My Octopus OTP3000 DIY needlewheel - Page 4

spongebobby · #76 08/25/2007, 03:26 PM

Slow Cobra & medic29

Do you have a way to check wattage and air scfh.

Dhnguyen & Kentrob11

I'm interested in making these for you but I don't have the dimensions for those particular pumps. These needlewheel's are made specific for the OTP3000 pump. I have no way of knowing if they will work on your particular set-up/pump.

dhnguyen · #77 08/25/2007, 03:37 PM

The OC2500 stock needle wheel has an OD of 1 and 7/8" just a hair shy of 2 inches while the center hole diameter is 7/16"

SlowCobra · #78 08/25/2007, 03:38 PM

I have a kill a watt and as much as I don't want to pony up the cash for an RMB meter after being loaned one by JCTewks I am going to have to buy one.

squin · #79 08/25/2007, 06:08 PM

I would love to try one of these out on my PCI PS-3000. I have both the older (larger needle wheel) and newer (smaller needle wheel) OTP3000 pumps to test on. Currently running the original (larger needle wheel) pump with most of the discussed mods, and pulling 30-31 SCFH at 83 watts. I know, 83 watts is to high, and I expect it will shorten the life of the pump. Especially since these pumps already run hot.

Maybe its just me, but the recirc skimmers seem to be a little harder to tweak. Finding a spare venturi was a pita, and when I finally got one the union connections were opposite from what I have on my skimmer. If I can get to 30 SCFH at the rated 65 watts on an OTP3000 I would be stoked.

Solly · #80 08/25/2007, 06:23 PM

I'm also interested in trying some of these for a pair of eheim 1262's on an AP902 clone I'm building. If you want I'd be happy to send you an eheim 1262 so you can get all the measurements.

-Solly

medic29 · #81 08/25/2007, 07:25 PM

SB....yes I do have both a kill-a-watt meter and scfh meter.

customcolor · #82 08/25/2007, 07:29 PM

you guys are realy making me wish i had an Octopus pump. that star is realy going to chew the air up, beter than triangle

JRaquatics · #83 08/25/2007, 07:41 PM

I am interested also but it looks like there are more than enough people ahead of me with octo 200

liveforphysics · #84 08/25/2007, 08:32 PM

In reguards to weight reduction, once the motor reaches synchronous RPM, the rotational mass no longer negatively effects drive current, and very likely lowers it due to more constant rotor speeds.

The holes milled to lower weight will certianly increase fluid drag, causeing the rotor to be phase slipped further increaseing current draw.

Weight is only an issue for starting. Once started, heavy with minimal drag becomes ideal. Heavy will only hurt current draw if you can't get to to reach synchronous RPM on startup, but again drag would be the main factor in this.

Best Wishes,
-Luke

JRaquatics · #85 08/25/2007, 08:34 PM

I have a kilawatt and a dwyer meter.

koraltek · #86 08/26/2007, 11:35 AM

i work at a reef shop with many different nw skimmer types, octopus, aqua euro, euro reef, ati, etc...
what skimmer do YOU want to try your mod on?

i also have dweyer air meter and killawatt of coarse, and the ability to do daily test logging.
im also designing a good cheap skimmer with the quiet one 3000, mesh modded, but would be interested in seeing how these hold up to mesh as well in the same pumps, would love to have no start up issues

SlowCobra · #87 08/26/2007, 01:46 PM

SB PM sent. I took the plunge and ordered a flowmeter today.

spongebobby · #88 08/27/2007, 12:25 PM

Well I ran the Star design all day yesterday. Initially I thought It was not as good as the last diamond wheel but after about an hour of running the thing was producing an insane amout of real thick foam. I went to cut firewood and came back about hr. later to find that it was making so much foam that it pushed the lid completely of the skimmer cup and had a towering foam head. Only downside is wattage was 93 watts... Back to the drawing board. This was the most wattage I have seen on any mods I have done. Upside was it was also the most fine amount of bubbles to date.

Next change is reducing the amount of through holes by half and increasing thickness of base to .100 thick.

Slow cobra & medic29

Can you please send me your addy's via PM. You are the "UNLUCKY" test subjects.

