Pneumatic

[philip_taylor]

Pneumatic

Marauder is 560 mm * 480 mm and 140 mm tall. The four sides slope up at 45 degrees. I need to make my bot smaller. It is far too large. Marauder is also too big.

Have you drawn any possible layouts, Chad? Will you need to take any special precautions with your polyquest battery?

[wazio]

Pneumatic

I would like to keep my bot no bigger 18x18. I think I should be able to keep it less than that actually, I hope. My bot is probably going to look alot like yours with the pyarmyd shape.

I think I will have a 1/4 base plate and have a shell of armor.. Some sort or titanium and UHMW mix I think. I should have about 10 pounds for armor.

The batt I am going to put into a box of foam. From testing here in the US, we have found out that they will break if they have alot of shock, so I will do all that I can to protect it...

I will start the CAD of the bot tonight now that I know that the system works.

I set a roll of duck tape on top of the ram and it went about 10 in the air. from what you all tell me this thing should send a 30lb bot about 6 in the air. So when I see a roll of duck tape only go 10 I wonder how high a 30lb bot will go. So went I add the arm will that change this? I am kinda worried about how well it will work now.. I am still going to put the ram 3 away from the pivot point.

But the last big thing that I am going to need help with is the arm shape... Anybody have some pictures of a good arm shape? Will it matter if I have a long wedge looking one, or will I need a short one that shoots straight up? Tips would be great!!! Thanks guys.

[maddox]

Pneumatic

You suffer from a lack of flow.
The valve and ram entrance are big enough, but the let trough of a pinvalve is feeble compared to the valve.

For arm form, we found the Gravity style shallow wedge most satisfactionary

[wazio]

Pneumatic

Well, then it sounds like a bigger valve, or at least one that has more flow. . . How can I improve my flow? And where can I find some up to date pics of Gravity?

[ewan]

Pneumatic

ere ya go

http://www.bugs.nl/media/album/view.php?&path=L3J3L3J3Ny9ubC1tYXJpZW4vcGljMTAuanB nhttp://www.bugs.nl/media/album/view....ZW4vcGljMTAuan Bn

Theres been a few incarnations since then but they havent been half as good at launching bots. Remember that its a very long arm and the ram is placed very far back, giving lots of speed at the end of the arm. You need a BIG ram to do this with lots of flowrate, hopefully yours should scale down from a gravity design ok.

[ewan]

Pneumatic

You can see where the ram is better in this pic

http://www.bugs.nl/media/album/view.php?&path=L3J3L3J3Ny91ay1hZGFtLWNsYXJrLzEwMV8 wMTEzLkpQRw==http://www.bugs.nl/media/album/view....LWNsYXJrLzEwMV 8wMTEzLkpQRw==

[killercarrot]

Pneumatic

Its well worth running your designs through Noels flipper calculator, otherwise you might end up with a nice looking setup that could work so much better.
the excel spreadsheet is downloadable here:http://www.hassockshog.co.uk/flipper_calculator.htmhttp://www.hassockshog.co.uk/flipper_calculator.htm

I have used it to optimise the output of a couple of flippers, feather and heavy and its reasonably accurate

[maddox]

Pneumatic

Chad, the Burkert valve isnt the problem, its the let trough of the bottle exit.This is easely solved with the buffertank.

Ewan, Chads ram is a 70bore*80stroke ram. For a feather HUGE. He can afford to have a long flipperarm.

[ewan]

Pneumatic

lol, yup, very big

Hey Chad, did you ever get closer to finishing the hammer-feather? Whereabouts can I see the most recent pics of it?

[robotic_ants]

Pneumatic

Skewer

[woody]

Pneumatic

Chad ...I agree with Mario.
The Burkert should be able to flow 46 litres or 12 gallons per sec @ 750 psi with a pressure drop of 5 psi according to the PACulator.

http://www.proautocon.com/PACulator.exehttp://www.proautocon.com/PACulator.exe
Cv of valve 2
Inlet pressure 750 psi
Specific Gravity of CO2= 1.52 ( Thats Density in the programme.)


Note :- Your ram has a capacity of 1/3 litre ....do the math to get a fill time.

You seem to be making the classic mistake of putting a big valve on a small supply.
The internal passageways of your paintball valve are less than 1/16 and if memory serves me right closer to 1/32 and restricted by direction changes.

If you replaced your bath taps with fire hydrants would you be able to fill your bath in seconds?
NO ... it would take much the same time as before.

So use a buffer tank ( a buffer tank contains a readily available and unrestricted head of gas )
I.E. A suitably rated pressure vessel with an outlet bore the same size as your valves inlet bore and enough capacity to suit ... A capacity / volume of 2 or 3 times your rams volume as a rough guide

Woody



(Message edited by woody on January 15, 2006)

[jamesb]

Pneumatic

wait a second....
70mm x 80mm?
full pressure?

[woody]

Pneumatic

Yes and Yes....

[maddox]

Pneumatic

James, yours is bigger.

[wazio]

Pneumatic

Ok, today I made a manafold so that everything can plug into 1 block. My girlfriend is here so I have not had a chance to test it yet, but it has the 9oz buffer tank + all the area inside the manaflod. Hopefully this will help out. New picture is on the profile.