Z braces designed for the Sovol SV03 that use threaded rods from home depot. designed cause I couldn't find any file that fits my needs. I have it on my printer and the top feels way more sturdy. 

instructions:

you'll need two 3/8" threaded rods cut to about 60.5 cm each, if you can, measure it yourself just to make sure the length is right. you'll also need 8 nuts that fit the rods, I got nylon nuts because they hold better against vibrations, I bought those and the rods from home depot.

after printing the parts, use m4x12 screws with T-nuts like those that came with the printer to connect the "extrusion-connection" parts to the aluminum extrusion at the top and the front of the printer, try to have them line up and make sure the print bed doesn't hit them when moving forward. next thread the nuts on the rods, one before each "rod-connection" part and one inserted into the part, see the pictures for more information. finally, insert an m4x25 screw into each "extrusion-connection" part and a regular m4 nut into the "rod-connection" connected to the rods. insert the M4x25 screws into the "rod-connection" with the side of the nuts facing outwards and you should be done!

I'm also planning on selling kits for the parts used (with the rods cut to length), maybe also including the prints, please write a comment if you'll be interested in that or if you have any questions about the Z-braces.