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. 

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.