675A Robot Reveal

Alright guys this is my first ever robot reveal. Let’s start off with some pictures:


The Drive Train:
4 - 393 motors (Speed)
2 - Integrated Encoder Modules
Direct drive (no chain or gears)

The Arm:
4 - 3-wire motors
Geared 7:1 (84:12)
Arm weighs roughly 2 lbs
Raises from ground to high goal in less than 3 seconds

The Feeders:
2 - 269 motors
Double Big Flaps every 6-7 links

Score in every goal
Pre-assigned buttons on controller for each goal height
Holds maximum of 4 objects

We have had this robot built since December and have NEVER lost a match with it. We have won every tournament we have went to, being first alliance captain.
Our robot CANNOT stay flipped. The way we designed our arm allows it to travel past vertical and tilt the robot back up, if it ever flips that is. During competition or skills challenges we have never flipped. It requires the arm being full of objects with the arm past vertical, going full speed backward, and then jamming the drive forward to get it to flip.
Our drive train isn’t the most powerful pusher, but we are fast as our robot only weighs 15 lbs and most of the wait is in the drivetrain. Driving our robot in a normal competition, we never stall.
Since our robot has been built since December, we have had several months to iron out the problems and have had tons of time to practice.
We hope to have at least 2 autonomous’s per starting tile for WORLD!!! At the previous competitions, with autonomous and driver control, we could clear out the isolation zone within the first 10 seconds of driver control, even though we prefer the interaction zone.

Please ask any question you want.

Looks like a near-peak tank tread robot. I have a few questions, as I believe that there are a few key disadvantages to the tank tread design.

-Can you score over the 20in wall in isolation?
-Can you descore?
-I see that you do not have a plate on the top. Do objects ever fall out?
-Looks like a quad-omni drive. Do you get pushed sideways much?
-Is your scoring on the 30in goals accurate or do you sometimes miss?
-Can you get objects in corners?
-Do you have to to much lining up with goals to score on them?

The motors are pretty much the same as in my robot except the design is completely different. All in all, since you have never lost a match, it must be very reliable. See you at worlds!:smiley:

Yes we can score over the 20 inch wall
Yes, not every time but yes
Nope the tanke tread holds it in pretty well
We are so fast that we don’t get pushed too much
Our motors are placed so that if our arm is up we just drive up to it and it locks us in
Yes, with a little difficulty though
We only really have trouble lining up with the low goals :slight_smile:

Another thing I forgot to mention about my robot is it’s consistency with autonomous. Our autonomous has worked every time except the time where the field was severely setup wrong.

if the field is setup wrong why didnt u ask the refs if it could be reset properly?

It was more of the black gate being shifted a little away from us but we only missed two objects so it wasn’t a big deal. We didn’t actually notice the gate being shifted when we started.

Do you have any videos of this robot picking up/scoring game objects?

Did you have any other designs before you went to this one? If so, what kind?

Looks like a simple, yet effective robot. Good luck at World’s.

No I don’t have any recent videos on me. I can post one though if you would like. Suprizingly this is the first design we came up with. We haven’t made any major modifications to this design. And good luck to you too.

Looks like a very clean build. I wish my local teams could build this cleanly.
Nice use of 60t gears as intermediates between 4 motor pinions.
Simple arm allows self-righting, very nice.
Central Cortex location, easy to access.
Why no elastic to help the arm?
No polycarbonate?
Outer drive rails are supported only by 4 hexbar standoffs?
What is your motor port assignment?
How much of this is aluminum?

Here are some brainstorms for your consideration:

  • use an encoder to check the RPM of your arm motors during max lift, if less than 50 rpm, then you aren’t getting max power out of them.
  • Consider adding elastic (somehow) to help lift the arm even faster.
  • The front motors seem vulnerable to hard knocks; consider shielding them or moving them. Possibly this could include a goal-engaging v, to help your planned additional autonomus routines.
  • The arm lift motors seem vulnerable to hard knocks, consider moving them to the inside of the tower instead. If you added one more 60t, you could move the tower motors lower for better CG as well.
  • Consider simplifying the tower inner support, and extending it all the way up to the shoulder, so the shoulder axle doesn’t have to be cantilevered. Also consider that some kind of triangular brace will let the tower be sturdier even if it were built more lightly.
  • Consider adding some additional frame to support the outer drive rails.

We are only using polycarbonate for our autonomous selector, which I don’t think counts. We don’t use any elastic because we found it was more trouble than it is worth. We are using all of the ports on our cortex: 1&2 and 9&10: drive; 3-6: arm motors; 7&8: feeders. This allows a pretty spread out load on the breakers. the whole arm is aluminium as well as the horizontal braces for our drive train. Everything else is steel. The front motors have standoffs in front of them to prevent them from getting hit. We have planned to add some metal c-channel on top of them. The standoffs for the drive train have never given us problems and the spacing between the 2 is not in 1/2" increments.

Looks good, can’t wait to see it at worlds (as well as the 675D team).

One question, what is it that your autonomous does exactly? Also, do you have multiple autonomous modes?

Actually all of our robotics teams made it to world (A-E)! Our autonomous basically just scores as much as it can in as many goals as it can (not going to give specifics)

Sounds very impressive!

Also, where do you believe is the best place for this tank tread intake robot? (Isolation vs Interaction)

We like the interaction zone but we do good in the isolation. I think it really is all driver preference, unless your strategy depends on it (wall-bot).

Can you score in the opponent’s 20" isolation goal from your isolation zone? From what I’ve seen robots that follow the design you’re using usually can’t. In a high-level competition like what worlds will be it’s pretty much essential if you want to be able to play isolation effectively.

If you can, I’d be interested to hear how you managed it. The workaround that 2915c (Lynfield) came up with - and that we copied on an early season robot - is this:

Edit: I’m told that TooMuchStrategy from AURA actually came up with this and gave the idea to 2915c who built it. We built it ourselves later.

Can your conveyor belt effectively intake barrels when they are on their sides? That seems to be a major problem for conveyor bots this year.

Yes we can.

Yes it can, we use double (back to back) flaps that stiffens the flaps up and allows us to easily pick them up.

Hey team 1138B has a design just like your robot. We designed it with a short base, to score 30in interaction while being in the isolation zone. We can also score opp 20in. Anyway, nice design, hope to see you at worlds, and good luck.

Very nice robot!! I had one question though…

When your robot is at it’s (almost) max capacity, (say 2 objects can still fit in) is there ever a problem with your robot’s intake freezing while constantly intaking the other 2?

Sorry for taking a while to respond. Our robot only freezes if there is a barrel jammed in the back in just the right way.