The 100 Triple Z Mod

The 100 doesn't fully constrain the forward/aft bed tilt since it only has two leadscrews and the bearings are very far away.

This mod adds a third motor and leadscrew at the front left to constrain this tipping.

You need three anti-backlash leadscrew nuts with 16mm bolt circles to properly utilize it. My bed is very heavy so the two rear anti-backlash nuts are not operating, but the front one has nearly no weight on it, so it needs to have two springs crammed in so that it is always firmly pressed upwards.

Highly recommended but not necessary are matching Oldham couplings above the nuts to decouple leadscrew wobble.

I have the bed sensorless home at the bottom, with the anti-backlash nuts contacting the leadscrew couplers. You need to make sure to set the leadscrew couplers at the same heights above the motors to ensure that the bed is level when it homes.

I use this mod with three independent Z motor drivers. I haven't tried this with all three motors on one driver; it may work but it also might not. Who knows.

Print two copies of Bed Frame Side, with one mirrored. There'll be an unused leadscrew hole on the front right.

The frame part works the same as the stock v1.1, just with another motor mount.

The front bearing holes are also an adjustable clamp to control preload. Use short M3 screws and nuts. If your bearings/drylins are loose even with the clamp fully tightened, wrap them in masking tape to shim them.

Any standard The100 v1.1 bed frame center will work. The photo shows a custom kinematic mount I made for a Salad Fork 160 bed.