Tuesday, 14 January 2020

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

Monday, 2 December 2019

Workshop Upgrade: Painting Supplies Toolbox

Project parts
     After using the electronics project for a couple months, I decided it was time for my expanding collection of paints to find a new home, thus the newest addition to my toolbox collection. My main objectives were to have somewhere to keep the paints that was away from dust and random workshop debris, and have the ability to just open the case and have all the available colours right there with brushes, ready to use.

Outer shell panels laid out for assembly
    Some math and digital mockups quickly narrowed the final design down to a pair of shallow trays facing each other vertically with a joint in the middle of one to serve as the opening, basically a custom mini-cabinet with storage on the doors. Printed parts are mostly custom aside from the hinges (thing:1396038) and latches (thing:2425378), handle is the same one as the electronics box project. Once all the printed parts were ready it was time for assembly.

Assembled case with partially installed paint racks
    Assembly was simple, just an exercise in box building, complex bit was figuring out how to keep the paint tubes from falling out of the upper row if the case got inverted somehow. My solution was a simple piece of dowling bolted in at the right height. The rest of the assembly was just measuring the vertical offset with one of the paint tubes as a spacer, then screwing them all down.

Inside of completed case
Outside of completed case
     With the racks installed it was time to load the paint tubes and sort out the brush storage. The holders for each paint tube are designed to hold the tube upside down, this prevents the annoyance of shaking a tube to get the paint out after long storage, but does create an interesting problem for storing brushes. After fiddling around with a bunch of ideas I ultimately went with custom brush pots that are essentially dummy paint tubes with half the body cut off and left open.

Paint brush holders
    It's already been used on a couple of minor projects and works quite well, only thing I'm going to add to it eventually is storage for a mixing pallet and something to put water in for washing brushes or watering down paints.

Monday, 30 September 2019

Upgrading the Ender 3: Bond-tech gears, Bed Leveling Knobs and Part Fans

Ender 3 as currently configured
     After 6 months of using the Ender 3 in stock configuration I ran into a few areas that were showing signs of failing. So I thought I'd do a couple upgrades in the process of fixing them. Three key areas that were showing issues were the bed-springs, extruder idler arm, bed surface, and part-fan duct, so I picked out some upgrades for them.

1.75 mm Genuine BondTech drive gear kit.
    As the extruder is one of the highest wear parts on a 3D printer, any breakdown there is going to show up instantly in the printed parts. So I opted to upgrade to some BondTech drive gears with the original motor-end result is that I'm now able to print flexible filament without issue and haven't had a jam due to chewed up filament since. The housing is a PLA version of the official STL files from BondTech's website. They're surprisingly easy to print with an FDM machine-some slight supports in a couple minor areas and on the idler/compression arm and that was it.

Extruder Motor with BondTech mounting bracket
Fully assembled extruder block in use

   The next area that needed upgrading was my bed-levelling knobs. I came into the shop one morning to find one had spun clean off the bottom of the bed assembly from the vibrational force of normal operation. So I decided to install the same nyloc nuts solution that I've been using on my i3MK2 clone with some custom 3D printed replacement knobs.

Custom and Stock leveling knobs
New Leveling knobs fully installed, note M4 nyloc nut locking mounting screw
Flex-sure branded spring-steel build plate
    And speaking of the bed, I've been through a couple different printing substrates before settling on the current setup. I started with the official mag-bed upgrade after encountering bending issues with the strange flexible plate that came with the printer. The Creality mag-bed upgrade is much better than the starter plate, but the upper surface is far too rigid for practical use. Mine quickly developed cracks and started flaking apart with little bits stuck to prints. I was pleasantly surprised when a batch of spring steel plates that fit the Ender 3 build plate showed up on Amazon. It works perfectly with the magnet sheet from the official bed. I stuck some BuildTak on top and I've been using it ever since.

Radial part cooling fan (thing:3102082)
Electronics bay fan cover (thing: 3312856)
    And lastly are a couple upgrades from Thingiverse. First one is a 5015 radial part-cooling fan mount to replace the stock 4010 radial fan, (I've found that it gives about the same airflow with much lower noise levels, always a plus when working in the same space with the printer). The other upgrade is an elegant electronics bay intake cover, probably the simplest and most effective one I've found to date since it literally just snaps into place straight off the bed after printing. Combined, these two mods reduce the printer's noise level from a howl down to a minor background noise that is comfortable to work around.

