Slick as always. Just curious, how does the hatch mech work? I see there’s a velcro roller for a ground pickup, but there must be something else I’m missing. Either way, excited to see it in person this weekend!
It is tucked away by a cylinder in the photo, but here is a photo of it in action. It extends out over the bumper when we are handling hatches.
The limit switches detect contact with the hatch. The switches are placed to close the circuit only when the grabber is through the hatch. As soon as the switches close, the cylinder triggers grabbing the hatch and notify the driver it has grabbed the panel via Driver1 controller vibration and blinking LED strip located onboard the robot. The whole mechanism also has about 15 degrees of angle adjustment be able to grab and place even when slightly misaligned
Chains and belts are functionally equivalent when they are both properly tensioned. Each have their own pros and cons such as weight and so on, but your robot will not faster or more accurate just by switching between chain and belt or vice versa.
Honestly the reason we use chain is we have more experience and are more comfortable with them. We used versa blocks from vex to keep them tensioned and are happy because they are something we never have to worry about. We do not have the machining capabilities to accurately make C-C distances for belt and feel that if a versablock cam loosens a little, it’s just that a loose chain that we can quickly tighten during post-match checks. An equally loose versablock with belt can lead to a skipping belt and poor match performance. There are plenty of ways to mitigate this but at the end of the day we mainly choose chain because of more experience with it.
As for cad, we have a 6 student dedicated cad team, led by a remote mentor. Other build students jump in and cad items when necessary as well. We use Inventor for almost everything. Sometimes a part will be made in solidworks. We might be switching over to solidworks soon though.
We used the same style for our drive as we did last year since it was another elevator game and we liked the stability we got from it last year when the elevator was up.
We start with a 8wd with an 1/8" center drop on the two center wheels (the colsons) using versablocks. We then take the 2nd wheel from the front (the first colson) and shave it on a lathe to bring the first 3 wheels level with each other. The back colson becomes the only wheel raised, by an 1/8".
The short base length between the 3 wheels combined with the front wheel being an omni keeps turning scrub down but increases the length of contact with the ground from what a standard 6wd would give us. That way when the elevator is up and the base is moving, we are not teetering between the front and back wheels giving us some extra stability
We were not completely happy with the software side of the neo’s, but thought their power was valuable so we chose to run 2 neo’s/1 mini per gearbox. This allowed us to run our grayhill encoders directly to the SRX for the minicim on each side and then set the neo’s to follow that mini-cim. It was just easier and more familiar for our programmers. This allowed them to create the full auto’s that you see during the sandstorm period.
You are correct, we are using a nav-X, grayhill encoders on the drive, and the limelight for the auto this year.
your robot looks great this year. We had a great qual match together!
Thank you, we are barely making the short trip to HVR work right now but you never know!
2791’s robot looks amazing and it would a sight to see our drivers zipping around together. Good luck at championships!
Thank you for partnering with us (870) at SBPLI#2!!!
The Finals were EPIC!!
Too close for comfort on the scores.
Best of luck at NYC! We are hoping to see another Blue Banner from you there.
Hope to see you in Detroit.
The hatch panel slides are attached to a 6" stroke 3/4" bore cylinder. The whole mechanism is attached to a 7" stroke 3/4" bore cylinder that extends it out over the bumper when retrieving and delivering hatches.
Thanks for the wishes, you guys have an incredible robot and it’s always fun to play together. We will certainly stop by in Detroit