motor high gear/low gear switch...

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Posted by Anton Abaya at 1/29/2001 9:00 PM EST


Coach on team #419, Rambots, from UMass Boston / BC High and NONE AT THE MOMENT! .



we modified our motors according to Dr.J's advice...

and we also noticed that after running the motors, they would pop out of their low/high gear position and into neutral....

is this normal? what are the different ways to keep it in LOW or HIGH gear?

thanks all..

-anton

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Posted by PAUL GIANNOSA at 1/29/2001 9:43 PM EST


Engineer on team #27, TEAM RUSH, from OSMTECH and TEXTRON AUTOMOTIVE CO..


In Reply to: motor high gear/low gear switch...
Posted by Anton Abaya on 1/29/2001 9:00 PM EST:



:HI ANTON. WHAT WE DID LAST YR AND R DOING THIS YR, IS TO TURN A SPACER OUT OF NYLON ON THE LATHE AND PUT THE PLANETARY INTO HI(LAST YR) LOW(THIS YR) FROM INSIDE THE TRANS. WE NEVER HAD THE GEAR SET EVER POP OUT.

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Posted by Ken Leung at 1/29/2001 10:33 PM EST


Student on team #192, Gunn Robotics Team, from Henry M. Gunn Senior High School.


In Reply to: motor high gear/low gear switch...
Posted by Anton Abaya on 1/29/2001 9:00 PM EST:



What happens when you switch between high gear and low gear is you are choosing between two sets of planetary gears inside the gear box. Normally when switching gears on the hand drill, there is the plastic nob on top that you can push to go to high or low gear. Under that is a little metal strip that act as a lever, one end is being pushed by the nob and the other end it pushes a plastic ring with teeth inside that fit around the two planetary gear sets. So, to hold that plastic ring in place for either a high gear or low gear, you fabricate a similar ring without teehth inside(we used Aluminum last year), and that have to fit around the other planetary gear set you are not using, while it have enough thickness to prevent the plastic ring from engaging the planetary gear you don't want to use.

This method is extreemly reliabe, it worked really well for us lasty year, and we never had to worry about accidentally switching gear in the middle of the game.

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Posted by ChrisH at 1/30/2001 12:31 PM EST


Engineer on team #330, Beach 'Bots, from Hope Chapel Academy and NASA JPL, J & F Machine, Raytheon, et al.


In Reply to: motor high gear/low gear switch...
Posted by Anton Abaya on 1/29/2001 9:00 PM EST:



: is this normal? what are the different ways to keep it in LOW or HIGH gear?

Normal, but certainly not desireable. We have found that you just need to restrain the shift lever somehow. Some years we've just used a piece of wire to secure it in position. Last year we had a changable spacer that we just flipped from one side to the other but that was because we had a nice mount and we were going to try shifting, but never got there. Our gear ratio was pretty close to optimum anyway. But I'm not going to tell you what it was.

Chris Husmann, PE
Team 330 the Beach'Bots

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Posted by geoff at 1/31/2001 10:11 PM EST


Student on team #481 from de anza.


In Reply to: motor high gear/low gear switch...
Posted by Anton Abaya on 1/29/2001 9:00 PM EST:



I was just wondering how many of the teams out there are attempting to work a transmission into their robot this year?

-geoff

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Posted by Joe Johnson at 1/31/2001 10:34 PM EST


Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.


In Reply to: Re: motor high gear/low gear switch...
Posted by geoff on 1/31/2001 10:11 PM EST:



We are once again avoiding the shifting scene in 2001.

Again, I know a number of teams that use it to great
advantage, but, the stakes are too high for me to bet
at that table.

I only bet what I can afford to loose and the idea of
our robot running in rings or not running at all is too
scary for me to even think about.

Others have differing opinions...

Joe J.

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Posted by Andy Baker at 2/1/2001 8:57 AM EST


Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.


In Reply to: Re: motor high gear/low gear switch...
Posted by geoff on 1/31/2001 10:11 PM EST:



We'll be switching the arm from high to low on the drill motor gearbox, just like we did in '99 and '00.

We only had one match that we couldn't switch it over to high gear in '00 (out of about 50), so I'd say that it was a success.

From the input I'm getting from other teams that are using our '00 design, there are many others out there.

Andy B.