@ Lucas Warner. I hope this entry under lifetrac comes to your attention. Not sure how to contact you--I'm a novice user. I read most of your interesting log about Lifetrac5. I think this file of yours (i.e.,. File:LifeTrac4 (v5).skp) is for Lifetrac5. If it is, it looks to me like the design can and should be modified for Lifetrac6 to bring the articulating pivot closer to the ground. This would help lower the center of gravity and also reduce upward thrust on the pivot (which broke in LIfetrac1) by bringing the pivot closer to the horizontal plane of forward thrust (i.e., the plane of the wheel axles).