Team 842 Testing Shots

[Ether]

Originally Posted by rai337

Is there any specific reason why you put your pistons in such starting angle?

With a motor, you use a gearbox to trade speed for torque.

With a pneu cylinder, you use leverage to trade force for speed.

[Bewizardment]

How are you guys loading the ball? Does the arm go down further?

[sergioCorral842]

Originally Posted by Mr. Lim

How are you precisely varying the timing of the pulse to the solenoid? Are you just counting cycles in the teleop periodic loop? Does that limit you to about 20ms increments? Do you need anything more precise than that?


This is very cool stuff.

I basically use the Timer class. It does not seem to be having any issues with that.

[Duncan Macdonald]

That pile of broken ceiling tile has nothing to do with the robot right?

[sergioCorral842]

Originally Posted by Duncan Macdonald

That pile of broken ceiling tile has nothing to do with the robot right?

Robots*

[Team 2016]

Could this be used to pass or catch?

[Joey1939]

Originally Posted by sergioCorral842

I basically use the Timer class. It does not seem to be having any issues with that.

Could you please explain in greater detail how to implement this?

[sergioCorral842]

Originally Posted by Joey1939

Could you please explain in greater detail how to implement this?

Use the timer class to set the pistons to true for a certain amount of time then set them to false right after.

[JohnFogarty]

The amount of inspiration this video has given me cannot be quantified.


What solenoid are you using? is there any special storage tank between the solenoid and the cylinder? Or is it just


Compressor ---> Pressure Sensor -----> Storage Air Tank ----> Regulator ----> Solinoid ----> Cylinder.

*Forgive me for my lack of pneumatic knowledge if that order is so wrong that I deserve to be flogged.

[kuraikou]

Super cool!!! I look forward to seeing you at the AZ regional.

In the videos your team posted on Facebook you have another piston that goes up and down as you fire, what is the point in this and how does it work?

[falconmaster]

Originally Posted by JohnFogarty

The amount of inspiration this video has given me cannot be quantified.


What solenoid are you using? is there any special storage tank between the solenoid and the cylinder? Or is it just


Compressor ---> Pressure Sensor -----> Storage Air Tank ----> Regulator ----> Solinoid ----> Cylinder.

*Forgive me for my lack of pneumatic knowledge if that order is so wrong that I deserve to be flogged.

Compressor, pressure sensor, primary storage tank, regulator, secondary storage tank, solenoid, cylinder

[s_forbes]

Originally Posted by kuraikou

In the videos your team posted on Facebook you have another piston that goes up and down as you fire, what is the point in this and how does it work?

That additional piston gives us the ability to adjust the trajectory further. Just by varying the pulse to the main catapult cylinders, we are able to make a relatively lofty truss shot and a pretty hard/flat high goal shot. The geometry of the arm for those shots doesn't work for the in-front-of-the-1pt-goal high goal shot, so we added another degree of actuation.

We did a few quick tests today that make a self caught shot over the truss look feasible using these additional pistons; it will be pretty neat if we can pull that off in a match!

[mithril865]

First let me say how impressive this design is. The flexibility is incredible! Can you please provide more details on how you implemented it including cylinder dimensions (bore & stroke), release, distance cylinders are attached from the pivot, pneumatic connections, are you using 2 tanks per cylinder? are you using separate solenoids for each cylinder? Our team tried to replicate your set up tonight and couldn't get anywhere close to the range you demonstrated.

Thanks...

[waialua359]

Our team used a different mechanical approach to varying our shots with the same shooter mechanism.
After seeing this thread early yesterday, we have already tried with great success the software pulsing of the solenoids instead.

Thanks for sharing.

[nuclearnerd]

OK, we had similar size cylinders, similar sized catapult, and tanks directly connected to the cylinder ports (mechanical release - we didn't even get into large CV solenoid valves yet) and we could not make our shooter make long shots like yours. We clearly have some learning to do. I'm looking forward to seeing more of your system after build season!