Genuine Bondtech BMG Extruder (EXT-BMG)

I have three Anycubic Mega X printers and everything about them is great.. except for the absolute garbage extruders that come with them. Literally all three printers were unusable after a month because the extruders were unreliable and couldn't print for more than 20-40 minutes without slipping or completely failing to feed filament.I was ready to convert them to direct drive or just throw them in the trash until I saw someone mentioned that they just replaced the factory extruder with this Bondtech one and it fixed all of their issues. And sure enough, I just took off the old extruder assembly, installed this one and it's working great. So replacing the factory extruder does seem to fix the issue.So I'm very happy that I was able to swap out one part and turn my $350 paperweight of a printer back into a functional machine. So for the Anycubic Mega C at least, this can successfully be used as a direct replacement.The only real complaints that I have are that 1) the price is ridiculous for what you get. It's just a couple injected plastic parts and a few gears and screws. This doesn't include a new motor or anything elaborate. It's basically just a different style extruder body that you mount to your existing motor. It's infinitely better than the old one, but looking at it, it seems like it should be more like $30 and not $100.and 2) there are absolutely no instructions or pictures or anything. Just a cardboard box and the extruder parts. I've taken apart the other extruders to understand how they work etc. but I was still guessing as far as what parts I'm replacing vs reusing from the old printer. For the Mega X, I took off the whole old extruder body and internals, then took the gear and bearing off of the motor. Installed the new brass gear onto the motor shaft and then screwed everything together (all the holes lined up which was nice). So in hindsight it was easy, but I was still basically just holding things together and guessing the whole time.So now that I know it works and how to install it, I ordered two more for my other two Mega X printers.

The standard, cheapo extruders that came with my FlyingBear Tornado 2 struggled to shove/pull the filament through the 800mm+ Bowden tubes, even after replacing the stock tubes with the very nice Capricorn tubes. After researching various options, I chose the Bondtech. I wanted an off-the-shelf solution that was proven. A lot of people seemed to have decent luck with the clones...but some didn't.Like any extruder replacement, DON'T expect a drop-in replacement. I had to address 2 issues.1. It mounted fine in place of the standard (Mk.8?) type non-geared extruder. The instructions indicate that the drive hear must be mounted with the set screw end nearest the motor, and that simply won't work. The set screw will interfere with the extruder's gear. The drive gear must be installed with the non-set screw end closest to the motor unless perhaps there's a thick material between the motor and the extruder. On my printer, the motor was on the opposite side of 2mm thick steel and the gear still had to be flipped from what was recommend. I guess the Bondtech mount is 3mm thick, which would account for the difference.2. Because my previous extruder was not gear-driven, the addition of one gear in the drivetrain meant the motor direction was now reversed. You will have a few choices if you find this happening. a) change the motor direction flag in your firmware; b) reverse the wiring to the motor; c) flip the Bondtech upside down. I chose option C as it worked out fine to attach the Bowden tube to what Bondtech intended to be the inlet side.You will also need to reprogram the E-steps parameter in your firmware, when finished, to get the correct extrusion.Just on my second day of use, but about 10 hrs in and two successful prints, I am quite happy. I will update this review if my opinion changes.

The real BMG is beautifully high quality and works great. I am using it in a direct drive setup on my ender 5 with a micro swiss clone hotend. I bought it months to replace a bmg clone that wasn't working right, where I didn't want to modify my print head config. Turns out something else in the setup was the problem, and the clone is still fine. I use the clone to this day on an ender 3 printer and I must say the clones are a much better value especially on cheap creality printers like what I have. The design is not identical (bondtech is tighter and more complex; clone takes shortcuts on geometry and internal parts) and the machining quality on the gears and tolerances on other parts are so much sloppier on the clone. However the print results are exactly the same using a part that is a fraction of the price (15 bucks). I have noticed no difference with respect to extrusion quality or use with flexible filaments between the two setups where the hotend configs are identical besides the extruders. maybe the real BMG will last longer, but I have hundreds of hours more print time on the clone and it holds up. I don't like praising the knockoff product so much, but given the enormous price gap on essentially matched performance, it would be nice if bondtech could offer something comparable for less $$$

Have to adjust the Acceleration of the Extruder otherwise motor might skip on retracts because of the 3:1 gear ratio. So far handles fast and slow through a small bowden on my Ender 3 really well. Getting nice and even results. My only complaint was that the gear was grinding on some loose plastic that wasn't trimmed off it seemed, once I trimmed the plastic myself with a razor blade, gear worked smoothly. Little overpriced, but it is what it claims to be.