How Important are Rings?

VEX V5 Robotics Competition V5 Tipping Point (21/22)
41

I think the concern is that free pneumatics (yes yes, it’s not infinite free power, but it is still a very useful and powerful system that can now be used with no penalty other than ones inherent in the system) will replace these ingenious and very limited passive actuations.

while passive mechanisms are still going to be viable and are a great way to get extra power and actuations out of a limited robot, pneumatics are undeniably a more powerful and versitile way of achieving actuations than some sort of purely passive mechanism.

Is that neccesarily a bad thing? I don’t know. But I do know that it is more expensive, which is my main issue with the free pneumatics change. It’s pretty clear what the gdc’s stance on the matter is, but for what it’s worth I’d much rather be given a choice between pneumatics and one extra motor than to choose between the superior but expensive pneumatics, or the alternative of no additional power. Which isn’t that big an issue for me personally, but I think that pneumatics simply won’t be in the budget for so many teams, and because of that they are inherently going to be more limited in terms of robot power than other teams.

Also I just thinkl balanced choices are a great way to foster thoughtful design decisions, every team could be able to come up with their choice based on their engineering process and their org’s limitations, instead of just going with the obvious “yes, more power” or perhaps “we don’t have pneumatics, and we aren’t going to buy them, I guess we’re not using them”.

And yes, pneumatics are not an all-powerful tool that will make or break a team’s season. They aren’t good at providing large-power or frequent actuations because of the limited air, but all the low-frequency actuations you can do with them will certainly make a difference in a team’s competitive ability, especially with a game like tipping point with so many possibilities for actuating robot mechanisms.

the idea of sacreficing 2 motors for pneumatics in the past few years has been laughable, not only because you’d lose a ton of available power, but because the past few games has not really had many uses for pneumatics that would be work giving up any motors for. Change up was so simple that a 4 motor robot could play it, there was no need for anything pneumatically powered at all. And tower takeover might have benefited from pneumatic actuations, perhaps with cube locks or other clever mechanisms, but it was also a very power-demanding game, and teams couldn’t afford to lose 2 motors of power.

The reason you can’t compare the tradeoff of previous years to this year is because yes, power is king. But we’ve just been given both full power from motors, and the versatility and actuations from pneumatics with no tradeoffs, and I think the effects of removing any sort of tradeoff will be largely negative, especially among teams that would rather not use pneumatics (either because of price or preference)

42

But there are tradeoffs, but they’re not in the form the community is used to.

Let’s go back to FRC for a second:

  • In FRC there is no motor penalty for using pneumatics.
  • In FRC the tradeoff is having to design pneumatics into your robot, the weight of the various components, and the cost (which is far more expensive than cost in VRC because of various components FRC requires that VRC does not).
  • In FRC, there is no limit to the amount of air you can store, the number or size of cylinders you can use, and you have an on-board compressor to make sure you have enough air for an entire match. All of these should make pneumatics more attractive to teams.

However, there’s been a growing trend over the last 5-7 years where teams are choosing to NOT use pneumatics. Why?

  • Pneumatics are heavy and overall teams have been trending toward smaller and lighter robots. There’s only so much weight you can remove from a pneumatics system. At the end of the day, if you’re using pneumatics in FRC, you’re dedicating at least 5-10 lbs of your weight budget to it.
  • For many teams pneumatics are problematic. It’s very difficult to build a pneumatics system that does not leak air. These air leaks can be catastrophic if you’re relying on pneumatics for a mission critical part of your robot. You leave your pit full of air, you walk to your match, there’s a delay (maybe two) and next thing you know you’re down 10-20% of your air. Yes, you can recharge during a match, but this means you’re running an extra motor which means there’s less power from the battery available for your other motors.

@technik3k mentioned how a team with dome aspirations wouldn’t bet their season on a Rube Goldberg mechanism. Imagine betting your season on a hose not being cut straight, or a bad teflon tape job on a fitting, or a hose that got pulled out during a match.

43

While in first the extra weight might be an issue, it is less of an issue in VRC. FRC has a weight limit, and VRC does not.

44

While 10+ years ago, most top-tier FRC teams were pushing the weight and size limits, that’s completely reversed itself.

Now, the major design trend among the top performing teams in FRC for the past several years has been to aim to be as far below the weight and size limits as possible, to increase their acceleration times and overall mobility.

