Unlimited pneumatics

I thought the reasoning behind Vex’s standardized parts is so that there’s a level-ish playing field between the more affluent teams and the less so. Is a more expensive part like pneumatics or aluminum breaking this? (…Well it’s still relatively cheap compared to serious robotics, so probably not.)

Motors and cylinders are easy to limit because they’re discreet components, and easy to count, but aluminum would be really difficult to tell (8 pieces? What if they’re cut? etc.)

Hi Tabor

Firstly, I do not think that motors should be unlimited. Secondly, I do not know anywhere near enough about electronics to give any sort of informed opinion. I know that motor connects to motor controller connects somewhere into cortex - battery connects to cortex and makes motor go… :smiley:

My thinking is that you should use the minimum number of motors to carry out the tasks you want to achieve, at a speed that is driver controllable and that is not going to start shredding parts with massive peak loads. Fast driving is as much about precision as it is about speed, so “more power is better” only holds true up to a point. I am thinking more Lotus than Hummer. :slight_smile:

I have a question. Are the people voting for unlimited pneumatics the same people who are responsible for trying to to find sponsors for all their team activities (including travel!) and personally paying the bills? When it is your own bank account that is shrinking, you may have a different perspective.

Cheers, Paul

Agreed, any more than 15 pneumatic kits would be a bit of a struggle to fit inside an 18 inch robot…

I really liked this rule. Different teams used their 393s for different applications, which was interesting. Now, no thought needs to go into where to use the 393s. Just use them everywhere!

Agreed, pneumatics are undoubtedly useful, but I think teams are required to be smarter about how to use their power resources if they are limited, not when they are unlimited.

Yes, and one day you may imagine how you were ever able to build a robot out of aluminium when carbon fibre C channel is released :wink:

Cheers, Paul

Yes! I think what VEX has right now works fine for all VEX teams. Teams can always work up to or save for pneumatics. I think VEX has it right here.

So your issue is how much teams have to pay to stay competitive? Through the years this has definitely increased. In cleansweep I was 8-0-0 at worlds and ended up becoming the alliance captain and division finalists. My robot was all steel. Compared to the heap of aluminum and pnuematics on my current robot. :smiley:

I will admit that I am not the one who raises the money but as president of my team I am the one in charge of deciding how all money is spent. Things like wheels for my C team come before a fifth air tank for my robot. I have to make decisions every time we order parts. Would I rather have more spare motors or have my chassis be aluminum. This year my school started a C team so a lot of crazy robot ideas had to be tossed out when a 1000$ was put into just Vexnet kit motors and wheels.

Only 3 robots in my entire region use pnuematics so for us it isn’t something we “have” to do. If my region was different I could definitely see how the cost would make me want to limit them.

Its really not all to hard… May I remind you of this?


This is a 15 inch robot with a ton of pneumatics, In the bottom four inches of this robot there were 12 motors, 13 tanks, and four pistons. Once you started moving up there were upwards of eight more pistons and the intake was never completed 100%.

Needless to say I don’t understand how it could be difficult to fit so many parts into a small space.

As far as the cost thing goes, I agree that having more money to spend does make a difference, and choosing what to spend it on makes even more of a difference. BUT I’m sure many people will agree that it’s not the whole competition. When I was 12 (this would’ve been the 2008-2009 season) my middle school team had a protobot kit and some extra metal and that was it. SO we reinforced the heck out of that protobot and made the arm better (with a HUGE range of motion, it could pick up cubes on both sides).Then we spent 2 hours every day practicing driving and programming. We went to worlds, and a lot of unaltered protobot teams (who probably had the same budget) didn’t. A lot of other factors are worth more than money.

That being said, I think motors should be limited, while pneumatic tanks and cylinders be unlimited. The thought behind this is that first year, inexperienced teams will not have the budget (usually) for pneumatics. They’re going to be using motors, and unless they’re given a limit, they might think “BIGGER IS BETTER” and put 12 motors on their arm, expecting one battery to run it. I think the 10 motor limit is needed to “keep them out of trouble,” so to speak. I’m not saying that all first year teams would do this, but if someone didn’t do their homework on the subject, adding more and more motors without thinking it through, their team would run into a BIG design problem.

THAT being said, I’m presuming more experienced teams would have the budget and the knowledge to use pneumatics in an efficient and safe manner. If a more experienced team wants four pneumatic tanks and 8 pistons, or MORE, and has thought out the risks, benefits, and so on, that would be allright. They’d have the knowledge and experience that would keep them from getting into serious design problems with large amounts of pneumatics. Given their know-how, they’d be given “a longer leash,” so to speak.

