Burkerts

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?

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 .

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.

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.

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.

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

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.

If I remenber correctly, Dantomkia had problems with burkets not fireing properly at 24v on a nice full tank. They got a voltage increaser (probably wrong word but brings 24v to 36v). This gave them no problems.

Contact bugs about these.
Regards
Ian

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.

Have you concidered a 12 v coil on your Burkert?

They dont seem to be listed as a std option.

They are no option, and the Burkert coils are bigger than standard pneumatic coils,and smaller than the hydraulic ones.

Otherwise I would buy Burkerts with 12V coils anytime

If there is intrest in my voltage booster I can whip up another batch. Just mail me :)
They look like this: http://www.bugs.nl/media/album/view.php?&path=L3Byb2plY3RzL3ZvbHRhZ2UtYm9vc3Rlci9 JbWdfMDg2NmIuanBnhttp://www.bugs.nl/media/album/view....Z2UtYm9vc3Rlci 9JbWdfMDg2NmIuanBn
Ive also made some luxury models pored in resin to make them shockproof :)

http://www.jaksa.si/English/coils.htmlhttp://www.jaksa.si/English/coils.html

Any of these suitable Mario?

I have bought a Burkert 12 v coil for my 5404.

Got a reference number Phil?
It sure would help to run 12v coils.

Valves can dry out over time and stick...

Ive seen a small amount of hydraulic oil make a big difference in a pneumatic system by lubricating the valves.

However, I would point out that it is possible, depending on the valve material, that the oil could react with the valve seals.

Dont use combustable lubricants like WD40, or normal oils, as these could combust under the pressures involved...

CO2 is on the other side a perfect fire extinguishing gas.
I never encountered a dieseling effect, and I dare to say that some of the rams I did build are strong and fast enough to get that effect.Actualy not. In a CO2 system there is no free oxygen to react, and on the non pressured side of the piston we dont want to have any pressure build up.
I would be surprised if we get a diesel effect in a good designed and build Full pressure CO2 using system. Is that a Gravity or a Dantomkia setup.

I use the very sticky molycote 111 silicone grease in my rams. And the Burkert valves are equipped with sealing materials that can stand a lot off chemicals. But Silicon grease/oil is mostly the safest bet you can make.

Woody, there are a couple of numbers. AC10-Z3-5-38AA (I think. The last few were a bit hard to read.) and 130104Z. The coil came from Burkert in Sydney, Australia. Your local Burkert should be able to help you.