We are a team of two attending Collingwood School in Vancouver, Canada. You might know us better by the name of “Collingwood Cogs”, but we prefer “B.I.S.C.U.I.T. Robotics”.
We have decided to completely rebuild our robot, so, we thought somebody, somewhere could benefit from an in-depth view at our robot. Here we go!
*Please keep in mind that since the above photos were taken we have made several tweaks to the robot. However, the main features all stay the same.
I have also uploaded my design notebook. This is not an up-to-date version. I got swamped with school work in the middle of the term and had no time to update the notebook.
Finally I have made an Imgur album of all the photos I took during the build. Feel free to take look through them.
That’s all. I hope you took something from this reveal! If you have any question, please fire away.
If you want to see a time lapse of part of our 2.0 build you can see it here.
Just wondering… is your robot able to cross the bump?
Also, why only one drive encoder?
Yeah, it crosses the bump very easily. It could cross the bump backwards without the chain, but not forwards. The chain was added to help it cross the bump forwards. It sorta keeps up the momentum while there are no wheels touching the bump.
I didn’t really see any changes from using an encoder on each side. It was just as accurate driving and turning with only one encoder.
Hmm, interesting intake. It’s good to see something different.
What does BISCUIT stand for?
Haha, I was waiting for that question…but, I won’t be answering it. Sorry…maybe somebody will be able to guess
Buckyball-Intaking Super Cool Unbelievably Ingenious… Tobor?
Buckyball-Intaking Super Cool Unbelievably Ingenious… Tank*
Ahah! This site was able to decode it! http://www.acronym-maker.com/generate/?w=BISCUIT&wl=
Your robot looks very solid. Looking at your Imgur album, I have a few things I would suggest to fine tune your robot, although by all means, if any of these suggested chances aren’t possible to make, your robot will be just fine without them.
~ I notice a few places where you seem to be using 1x25 strips for structural stability. These strips, as I’m sure you know, bend very easily. You would be much better off using pieces of C-channel and standoffs in places such as
~ Just at a quick glance at , I like how you have that C-channel crossbar in the middle of your robot, where your Cortex is mounted. However, I know from experience with the exact same setup this year that if you replace that C-channel with one that spans the entire width of the robot, the entire bot will be much more rigid and you won’t have to worry about the inner bars of your drivetrain caving in due to the weight on them.
~ I see a few places where you have a long axle spanning any particular part of your robot with little support across it ( and in particular). Without some sort of support closer to where on those axles the load will be most heavy, it will twist and eventually break. An easy fix for this is to mount the pillow bearings closer to the conveyor belt and cut the excess metal off the axle.
~ Keps nuts tend to fall off rather easily. I try my best to only use them for prototyping, then switch to Nylock nuts when I finalize my design.
~ Without some sort of support in front of your lift towers ( ) securing them to the drivetrain, the towers are going to shake and loosen whenever your lift arms move. I recommend either triangles connecting the towers to the drivetrain ( ) or an L-bar mounted directly above your wheels on standoffs that is then bolted directly to the lift towers ( ). As a rule of thumb, strive for as many points of contact as possible.
~ What advantage do the zip ties on the conveyor belt have? (Not a suggestion, but a question nonetheless)
Has this robot competed yet? If so, how did you do? Keep up the good work!
-Yea, the strips that position the intake are less than ideal. However, we had an odd number of holes between c-channels coming out of the tower. So, we couldn’t really find a way to mount the hopper in the center without bending metal. We have planned our next robot carefully to avoid this issue.
-The robot is actually very rigid. It’s almost impossible to twist the base(You’ll have to take my word). This is due to the c-channel box at the rear of the robot. That box is actually the structural heart of our entire robot. (https://lh4.googleusercontent.com/HlvSdABex4woHrBDSVPY2PKVSj-RNsj_WppR95xrRFo3W4E1Ef0THc6l4hpwpxkAkD3vAVtZCpaW4wRmRCnJsDl_EkmpSPs_6MDM_AXMcD5rI0YgqgWG8ybY). We could have added a longer bar, but I don’t see much added benefit.
-Yea, the long axle thing was something I wanted to change. However, I was too lazy and it worked fine…so I let it be… lol
-Our entire robot uses lock nuts. Maybe some of the older photos have keps nuts. However, not the version I have right now. I’m pretty proud to say that not one screw fell off our robot during competitions.
-The c-channel box ([https://lh4.googleusercontent.com/HlvSdABex4woHrBDSVPY2PKVSj-RNsj_WppR95xrRFo3W4E1Ef0THc6l4hpwpxkAkD3vAVtZCpaW4wRmRCnJsDl_EkmpSPs_6MDM_AXMcD5rI0YgqgWG8ybY) at the back of the robot supports the towers very well. We haven’t had any issues with wobbly towers.
-The zip-tie intake lets me intake bucky-balls from a further distance while still being flexible. This benefits me when I try to pick up stuff from the corners. It also lets me score the balls into the cylinder by sort of throwing them out the top of the intake. With a tank tread intake the balls would just bob up and down on top of our hopper and never actually fall into the cylinder.
We have competed at 3(?) tournaments. The first one we placed 11th in qualifiers and were 7th alliance captains. The second one we did very bad and placed 31st in qualifiers. In the last tournament we placed 5th in qualifiers and were 4th alliance captains. In the same tournament we made it to semi-finals and lost our third match because an alliance partners robot tipped :(. I think we would have won that match and possibly the finals…but oh well…
So, in short we didn’t do spectacularly…but we did alright. I kinda hate(not really) having robosavages in my division
Thanks for the comments!!](https://lh4.googleusercontent.com/HlvSdABex4woHrBDSVPY2PKVSj-RNsj_WppR95xrRFo3W4E1Ef0THc6l4hpwpxkAkD3vAVtZCpaW4wRmRCnJsDl_EkmpSPs_6MDM_AXMcD5rI0YgqgWG8ybY) at the back of the robot supports the towers very well. We haven’t had any issues with wobbly towers.)
It seems very solid, impressively beautiful in its simplicity. One question, though. Does the traction wheel give you any extra friction while turning? (the math says it will, but I wanted to know if it was noticeable)
It is very different from all Omni’s. However, with all Omni’s I found that the robot drifted too much. I had more control with the extra traction.
Thanks for the explanation! It’s something I’m considering on my bot now, too.
Yeah, anytime. I like it much more than all Omni’s.
This was a great robot but like most robots with a 1 bar lift, the scoring is very slow since the balls need to fight gravity and go up with the chain. B.I.S.C.U.I.T 's new robot will have a 6 bar with a twist for very fast scoring