SpudFiles

Hi guys.
I did the real test of the system today, with relatively low pressure, somewhere around 200 psi. The test was a big failure, the solenoid was not able of open the valve, apparently with pressure the o-rings get tighter, eventually locking the valve stem. Youtube isn't working for me so I can't upload a video, but I will keep trying.
Also at 400psi (the operation pressure I was planing), sometimes the o-rings pop off, quite a big problem and tricky to solve.
So I'm looking for bigger solenoid now as I don't want to abandon this project yet. I found out that some nail guns work with a solenoid, if they are able of shooting a nail into wood, it's for sure enough to open this valve. In case I couldn't find one, I probably make my own solenoid.
Now I'm really surprised how did the russians put this concept working

wyz2285 wrote:Now I'm really surprised how did the russians put this concept working

Low friction and being Russian

Low friction but still being air tight is kind hard
How did they keep the valve seal? I don't see any o-rings or seals

Looking at the diagram the yellow part is a seal, on the other side it looks like the bolt seals against the light gray part so it's only 100% sealed when the valve is at rest.

Well so a black bird uses CO2 right? that's 800 psi at least.
Considering the yellow part is not a o-ing, it has to be extremely tight to seal; also for the valve to seal to the light grey part, the spring has to be very strong too These are the parts that I don't understand

wyz2285 wrote:also for the valve to seal to the light grey part, the spring has to be very strong too

No, pressure difference seals it.

Ah right. But still so, it's a big obstacle to the hammer anyway

wyz2285 wrote:Ah right. But still so, it's a big obstacle to the hammer anyway

... but once it begins to move, pressure actually helps the bolt to open

But the solenoid is weaker in the beging, so it's still very hard.
I'm looking for a new solenoid or make my own.

Here is a parts layout for you.
I will e-mail schematic and PCB file.

Thank you very much dewey-1 !

I have a video now about this concept, but no firing, not connected to a air source either. Even through it won´t work with the designed pressure (400 psi), the mechanism is working well, and would work with 100-150 psi, but the power also would be very lame
So do you guys still what to see the video? Basiclly it´s just the solenoid opening the valve, nothing else.
For those who wants to make simular mechanism, here is tip: use a very strong solenoid, and here is a diagram of the valve in case you can machine the valve stem and body.

What is the power rating of your solenoid valve ?


I wonder If you can boost it slightly by using a capacitor and slight over-voltage, the energised time is quite short so you could probably get away with it without overheating.

0.8 N holding power, but doesn´t means it´s strong enough during the aceleration of the injection pin. I use a timer circuit to control it, so I can´t use a capacitor. With 12v, after working for 30 sec it already starts heating, so not a good idea either.

No Watt rating ? Or Current rating in Amps ?

I use a timer circuit to control it, so I can´t use a capacitor.

Sure you can, using a MOSFET or relay, you can run it on a different power source to the timing circuit.

after working for 30 sec it already starts heating

Continuously or pulses ?

I have a 12V 25W solenoid pretty similar to yours in construction, (not too sure about the holding force, but it's rated to 0.2N at 15mm so can probably hold a couple of kg), it is triggered through the means of a N-channel MOSFET by a microcontroller that outputs 5V max and the solenoid is powered by a 12V 3A wall supply.

I've also run my 24V solenoid spool valves on 27V, if left on they would heat up pretty fast, but only a few milliseconds at a time are needed to fire the airgun.