|Home > Robots > HAZARD > April/May|
|Paramount to this design was the use of some type of mechanical clutch to avoid a destructive shock in the mechanics when the blade hit. I was pretty certain a friction clutch would be the key and it was former teammate Mike Bell that suggested I use some phenolic washers for the clutch material.|
Boker's, a huge washer manufacturer, wanted $300 to tool up to pop ten of these out for me.
|So I turned for help to the people in rec.crafts.metalworking on USENET. One machinist suggested I just buy a sheet of the material and two hole saws. The trick lie in cleverly mounting the two saws on the same arbor to force them to cut out a concentric washer.|
Bingo, $30 for ten washers and I was in business.
|This worked really well though getting the preload on the washer for proper friction was through trial and error.|
|The arena killsaws were a big worry to us so we used some REALLY hard sheet steel to line the bottom of the robot. This stuff practically exploded out of the box when I opened it as it as coiled so tightly.|
It took about six hours of work to get it all drilled and mounted - I think we went through about 32 drill bits in the process.
|Ah, a beautiful Sunday evening behind Netaphor Software, the Orange County mecca of robot weapon testing. Lots of solid cement walls to restrain shapnel and deserted.
Tony and I get to work, unloading HAZARD from the truck. Time to see if all our chormoly, heat treating and compliance measures hold up to some real targets.
|Today's test subjects will be: an old wood 2x4, a 30 lb. shopping cart (chopping cart?) and some solid 4x4 posts.|
|In his additional role as driver, Tony will have final say in what it hits and when. I however hold my finger on the E-Stop button in case I detect a mechanical failure.|
Our mascot six pack eagerly wishes to join in the festivities as well.
|HAZARD is charged and ready to rock.
I added marking tape to the edges so we could see the interdiction radius when it was spinning. Safety first.
|After the first test, the robot tried to rip itself apart. One half of the Lexan top came flying off and the other half was twanged as well. So we tried to duct tape it all together in the remaining minutes of daylight for a few more tests.|
Here is were we started thinking that HAZARD was going to be it's own worst enemy in the arena.
|The resulting wreckage yard. Much of the mess was caused by a old Commodore 64 computer monitor that tasted the blade. I was driving and though I briefly saw the explosion of glass coming at me, I do remember feeling the pieces rolling by my sandled shoes like a breaking wave on a seashore.
It took us almost an hour to clean it all up.
|This is what happens when the target can't move out of the way fast enough. And the exit wound on the back is a LOT larger.|
One of the first blade tests
6.5 megs, 25 seconds
Commodore 64 monitor
6.4 megs, 24 seconds
One of the last blade tests
5.7 megs, 22 seconds