LIMITED QUANTITY AVAILABLE... For a long time.
These brackets made from 6061 aluminum, with the printed board mount in Taulman 910 nylon. They are intended to work on the Wanhao D6 and Monoprice Maker Ultimate.
They are super rigid. Enough so that I was able to cut down retraction, and achieve much higher extrusion precision versus the printed bracket.
The second biggest benefit of this mount, aside from rigidity, is you'll maintain full range of motion with the factory stepper motor. The other brackets you will lose Y travel with a stock stepper.
Lastly, this mount allows you to use the Bowden bushing on the bottom of the extruder, and use a piece of teflon tube to fully constrain your filament. This means you should have trouble free printing with flexible filaments.
I did do a bunch of weight reduction. It it's heavier than the printed counterpart but it's not as heavy as it looks. If you're concerned, it weighs in at 37 grams. My bracket printed in CF Polycarbonate weighed 21g by comparison.
I know this isn't very cheap, but it's reasonable considering the amount of work. Also, you still come out ahead with buying clone BMG and my bracket over buying an authentic BMG kit.
Includes the bmg mount, the ribbon cable board mount, all required hardware, and a length of teflon tube. The tube will need trimmed flush with the bottom of the mount. The extruder itself is not included.