My Octopus OTP3000 DIY needlewheel

[spongebobby]

Well after many months of playing with mesh mod and venturi's I decided to create my own true needlewheel for the Octopus OTP 3000 pump. I looked at many different needlewheels and have created many but I think that I am getting it narrowed down to a good design. I am not posting any numbers as of yet but it far surpasses the stock performance on this particular skimmer (DNW-200). I have been working on concintricity of the whole assembly while spinning to keep wattage and drag down. The first NW pins were round and wattage and air draw were only about 10-15% better,not quite as good as mesh mod. Then I reduced the amount of pins and made them bigger but it wasn't any better...performance suffered on this on. Then it was 3 rows of pins, then 4 ,5. I just couldn't get the performance I was after. Then a Design Eng. suggested making the pins square, more edges to cut and mix the air/water mixture.Now I am playing with the amount of pins/rows/size of pin. This is the latest

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If you have any advice or idea's post them here. I have a new test pump and spare needlewheels coming Monday to continue testing these out so more to follow.

Robert

[luke33]

Looks good, will be glad to see the results. The only prob i see with this is how is everyone suppose to make them.

[spongebobby]

Once im happy with the final product I will be happy to give them away .........for a fair price .

Really I never gave much thought about other ppl reproducing them. I just wanted to maximize my skimmer efficiency without having to deal with meshmodding and such. I have about 40-50 machine hours total so far.Probably machined at least a dozen needlewheels so far. I think i'm getting close though.

[patej]

looking good,,,,

[Ewan]

Very innovative! They look great, fwiw.
E.

[JCTewks]

Are those aluminum heatsink material? are you going to make the final product out of plastic? what machine are you using to mfr these?

[won digity]

that looks good... did u make those on a table saw?

edit: oh,, nevermind the table saw coment.. I see that they aren't

[JCTewks]

spngebobby: have you tried rotating the square pins 45deg.? I would think that would get you less drag with angled faces to the water instead of squared faces pushing into the water. Also, with them rotated, there will be a sharp edge to "cut" the air instead of just a blunt face hitting the air.

[spongebobby]

That's a great idea JCTewks. That will be my next change. I may be able to run less rows also and still get the same performance.
Thanks

[spongebobby]

Here is a quick dwg. [IMG][/IMG]

I will try to machine one this week.

[JCTewks]

that's what i was thinking!! Are you using a CNC mill or Lathe to machine that? What CAD are you using?

In my mind I've pictured a pinwheel similiar to that one, only with just one outer row of pins, and mesh in the center.

You'll want some holes through the base plate on that as well for decreased weight, and water circulation to the cooling channels around the magnet. Solid plates tend to hinder the pump from cooling itself.

[spongebobby]

Yes I made them on a CNC mill (high speed). I use Solidworks to draw and Solidcam to program with. I will try to add some holes. They will be awful small in the area where the pins are but around the hex I should be able to fit some nice sized holes.

[koraltek]

wow, very impressive, watching closely

[spongebobby]

Well I just finished machining the latest one and will post pic's of it tonight. I think this is the one........ I HOPE....

[JCTewks]

eagerly awaiting the pics

[dhnguyen]

Impressive CNC work no doubt. Keep us updated once you can get the design to pull more air than the mesh.

[spongebobby]

Well here are the pics of the latest one.. It has been running for 2 hrs. I only have the skimmer filled just enough to cover return from OTP3000. So far I would say that the pump is definately cooler to the touch than it was running mesh-mod.It's hard to tell how much air it's pulling but it's sucking alot harder through the venturi hose. I have an air meter but it's out on loan

Thanks for the comps dhnguyen

Well here's the pics.
[IMG][/IMG]
[IMG][/IMG]

[customcolor]

that is insane. what is you spacing between the needles. thats got to be a heck of a small endmill

[spongebobby]

I'm using a 5/64 .500 LOC 3fl carbide micro endmill. The spacing between the square's are .085 on the radius and .100 from row to row. Run time is 18 min 36 sec. from start to finish. I'm running 10000 mm/min on the feed rate. Like I said earlier this is on a very nice High Speed machine center. Spindle RPM is 30000.They could be made on a standard VMC but they would take probably 1.5 hrs to make one.

The material is 2.284(same dia. as stock needlewheel) round and .490 thick slug. Material is acetron,delrin,etc....

Update....I am running it on the tank now and within 45 sec. of hooking it up I had to adjust the ball valve almost to full open because it started to flood the cup. The water level in the skimmer use to be right under the union on the cup now its below the angle part by about 1/8 inch. She is really putting out some thick foam. I did just clean the cup so I will give it some time to slime up the cup. So far I beleive it's pulling alot more air than the mesh-mod(sucking on my finger pretty hard). If i covered the venturi hose with mesh-mod it would just make a clunking noise. When I do it now it sucks so hard it collapses the stock air hose but venturi is opened up with a drill bit as big as I could get it with-out breaking through.

[JCTewks]

IF you get into making more I'd like to get one from you and play with some different venturi's.

Looks real good...Is this one performing better than the one with the sguares the other way? I hope it wasn't to hard to program those holes in there, but i think it will help with longevity of the pump.

what is the weight of that compared to the stock NW? Also, do you have a kill-a-watt?

[SlowCobra]

I'm with Jeff on this one. If the watts are around stock and that thing is performing that well I would be interested in one as well.

[shelburn61]

What material is it made from?

Get an air meter for (*&*)_%% sake!!!

[spongebobby]

I checked the watts this morning and they were at 86 on the kill-a-watt. I believe the pump is rated for 60 watts I think, so it's pretty close. As far as air draw it's sucking quite abit more than it did stock. Start up problems are not a problem at all. Doesn't chatter at all. It made about a cup of nog from 10 pm last night to 10 am this morning.



Gonna try and get my air meter back today.....

Stay tuned

[spongebobby]

Originally posted by shelburn61
What material is it made from?

Get an air meter for (*&*)_%% sake!!!

Delrin

[slc-reef]

Great Idea