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Afternoon all,
I'm designing a simple 10bar system and need a little help working out which ports are what on the following solenoid valve
http://www.ebay.co.uk/itm/3805306028...888%26_rdc%3D1
I'd be using bungee cord to return the piston so I'm hoping that the ports inline with each other could be used for the gas input and output, then the port on the side as exhaust. I'd obviously be using a 12v solenoid in place of this version.
Cheers
Dan
"AC 220V".... meaning it needs 220volts AC to fire it... look for one with a 12 or 24v coil.
.Quote:
Originally Posted by Danjr1
(For some reason it wants more characters)
I've been searching and I don't think it would work. According to the two websites below, the port on the side is the inlet and the two ports inline with each other are the outputs. Could someone please just confirm that I've read that right?
http://pneumatic-components.en.hisup...oid-Valve.html
http://nbmake.en.alibaba.com/product...gas_valve.html
According to the diagram in the first link it should be fine as a 3/2 valve. Your actuator port is connected to A allowing it to normally vent. When the valve is operated your supply (P) is connected to the actuator (making it go up).
you might want to go a step further and get yourself a 5/2 valve with qev and buffer tank for a more powerful system, its still low press but slightly more complex. Imho it's worth the extra effort.
Cheers all. Kane, just so I'm clear, I'd connect port A which seems to be the port at right angles to the others to the cylinder then whichever one port P is to the co2 system? Just a pain that I'll have to add another right angle to the system!
Liftoff, I looked at 5/2 LP systems before but it was the weight and complexity that put me off.
Does anybody know what the flow rate of a 10 bar paintball regulator and a 3/8" 3/2 valve are separately in litres/ minute? just rough approximations would be fine, trying to use the hassocks hog pneumatic calculator to help design the system. I won a 80mm bore 40mm stroke cylinder on eBay so need to get a move on with the rest of the system!
Dan you mind me asking what what's the pneumatic system for, is it a flipper, lifter etc? Reason I ask is that with this set up I see it will be a bit slow reacting. I got a LP paintball reg and a 1/2" 5/2 valve, but that's only the size of the fitting it will take. The actual port hole will be much smaller. Same with the regulator, flow rate is very small, the inlet is barely 2mm in diameter! Check the port sizes of the ram as well, although it might be listed as 3/8" inlet/outlet, the actual hole will be much smaller. If the set up is for a lifter, then it's ok, but I can't see it will make a decent flipper without modifying your setup
will need to have another proper think about the design. cheers for the advice!
I use a 3/8" valve in the heavyweight I'm sure it will be ok for a feather. But check the manufacturer website for flow rates.
ive got a feeling that without a buffer, the system i had in mind wouldn't really fire quick enough to be effective. I never considered what Liftoff said regarding the size of the holes in the on/off valve, paintball reg, 3/2 valve and the cylinder itself and what that can do to the flow so id rather not commit to buying all the other parts without really knowing how effective the system would be.
Edit* just used a flow rate of 1500 litres per minute for the valve and guesstimated 600 litres per minute for the reg. Can someone just clarify if im in the right ballpark for both figures?
Cheers
Dan
Dont know if those figures are correct, but what I'm sure of is that the regulator flow rate is really low, it takes about 2seconds to fill the buffer tank up to 8bar, that's too long. The regulator will be your weakest link as all will depend on it, its useless having a ram and valves with large ports and high flow rates if air is just trickling through the regulator. If I were in you I'd go for a 5/2 valve with buffer and QEV set up. It's not so complicated as it sounds, and parts should not cost too much. I'm currently replacing a similar set up to a more compact one on my robot, have a look at my build diary, there are all the parts used (mostly off ebay). If you need any help on how to build it or anything else I can guide you. I will be rigging the new set up for a test fire soonish....results might be helpful for you.;)
Cheers mate, ill keep a watch on your build thread. I've had another go at the design and its now got a 9oz main tank, 9oz buffer still with the 3/2 valve. I wanted to use a full steel monocoque chassis but ill change for 8-15mm HDPE for that.
That's the way to go, just a small note regarding the buffer, I think the 9oz bottle is small for the ram you mentioned earlier. A 12oz bottle will be better suited.
the 9oz should do according to the spreadsheet. its just under twice the capacity of the ram. Any bigger than that and the robot will end up massive and complicated to plumb.
hmmm, twice the size of the ram is on the lower side... I'd be more confident with a 3:1 ratio, otherwise you will have a large pressure drop. Maybe someone else can confirm this. Btw, the difference between a 12 and a 9 oz bottle is not that much, the 9 oz bottle measures 26cm by 5.5cm dia. the 12 oz is 26cm by 8cm dia. Regarding plumbing, if you select your components wisely you can fit the whole system in a very tight space and keep weight to a minimum.
Just as an example in my first version of my robot I used 1/2" fittings and valves throughout, need less to say the system was heavy and quite large. The new redesigned system uses mainly 1/8" fittings and valves and only where necessary did I use 1/2" parts. This way I'm to loose about 1.3kg off the pneumatic system!
