Hi, I was just wondering if someone could measure the inside diameter of the aluminum tube for me?
Are the hubs a tight fit? (very close diameter)
Has anyone had any trouble with the tube wobbling on the hub? I thought it might be able to with only one screw to hold it one?
Thanks
Typical values are…
OD of hubs = 0.425"
ID of tube = 0.430"
They are not wobbly at all. The single screw holds it very rigidly.
The only trouble I have with the tube/hub is there is a little rotational slop. So, take your time to align the brackets on the ends of the tubes to make sure they parallel / perpendicular, etc, before you tighten the machine screw holding the tube in place.
Some would call this an adjustable mechanical arrangement. Are we in agreement that after tightening it’s a strong mechanical assembly? 
I think that if I am nitpicking the diameter of the screw hole, there are no other major issues 
(I made Jim roll his eyes, I am such a bad girl!)
Kroony, for example, I handle my bot cantilevered all the time (i.e., holding it by the end of a tube connected assembly). There is no flex - You needn’t worry.
Thanks for the info.
The reason I’m asking is that I need something that can handle a lot of weight. Up to about 8lbs at around 18".
The torque this would produce along with materials alond the length would be about 3,000oz-in, so I need a lot of strength. I would still love to be able to use readily available brackets such as Lynxmotion ones, but I’m not sure if they will all be strong enough.
Do you think they would be ok? Or if not, any other ideas? I guess it’s a different market at this size, but I just can’t find anything a little bit bigger.
There is probably some mathematical formulas to calculate the strength of the tubing. It’s 0.50" OD with a 0.035" wall thickness. The material is 6061T6 aluminum. I can tell you round tubing is some of the strongest material to work with. that’s why you see it so much in nature. I took a 6" part with the sole intention of destroying it, placed it on the edge of a table and tried to bend it in half. I could not do it.
I agree, 6061T6 is an impressive material.
