BCZAMD Ender 3 Upgrade Parts Dual Z Axis Set Dual Z Tension with Pulley Lead Screw Kit for Ender 3 3D Printer Single Motor Dual Z-axis

New Review >> Dec-2020, I wrote an "ok" review for this product, the seller reached out to me and we discussed the issue. Overall, very simple - the initial belt supplied was a bit too short. Because it was short, when assembling it, I had to pull everything inboard slightly to get it to fit and that caused some binding. Long story short, the seller was in constant contact and has provided a slightly longer (2mm) belt. After removing the old one and making the kit"square" like it should have been from day 1, I popped the longer belt on and it worked flawlessly. Was able to get it to travel full up and down with no binding. Very pleased that the seller stood behind his product and went what I will say is the extra mile (KM) to earn my business. I would not hesitate to get this kit (with the longer 618mm belt).Old review>>> I've had this and have installed it and kept past my return period - so I have time to write an honest review....The online instructions are great - after you find them - there needs to be a link or mention of this INSIDE of the packaging. The bag of parts you get is spooky and scary until you watch the video - then it all makes sense.The belt - there is a lot of talk about the belt being too shore and the vendor stating that it is not - well, the belt works - BUT it is too short - let me tell you why. The belt forces you to draw the rollers at the top of the shafts together to get it on - by doing this the lead screws come out of alignment - so this means the carriage binds up when it travels upwards. If you print only on the bottom 1/3 of your Z distance - it works great - but the misalignment causes issues as the gantry travels upwards. Simply adding 2 or 3 additional teeth AND a idler pulley that could accomodate would solve this issue.I would be happy to revise this review if the manufacturer were to reach out to me and provide some updated parts to try. I am presently using it as I cannot return it, but have to consider larger prints as something I have to do extra steps to to make work properly.

I recently switched to direct drive, putting a bit more weight on the x axis with the stepper and added parts. I decided to look into what options were available for dual z for added rigidity to take on the extra weight. This product was one of the only ones with Prime shipping but with lack of any reviews I was skeptic.The overall quality is good. All parts were included but it does lack directions, though in one of the above pictures they tell you what search term to use to view their assembly/instruction video. Some advice just to look more professional, I would include a card with QR code or something that links to the install video or a pdf with instructions.The z lead screws were straight and good quality. No visible bend or warping.The only gripe I really have is that the screws are not Hex. I would have really liked it if they stuck with the same screw type as the stock Ender 3 screws so when maintenance is needed, I can use the same Hex wrenches on everything.Overall, the solution works and is of good quality.If I encounter any problems after testing I will update.*Update*After about 2 months of use I have decided to update and give a full 5 starts. This product does what it is meant if installed correctly and I have no problems. Some upgrades cause more problems than they solve but this product works great at a price point better than most other similar solutions.

I would say this is a must for an Ender 3. From what I can read online, they all have sag on the right side of the gantry. Installing this kit will completely eliminate that sag, in turn making your bed and prints that much more leveled out. After install, don't forget to level the gantry one last time. Am easy way to do this, on the right side worm gear, loosen the set screws for the belt, and at the same time raise the gantry. Then tighten the set screws back. See my pics for what I mean. Doing that leveled out my gantry within a 1/16th. Also, the belt seems short but it isn't, you need to wrap the belt around 1 gear, then take the other gear(while it's not attached to the worm drive) and stretch it onto the worm drive, then tighten the set screws.

I wanted a belt drive and not a second stepper motor as the latter can get out of sync.This kit doesn't do anything to hold the right side lead screw fixed allowing it to float up or down, thereby making it a useless mod. The left side is held captive by the stepper motor bearings and can't move.I needed to add a collar to the new lead screw below the upper bearing and along with two plastic collars that were in the kit, I clamped it with the the pulley, a bit rube-goldberg but it works.The belt is just long enough to make it between the two screw centers so no tensioner was necessary.I also found it necessary to swap out the 8mm nuts with brass anti-backlash parts to get rid of all the play. A 8mm handwheel makes it easy to manually position the Z axis.My machine is an Ender 3V2.