SecKit SK-Tank Biqu H2 Mount

This is a mount for a Biqu H2 extruder/hotend combo, to go on a SecKit SK-Tank X carriage. It takes a 5015 blower fan (see link below) and either an inductive probe or a BLTouch. There are zip tie slots included as well, and the fan duct is a separate part so it should be easy to replace without disassembling the whole unit.

Altogether you can expect the complete assembly (not counting the carriage) to weigh under 300 grams, saving ~100-120 grams over the stock setup. It should also get you a cm or two of extra Z, since it's significantly shorter than the stock assembly. There is a replacement Z endstop finger included, to allow the bed to come up high enough.

You will need to disassemble the H2 to get it in the mount. Once you take it apart, the back half with the stepper will slide in from the back, then you can put the front back on. The forward fan mount (by the probe) takes a 4mm M4 brass insert. It should be obvious from the pictures where the fan duct and fan bracket go.

The fan sits as low as I felt I could get away with, in order to avoid overly constraining airflow into the intake (which is on top, between the fan and the H2). Consequently the heads on the fan mount screws may hit the bed, depending on how big they are. You will want to either use screws with low-profile heads to mount the fan, or (better) file away some material from the bottom of the fan screw channels so the screw heads can sit flush with the fan surface. The latter method will also let you use shorter screws, saving weight and preventing the front one from going too deep into the part as there is not much clearance past the brass insert.

Finally, you will need to print the fan duct in ABS, ASA, or some other high-temperature filament so it doesn't deform easily due to its proximity to the heater. I recommend printing it with supports touching buildplate only, and with part cooling near the tip (assuming printing it tip up), and/or a generous minimum layer time; otherwise you may find that holes are left in the tip.

EDIT: I've added a version for BLTouch, without the springs. I will make another version to support using the springs.

EDIT 2021-08-30: I have also just added a version for inductive probe including a mount for an ADXL345 3-axis accelerometer. This is useful for setting up Klipper input shaping. As I have time I plan to add this to the BLTouch version as well.

Enjoy!

Biqu H2 extruder/hotend combo: https://www.aliexpress.com/item/1005002018360184.html
5015 24V blower fan: https://www.amazon.com/gp/product/B0886BQRX4
BLTouch: https://www.amazon.com/ANTCLABS-BLTouch-Leveling-Premium-Extension/dp/B076PQG1FF

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