80/20 Inc.

[Trish Fisher]

Thank you everyone for your replies!!!

The FIRST Community is the best!

Trish
Parent Volunteer and FRC2240 Team Mgr.

[JamesCH95]

I've never used 8020 on a competition robot (always been a weight concern) I have used it professionally though.

I think it really does get you "80% of what you want, for 20% of the effort."

As a side note: we've never had an issue with the kit-bot frame never being stiff enough or strong enough. Though we always mount a board in the center of the frame (plywood or composite) to mount electronics and stiffen the frame. Welding the kit frame drops about 3lbs in fasteners and brackets.

[Siri]

Originally Posted by Jon Stratis

Last year, I saw team with a bunch of 80/20 on their robot come in 30+ lbs over the weight limit at a pre-ship scrimmage... I believe they made the limit just by replacing that with simple 1" square stock.

Regarding the weight issue, be careful how you replace 80/20. The common (and lightest) 1" square profile (1010), is .5097lb/ft. Compare to different 6061-T6 Al profiles.

lb/ft............Extrusion Profile..............................Length req. for -30lbs
0.513.........1" (1/8") square tube......................N/A
0.5097......80/20 1010 Profile.......................N/A
0.410.........1" (1/8") channel.............................301ft
0.285.........1" (1/16") square tube....................134ft
0.280.........1" (1/8") angle......................,.........131ft
Values vary slightly, primarily depending on the exact extrusion spec (AA, AS, etc).

Depending on your application, you'll likely be able to get away with lighter-weight extrusions in many situations (U-channel is usually* a reasonable structural substitute), but it's not as big a difference as many think.


*As in not always.