rcmike
Active member
No timer, it was one of these float switches. http://www.championlighting.com/home.php?cat=388
DIY Wavebox! (With modded MJ)
- Thread starter smcnally
- Start date
rcmike
Active member
No timer, it was one of these float switches. http://www.championlighting.com/home.php?cat=388
celebrityovernight
Member
hey mike, thanks
This has all been very interesting reading but I believe something simple may have been over looked.
In the original design the pump needed to be turned on an off with a timer. MJs will operate in both directions push and pull and when they choke abit they tend to reverse direction on their own.
So what if the box is closed except for the outlet on the box. And you use a valve to introduce a air void in the top of the chamber. And then close the valve so no more air gets in or out.
What would happen when you turn the pump on.
If it runs in reverse it compresses the air in the top of the box and chokes the pump causing it to reverse direction on its own. As it starts pumping out the displaced water creates a vacume and chokes the pump again and it reverses and repeats the cycle. Key here is the pump is always on.
Experimentation with the amount of air needed to get the timing needed would be adjusted with the valve. The more air in the chamber the longer the pump flows in one direction before reverseing. This should be very quiet as well. No Stopper needed.
The only thing is you may have to use thicker acylic to achieve a rigid enough chamber.
Please someone give this a try. It will be a month before I can get to this.
Dan
In the original design the pump needed to be turned on an off with a timer. MJs will operate in both directions push and pull and when they choke abit they tend to reverse direction on their own.
So what if the box is closed except for the outlet on the box. And you use a valve to introduce a air void in the top of the chamber. And then close the valve so no more air gets in or out.
What would happen when you turn the pump on.
If it runs in reverse it compresses the air in the top of the box and chokes the pump causing it to reverse direction on its own. As it starts pumping out the displaced water creates a vacume and chokes the pump again and it reverses and repeats the cycle. Key here is the pump is always on.
Experimentation with the amount of air needed to get the timing needed would be adjusted with the valve. The more air in the chamber the longer the pump flows in one direction before reverseing. This should be very quiet as well. No Stopper needed.
The only thing is you may have to use thicker acylic to achieve a rigid enough chamber.
Please someone give this a try. It will be a month before I can get to this.
Dan
hahnmeister
In Memoriam
The problem is that although you are starting and stopping the prop and air in the chamber, all you are doing is starting and stopping, not reversing... and you need this chamber to both fill with water and purge it... not just purge and stop, purge and stop...
by manipulating the air, you are doing a similar thing to the Reverse Carlson Surge.
Which makes me wonder... is there a way to combine a powerhead like the MJ with the air-gap plumbing like with the RCSD...??? This could be a solution without any mechanicals other than the pump, where all the valves rely on the natural pressure differences of the system through creative use of airgaps/traps.
by manipulating the air, you are doing a similar thing to the Reverse Carlson Surge.
Which makes me wonder... is there a way to combine a powerhead like the MJ with the air-gap plumbing like with the RCSD...??? This could be a solution without any mechanicals other than the pump, where all the valves rely on the natural pressure differences of the system through creative use of airgaps/traps.
Hahn, I know these pumps reverse on their own when choked. Thats sometimes why they spin backwards with larger props. But I think you caught onto that Idea with your last paragraph. I don't know what the reverse carlson surge is but I would assume it to be very similar if its using air traps to create an area for compression or vacume to occur.
To get the adjustment persision nessesary may require a void with much smaller dimmensions than the actual wave box itself. Therefore PVC pipe may be nessesary to extend the air void above the box to achieve the required precision. Although 2" Pipe is quite large it has an area of 3.14 so the math gets easy if it graduated in tenths of an inch. You box could be graduated the same way in tenths of an inch.
My Guess is that with the no air in the box the pump would not go forward or reverse. Idea here is that fluid is non compressable. Therefore some cubic inches of air is required to achieve the nessesary function. I would start this experiment with the box full of water and the extension PVC Pipe full of air. The extension what ever it is should be clear so you can see the water level inside the pipe if less air is needed and should be around 4" in hieght.
With a 2" Pipe full of air you would have 13.35 Cubic inches of air.
If the pump completly empties the box or fails to choke, draw water up into the tube by opening the valve on top of it and lowering the box into the water until water comes up into the pipe. Close the valve up and run.
If the pump reverses to quickly more air needs to be added to the box. Since you want to messure air that is not under pressure the valve would have to be opened and the box raised above the water line to add air to the box.
Make very large corections at first to try to bracket the desired timing. We know this will be just a hare under one second for most tanks.
Anticipate water comming up into the pipe when the pump runs in reverse and compresses the air void if you start the experiment as I have stated above.
Hope to here how this works out soon.
Thanks,
Dan
To get the adjustment persision nessesary may require a void with much smaller dimmensions than the actual wave box itself. Therefore PVC pipe may be nessesary to extend the air void above the box to achieve the required precision. Although 2" Pipe is quite large it has an area of 3.14 so the math gets easy if it graduated in tenths of an inch. You box could be graduated the same way in tenths of an inch.
My Guess is that with the no air in the box the pump would not go forward or reverse. Idea here is that fluid is non compressable. Therefore some cubic inches of air is required to achieve the nessesary function. I would start this experiment with the box full of water and the extension PVC Pipe full of air. The extension what ever it is should be clear so you can see the water level inside the pipe if less air is needed and should be around 4" in hieght.
With a 2" Pipe full of air you would have 13.35 Cubic inches of air.
If the pump completly empties the box or fails to choke, draw water up into the tube by opening the valve on top of it and lowering the box into the water until water comes up into the pipe. Close the valve up and run.
If the pump reverses to quickly more air needs to be added to the box. Since you want to messure air that is not under pressure the valve would have to be opened and the box raised above the water line to add air to the box.
Make very large corections at first to try to bracket the desired timing. We know this will be just a hare under one second for most tanks.
Anticipate water comming up into the pipe when the pump runs in reverse and compresses the air void if you start the experiment as I have stated above.
Hope to here how this works out soon.
Thanks,
Dan
hahnmeister
In Memoriam
Im talking about taking it a step further by eliminating the vlaves all together, and simply using a system of air gaps and water gaps in pipes to control the flow.
I posted a link on the RCSD in the last few pages.
I posted a link on the RCSD in the last few pages.
Ddavis are you saying use a normal box (air tight except for output hole) add a length of tubing to the top? Like as a diaphram of sort? Sounds like it would work however are you sure that after it expells all of its water it will (the pump/prop) reverse? Could we expect it to work every time? I'm not sure I've ever starved a pump so I'm a lil foggy on how it changes directions given your idea... or maybe I missed the point entirely...
Nevermind above I think I figured out what your saying...
Pump extracts water from box untill vacumm is created wich starves pump then reverses untill pressure starves pump and reverses again...
Right?
How about some airline tubing that goes to a bottle of air like a gatorade bottle then the air could be adjusted easier.... instead of the pipe..
Pump extracts water from box untill vacumm is created wich starves pump then reverses untill pressure starves pump and reverses again...
Right?
How about some airline tubing that goes to a bottle of air like a gatorade bottle then the air could be adjusted easier.... instead of the pipe..
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I don't think it really matters what you use for the air trap as long as there is sufficient capacity. 2" is an easy volume calc. PI.
Keep in mind from most of the footage on this device in operation about 64 Cubic inches corresponds to the timing. This is with the pump fighting about a 4-8" head pressure in the tank. And I do believe the pump could almost empty the chamber against 12" of head. They are that strong.
Good Luck,
Jean,
No I don't mind. I hardly think this is an origenal idea I just wouldn't sell it. I'm sure there are patents out there and I wouldn't want anyone to get stung.
Keep in mind from most of the footage on this device in operation about 64 Cubic inches corresponds to the timing. This is with the pump fighting about a 4-8" head pressure in the tank. And I do believe the pump could almost empty the chamber against 12" of head. They are that strong.
Good Luck,
Jean,
No I don't mind. I hardly think this is an origenal idea I just wouldn't sell it. I'm sure there are patents out there and I wouldn't want anyone to get stung.
To answer the won't work question. I've seen it happen, I'm sure other have as well. When you make the pump fight for water it reverses all on its own. I'm just making it possible to fight both directions. All it takes is enough resistance for the frequency in the pumps electro magnet to outrun the propeller drive magnets and it will reverse.
It will however require some baby sitting. Over time as calcification or other friction sources build up the timing will change and the duration of each cycle will be less and less. Calcification can to some degree can be reduced.
The other thing is air bubbles in the water column can get pulled inside the box and perhaps add to the air already trapped. I believe this may take awhile to have any effect unless there is a significant amount of air entraned in the water column already.
Regardless, any of these issues are easily remidied with simple maintenance of the pump or monitoring/adjustment of the air trap itself.
This implies that the make the pump easily removable and the airtrap easily adjustable.
Making the propeller smaller may reduce the pumps sensitivity to changing conditions but not take it away entirely.
Again good luck.
It will however require some baby sitting. Over time as calcification or other friction sources build up the timing will change and the duration of each cycle will be less and less. Calcification can to some degree can be reduced.
The other thing is air bubbles in the water column can get pulled inside the box and perhaps add to the air already trapped. I believe this may take awhile to have any effect unless there is a significant amount of air entraned in the water column already.
Regardless, any of these issues are easily remidied with simple maintenance of the pump or monitoring/adjustment of the air trap itself.
This implies that the make the pump easily removable and the airtrap easily adjustable.
Making the propeller smaller may reduce the pumps sensitivity to changing conditions but not take it away entirely.
Again good luck.
I've thought about that design before and figured if water tryies to enter the small volume tube there may be resistance from the tube that has no bering on the air trap itself.
These pumps move alot of water. Thats why I'm figuring a large diameter pipe rather than a small 1/8th to 3/16 airline tube connected to the box.
These pumps move alot of water. Thats why I'm figuring a large diameter pipe rather than a small 1/8th to 3/16 airline tube connected to the box.
