pic: FRC 422: The Mech Tech Dragons 2018

Presenting our 19th competition season robot, “Axiom”

Hope to get more photos and videos of it and its twin Clyde this week during practice. They will be on our

Facebook: http://facebook.com/frc422
Twitter: http://twitter.com/frc422
YouTube: http://youtube.com/mechtechdragons

We are competing at

CHS District Northern Virginia Event March 2-4
CHS District Hampton Roads Event March 16-18

with the hopes of qualifying into the CHS District Championship and the Detroit Postseason Event.

We’re excited as heck and ready to play FIRST Power Up! Thanks to the sponsors and families of our team that helped make this one of our best build seasons ever.

1 Like


1 Like

Lets go #teamhandoff!!!

Looks great, can’t wait to see it compete this weekend.

while there are plenty of fun features on this machine, a favorite are the two air tanks with 2 clamps securing them. Sure, we would like to have more air tanks but we only had enough clamps to pass inspection with 2.

1 Like

What’s the blue stuff on the inner bolts on your intake?

And what is the grey rope around the intake motor for?

1 Like

At this point, I kinda want to just put the clamps on it and then zip tie the clamps down rather than using bolts…

It’s actually kelly green! It’s a vinyl liquid covering the nuts.
The rope functions as a hard stop to guide the intake into the proper orientation depending on the angle of approach for the cube. Deliver a beautiful intake, worked on tirelessly through 3 hard iterations and hundreds of iterations in Fusion 360, just to test it and find out it works better with some rope dangling on it…

1 Like

If it doesn’t perform better with random rope or zipties, it isn’t real. We find this be the case with far to many things we make too.

Using it as loctite without the tendency to eat polycarb, or is it to cover all nuts and bolt ends to protect the cube covers and belts?

Is it just to protect the belt from potentially hitting a nut or bolt?

Are you all using a sensor or current monitoring to see when you have a cube and automate the handoff?

How do the bumper attachments work?

1 Like

We don’t want to eat anything, and there were some adjustments between some revisions where this was a concern.

1 Like

There is a beam break sensor in the gap on the front that helps detect:
-cube in the intake zone to initiate the auto snap
-collision detection on the fence for a center split auto
-collision detection in any cross field autos to freeze the routine if we see something we shouldn’t (namely an alliance partner)

It was designed for #1 but eventually 2 and 3 turned out to be useful features when we took the sensor off the intake and put it on the drive base

Current monitoring shuts off the sides independently to center the cube before it retracts itself into the robot. At least, it’s supposed to. That will probably be part of some tuning on Saturday while the drivers have manual backups.

Bumpers are 2 C-styles with 3 mount points. 2 on the long side, 1 on the back, 0 on the front (no room!). Attachments are thumbscrews with rivnuts. Takes about 50 seconds to swap a set.

1 Like

That’s pretty cool! How far out can it detect stuff / will you be able to actually stop fast enough if you see an alliance member?

1 Like

I like the fact you guys are using an IR sensor to detect cube intake, whether or not you secured the cube or not. We are using the same sensors, along with limits on the elevator for different stages.

I can’t remember what we have it set for the measurement. It has a screw on the back to dial in the distance. We don’t have any auto modes yet that move so fast the detection would cause an issue, but that is something we will have to look out for.

1 Like

Love the bot, great job Wil and team! Can’t wait to see y’all compete. Do you have any closer up photos of the elevator carriage and cube carrying mechanism? They look really interesting but blend in with the rest of the robot.

I will try to get more photos and video in drive practice tomorrow, but my favorite features the students developed over the season revolve around how slick the handoff operation is. We (I) love 118’s 2011 robot and thought this would be an even better game to commit to a handoff operation.

For the carriage, the whole assembly weighs, I think, around 4 pounds. The plate is some old FR4/10 Garolite cut to fit in between two spacers that sit on the intake that give us a 3/4" by 10 inch gap in which the plate wedges itself under the cube when the intake clocks up. As it clocks up, the finger engages and pulls the cube down onto the plate and into the face of the carriage. While in transit, the cube has 6 points of contact plus the carriage plate and face. After numerous embarrassing instances with gear manipulation last year, “touch it, own it” was priority #4 after driving, driving, and driving.

To score on the scale, the finger has a neat trick that is hard to see unless you’re up close. It’s actually part of an arm. When the finger retracts, it rotates the arm around an elbow and delivers a sharp kick to the bottom half of the cube. It usually allows us to deposit the cube in a 13" tall configuration. While advantageous, it’s incidental to the design and therefore inconsistent.

Some bonus content we were able to pull off includes the following description: The carriage has a hard stop that puts it above its total available travel, allowing the plate to sit at 20". This height was chosen because we wanted the intake to be able to score in the exchange and the switch without the elevator, and the elevator able to score in the scale and the switch without the intake. We’re able to take cubes directly out of the portal without them touching the ground. Not necessarily sure of the tactical necessity of it, but it was something that got baked into the overall design without any compromises and is a neat thing to talk to judges about. A side effect of the carriage getting stopped higher than its potential minimum is that it gave us enough space to tuck in a camera about 5-6 inches under the carriage plate. The camera gives us any visual data we could want, from seeing a cube in front of the robot, secured in the intake, the intake cocked up and locked on the handoff, and when raised, how we can position the cube on the scale plate.

1 Like