Backyard Aquaponics
A place to discuss aquaponics

They are working ok, I have a bit of trouble with bounce they open up a little which can cause a loss of flow to the open bed, so I upped the fill time a little to compensate. I also put some closed cell fast recovery foam on the outlet to cushion and seal the plug, that seems to have reduced the problem to manageable levels.

The tricky part is making sure the guides keep the plug rod running straight. My actuators have a rod that has a 90 degree bend at the end, it would be better if the rod sat in the middle of the actuator shaft.

Regarding the actuator if they are like mine they are designed to operate with a 12v system pulsed for 0.2 seconds. You could also run them at a lower voltage I have had them run at 6v they might even work at 3v.

I noticed you mentioned somewhere that you were going to try some solenoids, don't they draw current the whole time they are active? If so it could be a severe waste of energy.

So you pulse for .2 seconds to close the valve and then pulse again to open the valve?

For what I'm trying to do, I only need to close a valve momentarily (less than 10 seconds) each time, the valve automatically re-opens by a spring. I figured it would be reasonable to energize a solenoid for several seconds every 15 or 20 minutes or so. However, if I can figure out how to properly use one of those actuators........ that might still be a better choice.
This is the kind of actuator I got. Only two wires
http://www.commandocaralarms.com/itemdetails.asp?ProductID=552


At least it mostly looks like that but the plastic body is grey.

One of the things that I have noticed with the current slow drain design that does not happen in the siphon design is that the overflow to sump while the GB drains means poo goes into the sump and back to the fish tank, so it is not as efficient in removing the solids as the siphon system.

Still growth seems to be ok

photos to follow. TCLynx here is a photo of the bend I mentioned.

I am also experimenting with a bed as a starter bed for outdoor AP and dirt garden, dirt garden trays are coir fed and watered by ap flood and wick effect, scoria tubes are for transplant direct to trout AP.

Note the stupid seed that slipped its tube.

I've done the seed starting bed thing, works pretty good actually.
However, I'll warn you that the cardboard tubes probably won't last long enough. I found that those peat pots didn't really last long enough though peat pellets do last so long as critters don't start digging up your seedling looking for worms to eat.

What you might want to do if the solids going back to the sump tank becomes an issue, is set the overflow to go to a bed that has a siphon or something in it so you can always allow the overflow to be filtered by a bed.

Ok, so with those car door actuators, I need to be able to reverse the polarity of the pulse then don't I? When I had first tested it out, for some reason the thing seemed to be springing back when the voltage was released so I guess that might be why my mind didn't wrap around the proper wiring/use of the thing.

I'll put up some details of my controllers on the repeat cycle timers thread
viewtopic.php?f=8&t=6077

You can't use these actuators to actually hold the valve open or closed - design the valve so the water flow or a detent of some sort holds the open or closed position and the actuator just shifts between the two positions - click the door lock on your car and you will get the idea. The lock flicks over from open to closed mechanically, the actuator just kicks it over the middle hump.

John

Yep, I was hoping the weight of water would press closed. The system will hold open no problem and it stays closed if it does not bounce. If it bounces it stays put slightly open. With the flap valves water pressure does seem to help or maybe it's just more resistance to move the flap therefore less bounce.

One idea I have considered is a small piece of heat-shrink at the and of each point of travel and a rubber fitting on the guide. When the heat-srink is pushed through the rubber the resistance increases a bit. So there is enough resistance at fully closed and open to stop the bounce. I have tried rubber on the guide it helps but it is hard to adjust so it does not impede the main movement.

Right now I'm using springs so. Currently the one spring hods the valve open and we are just manually pushing the bar down to close the valve momentarily. Whit a slightly lower hanger for the spring, the valve will not spring back open but can be switched from position to position and will remain at either. The water pressure against the flap tends to hold it in place and once past the initial umph of opening the valve, it doesn't take much to hold it open.

Guys,
what's the maximum stroke/travel of those door actuators?
Could one be used to lift a toilet flap valve similar to what TCL uses in her Barrel ponics header tank setup?

So it could be used to drain a grow bed after a set time via a cycle timer. This is how I plan to sequence a few GB's with continious pumping, just drain at intervals instead of changing flow betweeen GBs. In an attempt to minimise my sump tank volume.

I guess it depends if the actuator can lift the flap up higher enough to start the outflow? If not a lever setup like an off centre seesaw might work to correct the travel, but inturn will increase the required force from the actuator to lift the valve.