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Unread 01-01-2004, 19:45
Unsung FIRST Hero
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: Picking Out Roller Chain

Quote:
Originally Posted by Raul
You can be extra safe or you can be competative - its your choice.
Okay Raul... now I'll bite...
I agree with EVERYTHING you said, except this above statement.

In my experience (not nearly as extensive as yours ) in this competition "extra safe" IS competative. To argue that the choice is limited to one or the other seems dangerous.

I would urge everyone in this competition, especially rookies to "play it safe" and not to walk on the razor's edge when designing their robot. It's the same as with drivetrain speeds... "Sure, you might want to be an extra foot/sec faster but what good is it going to do you when (the planets misallign and) you pop your breaker?"

Sure, 1/4" chain weighs less, but the phrase is "better safe than sorry". I would advise most teams to "spend the weight where it matters".
You can have the most elegant mechanism in the world, but it's no good when your drive is dead, and it's doing semi-circles across the field. I've seen this happen to the BEST of teams, and I'll tell ya... probably 80% of the time it's a #25 chain which blew off it's sprocket.

It's not usually a loading issue, so much as a misallignment issue. As mentioned above, #35 is MUCH (MUCH!) more forgiving when it comes to allignment.

So yes... I agree with Raul...
Analyze everything, have numbers to back up all your decisions, and don't just "Take someone's word on it".

But... also ask yourself if one extra factor of safety would be in your best interest...

Safer IS better.

John

PS - Raul, if you haven't had any #25 problems... then all I have to say is: "I sure wish I could build em like Stang does!" (I guess I say that anyways... such beautiful robots...)
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In the interest of full disclosure: I work for VEX Robotics a subsidiary of Innovation First International (IFI) Crown Supplier & Proud Supporter of FIRST