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Unread 17-10-2004, 22:05
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JVN JVN is offline
@JohnVNeun
AKA: John Vielkind-Neun
FRC #0148 (Robowranglers)
Team Role: Engineer
 
Join Date: May 2001
Rookie Year: 2000
Location: Greenville, Tx
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Re: Is a shifting transmission really necessary?

Quote:
Originally Posted by Jay TenBrink
John,

We design for a higher max current draw. With the addition of the little blue battery this year it is possible to increase the max current draw of the drive system without putting the controller to sleep if you momentarily drop under 8 volts.

Our efficiency is such that we can achieve 10 ft/sec. max speed (which is all we feel we need) and we are also able to break all four knobby pneumatic tires loose at the low end.

In 2003 we had a 4 motor system with a robot weighing 115#. This year we weighed 130# and had a 6 motor drive.

You are extremely correct: It is important to get there fast. Once you are there, you want to be able to stand your ground. We have been able to accomplish both with a one speed gearbox.

Thanks for the comments all,

Jay
Note: much of the theory here, and the debates between 4 motor vs 6 motor vs shifting were discussed in depth last year in this thread: http://www.chiefdelphi.com/forums/sh...ad.php?t=22604


Jay,
Would you be willing to share more details about your gearbox?
Ratios and such?

Based on experience running these numbers, I know how the power output from a 6-motor drive would be enough to slip wheels at 10 fps. (As I discussed in my initial post.)

This is really the "other" option.
Again, it's all about tradeoffs -- either you build a shifter, or you add more power (more motors). 494 has taken the Tim Allen approach, and it has suited them well.




I'm just curious about where exactly you're loading your motors.
Obviously, I know how well it works (I've seen you in action several times now).

How far can you really push the envelope?

Probably further, than I am willing.
Perhaps my reluctance to toe the line is hurting me, I know I've been accused of this before.

I'm never averse to taking pointers from a national champ,
John
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