This didn't adversely affect flow-rates?Quote:
Originally Posted by Liftoff
Not necessarily, you only need good flow (large fittings) from the buffer tank to the ram, all the rest does not have any effect on flow. So the main plumbing and valve can be made as small as possible. The only downside I can think of is slower buffer recharge time, which I can live with.
have you tried this?
http://www.hassockshog.co.uk/flipper_calculator.htm
its pretty good!
Yeah I've already seen that before, I think it was on team onslaught website. It's helpful to get you started and point you in the right direction, but in the end the values on the spreadsheet and the real world results will be different. You'll learn as you go from your own mistakes and advice taken from others.
Industrial guideline is 5 times used volume per cycle of a machine.Quote:
Originally Posted by Danjr1
I use the 3 times ramvolume as a guideline. Less that that is really suboptimal.
Does anyone know of a cheap place to get LP pneumatic fittings? Every website i seem to look at is very expensive!
ebay can be good
rather stupidly, never thought of that! Cheers
If i wish to use a paintball tank as a buffer, what do people do for a fitment in place of the on/off valve or the pin valve? I'm thinking i could just drill the pin section out of a pin valve and use that?
Gerroff! They're MINE! lolQuote:
Originally Posted by plargen
Yeah, tons of fittings, all sizes and materials.
The paintball tanks have a not uncommon thread in the neck, according to Woodies site 5/8-18UNF.Quote:
Originally Posted by Danjr1
You can have the pin-valve or on/off valve replaced by an hydraulic coupling.
It's also possible to enlarge the tread to 3/8 or 1/2 bsp. but that means you'll need a recertification.
That's right use the pin valve and drill the internals out, the burst disc take it off and keep it as a spare, and the hole either blank it off or put a pressure gauge in.Quote:
Originally Posted by Danjr1
For pneumatic fittings I use this ebay shop, he's got metal push fittings good for 15bar, much better than the plastic ones.
http://stores.ebay.co.uk/cpmpneumatics?_trksid=p2047675.l2563
This is how the pin valve looks like after rework. I think its the easiest way to do it, or as Mario said find a suitable hydraulic coupling...if you can...:-|
Attachment 3674Attachment 3675
evening all,
the valve has arrived and i was hoping that someone could explain the diagram on the side and which ports are A, R and P?
I'm a little confused as the ports on the side appear to have no difference at all (they are linked?!)by a gapping hole but from what i can gather/ guess:
The ports on the side are inlets (one would need plugging)
The port on the opposite side to the sticker diagram is the outlet to the piston
The exhaust (normally open) is up through the valve and out of where the male thread is.
Attachment 3704Attachment 3705Attachment 3706
Cheers
Dan
Dan the decal is misleading, but that valve should operate as follows, port (P) the one opposite to the diagram decal is the pressure side (from buffer tank). Port (A) is the user, and should be connected to the ram. Port (R) is the return, ie its the exhaust from the ram and should not be connected to anything. In the normal position, port P is closed. Port A and R are connected (air in the ram is exhausted through port R)
When solenoid is energised, Port P is connected to port A, air from buffer tank flows to the ram. Port R is closed.
To be honest, these valves look so awful in terms of flow that I'm thinking that I might end up having to use larger 2 way 2 position valves with 4mm orifices (one normally open as the exhaust, the other normally closed as the inlet) but that would mean drilling a hole in the side of the ram and having a home made adapter welded on.
The only useful advice I can give you for better flow is a 5/2 valve+QEV+buffer setup. With this setup the size of the solenoid valve becomes irrelevant...what will matter will be the sizes of the ram orifice, the QEV and connections to the buffer.
to be honest, I'm getting fed up with trying to find pneumatic parts to fit into the design of bot i wanted to i might as well go to a drum spinner with interchangeable weaponry! will be much much easier!
obviously using a small 1mm diameter hole in the bottom of the ram in the same way as a full pressure system would work on a low pressure but what i was wondering was how much of a detrimental effect it would when firing?
I'd say the effect will be negligible, compare the areas of the inlet to the exhaust holes, the larger the difference the better
Cheers dude. I could maybe go for a 0.5mm hole maybe?
What do people reckon the flow rate in litres per minute would be on the valve below? Im not too sure whether id believe 12000 litres per minute as in their graph!
http://www.ebay.co.uk/itm/New-3-8-El...item1c1a8c45f1
Check out this.
It's a gamble, but if the price can easily be beaten, it's one I would take. I didn't realise you were only dealing with 10bar.. many solenoids are rated at this because of what the coil will handle under pressure, not the rest of the valve. Well you can overvolt a coil just the same as for motors...and the vast majority are rated up to 8bar anyhow.
If you go for this and find one you want, you could re-list them either individually or with a better listing than this one anyhow.
http://www.ebay.co.uk/itm/Pneumatic-...item4d0c918520
I'm actually tempted miself, but I have a couple of festo banks already so I'd happily get out of your way. Let me know, so we don't end up in a bidding war.
Cheers dude but I won't be bidding on them. Beginning to learn that pneumatics aren't my thing
True, even without overvolting the solenoid and increasing the pressure, the valve will work...most 5/2 valves are pilot operated, so the solenoid just opens a small orifice and the valve spool moves pneumatically. ...but there is so much pressure you can increase on an 8bar rated valve. At above 11 bar air will start leaking at the valve heads.Quote:
Originally Posted by Bacon Wizard