With the initial design of the ExoSlides, the goal was to improve on roller-follower linear slide design (i.e. V-Wheels) by reducing maintenance and improving accuracy, while making the design modular and easy to mount to. I believe that goal was met, and we use the ExoSlides daily on our 3D printers with virtually no maintenance for months on end, which achieving high quality prints. We’ve heard from numerous customers with the same positive experience.

As ExoSlides ride on the aluminum extrusions, this eliminates the need for custom rails (i.e. MGN12 etc) and much longer travels can be used at minimal cost. This led to our development of the wormdrive gearboxes, as they similarly eliminate Z-lead screws, and much longer travels can be achieved with only a longer belt.

The wormdrive gearboxes also have many benefits over Z-lead screws. They are don’t suffer from Z-banding, which can affect machined lead screws if they are not absolutely perfectly machined or straight. Belt drive gearboxes can also allow the Z platform to not be over-constrained, and can even be mounted to the Z platform in an omega drive configuration.


Now for the Ender 5 Plus Z belt kit! We’ve used the gearboxes successfully in our ExoCube and Ender 3 Belt Z moving gantry designs, with perfectly smooth Z layers and no Z banding like most lead screws have. But the Ender 5 Plus is a bear, with a heavy moving bed, and four over-constrained economy LMU bearings. Not to be deterred, we developed a belt drive Z kit that had the benefits of only one Z motor to keep the bed level, and belt drive. Even with a host of improvements such as larger belts and toothed idlers, to achieve good results is somewhat difficult as all brackets and idlers must be perfectly aligned and the belt must be tight.

Sale of the Ender 5 Plus Z belt kit was paused, while we developed a more user-friendly kit. After countless hours testing various iterations, the current state is dual Z gearboxes mounted to the bed in omega drive configuration with 3mm GT belts. Even this design has to be adjusted just right. While the Z lead screws do indeed produce a cyclic banding on the Z, and the belt setup is an improvement, it is not entirely without artifacts, possibly due to the LMU bearings not having smooth movement and the belt drive having more friction than Z lead screws. To make a design I would be happy with would be a complete tear-up of the stock Z setup, with three gearboxes and a different Z bearing arrangement.

While we’ve had huge interest in the Ender 5 Plus Z kit, our mission is to only sell parts and kits that are a noticeable improvement over stock, with an ease of installation that the vast majority of customers can achieve. I strongly believe all our other kits meet this bar, but the Ender 5 Plus Z kit is not there (yet).

Users are always encouraged to make their own designs, and we will release the current Z omega brackets for those that want to do so using parts from our catalog (gearboxes, brackets, belt clips, etc). We just can't offer a kit that should be expected to work well without lots of fussing and attention.

I apologize to all those waiting for the Ender 5 Plus Z belt kit to be back in stock. In testing, it felt like we were continuously almost there, just a week away, yet each iteration never quite met the all criteria, and it's time to definitively put a pause on this kit for now. The good news is we've learned a great deal on belt drive Z setups in general, and will apply those lessons to future projects such as the ExoCube XL printer, so the time spend was not all wasted.

Posted by Giles Medlicott on Mar 13, 2023