I rushed into this project a bit too quickly and didnt spend enough time working out the kinks with the h-bot style gantry. for that style of gantry to work well i really needed to better match the linear bearings... by about halfway thru i realized a number of solutions for my design flaws but to do any decent upgrades i would need to scrap a good portion of pretty difficult to machine parts. now that i have a 3d printer and a small tig/mig/stick welder i might revisit the idea later on.