Robot in 3 Days Reveal (FRC inspired)

Judging by the 2900 views your one video has already had on YouTube, I’d say there are at least a few kids interested in seeing more.

Cameron and Aaron, very nice job. I love seeing something other than a flywheel shooter…and it actually works! Quick question, I feel like an idiot but I haven’t seen this part before (the part the worm gears are driving)…what is it? (By the way, the name of the robot…perfection)

https://g1kepa.bn1304.livefilestore.com/y2muPshsPONTQxd4iKhGBTpyOnm_u7YOd91nb1HMg7rwNyfCA2k95-w00GqZ4qyMvo_J1MsRTRy_wV700uqnm4WMQ6OIbaYkrV3Na0qE14w7OSbQ_thO9UITW9yLZLnV6IAztKVBmqUt_B6Se6R60JbcPOe06ZjD8iPI8fwJu4Fydg/wormgeardrive.png?psid=1

http://www.vexrobotics.com/vex/products/accessories/motion/276-2045.html

Thank you. We even have that darn pack and I didn’t notice that little piece!

Haha thank you! Yeah we had no clue that piece even existed until it fell out of the box when we were looking for parts for the tilt mechanism. Weird conincidence

Keep on the lookout, I will make a video detailing how everything works very soon!

This is a few pages back but never got replied to. 45 degrees is only optimal for shooting a target on the same level as the launcher. A raised target, like the high goal, can be hit with 2 different trajectories (assuming 1 given speed and 1 given distance; changing speed and distance opens many more possibilities). One is with a lower angle, with the target near the top of the projectile’s arc. The other is with a higher angle, with the projectile coming down from above. Given that the hole in the net is angled upward, the higher angle is ideal, because you are effectively increasing the size of the target.

Yes you are increasing the size of the target. But I’m pretty sure you also increase the sensitivity of the shot to small changes in speed and/or angle, thereby cancelling out the benefit of a larger target. This matches my intuition and the way people play sports like basketball.

I might look into the maths behind this if I have some spare time.

I can see what you’re saying but my intuition tends to run the opposite way. I don’t know for a fact but I would think people play basketball with lower angled shots because they simply don’t have the physical power to launch a basketball so high with any accuracy and precision - they would need to use their arms in a way that’s very different. Perhaps my own intuition is based on the way mortars are used in trench warfare - it’s harder to hide from something coming straight down upon you. On the other hand, I noticed some teams (929w’s summer reveal) using their flywheel shooters very effectively in nearly straight-line shots. I was amazed they could be so precise with such low-angled shots.

I guess only time will tell what works best in this game.

Basketball players are an example my physics teacher used to support shooting the higher angle. He likened a lower trajectory to players who rely on the rim and backboard to catch their shots.

And just think: if you shoot at a higher angle, the ball comes down and scores by encountering (…drum roll, please…) nothing but net. (Hint, hint)

http://hyperphysics.phy-astr.gsu.edu/hbase/imgmec/tra12.gif
So in this diagram the 60 degree angle would be desireable if your launcher has enough power to make up the lost range. Also as someone else was saying with the lower angle you dont have to worry about speed because you can shoot it with more than enough force and just aim for the backing of the net like 929w did. But if you can get your speed fairly consistent I think a higher angle shot would yield better accuracy.

During the recent concluded Singapore Vex, 8059 and 8068 used 2 distinctive approaches.
I had a detailed discussion with the mentor of 8068, and he decided to use the approach of shooting the balls as straight as possible towards the goal, while 8059 choose to loop the balls high into the goal.

Some how, we have a feeling that when looping the balls high into the air, the chances of the flight path of the balls affected by the wind, the aircon, etc, will be greater (even though mathematically and looking at the formula, the air resistance is not dependent on the path taken, but on the speed).

But of course, we do acknowledged that the horizontal cross-sectional area of the goal is greater than the vertical cross-sectional area. Hence, the problem faced by shooting the balls as straight as possible will be the difficulty in aiming.

8059 performed better in both the programming skills and robot skills. But it is still inconclusive. Because 8059 used a single flywheel approach while 8068 used double flywheel. So it is not apple to apple comparison.

I shall not hijack this thread further.

Once again, team 62 is proving to be an inspiration for the rest!
Can’t wait to meet up with you again in World!

I think it might be because a parabolic path will always be longer than a straight path (if both paths lead an object to the same position). Making the path longer will allow for more factors to affect the movement of the ball.

After seeing Singapore VEX, which one do you think is better in general? I am still debating on which type of shooter to use.

8059A used a 4-motor single flywheel shooter, and hit 28 (out of 32) balls into the high goal during programming skills. And with about 10sec left to spare.

Their next best programming skills score was 137. So it is definitely not flash in a pan or one hit wonder.

But think I can only conclusively say that 1 wheel shooter seem to be more consistent than a 2 wheel shooter. But can’t say much about the path taken.

Wow! 28 out of 32 balls! That is some amazing accuracy right there!

But do you know the reason why the 4 balls did not go into the net? I’m guessing it is because of the inconsistency of the density of the ball.

Given the updated rules in the June 15 update, would you be keen on changing to a 12 motor system? It has its pros and cons, but I can see it efficiently being used on your robot.

I watched a match somewhere where 8059 and 8068 played together. I believe that each team took half the driver loads, and it looked to be almost to the same accuracy. The only difference was that 8059 had a longer path of the ball and 8068 had a longer recovery time for the flywheel. Both seem outstandingly consistent.

However, I think that any slight movement to 8059 robot affected the precision of the ball greater than it did with 8068’s long range shooter as it hits the back of the net. Any comment?

Yes, we will be removing the pneumatics to add 2 motors somewhere. However, we don’t quite know where yet. In my opinion, I think we will see the majority of teams using 12 motors rather than pneumatics. 2 extra motors just seem way more powerful than pneumatics, especially with the 2 tank limit. It would be a more fair decision if the 2 tank limit was increased to something higher (Karthik ;)).

That also makes elevation(High) harder haha. Unless you smart peeps can find a way to do it without a transmission

Also, have you guys thought about the fact that your elastics could wear out after multiple runs of controlling? Be it snapping, or stretching, the shot would not be as powerful as before. Changing the elastics would also affect the power of the shot, so a very precise calibration with a range of similar rubber bands would be needed.

You don’t need a transmission for elevating, a lot of good designs are completely passive. We have thought about the problem of elastics changing, however we use high quality rubber bands that should be consistent throughout a day of competition. We will be replacing rubber bands before every competition just in case.

I think you are referring to the match whereby 8059B and 8068A were playing together during the QF or SF.
8059B is a 2-motor one-wheel shooter, and it certainly couldn’t match up with 8059A in terms of accuracy and speed. In fact, I think 8068A is a better base shooter than 8059B.

8068 have quite a few good robots, they even have robots that can do lifting as well as shooting from base. That’s very impressive.

But it is a fact that 8059A has the best shooting accuracy and speed.
I am sure 8068 will agree with that as well.

Let’s be objective and discuss about system and approach - 2-wheel shooter generally also has an additional issue of making sure both wheels are turning at identical speed throughout. Any slight difference in speed will cause the ball to move sideway and hence causing inaccuracies.

Look… I really don’t want to hijack this thread anymore. It is not fair for Cameron.

Anyway, 8059 will be doing our review very soon. We will discuss further over there