Burkerts

[blazerbotics]

At the weekend i had a problem with the burkerts sticking in Knightmare, thankfully they started to work about 1/2 hour before its fight, although it was taking along time to exhaust during the first fight. I was just wondering whats the best thing to stop them sticking or what to do when they do. Weve never had a problem with Merlins, which have probably had more use then the ones in Knightmare, but in merlin we run the valves at about 30v (we have an extra RX battery in line with the valves so we dont suffer with them not firing if theres a voltage drop i.e. when pushing somebody ect), could this help them stop sticking?

[marco]

normally a voltagedrop doesn´t matter , a burkert will even work at 12 volts . I had some problems with burkerts older than 2 years , you can buy a revisionset ( don´t know for sure if this is the right word) and make your burkert brand new .

[mute]

I wouldnt have thought 12V would provide enough force to activte the valve at 50 Bar.

Maybe they just got sticky? Our solenoids (not burkets) stick occasionally if we havent used them in a while. We just tap the head with something (cough hammer cough) to free them off. Just a guess but maybe its something to do with condensation (from the cold) and a soft iron core?

Give em a tap, switch em on and off a bit and they should free up.

[blazerbotics]

we could never fire our valves when moving, before we put the extra battery in.

The robot hadnt had a fight since filming series 7, but they did work last week, although the gas tank wasnt full so maybe that was why it could fire then. I did try tapping them at the time but didnt seem to do much. It all works fine at the moment, but i was just wondering incase it happend again.

[woody]

Is it possible that a little moisture may have got into your system and therefore cause your valves plunger to ice up?

taking along time to exhaust ... sounds to me like your inlet valve is slow to close .... i.e. both valves could be open when your exhausting.

[kronic]

We had a problem with our exhaust valve freezing up (mind you, we still do sometimes). Getting rid of our dip tubes in the fire extinguishers helped a lot.

Dave

[maddox]

Avoiding liquid CO2 in the system is always a good thing.
A burkert operates by the pressure difference , and a very small hole in the plunjer.
When that hole gets plugged, and liquid CO2 that is expanding will have pieces of solid CO2 in it, the valve wont close.The solid CO2 evaporates fast , so you never will find the culprit.

Battling liquid CO2 in the system was 1 of my main tasks from the first misfiring of Project II.

[maddox]

You remeber correctly, at 24V a burkert cant lift the plunjer to fire the valve at pressures above 850 psi-depends from solenoid to solenoid, but the pressure wont vary much- because a burkert was meant to fire 750 psi max. Overvolting the coil to 36V makes it possible to fire the valves at for us normal pressures. Also, the tests that Mike and company did on burkerts show that the body can take way more than 1000 psi.

Mike encountred this problem in Las Vegas, nice and hot day, So the pressure inside the bottle was maxing out.

After this, and seeing an increase in burkert use in feathers, were 24V is rare, Bugs made a voltage step up, and that does about anything between 9.6V and 24V to 36V.Amperes are limited tough.Also, the system is safe but cheap.

[philip_taylor]

Have you concidered a 12 v coil on your Burkert?