Compacting the arms...

Posted by Dan Richards at 2/15/2001 8:14 PM EST

Student on team #550, WCTS Robotics, from Warren County Vo-Tech and WCTS.

Hey. What’s the smallest diameter pipe or rod that will not bend (much) with 20 pounds on it? Anyone know? Also, I have a Victor that decided to short itself out and only go in reverse now. Anybody want it or know a use for it?

Posted by Tim Gates at 2/15/2001 10:57 PM EST

Engineer on team #288, RoboDawgs, from Grandville High School and X-Rite/Delphi.

In Reply to: Compacting the arms…
Posted by Dan Richards on 2/15/2001 8:14 PM EST:

That is a very broad question. When 20 pounds mass is in motion and you try to stop it, your going to have more than 20 pounds force exerted on the moment and at what distance from the pivot or fulcrum. Without more info about your application, I would suggest you try schedule 40 PVC, it’s surprisingly strong, light and quite resilient. Also, an I-beam cross section is very efficient if the force is applied vertical and without any lateral stresses.

Tim Gates

Tim Gates

Posted by Matt Leese at 2/15/2001 11:01 PM EST

Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Fiber Technologies & RIT.

In Reply to: Re: Compacting the arms…
Posted by Tim Gates on 2/15/2001 10:57 PM EST:

Well, Schedule 40 PVC is strong, sometimes. It’s much better at taking tension or compression forces than it is in taking lateral forces. So if you’re trying to make an arm out of it with some sort of weight attached, it’d be much more likely to break. At this point I think your best bet is to just try different materials and see what works. One thing that you might try is electrical conduit but it does tend to be rather heavy (it’s steel usually).

Matt

Posted by Joe Ross at 2/15/2001 11:24 PM EST

Engineer on team #330, Beach Bot, from Hope Chapel Academy and NASA/JPL , J&F Machine, and Raytheon.

In Reply to: Compacting the arms…
Posted by Dan Richards on 2/15/2001 8:14 PM EST:

: Hey. What’s the smallest diameter pipe or rod that will not bend (much) with 20 pounds on it? Anyone know? Also, I have a Victor that decided to short itself out and only go in reverse now. Anybody want it or know a use for it?

Was the victor connected improperly, or did it fail in normal use? If it failed in normal use, innovation first should replace it for you.