I have designed these bed supports to help with wobble and sag which is an inherent problem with the Ender 4.
ADDED a strain relief for the bed wires which clips onto the support frame. You will need to massage the wires a little to get them to sit right.
NOTE: Left Hand And Right Hand side have different knob screw alignments.
You will need to print these one at a time on a 45 degree angle to fit it on the bed.
(see Pictures for the orientation and supports I used.)
I Used 5 top and 5 bottom layers and 6 outline.
I wanted something which ,foremost, was functional, printable, easy to install and looked good.
All that is needed are 4 cable ties and it only takes minutes to install. I strongly recommend using the cable ties as this will give the best possible rigidity with these supports.
The clamps are a very tight fit on the bearing guides so I recommend to only clip on the top half, or less, to the bearing then slide it up at the same time as aligning the screw holes.
It can be a little tricky but it should fit well, at least it did on my machine.
I have included F360 file if you need to make adjustments.
You might notice that when up against the bed it does not sit flat, this is because I have offset the clamp a little to transfer some upward pressure at the front end of the support.
When re installing the bed level knobs, make sure to tighten them up all the way to completely compress the springs then re level the bed from there loosening off as little as possible. You DON'T want your knobs coming loose during a print.
NOTE: I have noticed that when you re level the bed and loosen the knobs, sometimes the spring does not decompress as the screw threads get caught on the support. You may need to giggle the screw so it releases.
Alternatively you could upgrade your bed springs and replace with longer screws but I dont think its needed.
Having these installed now, I believe their may be a little flex between the bearing guide and the metal rod, ultimately a second z axis screw, motor and guides would be ideal.