pneumatics for featherweight

[Rahulvyas]

Hi,
I am looking for a pneumatics setup for a feathweight flipper.
basically, i am looking for something that can lift 12kg bot.

But i dont want heavy stuff, can you also estimate the weight of the complete setup?

please link me the exact part name and size that needs to be used, and is pneumatics better or linear actuator?

Is it a good idea to use pneumatic flipper made on and out of a polycarbonate robot?

thanks,
Rahul

[Liftoff]

Weight for the setup depends on what type of components you'll use, my current setup weighs 2.5kg, my previous one was weighing more than twice the weight.

Most components are paintball stuff, and relatively inexpensive. The force this system delivers is about 300kg at 10bar, depending on how you connect your ram should be more than enough to throw 12kg robot in the air. Dont have any experience with linear actuators, but I think they make more of a lifter rather than a flipper.

Regarding polycarbonate and pneumatics I'm not sure, but I can tell you that recoil might be a problem depending on how you mount the ram. Mine was mounted vertical, on a base of 5mm hdpe. No problems at all, but being vertical, the force was transferred directly to the floor.

hope this helps a bit...

tmp_20130430_091433-2031416696.jpgtmp_20130503_174106-2093151804.jpg

[Rahulvyas]

Yes, thats helpful!
So approximately how much does it cost?
and can u name all the parts required to make a functional one? i have nothing related to pneumatics.

Also, paintball stuff might now be available here, I will get normal pneumatics stuff.

and if a 2.5kg robot can lift 10kg, thats awesome! thats what i want, but for me size is also a problem, i dont want a huge robot.

[Liftoff]

Will post the links to the various parts when I find some time. Off hand I dont remember the cost of the whole system, but it should be below £100.
By the way, 2.5kg is the weight of the pneumatics only! To that you have to add the weight of the robot...

[Liftoff]

So here's the list of parts I'm using, changed some of the components of the previous build to improve the efficiency and reduce weight.

Buffer/Main tank (x2)
http://www.ebay.co.uk/itm/PaintNoMor...item4ac26a5dfb

These tanks are fitted with pin-valves, the buffer tank does not require one so I modified the pin valve and used it as an adaptor. Thread on the valve is 1/2"bsp.
Have a look at the 8th and 9th posts of this thread:
http://www.fightingrobots.co.uk/thre...lve-help/page3

The main tank requires an on/off valve to be connected to the pin-valve:
http://www.ebay.co.uk/itm/New-CO2-AS...item417105e281

The main tank is connected to the regulator via a braided HP hose. The hose is connected to the on/off valve at one end and at the other end to an adaptor.
The adaptor is 1/8"npt to 1/2"bsp, and connects to the inlet (female thread) of the regulator.

The HP hose comes in different lengths, 6",8",10" or 36"
http://www.ebay.co.uk/itm/New-Paintb...item41715aef1d

Adaptor regulator to HP hose:
http://www.ebay.co.uk/itm/New-paintb...item4857c1c42a

Quick disconnect fittings (to connect HP hose to Regulator adaptor):
http://www.ebay.co.uk/itm/New-Paintb...item416f505f80

LP regulator:
http://www.ebay.co.uk/itm/NEW-PAINTB...item2a1dff3251

I use a 5/2way valve on my system and the ram is single acting, retract is by bungee. The valve I'm using is very small and rated at 8 bar, but will handle higher pressure. Ports are 1/8"bsp...the smallest possible, but this will not affect flow in any way.
http://www.ebay.co.uk/itm/DC-12V-2-P...item5aebfa2b74

Pneumatic fittings I used these, they are rated 15bar.
http://www.ebay.co.uk/itm/6mm-Push-H...item19d9a4c2cb

Quick exhaust valve there are two types, one is heavier than the other. This is the difference between the two (9th post)
http://www.fightingrobots.co.uk/thre...d-diary/page12

QEV
http://www.ebay.co.uk/itm/1pcs-QE-04...item51aa096206

Hope this helps.
Chris

[Rahulvyas]

Thanks for these links, i think they are very useful. i will try to find all the parts u linked near my place.

also, do u have a connection diagram for this?
and how do u refull co2 into the cylinder?

[Liftoff]

To fill a paintball bottle you'll need a Co2 fire extinguisher and a fill station similar to this:

http://www.ebay.co.uk/itm/NEW-Paintb...item41570db720

Basically you remove the nozzle from the extinguisher and connect the fill station instead. The paintball bottle is connected to the on/off valve on the fill station. One of ball valves on the fill station is a vent valve, the other is the fill valve. To fill close both valves and then open the extinguisher valve. Slowly open the fill valve, the pressure will also open the pin-valve on the paintball bottle. You have to weigh the amount of Co2 you're putting in the bottle ( they are marked 9,12 20oz etc).

When the weight is right close the fill valve and extinguisher valve, and open the vent valve...then you can disconnect the bottle from the fill station and you'll have a ''full'' bottle.

Best is you get someone who did this before to show you tho, as if not done right you might hurt yourself...we're talking about 50bar here.

[Rahulvyas]

Alright alright.

Other than that, can you recommend me linear actuators that i can use on my robot to lift a 15-20kg robot?. i will go with biohazard like 4 bar linkage on my other bot.
Please link me something from here-
http://www.aliexpress.com/store/108393

Basically,
i am thinking of making something easy and cheap. you tell what is a good idea for a beginner who just did wedges?
I have tried 4 bar mech already using some kiddo mechanical kit, it ran pretty good.

[maddox10]

15 kg lift over 300mm.

This will do that.

[Eventorizon]

Your cylinder is custom I take it and is reset by bungee cord or springs. Do you know of a good double acting system that is this tight?

[Liftoff]

Well yes, well spotted... the ram is a sort of hybrid one, started off as a standard 63x20mm ram off ebay, and then machined the outer cylinder and piston rod to my requirements. You'll find compact ones at reasonable prices off ebay (generally from Hong Kong or China) The main issue I find with them is the reduced port dia which does not help flow. Their advantage is that you can disassemble them, so you could drill the orifices to a more suitable size, clean and reassemble.

Something similar to this is what I started with, should be compact enough if used as is and have the ports taken care of.

http://www.ebay.co.uk/itm/CQ2B63-50-...item4850088561

[Rahulvyas]

What bore and length do i need the pneumatic cylinder of?

[maddox10]

Depends what you want to do.
Just lift over a good height . That you can do with a low pressure ram 40mm bore 100mm @6bar stroke ram.

Good flips or launches requires other stuff.

[Rahulvyas]

Thanks all guys.

I will go to the local store which sells big pneumatic stuff.
so does the 5 way valve have internal solenoid, or i need separate?

[maddox10]

I guess, if it's a shop that sells new stuff, that it will be a dissappointing trip.