Thanks Andrew

A picture is worth a 1000 words!
In NZ, a fairly basic robot, made from aluminium, will cost in the order of NZ$ 2,500. This is with no pneumatics fitted. This is the budget Lucas is working to this year, up to a cap of $3000 to include chargers, spare batteries, spare motors, et cetera.

If we wanted to theoretically compete on an equal footing and add the same pneumatic components that are described on this robot, we would have to purchase 6 x pneumatics kits @ $312.73 plus 7 x reservoirs @ $41.94. This is a grand total of NZ$2169.96 just on the pneumatics. We could almost fund another robot for our juniors for this investment, and in reality, that is the only sensible decision we could make given our budget.

By the way, Jesse, I think what your post should have said is “I think what VEX has right now works fine for all VEX teams except for 2941:slight_smile:

Thanks for all the feedback everyone. There are some really good discussion points.

Cheers, Paul

Just for some clarification on Torque’s post - 2500 NZD is equivalent to 2000 USD right now.

Also just for others 2500 NZ$ is about 2000 real $ :smiley:

One thing I always wondered about Oats and Lynfield. How much metal do you guys go through in a year? Last year I built 3 robots they all had the same arm just moved from different chasis. Team 64A probably buys 1 pack of alluminum C channels per year. With the shear number of robots teams like 2941A build in a year I would imagine they go through huge amounts of metal.

Pistons are a huge cost yes. It just seems like some teams spend a lot more money on spare motors and metal than others. My robot has 4 air tanks and 6 pistons but we also only have ever broken 1 393 motor and I know that isn’t true for teams like Jack Attack.

This sounds about right, I just crunched the numbers on our Toss Up robot and came up with $2185 USD not counting any spare parts, batteries, screws, or even thinking about pneumatics. Having set limits or set budgets makes you think through problems and develop creative solutions. My teams robot exploits the motion of several mechanisms to accomplish other tasks. If we had 2 more motors there would have been less engineering to accomplish the same tasks.

Those who plan on becoming engineers need to learn to keep things simple, it’s the low bidder who gets the contract when they offer a simple dependable effective product. Without limits you don’t develop these skills.

Cheeky scoundrel! I have a good mind to change my avatar :smiley:

Oats budget is tight. For Sack Attack the school had 4 robots operational. The school cannot fund anything towards robotics, apart from buying the original protobot kit, due to many other commitments, thus the costs are covered by generous sponsors and the shortfall covered by parents.

In terms of metal usage, 2941A Sack Attack did not change too significantly in concept from it’s first iteration, which was a 6-bar, conveyor/top roller design. The main change in shape was a widening of the intake. Your estimate of an extra pack of C channel for a season is pretty accurate.

In terms of motors, yes we chewed through a lot. I would estimate that 20 motors had to be replaced (for 4 robots). I would estimate that 2941A and 2941B would have clocked an average of 6 hours driving time each per week. I have heard that the motors are rated for 60 hours running? but have seen no facts to back this up.

Just to clarify, I am not against teams using pneumatics. I think they add a lot to design, to performance and to student learning about their operation. They are almost mandatory to compete at the highest level. I am just struggling to comprehend why teams are allowed to put as many on their robot as can physically fit!

Cheers, Paul

I’ve been pondering this question for a few days, and I came to the conclusion that the current rules are ‘good enough’ for the average team.

Pneumatic components are expensive. For the average team, this single factor does a great job of governing how much teams spend on cylinders and other hardware. A minimum system (just to say you have pneumatics doing *something *on your robot,) will run you ~$180. Most teams aren’t going to put lots of tanks and cylinders on their robot because they can’t afford to.

Some teams, however do have the budgets to put lots of pneumatics components on their robot(s). These teams have to consider other real-life engineering problems, including the added weight, space on the robot, potential battery usage from the solenoids, and having to add more time to their match prep for charging their tanks.

I think both the tradeoffs and cost of using pneumatics (especially this year, where every pound may count,) does a good job of governing what teams use. I would be disappointed to see an overzealous limit on pneumatics, as NAR and other sustainable programs have built ourselves a network of sponsors and donors that allow us to have freedom to use as many pneumatics components as we can fit on our robots. It would be somewhat of a punishment in my opinion as we have all worked hard to afford such things.

There’s nothing stopping teams from working hard to gain more sponsors for these components.

My biggest thing though, is you don’t need pneumatics to be competitive. An elegant and very effective robot design for Toss Up does in fact exist that does not utilize pneumatic components, and the same goes for every VRC game, ever.

Maybe I’m crazy, but I think limiting motors but keeping legal pneumatics components unlimited is the best route.


Very true. The past two years our robots have not had a complete set of pneumatics. The weight and space advantages of not having them are worth it in my opinion, unless you have a good use for them.