with how it turned out.

N7 Helmet nearly finished

     One thing that I decided to try differently on this prop was to apply some varnish to seal the paint against scratching or any weathering that I add later, so I coated it in some spare Varathane that I had in the shop, it actually adds a nice shine that works well for this model, so that was an unexpected bonus.

N7 Helmet with finished paint pre-varnish

N7 Helmet with varnish applied

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.

Prop Replica Building: Han Solo's DL-44 Blaster

DL-44 Blaster from Star Wars: A New Hope

     After installing the new magnetic bed surface on the Mega Kossel last time, I decided to test it out with another prop replica build. After some deliberation, I decided on Han Solo's DL-44 blaster pistol from Star Wars: A New Hope. Looking around Thingiverse quickly turned up a decent set of files for a static version, (thing:2230835) so that's the model I went with.

DL-44 flash suppressor

     As you can see, the parts printed quite nicely, so I decided to experiment with a couple alternate finishing and assembly techniques. Since the scope is setup to print in two parts with this model, I decided to try some friction welding to join them together instead of my usual 5-minute epoxy.

DL-44 Scope and Barrel after printing and sanding

     Friction welding is fairly straightforward to do, you just need some scrap filament of the type used in the parts and a Dremel with the optional collet kit or 3-jaw chuck add-ons. What you do is cut a small piece of filament, I found about 2 cm (1in) worked best, and stick it in the collet of the Dremel and use it as a sacrificial tool to weld the parts together. It does take some practice and patience to get a good joint but it worked fairly well. Afterwards there was a slight ridge of extra material on the part but some light sanding dealt with that in short order.

Glue-up of main parts

    For the bulk of the main parts I switched back to my normal go to solution of 5-minute epoxy and glued the main body sections together next. I've found that the Gorilla Glue brand stuff actually dries clear instead of slightly yellowed like the LePage stuff, makes it much better for builds like this.

Main Body after gluing with finished scope

    One thing that I did have issues with on the printed parts was the mounting screws for the scope clamps came out really badly, think it was just a slicing issue but looking at the reference images reminded me that I had some M3 cap screws that looked almost perfect in my spares bin, so I drilled out and tapped the parts to fit the screws and bolted things together.

M3 cap screws installed on scope brackets

    After gluing the remaining parts together, the next step is sanding any stray glue off prior to painting it. For this one I decided to layer the pain in 2 coats, a slightly blackened silver for the first one and then the cannon black overtop. This allows for some neat tricks with weathering the final piece since you can just lightly sand the areas that have wear to reveal the underlying paint instead of painting overtop.

DL-44 with first coat of paint applied

DL-44 half painted with initial weathering on muzzle

    After doing the rough coats on the main body and scope, it was time for some masking before painting the handle sides, this would probably have been easier if I'd left gluing them on for after they were painted, but some basic masking tape takes care of things quite nicely.

Masking applied to handle

Painted handle with masking in-place while drying.

DL-44 with basic paint scheme finished

      Once the basic paint was dry it was time to start weathering the prop, so I tried a couple of different techniques that I'd seen used online. I started off with some light sanding with 60-grit sandpaper to create some of the basic scuffing that is seen on the original prop. I followed up with some Scotch-Brite to dull finish to a slightly more matte effect overall and then got to doing some fine detail highlights with a silver marker.

DL-44 with wear marks partially applied

DL-44 Left side with wear marks

    After highlighting some of the surface details with the marker I gave the entire thing one final pass with the Scotch-Brite and then blasted the surface with my heat-gun to seal any residual damp spots. Overall, I'm fairly pleased with the result and I'll definitely be using some of these tricks for future builds.

Finished DL-44 Right Side

Finished DL-44 Left Side

Magnetic Print Bed Surface on a Budget

Mega Kossel with magnetic build plate

     When I rebuilt my Mini Kossel into the Mega Kossel last August, I installed upgraded rod-arms that allow for a maximum build diameter of 250mm (9.84 in), and I've been using a 190mm (7.5 in) piece of glass topped with Buildtak as my bed for the past 6 months, so I've really been using only 58% of my theoretical build diameter. I'd looked at upgrading the bed surface with the Buildtak Flexplate system in the past, but the only circular option currently available is a 300mm (12 in) set, far to large for my frame and 220mm heat-bed. Thus, I started looking at options for building my own custom version.

10-inch pizza lifter from the local dollar store

     Concept wise, the Flexplate system is fairly straightforward, an adhesive sheet with magnets in it that sticks to the printer's heat-bed or build plate, topped with a spring steel sheet with some Buildtak material on one side. For my version, I'm using some steel pizza lifters that I found at the local dollar store in the cooking supplies section of all things, $4 each and a bit of drilling to remove the riveted-on handle and I've got some fairly flat surface plates.

Adhesive backed magnets assortment from Lee Valley Tools

     For the magnetic part of things, I'm using some 6mm rare-earth magnets that I salvaged from an old toy building set that I had floating around, but Lee Valley sells some 1/4" ones that are a fairly close match. 

Bed mounting bracket with magnets installed

Other side of bed mount with magnets

I've designed a variation of the mounting brackets for my heat-bed that puts 36 of them in a ring around the entire bed, massive overkill when it comes to this type of magnet but having the bed surface start drifting loose is the last thing you want on a 3D printer of any type.

Corner brackets waiting for magnets

Brackets mounted on Mega Kossel

     After printing the brackets, I used some 5-minute epoxy to fix the magnets in place, I've found that it does an excellent job of holding parts to PLA prints under most conditions.

Magnetic bed fully installed on the Mega Kossel

     I've been using this bed configuration for the past 2 weeks already and it works quite well. This particular implementation is specific to the Mega Kossel, but if I was going to install something like this on an i3 style machine, I'd make custom brackets that put the magnets in a line along the front and back edges of the bed, then use a slightly oversize sheet of steel for the bed topping plate.