Saturday, 31 August 2019

Workshop Upgrade: Electronics Workstation in a Box

Mystery Box
     After doing a bunch of Electronics work on a recent project and having to chase my tools for such work though four or five toolboxes, I thought it was time to build something dedicated for such projects. After doing some research, I found inspiration in this 'Portable Electronics Workstaion' over on Instructibles, in particular the fold-down lid/worktop, so that got integrated with the design.

Initial tool layout inside the box
    Constructing the actual box was fairly straightforward, it's just some leftover birch plywood that was in the woodrack, cut to size and screwed together with some 2 inch 'deck screws', nothing fancy but it's very sturdy and I can dismantle it with a screwdriver if I ever want to change something. The hinges are thing:2401035, and the latches are thing:2425378, both fairly nice designs that work quite well with the handle being custom work of my own. I'm using one of the leftover steel plates from the Mega Kossel's old form as a working surface, flipped over the back is plain steel, plenty sturdy enough to handle a stray iron or other hot tool, I've just used some spare screws in pairs at the corners to clamp it to the inside of the lid for easy storage.

Second iteration of interior layout
    As for what's in the box, I've got my larger multimeter in the right-hand corner, then some hooks for electrical tape (thing:2900008), my soldering iron in a custom stand on the left, power-bar to control the iron along the bottom, and some needle-nose pliers and a multi-tool on the back wall. Just below the shelf is my de-soldering pump and an LED 'work-light' type flashlight, then some custom drawers on half of the shelf above. The drawers are filled with small consumables like heat-shrink tubing and solder, stuff that gets used all the time in small amounts during projects.

Fume extractor parts
    On the safety side, I've got a cheap filter mask just above the iron, along with a custom built fume extractor on the upper shelf. Parts wise, the fume extractor is a 6025 12V fan that was leftover from the airfiltered enclosure build, along with a section of a commercial fume extractor filter cut down to fit. I created a custom enclosure in Fusion360 to fit the fan, then printed the parts out and bolted things together.

Fume extractor with fan installed, filter waiting for installation
    Power is fairly simple, I've got an adapter for the batteries for my power drill that takes a 2.5mm barrel jack, so I just fitted a spare plug to the fan's power leads, simple and easy to maintain. The actual filter is activated carbon with a custom holder, it's secured with some M3 bolts for ease of replacement whenever needed. 

Completed Fume extractor ready for use
     Overall, I'm happy with how this workstation/toolbox turned out, it should make any future soldering and electronics projects much easier and safer going forward.

Completed toolbox ready to use.

Wednesday, 26 June 2019

Part Review: TMC2208 Stepper Drivers

MKS TMC2208 Stepper Driver
      During a recent maintenance session on the Mega Kossel, I installed some TMC2208 stepper drivers into the X/Y/Z sockets to replace the original drivers. Below is a short guide on how to install them on a printer board, along with my impressions after a month of use on a primary production printer.

Ramps 1.4 with TMC2208 drivers on main motion axis
    As you can see from the above picture, these drivers are meant as drop-in replacements for the popular A4988-series that the majority of 3D printers use by default, so upgrading to them works mostly the same way on any control board with plug-in drivers. The key to getting them socketed properly is to line up the pin marked 'EN' or 'Enable' with the same corner of the board socket, it's usually marked on the board, but for the Ramps-series it's the corner pin closest to the power input, centre top in the picture above. The other main change needed is to pull the third jumper in the step selector, make sure to do this before installing the driver since that pin is different between the A4988 and TMC2208 pin-outs.

    The most noticeable difference upon starting a print is just how quiet the printer is, there's barely any sound other than the actual belts moving and the cooling fans, quiet a difference from the A4988 drivers. They also have some nice effects on print quality, prints made before the upgrade had a slight ripple effect that was from minor vibrations shaking the nozzle slightly, those have been vastly reduced with the TMC2208 drivers installed.

3DBenchy post installation,
     This is the #3DBency being printed in the video clip, as you can see the ripple pattern is still present but vastly reduced, so I'm quite happy with the end result of the upgrade, minor stringing aside, I'll probably update my other printers with them eventually as well. In conclusion, are TMC/Trinamic drivers worth it? Yes if you want to make the printer drastically quieter without redoing the motor mounts or are looking to maximize print quality. 