The only major hit on weight and complexity that FRC teams are taking now is implementing full swerve drives.

45

This is true but frc has unlimited motors. So the more consistent power of motors for everything is used but in vrc the limit of 8 motors leaves teams restricted in how much power they have so pneumatics will be found on almost every high level robot for mogo lifts, claws, 2 speed transmissions.

Instead of releasing the max psi you can every time you instead use a pressure regulator and only do 50 psi so actuations are consistent.

But vex already required good funding to be the best of the best anyways so the pneumatics aren’t really a pay wall. All it adds is an extra layer of complexity which should make more interesting mechanisms.

46

FRC has a 16 motor limit because of the pdp

47

Oh, interesting. Maybe vrc could end up like frc in not using pneumatics but we will see at the end of the season.

48

They don’t have unlimited motors. And in FRC not every motor is equal (even if they physically are). There are several factors:

  • The number of slots on the Power Distribution Panel (16x, if you’re running nothing else through the PDP)
  • The size of the circuit breaker behind the motor (the PDP only has 8x 40A slots and the rest can be as high as 30A). This means that if you used all the same motor, a motor on a 30A breaker has a lower ceiling than a motor on a 40A breaker.
  • The amount of power the battery can output. Motors in FRC have gotten more and more power hungry, while the battery has effectively been the same for nearly 30 years. If you ran 16x motors on an FRC robot at the same time, you will start to hit the limits of what the battery is capable of producing. Also keep in mind that the FRC control system will brownout once Vbat dips under 6VDC.

There’s a lot of technical reasons why teams would want to run pneumatics, but they’re still trending away from it.

49

This is one of the most silly things I’ve read since vexlover72 was on the forum (may he Rest In Peace)

50

image

X drive problems with traction wheel - #6 by 2775Josh
https://www.vexforum.com/t/x-drive-problems-with-traction-wheel-2/alt/85098/201

51

In our teams opinion, we believe as long as you have a dominant MOGO robot, you should be in the clear.
What we have is a wheel base that connects to a passive intake which sucks the rings into a sort of bin. As long as you get the robot on the platform at the end with 3 mobile goals, it would be competitive in a match. Take it with a grain of salt, but we think it will be a very good combo.
These are the current schematics:
6m Drive
pneumatic lift
1 motor conveyor
1 motor tipper.
If anyone has any input I’d love to hear it, especially on our idea of hoarding ring.

52

I don’t think hoarding rings will be competitive, for a few reasons.

  1. Good luck making it effective. There are 72 rings
  2. RIngs can take up more space than you’d think, making it hard to hold enough to be effective
  3. You’re better off scoring them.
53

That makes sense, I think I agree with your sentiment.

54

I would agree that ring hoarding doesn’t seem very viable at the moment.

72 rings is a lot and in the time it’d take you to collect all the rings on the field your opponent is likely to have grabbed all that they need. Not to mention that they have a good number of match loads that are safe from your hoarding.

55

1 item that I feel nobody has mentioned concerning rings is skills. @Ben had already maxed no ring skills: Vex tipping point 283 pt. driver skills -38141B - YouTube

In order to be competitive in skills, i feel teams will have to be able to play rings.

56

Yeah I was thinking about the next step and I think 289 would be easy to add on. (Get all 3 preloads on the post for 9 points instead of just in the base) Or would parking be the next step? My best run so far had 6 second atop time so rings are definitely going to be relevant in skills but I guess only time will tell how much.

57

I agree. However, you can see that it took him the entire minute to get the goals onto the robot. Granted, this is not the best robot, so maybe you can cut that down to 45 seconds with a better robot, but then you would still have to park your robot(5 seconds). This gives you around 10 seconds left, and that is not a lot of time to spend scoring rings. Something like a plunger probably would not be fast enough

58

Yeah rings are needed next. I had 2 second stop here with a rather janky run. When this is perfected and there’s 10 seconds left rings will add on to help out.

59

I wonder if the tall goal will play a large part in skills. Skills is all about getting the most points for the quickest actions, and theoretically scoring rings on the tall goal should yield the highest points/second ratio for any ring based action.

60

maybe… I mean it does yield high points but I don’t know if a mogo claw and dr4b can all be fit into one robot just to score a few more points.

Honestly I think after a certain point (310) programming is really all that matters.