What feedrates do you/other people normally use with MDF?
cant help you there, im not into wood... im just going off what iv seen on the net


My problem with the X motors is one of the nuts is stiffer than the other, and the screws are a bit bent. I put them under tension to remove the bend, however that doesn't help when the gantry gets to the end of the bed since there's no give in it and as a result it often stalls
im assuming you slackened everything off at one end (nut housing and bearing housing) and ran the gantry to that end and nipped it up, then did the same at the outher end... back and forth a couple of times to make sure

i read somewhere that i might need to staighten my screws when they arrived, mine are only 750mm so i got away with it
i was thinking i would need a reasonably flat surface to find the curve and use my knee to ease it out
as long as its a nice lazy curve you should be able to get the worst of it out...... bit more of a problem if its a short bend, it would be pretty easy to make it worse

Hmm, I thought 3600mm/min was tedious
Z still works at 10000
your definitely 18 :)