Also understand that this is at your own risk and I will not be responsible for any problems you incur from trying these out. I would recommend only testing these when you are present and not leave them for any length of time. I also would recommend you purchase a new stock needlewheel so you can change back to stock after each test. I will be sending you both a few different designs to try and will need data on items like :

air flow
wattage draw
venturi stock/mod (if modded what has been done)
Your experiences with each test

If you still want to do it just shoot me a PM.

stay tuned

medic29 · #89 08/27/2007, 01:03 PM

SB....PM sent....

Also a couple of thoughts. This past weekend I did some testing and posted them in the Octopus skimmer mods thread...anyway, something you may want to check before and/or in addition to changing the design of the needlewheel is the venturi. I have casted blanks of the venturi based on the stock venturi design. I tested different diameters of the opening in the venturi, various diameters of the air line, etc. What I found out in reference to the amount of wattage the motor uses seems to be in reference to the amount of water that comes through the venturi.

When the diameter of the venturi was 3/8" the motor would pull no more than 45 watts. I went all the way up to 3/4" and the motor was pulling around 90 watts. I continued to experiement and am currently using a venturi with a 3/4" ID diameter, with tubing 3/8"OD & 1/4"ID positioned about 1/8" inside the venturi at 90*. The motor is pulling 60 watts and about 28-30scfh of air. It is making quite a bit of foam as well.

I'm thinking your design may work just fine if we fine tune the venturi.

Just my thoughts...

JRaquatics · #90 08/27/2007, 01:24 PM

I noticed the same a couple of weeks ago. Infact I went threw about 10-15 different style of venturis before I got to the one that gave me the magic #.

SlowCobra · #91 08/27/2007, 04:13 PM

PM sent

demo · #92 08/28/2007, 06:06 AM

Hey i like your work sponge any chance of getting one of these to test for a otp1000?? i have a octopus 110 recirc skimmer.

I'm in Australia and can provide you with a full wirtten report

liveforphysics · #93 08/28/2007, 06:46 AM

The speed that the prongs cut through the water on the tips is much faster than towards the center.

To create an optimized wheel in reguards to flow versus power consumption, you must have lower pin density, and/or shorter/slimmer pins on the outside of the ring than the inside. Symetrical blade layout and spaceing is never optimized, perticularly in slurry flow like we are pumping in a skimmer.

Any holes in the base plate is a mistake.

Rounding a smooth radius around the edge of the disk would be worth dropping a few watts.

It appears your object is to reduce power consumption at this point. The current draw varies directly with power consumption. The current draw is determined by the phase/slip angle of the rotor compaired to the timing of the windings being energized.

The lowest power consumption will occur is the field drops right as the rotor's magnet pole passes the half way point. This means too little resistance and too much resistance will both result in additional current draw. If you experiment with more and less pins on the wheel, you can find a point which will find a minimal power consumption with loads of output.

When you mention 90watt power draw and another person mentions half that amount of power draw, it indicates your motor is no able to stay synched. This means the motor is running weakly and will likely fail from excessive current draw.

If you would like specialized help designing a wheel, I do this stuff for a job.

Best Wishes,
-Luke

spongebobby · #94 08/28/2007, 08:14 AM

Liveforphysics...
Thanks for the help first off.. Now...Holes have to be in the bottom of the needlewheel or the magnet will get little to no water to cool it. I tried one without holes and the pump got super hot.I put holes in it and it cooled it down.

I may take you up on the offer of design

thanks

JRaquatics · #95 08/28/2007, 09:59 AM

Spongebobby- if you round out or even bevel the bottom side of the base will allow for water to flow behind and to the magnet. Just a thought.

RichConley · #96 08/28/2007, 02:10 PM

You really need to play around with the airmeter and killawatt and match the venturi to the impellar.

If you dont have both, you're pretty much just wasting your time.

spongebobby · #97 08/28/2007, 02:36 PM

Thanks for the vote of confidence...That is what i'm trying to do is match the needlewheel to the stock venturi. I believe I posted that earlier in this thread.

RichConley · #98 08/28/2007, 03:00 PM

Good luck. I've done a lot of meshmodding, and that stock venturi is pretty bad.

Flint&Eric · #99 08/28/2007, 03:03 PM

spongebobby, if you ever make one for an mj1200 i would be very interested...i know many others with nano's would be too.

eric

RichConley · #**100** 08/28/2007, 04:28 PM

Flint&Eric, the problem with the maxijet 1200 isnt the impellar, its the shroud... its too small. You'll get the same air from a MJ400 as a 1200. You need to either put a custom volute on it, or find a small pump with a bigger volute.