Z braces are all in vogue when it comes to upgrading a 3D printer. It seems if you want to squeeze the absolute maximum performance and print quality out of a machine the only way to get it is with a well-developed Z brace support system.
On face value the reason to install a Z brace seems to make a lot of sense. A component with mass (Y axis carriage and build plate) is moving along an axis at speed and then changing direction rapidly could cause unwanted oscillations and vibrations throughout the whole frame thus impacting with overall print quality. Z braces prevent this by triangulating the frame, strengthening the vertical component of the structure and in theory eliminating any wobble which would otherwise cause glitches in the print such as ghosting.
Some style of machines, such as core XY, will not suffer from these same problems because of the fundamental design and construction methodology. Z braces are intended more for use by Reprap Prusa style printers and there are bracing setups available for most machines out there either from the manufacture or by independent designers. Even Original Prusa’s have files available to download and print from the popular repositories and some manufactures have gone as far as providing them as standard equipment on their machines or as optional upgrade kits.
As I was aiming for a totally upgraded printer, the lure of a fully braced and wobble free frame was too irresistible for me to say no to. I had seen many different interpretations and design concepts for CR-10’s, mainly on Thingiverse, ranging from simple bracket and threaded rod assemblies to extravagant and over the top kits comprising of additional aluminium extrusion sections for the existing frame creating what can only be described as looking like a wannabe core XY machine. I settled for something in the middle of this range which also seems to be the most popular option on Thingiverse.
The design by MK42workshop has two different variants of the same basic design, one with solid parts the other featuring triangular truss-like voids. I chose the solid style of parts as I personally preferred the aesthetics over its alternative. The triangle holes just look a bit too try hard for me, like it’s trying to imitate a piece of construction equipment and that’s not the look I wanted to go for at all. As my CR-10 has the optional second Z lead screw and motor (standard on the CR-10s) installed, the gusset (shown crossed out in image below) intended for the back of the frame could not be mounted as the stepper motor gets in the way (pictured below). I’d rather have a second Z axis screw so didn’t end up printing this part, I figured there would be very little benefit, if any, of having the part included as part of the setup.
I ended up printing all parts for with an infill of 90% as I wanted make certain all the printed were as solid as possible with absolutely no flex, play or deformation. By the time all these components were printed with this infill, 90% might as well have been 100% given how closely packed in the infill ended up being within the parts. Thankfully although these were printed in PLA, which is not the strongest material which could have been used, all the parts came out super strong and feel almost unbreakable.
In addition to the printed parts, there are a few off the shelf items which must be purchased as part of the setup. This particular design required the use of 8mm continuous threaded rod at 600mm in length and 8 off 8mm nuts to suit. I used nyloc nuts for this as they won’t loosen up over time especially with the vibrations and constant temperature variations during operation of the printer. This hand full of components are the greatest financial cost of the whole setup but even then totaled only about 20 bucks or there abouts. Add to this a few 2020 T-Nuts and 5mm screws and all the components are accounted for and ready to go.
Assembly was straight forward, if you are used to fixing things on your printer then this will be easy as. Effort should especially be made to ensure that everything is square and symmetrical once the braces have been bolted into place on the frame. I did this by using the highly accurate method of a measuring tape and my own eyesight, ensuring equal lengths of the threaded rod on each side for if there was a difference then the frame would be out of square. I made sure to measure on multiple occasions: an initial measure after they were first put onto the printer; after all the nuts and bolts were tightened up; and after the printer had a chance to warm up to operational temperature and run a print or two. Presently there has been no need to adjust since these initial checks, this is probably down to the nyloc nuts which lock the nut onto the thread and don’t move at all.
The most noticeable difference after installing the bracing was how incredibly ridged and solid the frame became. While I was (somewhat naively) expecting a huge jump in print quality, reality of the situation was the complete opposite. The delta in print quality was minimal if even noticeable at all, while overall quality wasn’t reduced in anyway there really wasn’t a significant or noticeable improvement as I was banking on. Which begs the question, are these Z braces actually worth the effort and cost?
I suspect that if Z Braces were an actual advantageous component towards the overall quality of final printed items, I would expect them to be standard equipment on Original Prusa’s. But rather, they are only really standard on the printers from Chinese manufacturers, such as Creality and the CR-10 V2. Honestly, I suspect that these braces are a throwback to the original Reprap machines which look like a hodge-podge of carbon steel rods, printed parts and electronics cable tied anywhere and everywhere. In this instance Z braces were critical to the design of the machine, there was no beefy acrylic frame or aluminium extrusion for which to mount all the motors, lead screws and bearings, without they are wobbly as.
In the end I don’t believe this was worth the printing time and effort to install everything. The standard frame is pretty good out of the box and doesn’t directly cause that many print quality issues directly. I wouldn’t say don’t do this upgrade as each printer is different and some may benefit from this type of addition more than others, for my machine the pay off was minimal and for the time and effort put into getting it setup probably not worth it. It will stay on the printer but only because it’s a case of nothing gained nothing lost…