Ok- I think I understand it now. One problem though is if i make this setup:
[attachment=0:3gknt6ju]pneumatic picture.jpg[/attachment:3gknt6ju]
is i can't see how the gas can vent from the ram after a flip? how do i solve this?
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Ok- I think I understand it now. One problem though is if i make this setup:
[attachment=0:3gknt6ju]pneumatic picture.jpg[/attachment:3gknt6ju]
is i can't see how the gas can vent from the ram after a flip? how do i solve this?
A small 5/2 is all that's needed to feed/activate the QEV ... 1/8 5/2 will be fine..[attachment=0:10qhzu5g]pneumatic%20picture.jpg[/attachment:10qhzu5g]
Find the pdf for the QEV your going to use then look at the exhaust flow Cv.
http://www.norgren.com/document_resourc ... xhaust.pdf
And is it practical/possible to have a QEV with 8Cv?
http://www.hitechcontrols.com/camozzi/v ... c-vso.html
The 1/2 has an exhaust CV of 6.62 ...there is a 3/4.
Base has 3/4 QEV Inlet and a 1/4 QEV Exhaust ( this has the internal floating valve inverted ) ...
The retract has reduced pressure... about 3 bar... and exhaust is via 1/2 QEV
5/2 valve that operates this weird setup is 1/8
http://www.teamonslaught.fsnet.co.uk...re1%20005a.jpg
Am I right in thinking that a powder fire extinguisher tank being used as a buffer tank has to be in date?
No one at Tech check has ever taken an interest in the buffer tank dates.
Hi,
If I have a pin valve on my paintball bottle then can I have a valve after the regulator but before everything else as my on/off valve? Also if I have a on/off valve directly on my paintball bottle could I have it so it was only accessible from underneath the robot?
If you are using a pin-valve type cylinders with screw in connectors then it is a requirement that you use a remote isolation valve. This should be the first item after the cylinder (e.g. not after the regulator).Quote:
9.5 Isolation Valve
Gas cylinders charged to pressures of greater than 50psi must incorporate an isolation valve that can be
operated from outside of the robot.
9.6 Remote Isolation Valve
Gas cylinders that do not incorporate a valve (for example: the gas is released as soon as the cylinder is
screwed into it€Ÿs mating pneumatic connection) such as found on disposable welding bottles and €žfizzy
drinks€Ÿ machines must have an additional remote isolation valve accessible from outside of the robot.
9.6.1 Position
Any remote isolation valve shall be positioned so as to minimize the pipe length between it and the
cylinder. This pipe length must fully vent before the cylinder is fully unscrewed from the pneumatic
connection.
The valve must be accessible from outside the robot and this means without inverting it.
I know it may prove a tab arbitrary but can anyone give me a rough Newton value for the power output of a cylinder running on LP and HP. I'm unsure of the operating PSI of each system, but I'll read back and see if I can find it.
Cheers!
If you don't know the operating pressure, it's difficult.
On the other hand, just the power pushing up is rather simple.
radius*radius*pi*pressure= force
For power in kg,
Xcm*Xcm*3.14*Ybar= Kg
I'm just looking for typical values though, so don't have any measurements (nor a pneumatic setup of ay kind) I'm afraid.
Would you mind substituting some in? Thanks.
For a low pressure system you normally run around 10bar:
And a normal ram may be 50mm bore
So:
2.5cm*2.5cm*3.14*10bar= 200kg roughly
Wow! What on earth does a HP system produce!?
in was looking at around a ton coming off the ram if i remember correctly. (50 bore 100 stroke)
That's FP.
2.5*2.5*3.14*55= 1079,375 kg - [0.1*0.1*3.14*55=1.727] = 1077.648 kg
So we're talking about 2,000N of force in a LP system and 10,000N in a FP system. No wonder they fling robots about so easily.
The pneumatic supplier I have recommend that I used an old style steel ram as it would be a lot stronger than a new aluminium one. But the problem is it ways around 6kg which I think is a lot! Are most people ok with 10bar aluminium rams? By the way the ram is 80mm bore and 160mm stroke which I might have cut down to 100mm stroke.
Use the Ali one.
The 70*100 steel ram I have here, and that's a FP one, is less than 1.5 kg, and messures only 155mm in total length.
Commercial rams are just not optimized for RW.
don't listen to them, 6kg is a ridiculous amount for a fw ram. an aluminium ram that can take 10 bar will work just as good as a steel one.
Sounds fairy conclusive! Do most people have cushioning on there rams or not, the pneumatic guy said it was needed to stop the ram ripping itself apart- but now I don't trust him so much!
