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Two questions.

Has anyone had experience in retrofitting consumer (locally-available) square aluminum tube as telescoping structural support? Ergo; with 0.125" wall thickness square tube at an outside dimension (OD) of 1.5", would minor superficial sanding and end beveling of an inner square tube with OD of 1.25" enable a telescoping pair?

Furthermore, could said pair be capable of implementing a gas spring internally for vertical assist? See image below, noted: gas spring improperly sketched upside down.

Loads and dimensions can be provided if necessary.

enter image description here

ADDITION: Is there an implied ideal mount offset for a gas spring in this circumstance relative to the load distribution (please see 2nd attached image below)?

enter image description here

Katalpa
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2 Answers2

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Aluminium rubbing on aluminum generally will wear very rapidly. You generally want some sort of plastic bushing to reduce friction and wear. (Like with luggage handles there's just a little piece of plastic between the tubes) you should also have a bushing for the other end of the joint (the one inside that's not visible.)

You should do a beam analysis to check that the smaller beam won't buckle right at the joint.

The position of the piston shouldn't matter very much, but the minor benefit is probably worth the small effort to offset it.

Eph
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I have experience with both of these but not for this purpose.

Telescoping tubing usually has a thickness of .105" . Also alot of square tubing has flashing left on the inside. Both of these may cause issues with fit up.

As for the gas springs, I have only seen them go up to 500# force. Also since the gas is compressible the force is not constant across the length of travel. I would definitely try to mechanically prevent the gas spring from bottoming out.

Foremost the concern here is safety. What happens when one or both of the springs fail? Or if they are overloaded? Are there any pinch points? Is the operator in danger of 300# of force hitting the bottom of his chin when a pin is released? These are issues to consider when evaluating alternatives.

Acumen Simulator
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