Today I am doing parts 1 of my review of the Mellow Super HV control board. It’s a 32 bit board with WiFi, 8 stepper driver slots and, the key new feature, the ability to use much higher voltage inputs for the stepper drivers. It is compatible with Marlin, RepRapFirmware and Klipper and has an absolute shed load of IO options for accessories such as fans, filament run out sensors etc.
DISCLAIMER: This product was provided free of cost in return for a review and content production.
1 x Mellow Super HV – Aliexpress
The board arrived in your typical aliexpress brown packaging and inside was a neat blue box feature the Mellow branding and 2 clear containers which held the stepstick options I had selected. (2 high voltage TMC5160’s and 6 regular TMC2209’s)
Inside the box the board was nicely protected and I discovered a little bag of goodies!
So here is a list of all the extras bits that come with the board:
- RPi power from Mellow super adapter
- short USB C cable
- Connector for EVERY connection on the board + pins
- Crimp spades terminals for the power inputs/heated bed
- Jumpers for stepper settings
- Replaceable fan MOS boards
- Sticker for power terminal block
- Wifi antenna
- Instruction manual (for getting up and running with RepRapFirmware)
This list of extras is a nice touch. It means that you have everything you need to wire up the control board and get going except for the SD card. Honestly it would of been an awesome touch to include a pre-flashed sd card so that you could connect up the power and be going instantly but this isn’t something I’ve seen reliably happen from any company other than the Duet team.
Looking at the board itself as someone who is by no means an expert in PCB layout or manufacture. The layout is nice – connectors are kept as close to the edges as possible which is nice for keeping your wiring layout neat. Things are grouped by functionality making it quite easy to know what each part is going to do but will require you to be a bit more careful when swapping connectors around as for example the end stop for x isn’t groups with the x axis driver. This is a minor point though and I’d pick a neater layout over that grouping. The solder joints all look nice and clean and there are large built in heatsinks on the backside of the board providing cooling to the chips which switch the 5 heater channels and heated bed channel.
Overall first impressions are good. My plan with this board is as follows:
- Get board up and running with RRF (test how easy it is following their instructions!)
- Swap firmware over to Klipper – Specifically the RatOS branch used for the VCore3 as this is the intended machine for this board. Provide writeup detailing how to achieve this.
- Short term review running this board with Klipper at 24V for all steppers
- Long term review running this board with Klipper
- Pushing the speed limits by swapping in a high voltage supply for the X and Y axis!
I hope you enjoyed my unboxing post. Stay tuned!