Wednesday, 12 June 2019

Workshop Upgrade: Building a folding center bench.

3/4" hardwood plywood 
    Past month has been busy, had a couple of family projects to do, one of which resulted in a large stack of leftover plywood looking for a project. After tripping over the old plywood on sawhorses bench one more time, I decided it was time to replace it with something better suited to the job.

Workbench hardware, green brackets are thing:1259505
    Sorting through the stack revealed a pair of panels that combined to form a 30" by 84" worktop, a nice size for working on large projects but a bit cumbersome for my workspace all the time, so I needed to find some way of fixing that. Looking through my hardware bin turned up a 30" piano hinge, so I decided to make one side of the bench permanent and the other a folding extension that could be collapsed when not needed. More digging through the rafters turned up a couple lengths of 2" squares stock that could be cut down into legs and I was starting to get a feel for what my options were, so I fired up Fusion 360 to do some rough planning.

Rough design in Fusion 360
   Measuring the available materials fixed the workbench total height at 35" tall, so the design in F360 was useful for figuring out what length to cut the legs, along with providing a solid framework for the basic form. The old diagonal bracing angle iron from the Mega Kossel's previous frame proved to be exactly the right length for the long side bracing and shelf supports, so it got bolted onto the legs to help stiffen things. Bracing for the short sides is a couple lengths of 1/4" plywood that were in the stack, these also double as mounts for the 2.5" caster wheels.

Workbench assembled and folded
    Once the bulk of the assembly work was finished, it was time to give some thought to what type of finish to give the top, something hard-wearing and durable was needed, so I ultimately went with some semi-gloss Varathane that was leftover from another project. it's got 1 coat on all sides so far. Seems to be holding up fairly well, and I've got plenty more if it needs another coat later after some use.

Unfolded with first coat of Varathane drying
Folding Section Leg
    For supporting the fold-out section of the work-top, I was playing with a bunch of different ideas, but ultimately I decided to create a bolt-on leg that will clip to the underside of the worktop when not in use. This meant that I needed something light but strong, some leftover aluminum tubing from the Mega Kossel 2.0 fit the bill perfectly. The longest section that I had on hand was slightly short but I just modified the design for the mounting bracket and foot to account for that.

3D printed foot for folding section support
Folding support leg mounting bracket
    I'm fairly happy with how the leg came together, the printed parts were intended to have M5 bolts used to secure them but the fit as printed turned out to be nice and snug with friction alone, so the entire leg can be broken down without tools if needed or if something breaks at some point. There's a bit of a teaser for a future post in the mounting bracket for the leg, those are the former bed levelling knobs off my Ender 3 being used as wing-nuts to hold things in place, but more on that next time.

Friday, 17 May 2019

Household 3D Prints: Kitchen Knife Block

Kitchen Knife Block
    A few weeks ago I was washing some dishes in the kitchen and noticed the appalling state of the old wooden knife blocks, both were caked with dust and other debris, some seemed to have become ingrained into the finish, so I decided to 3D print a replacement that could actually hold all of the knives in a single block. The first step was looking at the full set to figure out what the basic sizes and styles were, came out as 2 cleavers, 5 regular ones, 2 pairing and 1 carving fork from a couple different sets. Most of them were fairly close in size for each type, so I took the length and width of the larges examples for each, then drew up a layout in Fusion 360.

Kitchen Knife Block in Fusion 360

     One issue that the old blocks had was it was difficult to access the handles for some of the knives due to the slots being tightly spaced, so I measured the handle widths and used double that dimension for the slot offset to fix this issue. Modelling the final form took about a day, then I loaded the model into my slicing program, ran the process with my standard settings and hit a snag. It was estimating over 1kg of PLA to print, and I didn't have any spools that big, so I decided to flip it on end and ditch the infill to see if that helped. It worked and got the weight down to 900g or so, so I turned it loose on the Mega Kossel with an almost full spool of PLA.

Finished Knife Block in use
    After almost 2 days of non-stop printing, it finished at 46 hours and an empty spool of PLA. I'd previously done a couple small prints with the reel, so I actually ended up doing the last 3 cm on the Ender 3 with another spool, then using my 3D pen to weld the 2 sections together. This thing is officially the single longest print I've ever done in the past 4 years, so I'm fairly pleased with how it turned out.