Some simple brackets to hold a RepRapPro mendel down and increase the stiffness of the frame laterally with the aim of improving Y axis accuracy.I'm quite surprised how much difference this makes - I tried flexing the frame and most of the movement seemed to be in the Z smooth rods so I thought anchoring them down would help and it appears to be at least twice as stiff (by the very scientific method of prodding it and seeing how far it moves).Z bracket isn't very well designed but it seems to do the job :-)Anyway, if you've got a suitable piece of wood handy it's quick to try...