Author Topic: my build diarys (Read 118321 times)

NFX · « **Reply #440 on:** September 13, 2011, 03:58:51 PM »

Ah, I remember something about bigger wheels having the effect of gearing the motors up on Top Gear once. So smaller wheels are good for high-speed motors because it gives them less stress. See, I'm learning stuff.

MikeNCR · « **Reply #441 on:** September 13, 2011, 04:12:29 PM »

Wheels in a way act like an additional stage of gearing

For example, a 3" wheel will roll 9.42" per revolution, as the circumference is pi*diameter, in addition the wheel functions as a 1.5" lever arm(radius of the circle)

Say you've got a 1000rpm gearbox with 90in-lbs of torque attached to this wheel, that means in 1 second the robot will travel 157 inches, or 13.08 ft. In addition the force the motor can exert at the wheel will be 60lbs, as the effective lever arm results in a reduction of force (90 / 1.5 = 60)

Perhaps you want to go faster, so you shove a 6" wheel on, this will result in a top speed of 26.16ft/second but due to the greater lever arm, you'll only have 30lbs of force on the ground. For every doubling of diameter, you double speed and halve the force, meaning you may get to a higher top speed, but you'll take a lot longer to get there.

haz · « **Reply #442 on:** September 16, 2011, 12:21:40 PM »

who wants me to smash stuff with it??

powerrave · « **Reply #443 on:** September 16, 2011, 12:50:15 PM »

I dare you to destroy something!

haz · « **Reply #444 on:** September 16, 2011, 01:23:42 PM »

will do, it puts nice holes in coke cans

GoldenFox93 · « **Reply #445 on:** September 16, 2011, 01:25:52 PM »

Quote from: haz on September 16, 2011, 01:23:42 PM

will do, it puts nice holes in coke cans

Ah, but is there anything in Robo Challenge that's armoured in thin aluminium? =P

haz · « **Reply #446 on:** September 16, 2011, 01:26:56 PM »

why would i fight it at robo chalange??

powerrave · « **Reply #447 on:** September 16, 2011, 01:32:55 PM »

Because you can.

haz · « **Reply #448 on:** September 16, 2011, 01:33:35 PM »

they dont have an arena for it there though

powerrave · « **Reply #449 on:** September 16, 2011, 01:37:18 PM »

Oh.. that might be a problem.

haz · « **Reply #450 on:** September 16, 2011, 01:38:03 PM »

yeah, will fight it next weekend though

GoldenFox93 · « **Reply #451 on:** September 16, 2011, 01:41:08 PM »

Quote from: haz on September 16, 2011, 01:26:56 PM

why would i fight it at robo chalange??

Ah, right. Thought they were the only UK Tournaments which allowed FW spinners.

haz · « **Reply #452 on:** September 16, 2011, 01:42:09 PM »

yeah, i dont own a fw spinner though

SKBT · « **Reply #453 on:** September 16, 2011, 06:38:21 PM »

Is that an ICBM powered or did you go with a brushed motor?

haz · « **Reply #454 on:** September 17, 2011, 03:06:03 AM »

its a brushless outrunner

haz · « **Reply #455 on:** September 17, 2011, 06:20:34 AM »

Tweedy · « **Reply #456 on:** September 17, 2011, 06:27:08 AM »

Are you allowed spinners in roaming robots then ?

haz · « **Reply #457 on:** September 17, 2011, 06:29:03 AM »

no cos there is no polycarbonate shell for them, ants are really a side show for the breaks. this is a competiton antweight.

Somebody · « **Reply #458 on:** September 17, 2011, 09:14:51 AM »

It has a ruler for a weapon?

NAME IT WELL CALCULATED DEATH

smashysmashy · « **Reply #459 on:** September 17, 2011, 12:04:47 PM »

Quote from: Somebody on September 17, 2011, 09:14:51 AM

It has a ruler for a weapon?

NAME IT WELL CALCULATED DEATH

I was thinking along those lines :L