Has anyone ever tried a DIY ocean motions?

[2dawghouse]

Has anyone ever tried to build one? I figured a design similar to this:

Body: use a 2" PVC slip cross. Cut the top of the slip down to almost flush to sit the motor on (Cut it down enough to allow the motor shaft to mount to the drum).

Drum: use a 2" spigt slip plug. Shave down the sides of the plug to fit smoothly inside the cross. Then cut out half of the side walls of the plug (similar to a drum of a SCWD). Mount straight in, top of the plug towards the motor.

Motor: I figured a 2 rpm 20 oz. torque motor would be adaquate.

Mount: Mount the motor on a cap (piece of acrylic or something similar) and drill a small hole to allow the shaft to protrude through the cap and mount onto the drum in the cross. Seal the cap with weldon 16.

Now my problem would be sealing around the shaft that goes through the cap (I was thinking about using an oring).

Any ideas for improvement or to seal the shaft would be appriciated.

[HarleyDude]

To try to duplicate what Paul does is very difficult. If you have a lathe, you could probably come close.

[2dawghouse]

I wouldnt think that I would need a lathe?

[2dawghouse]

I am not saying that what Paul does at ocean motions is easy, they have a very professional product and that usually means that it isnt easy to duplicate.

I figured that with the use of slip fittings and power tools (band saw, belt sander, etc.) I could avoid using a lathe. Essenatially I have the design and the plan for construction. I was wondering if anyone has better ideas and ways to seal the shaft through the cap.

[BeanAnimal]

In concept the devices are rather simple. On the other hand to build a reliable unit takes a good bit of trial and error. The shaft and seal will be hard to make watertight, especially without proper tooling. The better way is a MAG drive unit. You will also need to design the unit so it can be disassembled and cleaned.

If you have the proper tooling, the the project may be possible, if not, then your can better spend your DIY time and money on something else.

FWIW the Oceans Motions devices are superbly engineered and backed by customer service that is unmatched in the hobby.

[2dawghouse]

Bean, I appriciate the ideas. A mag drive unit, you mean attach a magnet to the shaft and then mount one inside the drum, that would require alot more torque. I could make the cap watertight and removeable.

[aninjaatemyshoe]

Weatherson created something similar to an OM using an acrylic tube, PVC, motor, and an Iwaki pump assembly. Here is a link:
http://www.weatherson.com/sinusoidal_valve.htm

It's pretty cool, but kinda involved. If you like to DIY, then it would be the way to go, but if your skills are limited like mine you'll just end up buying the OM in the end.

[RocketEngineer]

Just come crude estimates on Weatherson's sinusoidal valve:

Iwaki pump: $130 Acrylic Tube: $25 Acrylic Sheet: $45 Acrylic Bar: $12 Delrin Bar: $15 AC Syncronous 1RPM Motor: $21

Total: $248

OceansMotions Super Squirt: $259

Personally, I would buy it rather then try to build it. There are other items that cost a lot less to build then to buy.

[nancymccall]

yeah but if you deduct the price of the Iwaki pump which you will have to buy anyway, Weatherson's comes out to $118. and you get the joy of doing it your self. Sounds cool might have to go raid some tools and try it. Nancy

[BeanAnimal]

Add in the price of the tools, misc items and supplies and trial and error, you will spend a lot more than $300 :)

[hyperfocal]

Plus all the gas used driving back and forth to Home Depot ;)

[MinibowMatt]

take a look here:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1280064

[stugray]

For the shaft seal, you could use a 1/4" John Guest threaded fitting.

Remove the o-ring, dril out the body ( carefully ) replace the oring ( or a slightly thicker one ), press the shaft through - DONE!

Stu

[DarkFORCE]

I talked to CMcNeil about this. He has DIY one. I have alot of photos and some instructions from him. I just to not have access to a lathe and mill.

[2dawghouse]

I dont think that just sealing the shaft with orings will work, espcially considering that the shafts on the autotrol motors have a beveled flat tip, not completely round.

[CMcNeil]

just do a magdrive just like the original,then you only have one seal on the whole unit.

[BeanAnimal]

Yeah the problem with a "shaft seal" is the shaft deflection. You have a drum hanging off of a motor shaft and the drum is being hammered by water as it rotates. It will wear a seal out fairly quickly :)

[stugray]

Seals for these low cycle devices is not as hard as you would think.

If seals were that hard, how do our dart, barracuda, etc pumps last two years+ spinning at ~1800 RPM 24/7?

My other thought was to not care if you have leakage around the seal, but then you need to suspend the valve right above the water ( or IN the water ) & let it leak.

Stu

[noone]

http://www.youtube.com/watch?v=c091rObbRSw

http://www.youtube.com/watch?v=qkAavmPWXLY

[2dawghouse]

The potential problem with a leaking seal is the water hitting the motor. Until you actually run the unit, there is no true way of telling how much leakage.

Now for a simple body design. Without using a lathe, what ideas are out there for a body?

[stugray]

I had a design all drawn up that had four ports.

Two Slip/slip tees ( as the op started with ) butted end to end with cap at one end, input pipe at the other. This gives four output ports.

The inner rotating drum was to be just a different size pvc pipe with a gap between the rotating & non-rotating section ( you can get the gap really small if you mix different sizes of SCH40 & SCH80 ).

You then cut ports in the rotating section to expose the outputs as you want.

You would need a spider-like support at the input end to hold the shaft that rotates the drum.


Squirt water in one end of the pipe tees, rotate the inner drum, & there you go. The bit of blow-by that slips between the sections will be small compared the the switched flow, and not trying to make anything close tolerance will make it more robust.

You could rotate the drum-pipe with a shaft or a magnet.

Stu

[2dawghouse]

My idea was similar to that, instead I would use a pvc cross T, and use the top of the cross as a place to install the drum and mount the motor after sealing the drum in.