SCWD Mod

[Psycho graphic]

I'm getting ready to try modding a SCWD. So far I've got the top cut off and sanded smooth for the ABS fittings to be glued in place.

My goal is to enlarge the outputs for a little better flow.

I also plan to try to add another input to the top for more flow and hopefully by doing so, slow the flow going in through the bottom causing it to switch slower. I don't like how fast the stock SCWD switches ( about 5 seconds)

If the mods fail, I should at least have a SCWD that can be opened for cleaning.

After opening the unit up and dissassembling it, I'm surprsed these things don't clog up and stick within 15 minutes of use. There are 4 sets of tiny planetary gears for gear reduction and added torque to get the drum to spin. These would be jammed by the smallest bit of debris, which I would think is the reason most fail.

I would like to thank Zahner for donating his non working unit. I was able to get his working again after about 30 seconds of cleaning. The problem is from the factory, you can't get to the "guts" to clean it.

The top cut off and the gear drive and drum removed from the housing.

The drum removed from the gear drive.

The gear drive disassembled.

A pic with a penny for size comparison.

 

[fritz]

Oh man this thread is going to rock! ( I already love it) please keep us posted as to your progress.

 

[loismustdie]

Can I fix my broken SCWDs with the info you are providing? Or once they stop switching are they done?
Nice thread.

 

[leoskee]

Im not sure if the 2nd and 3rd link will work but try it out anyway.

There are several threads on RC that might help you.


http://www.reefcentral.com/forums/s...91&perpage=25&highlight=scwd mod&pagenumber=2

http://www.infoblvd.net/jkaszynski/tank/scwdnormal.avi regular scwd

http://www.infoblvd.net/jkaszynski/tank/scwd1inch.avi scwd mod

 

[digitalreefer]

Can I fix my broken SCWDs with the info you are providing? Or once they stop switching are they done?
Nice thread.

Chris I'd be curious to dismantle one too if you have a broken one. Assuming you can't fix it with the info provided of course! :splitspin

 

[loismustdie]

I have 4 on my tank and only 1 left that works.

 

[Psycho graphic]

Before anyone cuts one up that is'nt working, have you tried soaking in vinegar? The reason I posted the gear drive is to show everyone how small the gears are so they can see how easily they can jam. I'm going to look for thr ABS parts today. I don't know If I'll have any luck finding them on Sunday though.

One part of this mod will make it so you have access to the "guts" in order to clean or unjam it.

 

[Psycho graphic]

Leoskee, thanks for the link, there is a post there of exactly what I planned to do, well almost exactly.

 

[scarf_ace1981]

psycho great thread. i'd like to see tons more diys on MR

 

[leoskee]

I was thinking of giving it a try but since Im going to go with a closed loop I never got around to it. But I would still like to see what you are going to do. Good luck.

 

[Psycho graphic]

Even with having a plumber in the family, I'm finding it hard to find a 2" ABS cleanout to make the lid for this thing. As soon as I find one progress will continue.

 

[Psycho graphic]

Update

I finally got the parts to continue on with the mods. It is very hard to find ABS parts anymore, my nephew who works in the plumbing field told me is because it's inferior to PVC, but seeing as the housing of the SCWD is ABS that is what I wanted to use.

Being the Dumbass I am, I forgot to take pics of the fitting before I hacked it up. I put the pieces back together to show you what it looked like when I got it.

This is a 2" Street Cleanout.

The bottom removed.

After cutting the bottom off, there will be a lip that needs to be removed along with some of the threaded area to fit over the SCWD's body. if you look close you can see the area I bored out with a Drum Sander for a Dremel Tool.

I have read about the "Drums" catching on "Mold Flashing " on some models causing them to break, so I sanded any high spots on the inside of the SCWD. You can also see in this pic I removed the excess material used to glue the 2 halves of the body together above the outlets so the Cleanout can fit over it.

This pic shows the SCWD dry fit with a cap in place. If you are happy with the performance of the unit without any other mods, you will just need to glue the "Cleanout" to the body of the SCWD and wrap some Teflon Tape to the cap and you now have a SCWD that can be disassembled for cleaning and maintenance.

The next step for me is to drill out the outlets and add the 2nd inlet on the cap. I'm not sure if I want to drill the stock inlet as I think it might allow water to bypass the "Impellor" that makes it work.

I also plan to add some "Bracing" to the drum, as I can see it being the weak link to the unit.

Stay tuned,,,,,,,,,,,,,,,,,,,,,,,,

Same SCWD time, Same SCWD channel.

 

[Psycho graphic]

I could'nt find a 2"x1/2" adapter for the lid, all I could find is a 2"x1" adapter which means I would then need to add a 1"x1/2" adapter to that as I will be running 1/2 PVC to plumb it (it makes no sense to go larger as the most I will be able to drill the outlets is about the same I.D. as the 1/2" PVC). Using all those adapters would be not only bulky but pretty ugly also, so I went with a 2" plug and a 1 1/2"x1/2" adapter. I chose the plug also because it has about 1/3 the threads as the adapter and seeing as it has tapered threads, I did'nt want to cut it down, in other words, this way would stick out about 1/2" less. I then drilled out the plug to snugly fit the 1 1/2"x1/2" into it, I also cut about 1/2 the height of off to keep things compact. I think I'm going to run the SCWD upside/down to keep the flow to it as unrestricted as possible. I have a 90 screwed into the top so you can see how it will work a little better (it was the only screw in fitting I could find in my collection of fittings).

 

[Psycho graphic]

I dug up some fittings to show you how it will be plumbed. After I finalize it and test it I will know if I need to add any valves to it to control the flow.

 

[KathyC]

Wouldn't you need a valve anyway to isolate it so you could remove it to clean it once it gets clogged like they sometimes do?
And if I'm really beginning to understand this plumbing stuff, would you also need to add a union somewhere between the valve & the scwd?

 

[Psycho graphic]

Wouldn't you need a valve anyway to isolate it so you could remove it to clean it once it gets clogged like they sometimes do?
And if I'm really beginning to understand this plumbing stuff, would you also need to add a union somewhere between the valve & the scwd?

I won't need a valve to isolate it, if I need to service it, I will just shut the pump off. I also won't be using a union on it as it will be to bulky, I plan to use Vinyl tubing for the connections to save space.

 

[Psycho graphic]

As I said previously the weak link on these units seems to be the drum that blocks the outlets to direct the flow. I've heard from others that the drum breaks right where it attaches to the gear drive, seeing as this is the thinnest part I figured I would make a brace for it.

Here is the piece I made next to the drum. If it looks like the hole is too large, there is a boss around the hole and this fit snugly against it.

Here it is in place ready to be glued.

 

[Psycho graphic]

One last mod before testing. I'm not sure if this will do anything at all, but after looking through the hole in the cap, I thought the pressure coming from the top of the SCWD would negate the pressure coming from the bottom cancelling the ability of it to turn the impellor. I made this "diverter" to hopefully redirect the flow from above to the side where the outlets are. I hope it works as I was covered in PVC dust from grinding down the fitting to save on rotating weight.