Joe,
Thanks, I hope the work table idea pans out but I have to admit that getting the support rod holes drilled accurately enough takes some effort. I was trying for at least "within ball peen hammer range" accuracy.The rails have to be parallel in all directions of course and I knew from the start that it would be difficult to achieve with a mounting scheme like this.
Ahren,
Be my guest. Sometimes I do stuff like this "for effect" or for the entertainment value. I think it could have supported two more blocks. Not so sure how long the ABEC7 bearings would last with that kind of weight on them full time though.
The tubes have a small bow in the middle from the weight but that is all I could see happening. Your carriages are the least problem I expected to have. Do you have a recommended procedure for adjusting the bearing fit to the rails? For this test I made them just a little loose (but not sloppy loose).
CarveOne