On 19 Dec 2004 18:25:28 -0800, "AJ Quick" vaguely
proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email
I will "digest" what has been said here, and add one idea.
The one idea: quench and tempered steel. You will need to get this cut
from sheet, probably. Best with laser. This stuff makes spring steel
look like cookie dough! G. Its yield strength is enormous. The 350
Bn hard stuff has a "0.2% proof stress" (which I have been told is
equivalent to Yield) of around 1100-1200 MPa. 500 is even higher.
Definition Proof Stress: The stress that will cause a specified
small, permanent extension of a tensile test piece. Commonly the
stress to produce 0.2% extension is quoted in N/mm2 for steel. This
value approximates to the yield stress in materials not exhibiting a
definite yield point.
They are just machinable, and are weldable, with lots of care. they
can be bent. They must not be heated beyond very set levels, because
they are already fully treated.
Then George mentioned pivoting. The force on _your_ bot (pun intended)
will be enormous if another bot stops that bar, even if you slice into
it a few inches. The drive shaft and gearing will need to be some
serious stuff, or you need a good clutch. Try a rotating pan, with
pivoting blades a la slashers and rotary mowers. The boits I have seen
with rotary cutters had multiple teeth to have a similar effect.
Ernie mentioned hardened tips on strong bar. I again suggest the
350-500 hardness grades of QnT alloys. Tips should then be chosen for
hardness and extreme impact. From my (limited and often theoretical)
experience, this places the stuff you need into about the 600 650 Bn
range at max, or it starts to shatter too easily above
that.........ah! I see on
http://www.matchrockets.com/teamstupid/materials.html
that they recommend S7 treated to 55 Rc. Roughly the same. Perhaps I
was a little high, and getting toward brittle.
Hey,
I'm working on a design for a Battlebot for their 2005 competition in
Orlando Florida. I am working on a design that I feel will fair
extremely well against any others. Currently, I am looking at a
material to use for the weapon. My design calls for a flat bar, about
36-40" long x 3" wide x .5" thick.
What would be the best material to use? Keep in mind that this will be
a spinner, spinning at 3000rpm, putting a fair amount of kinetic energy
into the other bot.
Hardened S7 Toolsteel fare well against bending or breaking?
Could the peice be bent at a 45 degree angle a few inches from the
ends? Without them breaking off, or bending the whole thing.
Does anyone know of any shops that will sponsor a weapon of those
dimensions, with a huge strength and hardness?
Oh, and this bot isn't a pipe dream. ;-) We've got over $7000 invested
into it. But we still need more money! If anyone wants to donate,
Paypal
Please let me know!
AJ Quick
http://www.HHSRobotics.com/