diy "om" is it possible

1newfish · #1 11/22/2006, 05:13 PM

A lot of us would like to be able to build our own equipment to save money. skimmers,lighting,tanks, sumps and everything in between. so why not an "om" wavemaker.

The product is great, most every one who has one loves it. But from what i have seen of it, from the web site, there is no reason for it to cost $340.

So now i ask if any one has built one or has a good idea of how to do it, please let me and every one else who would like to try know how.

impur · #2 11/22/2006, 05:22 PM

There are a lot of DIY scwd mods, which are essentially the same thing minus the AC motor. I think one guy made an 8way. All of these scwd mods increase the flow so that shouldn't be an issue with them.

1newfish · #3 11/22/2006, 05:24 PM

do you have any links to these?

RandyStacyE · #4 11/22/2006, 05:53 PM

Here's a recent one:
http://archive.reefcentral.com/forum...hreadid=968594

RandyStacyE · #5 11/22/2006, 05:54 PM

It looks like the actual cylinder is the easy part. I'm sure 'driving it' will prove to be the tricky part.

Toast_Man · #6 11/22/2006, 05:56 PM

http://avdil.gtri.gatech.edu/RCM/RCM...ionSystem.html

BeanAnimal · #7 11/22/2006, 07:46 PM

The reason they "cost so much" is because they are so well made and the customer support is second to none.

You will be hard pressed to build something as reliable and compact for the same price.

There are plenty of examples of DIY sinusoidal and similar valves. Remember there are wear parts, these include seals if the unit is direct drive. SCWD rob tons of flow and convert it into mechanical motion to drive the mechanism. There is no comparison to a SCWD and an OM, they are not even in the same class with regards to efficiency and reliability.

There is plenty of stuff to DIY and save a bundle. This is not one of those items unless you have the resources to do precision machining and access to cheap raw materials.

I would dump my DIY project money into something that will save money and produce BETTER results than what that money could purchase for retail.

Keelay · #8 11/23/2006, 02:42 AM

I say go for it. The SCWD MOD route is definitely interesting to me (something like a 4 way). I've done one MOD (not the 4 way) that was so cheap and easy, I felt superhuman for a good half hour afterward.

The SCWD failures that I have read about are the drum cracking (happened to me), the drum catching (also happened to me), and the gears getting dirty/jamming.

The first two can be mitigated by reinforcing the drum and sanding the blobs out of the drums path. 5 min jobs each.

$40 + some PVC for a new housing, I could replace the gears in the MOD 8 times before equaling the cost of an OM.

There are definitely problems with SCWDs. The nice thing is they are easily identified and also easy to fix.

My $.02

BeanAnimal · #9 11/23/2006, 02:47 AM

The big problem with the SCWD is the amount of flow that it robs...

You can look at it another way... you could run half the pump and get the same flow out of an OM and save a LOT of electricity and time that could be otherwise spent DIYing somethign that you can't buy

I looked into building a DIY wave maker that was similar to the sinosuodal valve shown... but with many more ports. I drew up the plans and started gathering the raw materials to machine. This was of course before OMs existed. The project was a huge undertaking... It never got off the ground. I purchased an OM and never looked back. I spent the money on a DIY 50 gallon sump and DIY 6' tall skimmer instead

hahnmeister · #10 11/23/2006, 04:07 AM

http://www.weatherson.com/sinusoidal_valve.htm
Weatherson's is one of te nicest ones around... nicer than an OM really, and slick (he used parts from an iwaki pump to make the sealed shaft that runs from the motor to the drum). Its clear, and with multiple inlets/outlets, you can have fun making custom drums.

But the cost to make one is greater than just buying an OM unless you just happen to have the parts laying around like weatherson.

The only other advantage I can see to making your own would be that you could use a DC pump rather than the AC one. This would allow you to make it variable speed... something that nobody has done yet.

1newfish · #11 11/23/2006, 06:59 AM

Thank you all for your comments.

I'm suprised that more people have not chimend in. Never the less i will still try my hand at it. and of course post pics and updates.

virginiabreeze6 · #12 11/23/2006, 07:07 AM

Good luck and keep us posted. I purchased a 4 way some time back and it took 2 months of modifying it myself to stop the clicking from the pressure inside the sleeve.

Great product, just disappointed that I would have to drill and file to get it right.

BeanAnimal · #13 11/23/2006, 10:15 AM

virginia... did you call Paul at OM? He makes ANYTHING right. Was it a "4 way" or a squirt?

virginiabreeze6 · #14 11/23/2006, 12:43 PM

It was a 4 way, I did speak to Paul in the beginning, his suggestion was to purchase one of the new sleeves. I didn't feel I should have to purchase something to correct a new product. So, I modified it myself, now I am very happy with my OM after the changes.

Fluxion · #15 11/23/2006, 01:28 PM

I have built three versions of my own and I am working on my fourth.

