Using Extruded Aluminum for a 6DOF project

A materials question for the forum:

CLEOPHUS put his together with steel here:
https://www.xsimulator.net/community/threads/budget-steel-6dof-w-mm-arduino-chinese-12v-motors.9030/

And SilentChill with wood:
https://www.xsimulator.net/communit...s-sabertooth-2x32s-was-mms-and-arduinos.6948/

but is there a reason why the same couldn't be built with 80/20 extruded aluminum?

I thought deflection might be a factor and used the following calculators:
https://www.8020.net/deflection-calculator
vs
http://metalgeek.com/static/deflection.php

For comparison I took the 1.25"x 1.25"x 1/8" (converted to gauge 11) steel mentioned here against a 1.5"x 3" Light Extrusion
Both at 8' and 500lbs (assuming 200lb body and 300lb equipment) and supported at either end with a center load.

The deflection for the steel is .6693" to the aluminum .6735" (unless I'm doing something wrong in that comparison)

Cost of both the aluminum and hardware materials may be against it, but I could see some benefits:

• I could take it apart and move it more easily than something that I've welded (portability)
• Easier to reconfigure, adjust or add on
  

This is not impossible to do, but aluminum is often quite expensive compared to wood or steel
The 8020 aliminium profiles are very efficient, but considerably increase the construction budget

It is lighter, but it does not become portable

But it is very easily modifiable to adapt

Thanks obobo,
I figured as much regarding the cost factor. If I was to go that route I may be able to mitigate somewhat by purchasing used on ebay or locally. Still won't be as cheap as steel I'm sure.

As far as portability. I don't mean that the rig itself would be portable when constructed, as a factor of weight. Rather I mean that I have the ability to deconstruct the rig and rebuild it if it's not welded together. Not exclusive to this solution either. I could use nuts and bolts rather than welding.

If I had the money I would of used Ali profile its easy to use and very easy to modify, if built correctly it is very strong as well. It also looks very nice IMO and can be easily modded to fit peripherals and what ever else you want to put on it.

If you can afford it and can't weld I would go for it

Thanks for the input.

Might end up being a hybrid to satisfy the budget need: create a steel base which bolts together and an 80/20 aluminum upper, made primarily out of an existing rig of the same. Basically the added purchase would be 1.5x3 cross bars for rod mounting.

Great topic since i have lots of profiles available i think i will also build my rig this way