pic: FRC 4329 Presents Trogdor

The Lutheran Roboteers, FRC 4329, are proud to present our 2016 FIRST Stronghold robot - Trogdor.

Some info -

  • Single speed 4 CIM drive using WCP SS gearboxes
  • 2 775 Pro’s powering a 1:1 flywheel shooter using 4" Andymark wheels
  • 1 775 Pro powering a 10:1 multi-directional polycord intake system
  • Intake is actuated via a single pneumatic on the pivot
  • 2 floor firing actuators secure the robot for batter parking and to lift the robot up slightly while taking our shot from the batter.

What’s the brake caliper for ?

Probably used to hold their intake a different angles. Strait up to be inside perimeter at start of game, let it angle down so can go under portcullis and push down on the teeter totters

Our original intake pivot used a versaplanetary gearbox to rotate. The idea was that the disc brake would help secure the Intake and hold at a desired position without the need for elastic or stalling the motor. We killed a couple of gearboxes on various defenses and decided to find a way to use pneumatics instead.

We are now looking at 3 position cylinders or to still use the disc brake to halt the motion of the cylinder depending on which position we want via an encoder. The plan is to have a retracted position, intake position and portcullis / chivel de frise position.

All of this happened in the last 4 days so we just left it on for now :slight_smile:

Here’s a link to a few more images -



Looks really nice!

Are you planning to go under the portcullis? The intake looks like it is designed to, but the RoboRIO suggests otherwise.

I dig the yellow chords. Are those the ones you connect with the inserts or did you melt them together?

Very nice, looks sharp! What are your collector rollers made of? The clear plastic is pretty cool to see through, especially spotting the center bearing in the front roller. I also like how the centering belts are slaved off of the intake belts.

Also, what motor/gear combo did you have on collector lift that was giving you issues?

We actually have a very similar collector (and hope to add a similar shooter later with carry-in allowance, but prioritized climbing over shooting). Our collector uses 3 separate motors though, centering, intake, and rotate up/down. Our rotate is powered by a bag CIM geared 500:1, no brake mechanism (100:1 VersaPlanetary, then VP spur gears 14:70) So far no major issues, and only one smoked motor - from stalling against a hard-stop before limits and closed-loop control were added.

Yes we are - we need to still build the superstructure that will keep the portcullis gate above that height. We’re also going to add some protection for that top layer of the controls.

Yep they are hollow and we’re using the metal insert barbs. Only a few failures so far as we learn how to link them together better.

They are made from 1.25 OD polycarbonate, 1/16" thickness. Interfaces perfectly with 1.1.25" bearings.

We tried a MiniCIM into a 1:100 versaplanetary that was built using various stages (2 and 3). The issue wasn’t really the gearbox’s power, it was the way we were face mounting it using one of the versa gussets. It’s generally not a great idea to have your gearbox taking lots of shock loads as you ramp the intake into the various defenses that we’re planning on using it on. We want things to be extremely robust for this game so we made a decision to use pneumatics on the pivot and haven’t looked back.

Trogdor! What a great name for a robot! Why didn’t I think of that? Interesting design, too! What size are those drive wheels?

Take two cylinders of the same stroke that equal the stroke you currently have and mount them opposite each other, you now have a 3 position cylinder. If they are two diffrent strokes that equal the orginal stroke you have 4 positions. We switched our motor driven intake/shooter to a system like this and its is magic.

PM me if you want more info/pictures

All thanks go to Brian from 2791 for introducing this to me

Trogdor! The Burninator! Looks like you’ll be ready to fight back against that 10th Defense.

Thanks! I had to educate most of our students because they had no idea who Trogdor the Burninator was. I feel old.

We’re using the black versions of the 200 x 50 mm tires from this website: 8-10428 - 200 x 50 Knobby Tread Tire. | Lawn Mower Parts | MFG Supply They’re the same as the gray Andymark ones.

Thanks for the tip! I’ll shoot you a message for more info.

Fire game confirmed! Don’t forget to kick the player station wall if something doesn’t go the way you wanted it to. :smiley:

P.S. The think about kicking the player station wall was a joke. Don’t actually do that. Especially if you’re at the middle station.

Really really digging the disk brake, I never got to see that update on facebook!

Turned out awesome Ryan! How often are you guys expecting to run practice sessions with the second bot?

We’ll spend this Saturday getting the practice robot matching the bagged competition robot. It shouldn’t take much since we can put the competition intake & shooter on our practice robot since it all fit under 30 lbs for withholding -


Once we have that completed, we should have 2 weeks of drive team practice & autonomous development for St. Louis.

With all of the cool reveal videos FUN showed tonight, we wanted to post a quick teaser of Trogdor shooting: https://youtu.be/U78u0kuxJ-A

A more full length video will get filmed this weekend using our practice robot. Looking forward to seeing everyone at the St. Louis regional!

So a big thanks to Brent & 1493 here. With his advice we were able to get our 3 intake positions by using 2 large actuators and one small helper actuator. You can see our initial test here: https://youtu.be/1D2Iy8q8ayA We need a slightly longer actuator to bring it back up to full vertical but other than that we’re very happy with it.

Looks familiar :).

If we’ve made anything that looks similar to Wildstang then we must be doing something right :] See you guys week 5 in Chicago!

We did the same thing for our intake this year. We used a 6" and 4" cylinder mounted together to end up with a four position cylinder with 10" of stroke that when both are retracted is no longer than a 6". We retract the 6" to extend the intake to shoot and retract both the 4" and 6" to fully extend for pickup. You can see them in action in our reveal video.

Edit: should have read the second page. Looks good!