As an owner of a super squirt I would reccomend just buying one. To build one that performs as well as one built by OM will take a metal lathe to machine the parts at the very least.

I have a CNC router, metal lathe and milling machine plus a whole cabinet shop full of tools. Like I said I am on my fourth version and would reccomend just buying one. I'll post pics of the last one I built for my nano tank when I get time. I gotta go, the inlaws just pulled up. Time for dinner!

1newfish · #16 11/23/2006, 09:43 PM

well i now know that motors used on the om 8way cost $118.
that is from HURST pn pa 3202-003.
I suppose that is part of why they are so expensive.

Fluxion- i would love to see your pics.

BeanAnimal · #17 11/23/2006, 09:45 PM

Plenty of folks have been down this road... I love DIY but will be OMs from paul any day to save myself the trouble of building a debuging something that will cost me as much and not perform the same.

I keep finding excuses to buy a small lathe and mill... maybe one day.

fishesRdelicious · #18 11/24/2006, 01:23 AM

i agree that it takes too much time and tools to make these.
i went through probably ten different designs before i came up with this one. one thing that this design does is eliminates the need for a cyclinder and all the tight clearences, it could be square if i wanted.
it never really worked the way it could of because i lost interest because it was taking too much time. the hardest part i found was the magnet connection. there was too much friction the way i had it so the magnets would jump and stop spinning.
here are some pics:

RandyStacyE · #19 11/24/2006, 11:36 AM

That is a very cool idea! I can see how it's very tempting to try it. The plate is an excellent idea and nowhere near as much friction as a cylinder.

Spinning that plate from near the center is making those magnets work very hard. I see the difficulty though. It’s not like you can just move them outward. Some more powerful magnets and I’d bet you’ve got it licked.

RichConley · #20 11/24/2006, 12:48 PM

Quote:

Originally posted by BeanAnimal
The big problem with the SCWD is the amount of flow that it robs...

You can look at it another way... you could run half the pump and get the same flow out of an OM and save a LOT of electricity and time that could be otherwise spent DIYing somethign that you can't buy

Bean, the scwd robs flow because its 3/8" ports. All of the SCWD rebuild threads deal with this, and in many cases, they end up being less restrictive than an OM.

BeanAnimal · #21 11/24/2006, 04:13 PM

Sorry Rich... but the SCWD robs flow becuase it converts the movement of the water into mechanical energy. The OM has an outboard source of power. The SCWD uses a pretty fair amount of the flow to turn it's internal gear.

This is VERY BASIC fluid dynamics....

Bean

Keelay · #22 11/24/2006, 05:50 PM

So Bean just to clarify, you are saying that the amount of energy lost to turning the gear in a SCWD is more than the energy it takes to run the OM drum motor.

So for example, you have a pump running 1000GPH @ 100W without a scwd on on (no current switching) then connect the Modified SCWD and measure flow again. Let's say for argument that it is 900GPH still using 100W.

So for comparison you have the same pump connected to an OM and are measuring 1000GPH (no loss...again for argument sake)

So now you run out and find a pump that will push 1000GPH(or what ever flow rate you get with the OM inline) through the SCWD Mod but it uses 110W.

So now as long as the OM drum motor uses less than 10W it is more efficient.

Obviously these numbers are all made up, but I think this would be a way to compare efficiency of the Modded SCWD vs. an OM just to see how much flow loss translates to actual wattage. The real hard question to answer is how efficient are the gears at turning the drum vs the electric motor.

I think a great deal will depend on the particular MOD on the SCWD. I agree that the SCWD out of the box wouldn't compare in terms of performance.

RandyStacyE · #23 11/24/2006, 06:30 PM

I think he's saying that the SCWD robs some flow due to having to run the mechanics that make it operate.

Even the mods still require that the flow run the mechanics. The OM and other DIY 'OMs' have optimal flow because they have a separate driving motor to operate the mechanics.

When put to the test I'd bet most any OM or DIY OM would likely have a higher flow rate in comparison to a SCWD or a SCWD mod.

BeanAnimal · #24 11/24/2006, 08:42 PM

keeley... NO

We are not talking about energy consumption and the electric meter. Though We "could" talk about that. You will find that the electric motor will turn the drum more efficiently than the water if they are both being turned with the same torque.

In any case, I am talking about the loss of overall flow due to the SCWD compared to the flow from the SAMEE pump if used on an OM. The loss of flow is due to the fact that energy must be taken from the moving water to turn the gear

BeanAnimal · #25 11/24/2006, 10:26 PM

keeley... NO

We are not talking about energy consumption and the electric meter. Though We "could" talk about that. You will find that the electric motor will turn the drum more efficiently than the water if they are both being turned with the same torque.

In any case, I am talking about the loss of overall flow due to the SCWD compared to the flow from the SAMEE pump if used on an OM. The loss of flow is due to the fact that energy must be taken from the moving water to turn the gear