SpudFiles

One question, how could I make this automatic?

Random, but interesting.

QEV + pop-off pilot?

uhmm ever heard of solenoid valves + microcontroler/555 timer/time relay

or read my thread on time delay valves ?

POLAND_SPUD wrote:solenoid valves + microcontroler/555 timer/time relay

Second that.

What are you up to this time? Oh and hay, whats up?

Electronics are not an option out of principle. "time delay" = end to google searching funk.

This is close: jsr, I know a system with a qev+pop off is viable, just not sure how to implement it. Switching from a double acting cylinder to a spring return cylinder, etc.

I remeber a circut where adjusting a flow control valve adjusted the speed of reciprocation. I'd like something like that.

This is a prototype for a handheld tool, gonna keep the specifics under wraps until I find out someone else has already built it. Big news I've kicked smoking for a week now, thats about it. Normally not worth mentioning, but hey I've thought about it a few hundred times while working on this project.

CS wrote:Big news I've kicked smoking for a week now, thats about it. Normally not worth mentioning, but hey I've thought about it a few hundred times while working on this project.

Idle hands keep them busy!

Switching from a double acting cylinder to a spring return cylinder

That would basically be it.

Here's how I modded a QEV for full auto: http://www.spudfiles.com/forums/viewtop ... tml#338215

I remeber a circut where adjusting a flow control valve adjusted the speed of reciprocation. I'd like something like that.

Note how in my example the cyclic rate depends on how fast the air is being fed into the system.

For a double acting cylinder, you would need some sort of shuttle valve in the system.



We have pneumatic diaphragm pumps at work similar to this:

[youtube] [/youtube]

Around 1:30 there's some good animation of how it works.

time delay valves are air actuated valves. They've got a flow control valve (or just an orfice) to regulate flow of air to the pilot side once the pressure on the pilot side is high enough to overcome stiction, spring force etc. the valve switches to the other position

Here you can see one of them
http://www.esska-tech.co.uk/esska_eng_s ... type_.html

off the shelf time delay valves can be difficlt to get and/or expensive but you can build one with a regular air actuated valve and a flow control valve

ohh here is one I built and tested


As you can see it works though it didn't offer high enough flow for a fullauto high pressure pneumatic but it was due to the valve size and tubing only

Went ahead and made a qev+poppet valve setup. My poppet valve is 125psi and my compressor is 100psi, so I Macgyvered an external spring to lower its opening pressure. The bursts of air are to short to get a full extension of the cylinder.

Sound is crux, and the poppet valve exhausting is a problem. Going to stick with my orginal plan and have a exhaust line alongside the air in line. This way the exhausted air is discharged 50 feet away.

I'd like to make a mechanical switch that accomplishes the graph below. Seems simple enough but when I get down to thinking I can't figure out how to press the switch in one direction, but not the other direction.

I'd like to make a mechanical switch that accomplishes the graph below. Seems simple enough but when I get down to thinking I can't figure out how to press the switch in one direction, but not the other direction

uhmm you want to use just one switch??

that can be done - though you might have to remove the spring return from the valve to turn it into a a toggle valve