Chief Delphi - 2012 FRC Team 1717 Uncut

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Re: 2012 FRC Team 1717 Uncut

Quote:

Originally Posted by 42! (Post 1178781)

Thanks for the answer. It really sheds some light on the design of the module. On another gear question, Does your team manufacture their own bevel gears? Or do you source them from someone else?

I believe in 2011, 1717 used MC #6529K14. They of course finished the bore (hex) and cut down the face width to their needs. Not sure about this year or other years, though. They may have used something different.

Re: 2012 FRC Team 1717 Uncut

Quote:

Originally Posted by David Brinza (Post 1178414)

I read in the "1717 Uncut" CD thread that a couple of thousand hours were invested in this design.

Quote:

Originally Posted by IanW (Post 1178441)

I'm confused how ten people could even spend 2000 hours working on a model during the build season and still have time to actually fabricate it, let alone design the rest of the robot. I mean, with school, homework, sleep, and my team's build space not being open, I wasn't even able to put in 200 hours over the course of the entire build season, and that includes time spent CADding at home.

Quote:

Originally Posted by SuperNerd256 (Post 1178447)

I think the "2000 hours" is collectively over the course of the 4 year time period in which they started using swerve. It could be in one build season, but like you said it would be tough.

The wheel module design this year was completely new. The new motor allowance for this year allowed us to build independent swerve drive without sacrificing power for other mechanisms. We designed the module during this build season as rookie seniors. It took about 2000 man hours to both design and fabricate 10 wheel modules (4 for the official robot, 4 for the practice robot, and 2 spares). The fabrication process of the modules was quite time-consuming and tedious.

On average, we seniors put in about 500 hours during the robotics season. Some of us, including the programmers and drivers, exceeded 750 hours during the robotics season. We are able to dedicate this much time to robotics because we are in our second semester with a light course load. Also, we only get one opportunity to do this awesome competition so we are extremely excited and dedicated to building our robot!

Re: 2012 FRC Team 1717 Uncut

Quote:

Originally Posted by Gdeaver (Post 1178440)

I notice the wheel position sensor is not in the pictures. What sensor did you use.

Quote:

Originally Posted by Akash Rastogi (Post 1178445)

Do you mean a sensor for the rotation of the module? I believe it is pictured in the black bracket in this picture

Quote:

Originally Posted by Gdeaver (Post 1178449)

Looks like the sensor mount and a coupling but, what sensor was used. It does not appear that the timing belt pulleys are 1:1 so I'm guessing a quadrature encoder?

For turning, we keep track of our absolute position using a US Digital M4A. The sensor is setup 1:1 with the absolute wheel position. You can see the bent sheet metal bracket in Wheel Module Picture 3 to the front left.

For the drive, we are using an optical encoder that is attached to a small aluminum shaft. This shaft is directly coupled to the CIM motor and therefore one-to-one with the speed of the CIM. It keeps track of wheel rotations. You can see the flat mounting plate in Wheel Module Picture 4 right next to my thumb.

Re: 2012 FRC Team 1717 Uncut

Sorry about resurrecting an old thread (albeit an awesome thread), but I've been thinking about the accuracy of this shooter for the past week. Aside from the crosshairs and software put into shooting, what mechanical advantages did it have? Like what mechanically did they do to their shooter along with the code to make it so darn accurate?

Re: 2012 FRC Team 1717 Uncut

Jake, (or anyone else for that matter)
I have a question about swerve drive... is it common to allow some degree of freedom of being able to align the wheels perfectly straight if you want to go straight? It seems like if you tighten your grip too much you may run into oscillation. Assuming there is some tolerance what would be a good metric for this (I think I remember reading 2 or 3 degrees somewhere elsewhere in the forum).

Re: 2012 FRC Team 1717 Uncut

Quote:

Originally Posted by Mark Sheridan

Hello Jake,
I was wondering where you got your pulley's from? How did you mount the pulley that turns the swerve module? From pictures is looks like a clamping style pulley.

cheers,
Mark Sheridan
3309 mentor

The pulleys are made from pulley stock purchased from Stock Drive. The clamp is a custom machined part that clamps onto a specially designed custom cut pulley that originally came from a length of pulley stock.

Sorry for the late responses. Thanks for all of your interest in our robot!