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Posted by Raul at 1/28/2001 8:47 PM EST


Engineer on team #111, Wildstang, from Rolling Meadows & Wheeling HS and Motorola.


In Reply to: Re: Still a trade secret...
Posted by Glenn M. Krcek on 1/27/2001 9:15 AM EST:



OK, The spec in the official document says the top speed of the drill system is 400 RPM in low gear. Various sources say it is between 300 and 400 RPM. Does anyone know the true no-load RPM?

FYI - In all the past years our robot has had a "measured" top speed of between 5 and 7 ft/sec depending on what was most important to us for each year. For example, last year it took us 8 seconds to get across the field; not very quick, but we never had a problem with overheating our drive motors.

Raul

: : I will say this, you don't give your wheel diameter,
: : but at 64 to 1 from the motor the output shafts in low
: : gear and another 3 to 1 on top of that, even with an 8
: : inch wheel you will not be setting any speed records
: : (unless of course you shift your transmissions which is
: : tricky but possible with good design and good
: : software). By the way, you will have something like
: : 150 lbs available per motorized wheel at this ratio and
: : the 8 inch wheel. You will have a difficult time
: : getting that much tractiion on the carpet (imho).

: Dear Dr. Joe,
: We've calc our approx top speed w/ the drill motors switched in the 64:1 position to be the following:
: 20000rpm /64=312.5 say 300 rpm
: 300 rpm / 3 = 100 rpm @ wheels
: 100 rpm x 8Pi (for 8"dia whls) = 2513"per min say 2500"
: 2500 / 12 = 208 ft/min approx
: I am wondering if we blew it somewhere? I am thinking we have sufficient speed. We are concerned if we'll have sufficient traction, but addressing that with a special wheel design.
: Thanks for the reply.
: GMk

: : Joe J.