Review on WINSINN Dual Gear Extruder, Compatible With Ender 3 CR10 CR-10 Pro CR-10S Tornado Upgraded Aluminum Drive Feed For 3D Printer 1.75Mm Filament (Dual Connector) by Mike Pfettscher

UPDATE: I have installed this on two printers. I really like the gripping power of the filament. THE NEGATIVE: Despite all the mods prior to installation you really need to have the idler gear "FREE FLOAT" in the tension arm or it will grind. The picture with the two washers shows you want the gear will do actual steel vs the aluminum of the arm when it is driven down. I replaced the washer, cleaned up everything and made the following adjustments. 1) Moved the drive gear to the top of the motor shaft 2) no longer add tension to the spring with tension screw, just let it set on the weakest setting. No issues encountered so far. and I print a lot.I was using a Titan extruder clone prior to buying this one, but I was not too impressed since I had to crank the spring up like crazy and still ended up slipping at times.This extruder uses two hobbed gears to drive the filament vs the one one on the Titan. I like to read the "bad" reviews to see if there are any common issues with products. Once I received the extruder it looked like the common issue of having the idler gear grind into the idler arms was addressed by beveling the gear. I think this was the most common gripe. However, I have some long running prints, so I didn't want to take any chances. I quickly determined that the extruder just used common anodizing, which makes it pretty red, but it does not improve the hardness (compared to hard coat anodizing). Therefore I trimmed the idler gear by 0.017" off the gear side and added a washer. I also opted to polish the top and the bottom of the idler gear to eliminate any unnecessary friction. Lastly, I grabbed a M3 screw with a smooth shank to replace the fully threaded screw. Unfortunately, I didn't have one of the exactly the right size, so I trimmed a longer one to length and cut the head off and added a slit for a flat head screw driver. A dremmel with a cutoff wheel made quick work of it. I used locktite red on the screw to hold it all in place for the foreseeable future.Installation:Installation was quite painless. One thing you want to pay attention to is that you don't want to drive the idler gear up or down into the arm. So before you tighten the motor gear down (and add locktite blue) you want to look through the hole for the bowden tube and make sure that the hobbed gears are aligned. the should look like this: (o) In essence, you want them at the same height. Last but not least I added a drop of super high viscosity oil to the idler arm for added insurance.So far everything is looking great. Compared to the titan, there are no filament flakes on the extruder. Should something change, I'll update this review.P.S. What i called idler gear, should probably be called the 'passive' gear, since it is not driven by the motor.