MP3DP v2 BIQU H2 Direct Drive Hotend combo Option

I created a couple mounting fixtures that allow for installing a BIQU H2 direct drive hotend. I plan on maintaining this post for feedback and progress updates. as it stands, this is about 90% complete, with the need for some minor fitment changes and to make it more durable.

Files are available on my Thingiverse here.

Glamor Shots:
Front:
The fan is a 4020 Blower currently using someone elses’ design from Thingiverse. Link to that part is in my Thingiverse posted above. A word of warning, don’t use the fan as leverage when actuating the filament gate lever, I broke mine the first time doing so. not much can be done about that due to the way the part fan bracket has to be printed.

Right:
Not much to see here, except if you squint you can see that I filed the profile of the fan onto fan holder flange. this was done to allow access to the mount screws using a ball end allen key. But i couldn’t leave it there and matched the profile all around. I also plan on making a better part for this since the V2 version of the H2 uses a BIQU designed heat block that is more rectangular and offset differently than the Pheatus Dragonfly hotend of the original. More about this later.

Left:
Better view of the BLTouch mount. note that there is a spacer between the fan grille and the H2 assembly. I printed this with NinjaFlex, but can be printed in your high temp filament of choice. NinjaFlex adds some vibration suppression but should be printed regardless in order to offset the back of the grille and the hub of the fan to reduce possible friction and hissing.
Also, note how the wiring gets routed between the bracket and X carriage. That’s to enable using the filament gate lever w/o worries of ripping out a delicate fan wire. this gap is tight tolerance currently, which i plan on fixing ASAP. another thing is to orient the fan wires coming out the top to keep these away from the hotzone and handles wiring better.

Back:
See, standard V2 Carriage. reuses the same screw locations as the bracket would use for the standard extruders. Also, that rectangular opening at the top is for fixing the wiring loom to. it allows for standard vertical or optional horizontal fixing using Zipties (i hear thos are popular around here… :wink:

Bottom:
Just highlighting some of the fan clearance issues. It might be fine as is, but I want to change the offset or the inside diameter so the hotend isn’t touching the plastic.

Other notes:
The H2 kit comes with 24V heater and hotend fan, so plan accordingly!! I opted for a Mean Well 24V power supply found Here and 4020 blower fans found similar to Here.

Conclusion:
This is planned mod 1 of 2. The other is a mini 12864 screen bracket and an SKR 2 Electronics box, as I find Klipper much easier to use, and I have a half dozen Raspberry Pis laying around.

I would highly recommend going on Amazon and getting an M3 hardware assortment kit, if you haven’t already. I replaced a couple screws here and there because i like socket head screws, and the top and bottom angle brackets were designed with those in mind. I really like this kit here.

I’m also playing around with the idea for a toolhead quick disconnect, in case the H2 gets replaced with something better or you want to swap around toolheads for other reasons. however, that’s a very case by case issue and I don’t know how much I’ll document that here.

Feedback is always welcome!

This mod was originally discussed in a different post found here: MP3DP v2 build. There are probably more talking points in there that isn’t covered here.

Happy Building!

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Rev 1:
Notes:

  • I have not reprinted these parts yet, but I’ll let you decide if that’s good or bad.
  • The pics are model exports since they show better angles than my previous pics did.
  • The Model of the H2 is a V1 variant that I got from GrabCAD, which does stick out lower, but this illustrates that it should work on all H2s, old and new.
  • BLTouch is also a model from GrabCAD, so the tip may be lower or higher. the max Z dimension is 5.5mm, with is within the 6mm envelope on the BLTouch v3.1 spec sheet.

Changes:

  • Opened up the hotend/BLTouch wire harness via a tad
  • Added a slot for keeping the part fan wire out of the way using (you guessed it) a 5.5LBs ziptie
  • Beefed up the top main harness ziptie square.
  • Corrected the BLTouch mount and geometry.
    ** This includes the spacing of the mount screw locations.

Iso:
Mainly shows the new slot for a ziptie mount for the 4020 part cooling fan.

Front:
This highlights the beefed up ziptie mount for the harness

Left:
Doesn’t show much, but allow you to see the alignment of the BLTouch tip and the Nozzle.

Assembly Drawing:

STLs on my Thingiverse!

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