It didn’t take long to figure out that a dead X axis and an message saying “TMC CONNECTION ERROR” meant that one of the stepper drivers on the SKR E3 Mini 3D printer control board had released the magic smoke. Manufacturer BigTreeTech replaced the board under warranty, and the printer was back up and running in short order. But instead of tossing it in the trash, [Simon] wondered how hard it would be to repair the dead board.
The short answer is, not very hard. There was no question as to which of the four TMC2209 drivers was shot, since the X motor was the only one experiencing a problem. The drivers unfortunately aren’t socketed on this board, but after a little kiss with the hot air, the old chip was off.
[Simon] didn’t have any spare TMC2209 chips, but the TMC2208 has the same pinout and is a drop-in replacement. The TMC2208 is rated for a bit less current, but it shouldn’t be a problem under normal circumstances.
Other than the stepper connector getting a little toasty during the installation, the swap went off without a hitch and the board was up and running again. [Simon] ended up putting the now repaired SKR E3 Mini in his Ender 3; a nice 32-bit upgrade compared to the ATmega1284 that was originally running the show. Though in the past, he’s managed to squeeze a bit more performance out of the older 8-bit board as well.
We’d love to say that all of our projects worked perfectly on the first try, but the average Hackaday reader is a bit too experienced to buy a fib like that. The reality is, DIY projects rarely get everything right out of the gate. It takes some time to identify issues and work out all the kinks. But of course, that’s half the fun.
For a perfect example of this process, check out the latest update on the 3D printed DSLR camera mount that [isaac879] has been working on. When we last checked in with this project over the summer the mount was already impressive, but with the latest improvements and the addition of a whole new axis of movement, this homebrew camera motion system is an extremely compelling project for anyone who wants to take their project videos to the next level.
Back in June, the mount [isaac879] showed off was only capable of pan and tilt. But as you can see in the video after the break, he’s since mounted that to a track made of 20×40 aluminum extrusion and added another stepper motor. This allows the pan/tilt mount to move itself back and forth on the track to get those slick panning shots that all the cool kids use in their videos nowadays.
But even if you’re not interested in the slider aspect, the core pan/tilt mount has also received a number of refinements over the last few months. Perhaps the most obvious is the switch over to thinner and lighter stepper motors. Reducing mass is always an improvement with a moving system like this, and in the case of the pan motor, the shorter can prevents a potential collision with the camera itself. Obviously the smaller motors are weaker, but [isaac879] considers that a feature; the mini motors will just start skipping steps if things get bound up instead of potentially damaging your expensive camera.
He’s switched to flange bearings to help hold the frame together, improved wire routing, added a mounting point for the electronics, reprinted the pinion gears in a flexible filament to help absorb some vibrations, and switched over to TMC2208 stepper drivers. The new drivers may actually be one of the biggest usability upgrades, as they allow the entire mount to move faster and more accurately. Critically, [isaac879] also reports the new drivers have solved a troublesome vibration issue he was seeing when the camera was moving slowly.
The Creality Ender 3 is part of the new wave of budget 3D printers, available for less than $250 from many online retailers. For the money, it’s hard to complain about the machine, and it’s more than suitable for anyone looking to get make their first steps into the world of FDM printing. But there’s certainly room for improvement, and as [Simon] shows in a recent blog post, a little effort can go a long way towards pushing this entry-level printer to the next level.
The first step was to replace the printer’s stepper drivers with something a bit more modern. Normally the Ender 3 uses common A4988 drivers, but [Simon] wanted to replace them with newer Trinamic drivers that offer quieter operation. Luckily, Trinamic makes a drop-in replacement for the A4988 that makes installation relatively easy. You’ll need to change out a few caps and remove some resistors from the board to make everyone play nice, but that shouldn’t pose a challenge to anyone who knows their way around a soldering iron.
Beyond quieter running steppers, the Trinamic TMC2208 drivers also offer direct UART control mode. Of course the Ender’s board was never designed for this, so the MCU doesn’t have enough free pins to establish serial communications with the three drivers (for the X, Y, and Z axes). But [Simon] realized if he sacrificed the SD card slot on the board, the six pins that would free on the controller could be cut and rewired to the driver’s UART pins.