AC-70 Stream Mod

[dngspot]

It seems like a year ago I was cruising The "Hitchhiker's Guide" to the Maxi-Stream mod at RC. These guys where getting incredible flow from MJ 400, 600, 900 and 1200 pumps, I thought I would look further into the post, then discovered it was like driving through New Mexico, a few cool sights but enough desert already, it was long. Finally I came across a post by a guy called Ball. He mod'ed a AC-70 and he claimed it put out 3000 gph. Being who I am, I had to try this; it sparked my DIY fever and tickled my cheap wallet. 3000 gph for under $50.00, they advertised. My final build price was about $65.00, but still this is better than a Tunse or Seo price tag.
I got the stuff and began to build, the shroud was a pain to say the least, I wasted about 6 of those 2" to 1.5" reducers before I figured how to cut the slots with out breaking them off. I used a miter saw in a rather dangerous way and do not want to be responsible for anyone loosing a finger, so this is done at your own risk. I locked the trigger in the on position locked the guard in the up position. I wrapped a piece of tape around the reducer at the large end, then marked tape every 3/8 inch, all the way around. I then took the reducer over to my table saw and set the fence about 1/8 inch from the blade and the blade about 1/16 inch high. I then put the big edge against the fence and moved it over the blade, then rotated the reducer until I had a slot all the way around the base of the reducer. I then took it to the miter saw and began cutting it on each mark, it helps if you do not cut the big end at the opening, I had to start on the large part and cut through to the shoulder. This takes some practice and is DANGEROUS, DO THIS AT YOUR OWN RISK AND KEEP YOUR FINGERS AWAY FROM THE BLADE. I cut two blade thicknesses at each mark. After the reducer is cut then I used a Dremel tool to remove enough of that base grove to allow the tabs on the AC to clear. This will allow the reducer to be lowered to the base of the pump and turned to lock. As for the shaft for the prop, I got a cheep plastic pen and some ro hose, I cut the pen so it was high enough to mount to the impeller magnet and the prop would be about 1/4 inch from the edge of the top of the reducer. I also cut a slot to fit the key on the impeller magnet. I inserted the ro hose into the pen and glued it with super glue. I then purchased a Sidwinder 1.5 x 1.5" prop from Great Planes Hobby, Part number GBMB 1090. I drilled it to accept a #8 nylon screw from Home Depot. I then glued the prop to the screw and the screw to the ro tubing. Check the rotation before you glue, assemble and test first. I then glued the prop shaft assembly to the magnet. You may have a problem with the rotation if so then you will need drill the side of the coupler just above the prop and insert a piece of ridged tubing to act as a stop. Put it together and let her roll.

Here are a few pics.

 

[dngspot]

Oh yea, these little guys move water, alot of water. I do not know if it is 3000 gph, but they will raise the water in a 5 gallon bucket about 3 inches, with a 8 inch spred.

 

[dngspot]

I ran across a thread on RC. This guy built this and posted instructions. This is not a dngspot original. Here is his link http://reefcentral.com/forums/showthread.php?s=&threadid=1205480

Here is how I did it.

I first followed his instructions and they did not work. The magnets are too weak to support my AC-70 mods. He also installed his Maxi Jets in a 75g tank and the glass is thinner than my 210g. Digging the magnets from the resin was not fun.

My shower head came from Ace Hardware. They were $1.99. They look like this before they are cut. I think that the numbers on the tape are the SKU.

I took them apart and cut the piece that is the shower head. I did not get a pic of the item when it was apart but have one of the finished parts. The second pic are the parts that are discarded.

 

[dngspot]

When the parts are reassembled they should look like this. Notice the little feet on the bottom, I cut groves in them to anchor them in the resin. When poring the resin take the assembly apart and just the lower part with the legs, it will be cast with the magnets.

Here is a pic of the container and parts. I have pored the resin in the pic. The magnets are placed in the container first then the shower head piece is placed on top of them. I filled the compartments with resin to the edge below the threads. The other two magnets are just covered with resin, about 1/2 inch.

After the resin cures, let is sit overnight, they should look like this.

 

[dngspot]

The shower heads have 1/2 inch pipe threads on the pivot end. I had some old parts from a sprinkler installation and had a 1/2 riser. It is segmented so it can be cut. I remove one of the segments and set it aside. I removed the back panel of my AC-70 and drilled a hole. The hole is large enough to accept the 1/2 inch segment. I then assembled the pump and tested. Here is a pic of the riser.

These are the supplies that I used.
Magnets are $4.00 each.
My guess is each cost about $16.00 with the other supplies. I will get about 16 magnet mods from the resin.

 

[dngspot]

And the finished resut.

I used http://www.kjmagnetics.com/proddetail.asp?prod=DX04. If I do any more I would use http://www.kjmagnetics.com/proddetail.asp?prod=BY0X02. They will hold twice the amount than the round ones do.

 

[billaweed]

wow dude.. I was looking for some mods for my AC-70's.. this is great.. where did you get the impellers/mods from?

 

[dngspot]

The impellers are from the original pump. I took the white paddle wheel off of the magnet and fit the modified pen to it. I then slid a piece of RO tubing in the pen and then the prop and screw.