Pause a piston?

[cliff451]

I was charged with the job of stopping a pnumatic piston in the middle of it's stroke. I first thought of getting both sides of the solenoid to fire at once and realized that it wouldn't work.

Can I take two single throw solenoids and have them act against eachother in the middle of the stroke? I haven't tried it yet and need ideas. If anyone has tried this let me know!
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cliff451

[Chris_Elston]

Originally Posted by cliff451

I was charged with the job of stopping a pnumatic piston in the middle of it's stroke. I first thought of getting both sides of the solenoid to fire at once and realized that it wouldn't work.

Can I take two single throw solenoids and have them act against eachother in the middle of the stroke? I haven't tried it yet and need ideas. If anyone has tried this let me know!
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cliff451

What you are looking for is a double valve, with a center CLOSED port.

It's a 3-position valve. SMC has them in the same series as the kit of part valve, only you need the center closed version.

[Hito Seika]

last year we used a double solenoid on a five port valve with a closed neutral position.
the 5 ports are for:
air supply
output 1 (extend)
exhaust ouput line 1
output 2 ( retract)
exhaust output line 2

[cliff451]

What you are looking for is a double valve, with a center CLOSED port.

It's a 3-position valve. SMC has them in the same series as the kit of part valve, only you need the center closed version.

Thanks a ton, I'll check that out

[Fred Sayre]

You can also run the vent valve on the first solenoid to another solenoid. That way you can control direction with the first, and start/stop/pulse whatever with the second. It is not the most precise system but has worked for me before on a previous team.

[cliff451]

You can also run the vent valve on the first solenoid to another solenoid. That way you can control direction with the first, and start/stop/pulse whatever with the second. It is not the most precise system but has worked for me before on a previous team.

Thats a good idea too! I can actually try it!

[IndySam]

You can tie two cylinders together, fire one for half way both for full stroke. Much easier, precise and reliable.

This is also a good way to make the stroke lengths you need that are not legally available. Last year we made a 14" stroke this way.