What to do without Pneumatics

This year, the use of pneumatics has become essential for robots that hope to compete at the highest level. My team does not have pneumatics due to the limitation of sites my team can buy from (our school is annoying). I currently am doing what many top teams are doing using a 1m lift, 1m ring mech, but I also have to have a 1m clamp and 1m filter. This has unfortunately stopped me from being able to use 6m drive and so I cannot climb the ramp with more than 2 mobile goals (even that sometimes doesn’t work because my drive gets tired really fast carrying around 2 goals). Does anyone have any ideas on how I can implement motor sharing?
Thanks!

Here are some tutorials from the forum and Youtube that could help.

Ratchets:
Our experience with Ratchet Mechanisms in Change Up (62X)
VEX Ratchet Tutorial
315G Ratchets Explained (6 motor drive, 2 motors for everything else)
Smallest vex ratchet

Differentials:
Vex Differentials Explained
Differential transmission - power takeoff from the drivetrain motors
Differentials —“Some help from my fellow SCA member”
Differential Concept
Please share some examples to understand Differential & Bevel Gear Pack use case for vexiq

9 Likes

better solution: make passives

8 Likes

Ugg. I hate this kind of thinking. Ethan has said think about passives, a good direction to go. What are teams using pneumatics for? What game advantage does that give them. What can you do to design past that?

After coming from an FRC team that did amazing things with pneumatics, I’m hugely disappointed with the VEX V5 setup. There is limited air, limited throw, limited holding. While everyone thinks about this kind of implementation Amazing Syringe Robot Hand DIY - YouTube the reality is that it’s a go to point A, now to Point B, now back to Point A. No adjustments no smooth movements, etc.

But enough of my January rant, let’s get you going.

Tell us about your drive base. 4 motors is the goal to leave 4 for gripping grabbing, etc. Is that correct?

Are you doing 4 individual motors, one per wheel or are you ganging the motors together to drive a side (tank drive). Is traction your issue with 4 wheels, have you looked at 6 ( or the very cool 8 wheel drive I saw just before Christmas?)

2 Likes

Don’t do motor sharing. It’s just not worth it. If you’re building a metabot, not having pneumatics means you need to do 2 motor lift and 1 motor claw with a 4 motor drive instead of a 1 motor lift and pneumatic claw with a 6 motor drive. It’s unfortunate, but you can still be very competitive. Motor sharing is far far more complicated than a robot needs to be in this game.

If you have your heart dead-set on motor sharing, maybe use a differential on your drive to power the lift.

1 Like

I’d like to read this as “don’t try to share motors across functions, but it’s OK to gang motors together, like in a drive base for more power” Am I correct?

1 Like

Yes, that is what I meant. Using complicated ratchets and diffies is hard, requires lots of effort, and grants very limited benefit. Hence why I advise staying away from them.

10 Likes

Would it be a good idea to do a 6m drive with a 1m lift and 1m claw?

Sure, but then you have no back goal lift or ring intake.

So is a ring intake or a 6m drive more important?

It really depends on your driving style and your regional meta.

1 Like

Today I learned that there are Regional Meta robots. Care to post the PA and MD regional Meta’s? Delmarva is all over the place with designs.

1 Like

I don’t live there, so I don’t know. But if you live in a place with a ton of mogo-only robots, rings become a lot more valuable, and if you live in a region with tons of ring bots, mogo hoarding becomes more important.

1 Like

Would it be possible to share lift and clamp motor, and just leave drivetrain alone?

For example, have a clamp that is normally closed with with elastics and forced open with motor power after lift reaches over full down or full up positions. That is with the extra range from the same motor that powers the lift.

That is what I thought but I didn’t know if there were any ways to share motors without making an overly complex robot.

Ohio moment
20 char.

1 Like

4M Drive shouldn’t hinder you from driving around or climbing the platform with 2 mobile goals.

6M Drive is a nice to have especially for auton, but it isn’t neccessary.

2 Likes

My 4m drive 360rpm chassis on 3.25s cant climb with too and burns out after ~4 minutes of driving.

(I am likely going to lower the speed of my chassis.)

1 Like

Yeah, maybe try a lower speed like 257 on 4" or direct 200.

1 Like

I am likely gonna switch to something like this before states (coder was mad when I said I was gonna switch rpm and mess up codes)

1 Like