Team Shakey Build Diary- Featherweight

[Shakey]

For my As level resistant materials I am building a featherweight (mainly because they have a welder and free steel.). Though Since I only get one shot at building a featherweight I will be starting with a more ambitious robot of a 4 bar pneumatic Flipper. I have built quite a few smaller antweights so I have some experience except for the pneumatics.

I have picked up quite a few of the parts already:
600g CO2 tank
4oz CO2 Tank (a very small buffer)
4 Drill Motors (already locked the clutches)
Trevor Regulator
16bar 50mm Bore 80mm Stroke Pneumatic ram
Spektrum DX6i

I plan on running it with electronise 30A speed controllers, a 4cell lipo (14.4v) and a spektrum receiver (not the cheap hobbyking ones). The Ram is double Acting And I think I will use it that way despite the fact it uses more CO2.

The chassis will bemostly 8mm HDPE (on order) reinforced with steel and a steel flipper frame (bolted and welded). Some 75mm Robochallenge blue wheels for the drills and it should be good to go.

I have some pictures of the rough layout here:



This is a quick CAD of the flipper I am working on. The flipper it self has a tip travel of 240mm, with the ram at 16bar it should be okay for flipping.


The only difficulty at the moment is 16 bar fittings and trying to fit the 4OZ cylinder onto the system ( I will remove the pin valve eventually).

Cheers,
Alex

[Ellis]

This looks fantastic. It will be great to see a 4 bar flipper, their forwards and upwards motion is superior (in my opinion) to rear and front hinged weapons. I shall be observing carefully as progress is made!

[razerdave]

Are you planning to power the front bars or the back bars ?

[Laser]

I'm planning on a 4-bar LP flipper :twisted:

Where did you get your main tank from?

[Shakey]

I am planning to power the front bars so the ram can sit inside it and because it has more power extending then when retracting.

The CO2 bottle was from roaming robots if I remember correctly. 4 Bar flippers are very nice to watch I think, my inspiration came from the american super heavyweight named Ziggy.

[blazerbotics]

You'll struggle to get a cheap 16bar valve, most will only go to 10.

[Shakey]

You'll struggle to get a cheap 16bar valve, most will only go to 10.

That is the component that is proving to be the hardest to find right now.

If anyone knows of any suitable 16 bar 5/2 valves it would be a great help, I don't really have enough experience to know exactly what to look for in a valve.

Until then there is a 10bar one lying around so I'll just regulate it to run off 10 bar until a 16 bar valve is found.

[blazerbotics]

The Parker 'Viking Extreme' valves go to 16bar, RS sell them.

[maddox10]

@16 bar, that ram uses 4.5 liter of gas in each action.

20oz bottle =600 grams of CO2 = 307 liter of gas= 65 actions. (rounded off to 50)

Maybe , if you're running out of weight, to consider to use a 12 or 9oz paintball bottle?

[Shakey]

Ah thanks for that blazerbotics.

Also that is a lot more flips than I was expecting to get out of the bottle so I'll see about moving to a 12oz one that is lying around the house somewhere.

One small question, what ground clearance between the arena and the base of your chassis would be good? This is for running at the roaming robots type events so the arena gets quite damaged towards the end.

Cheers,
Alex

EDIT: What issues are there with valves and failsafing? I take it you just need a failsafe to keep the last known command on the channel the valve is on so it willnot fire when signal is lost?