Delta bed high and low spots - Need help please

Hi Guys


I have been having A LOT of first layer problems with my delta printer (Kickstarter kit)


I have calibrated and re calibrated using Repetier host and the manual 'paper calibration' and still the first layer is showing high and low spots. Generally it is high in front of each tower and low between them. (see embedded pic to better show the issue)
http://3dprintboard.com/attachment.p...tid=5532&stc=1


I have researched online and read many forums posts showing various problems and solutions such as rod length, horizontal offset and end effector offsets not being correct. I have checked and tweaked these values on my own machine with no luck! I have spent days trying to get it to print flat without failing and just cant get it work. I am just about at the point of pulling my hair out over it!


If any of you guys out there can help me at all I would be greatly appreciative!!


A little info on the machine:
Kickstarter project - Deltatrix
Wooden frame construction with Igus dry linear rails for sliders.
280mm carbon rods with rod end bearings
275mm dia printable bed
Arduino DUE wid RADDS shield
20tooth pullys with GT2 belts
32bit microstepping with 0.9deg nema 17 steppers
Repetier 0.92 firmware


If there is any further info I can give you to help me solve this issue I will, please ask.


Many thanks in advance for any help you can give!