Projects

Anet A8 All Metal frame Modification and Upgrade

Sept 6, 2020

The  build and design of my new Anet A8 is similar to the original however, there are many design upgrades and changes made. Though I would have like to have gone to a larger build platform, I still have the ability to do so within its current footprint. I made the decision to upgrade the A8 to an all metal unit (frame) and rid myself of the acrylic structure.  That was my first goal. The second was finding a much better way to manage the electrical cables and electronics, a cleaner look.

So one printer is just not enough. While my Anet A8 printer provided a starting point for me with over a year of fiddling and fixing, I find it ironic that most of my  time is spent is trying to improve the safety and quality of my printer. I’m always looking for ways to make improvements. There is a plethora of information on the net of improving the safety of an Anet A8 and you can spend all sorts of time researching, re-mixing, printing, and customizing. It is fun. In the end, you find yourself engulfed in continuous improvement.

I ventured out to find some 2040 extrusion and kit parts to make a duplicate of my printer and use most of the same parts and components as possible. I headed off  to see what was already being used by others.  I found a number of sites but what peeked my interest was BLV projects by Ben Levi.  The site was great absolutely well thought out and some very interesting design concepts.  So I was able to download the suggested upgrades and started to plan out my project.  I didn’t use all of the same parts, but instead I tailor made or re-mixed components that fit my project for my taste.  The X, Z axis were almost print out of the box but the Y was changed significantly.  I wanted to stay away from the 8 mm round rails and upgrade to MGN style linear rails purely for preference on all axes, and I personally did not like the amount of  flex the rail exhibited for that size.

 The heated bed is 235 X 235 mm  but I could have gone up to a 280 X 280 mm if I could have found a suitable one.  I still have the ability to change that later on. Also of note, the cost of aluminum extrusion is very high, and there are other materials that could be used to reduce cost. They do look good and are easy to assemble.  The combination of the apple green printed parts and the black anodized finish on the rail looks amazing.

Another change that I wanted to make regarding the mechanical frame is improving the Z  Axis by using anti-backlash nuts to prevent creep.  As the  weight of the x carriage increases,  in the relaxed state when the Z motors are not powered tent to push down on the lead screw causing out of rig situation.  I also want to have the ability to change the hotend with relative ease and have a standard mounting platform where I can basically bolt on and off different products. Along those same lines install common electrical connectors closer to the hotend to least disturb the electronic wiring.

The frame is basically bullet proof. Simply over-engineered for its size. The Prusia style printer is without a doubt is a solid design and works great. Some of the other improvements that I am incorporating is upgraded 32 bit main board, MOSFET drivers for both the bed and hotend, and upgraded power supply. I am actually thinking of converting and adapting a CPU power supply to power the various electronics.  This would be lighting, camera, Raspberry Pi and other peripherals that use both 3.3 V and 5 V power.  The common style power supply units work fine, but I have have experience several failures when pushed hard by adding  buck DC-DC converters and all sorts of other power hungry devices.

I am just about wrapping up the various frame components and getting ready to look at managing the electrical and electronics.

The amount of insight and knowledge gained from problem solving while building this unit is invaluable. The experiences give you a much clearer picture of what to look for, and how to deal with mechanical issues before you actually do the build. Even when you find a compatible design on any of the websites, there are always slight variations that just don’t work exactly as you want them and you improvise.

Aligning the X, Y and Z Axis.

The 12 mm linear rails are super smooth and have no excess play compared to the typical 8mm rods