Hi! We are team 3946-E From Denver, Colorado. School: Kent Denver. 21-22 team members: Jack Hughes, Gavin Dhanda, Julian Dhanda, Landon Ellis, Henry Johnson, Ishan Tandon. Feel free to ask any questions about our robot!
Because our differential causes varied but usually slow conveyor speeds, we decided on the plexi circle hood design. The key was lining up the central axis of the tube that the hood created with the post of the mobile goal (so if the post was longer it’d stay right in the middle of the hood all the way through). Aside from that, we used two zip ties that are secured around a standoff inside the hood and then go out through the hood and are capped by a second ziptie head. That forced the rings to smoothly realign to drop straight onto the goal.
The piston we are triggering slides a set of two gears side to side to change the ratio between the motors and the drive wheels. One setting outputs 333rpm and the other 120rpm. We made it so that this bot could always win the tall goal but it was also 33 pounds and that ratio was causing burnout so after auton we kept it on low gear.
A shorter piston would also go a long way to help with air consumption and space requirements, the throw on that piston is far too long that what is necessary
Unfortunately vex only has two piston sizes, they are very similar in length and the other one uses twice the Air but yes, a pancake cylinder would be ideal
3 hours in cad and two hours to add to the real bot. We are rebuilding and yes, there will be transmission(s) on our worlds robot. However, our states robot didn’t have any.
And another issue (as E’s driver) is that because the motors burn so quickly from occasionally fighting each other, it was impractical for the lift to be manual, so we relied on lift presets, making adjustment in lift height impossible during match
In theory, yes, this is something we looked into but practical space and air consumption limitations along with the thing already being super heavy just added to the ultimate conclusion that it wasn’t worth it.
you need to grind the outer wall of the shifting gears round so that they can shift any time without getting stuck. Also, use double action piston and high strength gears, they use save you from lots of trouble
We ended up sanding not to worry, but the other two were impossible due to form factor/air consumption. You can see how complex that robot was in the pikes peak semifinals video. (We have since redesigned)
@@EKentDenverRobotics Well, if you wish to have a 6motor drive with high speed gear ratio and can carry 3goal +pushing the forth goal on the platform, these are probably the only way. And by the way, lots of the robots are now using 8~10 pistons, if you feel the gas consumption is too high, you probably should consider regulators and rubber bands
my team is also making a transmission so I was wondering what you meant by grinding the outer wheels round. Does that just mean sanding down the teeth so instead of going straight vertical they are rounded?
Yes, that is typically what is done in vex transmissions. The easiest way to do this is to put the gear on a shaft, put that in a drill, and rotate the gear against sandpaper or a file. Hold the abrasive item at a 45 degree angle to the gear around the top edge until it’s noticeably angled. Hope this helps!
Nope double parking isn't hard when you have little higher chasy. Look at matches of 5 or 6 sec double parks. Auto is the key but having claw is completely useless as you saw in match
