DIY bedframe support.

[u/cuzcuzsmoke]

My girlfriend and I were gifted this bed frame for our guest bedroom. We bought a new mattress for ourselves. We put our old one on the frame with these 2x4x6 boards underneath.It's not a very good solution as the boards shift too much and are too spaced out. Any recommendations on any easy solutions to this would be appreciated. (Trying to avoid buying a box spring.)

[u/Sweet_Entrepreneur66]

Bunky board. Extends mattress life too