these are very much rough and ready, others (Ross, routercnc, et al) can do the more detailed analysis... and tell me I am wrong!
never Irving, I'm not that brave, Ive looked in to composite beam design an it gets a bit messy, the main factor that I have a problem with (calculation wise) is that once the hiwin rails are bolted on the ali structure is made a lot stronger,

Im still struggling with the spindle design math, I think I would just model the structure and put it in FEA as I'm getting lazy...:heehee: