DIY Wavebox! (With modded MJ)
- Thread starter smcnally
- Start date
aninjaatemyshoe
New member
Well, I just got my TAAM wavemaker in and it seems that it would work on the wavebox. The fastest on/off periods seem to be quick enough to accomplish the wave effect. However, the controls are a bit finicky and adjusting the time on/time off will be rather difficult. One of the big hurdles is that there is both a time on and time off dial, but they don't seem to be exactly 1:1. The shortest on setting seems to be a bit shorter than the shortest off setting. That means adjusting the time periods will be that much more of a headache. I'm probably going to loose my mind trying to get it just right when I use it...
Overall, I'd say that its probably going to be worth the price to accomplish this. The only other reasonable option that I know of it to use one of those Omron controllers (the cost around $50).
Overall, I'd say that its probably going to be worth the price to accomplish this. The only other reasonable option that I know of it to use one of those Omron controllers (the cost around $50).
Beenalongtime79
New member
Well, certainly, keep us updated on results ninja
GuySmilie
Premium Member
Just read quickly thru this thread. My immediate thought early on was why fight the electrical aspect (motors spinning correctly, not burning out, etc). Use pneumatic control, as several others have suggested.
Since this wave box functions mainly due to the resonance of the particular tank it is attached to, the resonance will be slightly different for each tank. By using strategically timed 'puffs' of compressed air and simple flapper-type valves to control water movement into and out of the chamber, I think the original box chamber idea could be made to work with air. Even a length of 1" or 2" diameter clear acrylic tube could be used. Air supply could be from a air pump feeding a small air tank, like the little 3 gallon kind used for emergency tire inflation.
Just thinking out loud here, but it looks like playing with the resonance thing, you would not need a very large puff of compressed air every cycle (or even every other cycle) once you get this thing moving its water column.
Using the dynamic movement of the water column, wouldn't it keep itself going? Not quite perpetual motion, but along that line of thought. Sorry if this all sounds silly. My expertise is in RF engineering and not fluid dynamics
I wish I had the time to play around with this more!
Guy
Since this wave box functions mainly due to the resonance of the particular tank it is attached to, the resonance will be slightly different for each tank. By using strategically timed 'puffs' of compressed air and simple flapper-type valves to control water movement into and out of the chamber, I think the original box chamber idea could be made to work with air. Even a length of 1" or 2" diameter clear acrylic tube could be used. Air supply could be from a air pump feeding a small air tank, like the little 3 gallon kind used for emergency tire inflation.
Just thinking out loud here, but it looks like playing with the resonance thing, you would not need a very large puff of compressed air every cycle (or even every other cycle) once you get this thing moving its water column.
Using the dynamic movement of the water column, wouldn't it keep itself going? Not quite perpetual motion, but along that line of thought. Sorry if this all sounds silly. My expertise is in RF engineering and not fluid dynamics
I wish I had the time to play around with this more!Guy
jpatrician
Premium Member
Any updates?
The big issue with stopping/starting an AC motor like that is that it consumes a lot more power during its starting transient stage (inrush current) thereby reducing it's life expectancy ( more current = more I^2*R power loss within the coil which is lost as heat, weakening the conductor(coil)). If you could gently ramp up the input voltage instead of a hard 'on' and 'off' you would save increase the motor's lifespan. I may someday attempt it with an FPGA but hopefully some copmany has already accompished this.
I suppose the MJ's are so cheap that you can keep a few extras stocked for when they fail.
I suppose the MJ's are so cheap that you can keep a few extras stocked for when they fail.
hahnmeister
In Memoriam
Thats why I suggest a mechanical solution rather than an electrical control one. The pump can run constantly, its just a drum valve that rotates.
college429
Member
If all you need is displacement of water, why doesn't someone just build something that plunges a float down into the water periodically. It doesn't seem you need a box at all. This seems to me to be the easiest way to create a wave. You could mount the mechanism on top of the canopy, with a small hole for the shaft and a float on the end that plunges into the water slowely to make a wave.
What do you think?
What do you think?
aninjaatemyshoe
New member
The problem with the direct mechanical solution is designing something that can last for tons of cycles in an environment that is highly corrosive towards metals. It would more than likely take up a good portion of real estate at the top of the tank and be an eyesore. Even the wave2k, which is designed to provide the mechanical solution while taking up as little room outside the tank, looks awful IMO.
hahnmeister
In Memoriam
Then you have to get more creative. I was thinking something alng the lines of a variable speed spinning valve... nothing more to wear and tear than a pump really, if that. Something that has 60rpm or something like that. I think I could make it into a smaller box than a tunze unit. The pump is still used, only a spinning nylon pipe inside of another pipe determines if the flow from the MJ1200 goes inside the box, or into the tank. This same spinning pipe would determine the intake as well... from inside the box, or the tank. Then, all that is left is to power the spinning rod... thats where Im seeing the challenge. Nothing too hard, and nothing too nasty, bulky, etc... like one of those wavemaker 2000 units...
The idea is much like the air powered wave box that someone made a while back... the air pump constantly pumps air into the box, and a valve at the top of it rotates from on and off at a rather fast pace (say, 60cycles per minute) and the box fills with air, then all the air goes out... and this process pushes the water level inside the box up and down.
hahnmeister
In Memoriam
Thats along the lines of what I am talking about. A fast rotating drum valve on the intake and outlet to manipulate the water entering and leaving the box. A pipe within a pipe if ported out properly.
Thats just an early, crude idea I had... I realize that the pump needs to have an outlet that isnt obstructed ever, but rather just has its output switched from going into the tank to back into the wavebox.
aninjaatemyshoe
New member
I like the rotating drum valve idea. Has anyone ever DIYed something similar?
hahnmeister
In Memoriam
The drum I did above is sorta off. I have revised it since, but you get the idea. The tricky part is to find a motor to rotate the drum/pipe. I was thinking perhaps a DC motor, for variable speed, and then linking it via a rubber belt (large o-ring).
Or, the drum isnt really needed. If there was some mechanism that would bob the pipe, or even just a slotted strip of acrylic/plastic, up and down, that would work as well as far as controlling the flow of the pump.
But otherwise, there are two main things to control here with the pipe-valve (spool valve is the real term?). One is the flow of water into the box via gravity, and the other is the flow of water out of the box via the pump. When the pump is pushing water into the tank from the box, the flow into the box via gravity needs to be stopped. Then, when the flow of water from the box is open, the flow from the pump needs to be looped back into the box. This way, the water will either be from the box into the tank, or from the tank into the box. The rate is determined by how fast the valve moves.. thus the reason for a DC motor to power it. The only other thing to watch is that the valve doesnt rotate so slow that the pump is able to run dry when the inlet valve it shut and the pump is pumping into the tank.
Or, the drum isnt really needed. If there was some mechanism that would bob the pipe, or even just a slotted strip of acrylic/plastic, up and down, that would work as well as far as controlling the flow of the pump.
But otherwise, there are two main things to control here with the pipe-valve (spool valve is the real term?). One is the flow of water into the box via gravity, and the other is the flow of water out of the box via the pump. When the pump is pushing water into the tank from the box, the flow into the box via gravity needs to be stopped. Then, when the flow of water from the box is open, the flow from the pump needs to be looped back into the box. This way, the water will either be from the box into the tank, or from the tank into the box. The rate is determined by how fast the valve moves.. thus the reason for a DC motor to power it. The only other thing to watch is that the valve doesnt rotate so slow that the pump is able to run dry when the inlet valve it shut and the pump is pumping into the tank.
hahnmeister
In Memoriam
I updated the pics of the wavebox...
A rotating pipe, or a bobbing one... you pick.
A rotating pipe, or a bobbing one... you pick.
Green Thumb
New member
I have to admit I like smcnally's idea of the wave box better, a little more tangible too.
Let us know when you actualy start working on your prototype though, it will be interesting to see what that can do...
Let us know when you actualy start working on your prototype though, it will be interesting to see what that can do...
Tigger240
New member
hahn, i do like your idea, just sounds like alot of tedious math calcs, or lots of trial and error, especially when were talking about 1/10ths of second timing is involved. Id think that the clicking with the maximods can be avoided with the koralin type bump stop - just a real long shaft where the prop is no longer in the magnetic field and returns. i will be playing with this once my new tank is finished.