Cushioning is .. IMO .. a good idea.
Depends Woody. The Gravity/Cutlet system doesn't need it, the dampening is done on the heavy moving mass, the arm, what is mechanicaly seperate from the piston.
But for a classic setup -Chaos II-, it is mandatory.
But it adds size to the ram. A lot of it.
Of course it depends.
However the question appears to be about a standard pneumatic ram ( double acting ) mechanically attached to the bot base and flipper arm... rather than a single acting F.P. ram with the flipper arm free to move and restrained/damped by bungee cord.
Hence ..IF Max has access to machining facilities and feels competent it may pay him to remove the return / base cushioning and thus shorten the ram.Quote:
Cushioning is .. IMO .. a good idea.
I know I have asked before but I got 2 answers so I dint know which is correct. What length is a 20oz paintball bottle? Is it 330mm long or 238mm long?
I messured mine 20 seconds ago.
The bottle itself is 260mm long, with the on/off valve mounted, 295mm. Diameter 84mm
Remember to add on something extra for the fitting that will screw on to the bottle.
I just received my paintball bottle and the on/off valve. Do I just put some molegrips on the old pin valve and wind it off and then screw on the new one or is loctite/araldite necessary?
Also I can't screw my Trevor regulator onto my on/off valve! When I try to screw it in the thread on the valve can't reach the thread on the regulator, do other people have this problem?
Quote:
Originally Posted by Max
Remove with grips and I use a drop of sealing compound. when screwing in the new valve.
The Trevor regulator isn't supposed to fit a paintball valve ...the threads are different between a paintball and European CO2 cylinder.Quote:
Also I can't screw my Trevor regulator onto my on/off valve! When I try to screw it in the thread on the valve can't reach the thread on the regulator, do other people have this problem?
Ok I see- so I guess I need some hydraulic adapters but first I need to know the threads:
1) what thread is on the on/off valve? I think it is the same as the one coming out of the valve on a co2 fire extinguisher
2) what is the thread on the Trevor regulator?
Thanks
1. 1/2 or there abouts
2. the trev reg has a co2 nut. easiest thing to do is to take it off and put on a 1/2 one
NOT THE SAME!Quote:
Originally Posted by Max
American CGA 320(Compressed Gas Association )
0.825-14 threads per inch NGO( National Gas Outlet )
on your paintball valve ... a 1/2 BSP nut will screw on but a standard nut is no good for your/our application.
British BS341 No. 8 ( British Standard 341 Part 1 (.860 in x 14 threads per inch) )
European DIN 477 No. 6 ( 21.8 mm 14 threads per inch ) for a CO2 cylinder valve /nut.
Ok- The nut on my (2nd hand) Trevor regulator deffinatly screws onto my Co2 fire extinguisher (quite an old one). The thread on the extinguisher and on off valve look pretty simular but from what woody said there is a subtle difference. I think my on/off valve could screw into my regulator but the thread does start early enough (look at the picture)
[attachment=0:3b5etuuv]on off valve.JPG[/attachment:3b5etuuv]
I thought i could file the end of the on/off valve down with a grinder/file so the thread starts instantly- does this sound wise or will it mean i cant use the Valve as it has been modified?
Quote:
Originally Posted by Max
Do not do that. It will ruin the on/off valve, as the CO2 nut on a Trevor is actualy barely contacting the smaller thread on the valve.
It's in the same order as trying to put a 1/4 UNC nut on a M6 bolt. hey, it fits, but why does the thread strip?.
I never treid it, as my gutfeeling tells me it could result in a flying regulator.
So what do I do to connect them? Where do I get the right nut to replace the co2 nut? And if I change it will the new nut 'come out further' so it will reach the thread on my on/off valve?
The nut your after is this http://www.weldability-sif.com/pages/vi ... g=daco2nut
and have alook at this website http://www.teamonslaught.fsnet.co.uk/co2_info.htm
thats the wrong nut. he needs a 1/2 bsp nut, that one is just another co2 nut.
try ebay or rs components for a suitable nut.
Jonny is correct the trevor reg has a nut that is the equiv of the daconut I linked to on MY co2 page.Quote:
Originally Posted by Hard Time
The solution isn't that easy with off the shelf parts.
I suspect that something could be knocked up with one of these and some thought....
http://www.ebay.co.uk/itm/New-CO2-ASA-A ... 415fae4574
Didn't Jonno sell co2 bottles that fit straight into a Trevor regulator?
Sorry to keep asking but if I could get an adapter which went straight from the on/ off valve to the regulator would I need a 1000psi pvr?