02-02-2014 14:21

BurkeHalderman

Re: pic: Team 48 Something or Other

Is that a rack and pinion I see? Looks real nice! Looking forward to checking this out in person.

02-02-2014 14:42

Cash4587

Re: pic: Team 48 Something or Other

Looks to me like this could be a motor powered linear shooter?

02-02-2014 17:08

Orion.DeYoe

Re: pic: Team 48 Something or Other

Very nice. We looked at a mechanism identical to this. I can't wait to see if the application is the same.

02-02-2014 18:19

Travis Hoffman

Re: pic: Team 48 Something or Other

It's in there somewhere.

Not exactly. A few key items are not present in this picture.

02-02-2014 21:09

mwmac

Re: pic: Team 48 Something or Other

Looks like the muzzle of a linear shooter, just missing the winch mechanism, a striker plate and some bungees...looking forward to seeing more..

02-02-2014 22:03

Travis Hoffman

Re: pic: Team 48 Something or Other

The winch mechanism will remain missing.

03-02-2014 01:42

Whippet

Re: pic: Team 48 Something or Other

Looks suspiciously like a high goal blocker to me.

03-02-2014 07:40

A_Reed

Re: pic: Team 48 Something or Other

High goal blockers don't require 100:1 gearing.

03-02-2014 10:01

Chris is me

Re: pic: Team 48 Something or Other

Here's a random, shot in the dark guess. Does the pinion gear have some teeth missing, by design?

Based on the short size of your linear punch (that whole assembly is ~14 inches long, right?), I'm guessing you're doing some kind of arm / claw shooter.

03-02-2014 10:32

Travis Hoffman

Re: pic: Team 48 Something or Other

Magic 8 Ball says, "Outlook Good".

03-02-2014 11:29

Chris is me

Re: pic: Team 48 Something or Other

I'm quite excited to see this. We have a lot of similarities in our robot design. I only wish we had thought to use a clever mechanism like this instead of a winch and shifter. Did you find OTS rack gears that didn't weigh a ton or did you make your own?

03-02-2014 14:25

Travis Hoffman

Re: pic: Team 48 Something or Other

All gears are steel and were purchased from AndyMark, including the 56-T pinion. We bought the 20 DP, 14.5* PA rack gear from McMaster (http://www.mcmaster.com/#6295K113). The total stroke of the unit is 6" (incl. 4" of ball contact), so the rack isn't that heavy.

Here is a test fire of the prototype at about 100 lbs. of tension. We are expecting to add some more tension for the final iteration:

http://www.youtube.com/watch?v=5r2GO3_s-9s

igus' Y.E.S. program (http://www.igus.com/wpck/4856) graciously supplied the 1" aluminum shaft we're using as the punch rod, as well as the open-top linear bearing pillow blocks (which conveniently let the 3/8" wide rack gear slide right through them, contributing to the compactness of the launcher design).

One of the benefits of this linear punch design over others is that there is zero drag on the action from the unwinding of a winch spool.

03-02-2014 14:37

eddie12390

Re: pic: Team 48 Something or Other

I can't wait to see this in person at the Greater Pittsburgh Regional. I can still remember your bot from 2012.