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#151
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Okay, I've had the chance to check. I have 2 K4s with Dumas 3004 props (unchanged); both work fine modded. Checked the current/wattage used....15-watts each. This is the rated wattage so it shouldn't be hurting the motor.
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Rick |
#152
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The K4 motor is rated 12W not 15W. But I don't think it will have much issue.
You can estimate the flow by the wattage, for anything between 1000gph to 2000gph, just multiply the wattage by 100 to get the approximate flow. |
#153
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How do you come up with that way of estimating. It seems intriging, but I think it would also have to do with the size of the magnet, size of the prop, pitch of the prop and other factors, including rpm's of the shaft.
Just curious, how you came about this figure??
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Rick |
#154
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Just pulled them out of my hat
All AC pump props spin at the same speed regardless the size of driver or prop. The speed has to do with the AC frequency. |
#155
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jacmyoung: I love how you have worked out a polished mod for these pumps, but I don't think that wattage * 100 measure is even close.
These presumably spin at the same RPM as MJ mods (no numbers, but based on same prop performance they must). That would put a dumas 3004 unmodified close to 2000 gph. medic: good work getting the 3004 on there, I was waiting for someone to try one of these low pitch but large props! They seem perfect for the K4 given the large shroud. What did you use for a magnet, the MJ 1200 mag? |
#156
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Yep, plus I still had some carbon fiber tubing lying around so I used it and was able to cut it to length where the magnet would come out of the motor when the prop was turning the wrong direction, the pop back in and start turning in the right direction. Works pretty good.
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Rick |
#157
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Interesting I had to trim back my Dumas 3004 quite a bit for it to work with my K4 motor. What was the watt rating on that MJMod with untrimmed D3004?
I do see D3004 is very different than most all other props we use, in that it has a much bigger diameter but very low pitch. Maybe such design is more efficient? |
#158
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So finding the best propeller for the tourque this motor can generate is not as easy as it appears, there's a lot to it. At times a smaller prop with a higher pitch will generate more flow than a larger prop with less pitch... or one with an extra blade... If I'm not mistaken the larger the slip the less tourque the propeller will have, that will play a big role in determining the best propeller. +++ Edit: Actually, I believe it is more correct to say that as slip rises from 0%, rotor tourque actually increases but beyond a certain slip % it will start to drop considerably. I think I got it right this time as 0% slip woud mean 0 tourque as the rotor would be under no load. +++ Again, knowledge from another hobby but I do believe AC motors are all pretty much the same in these aspects. One question, I have a standard 180g All-Glass tank, is the magnetic mount on the #4 model strong enough to rely on? Where did I read someone had theirs slip down on 1/2" glass??
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Giancarlo Podio Last edited by gpodio; 04/27/2007 at 03:10 PM. |
#159
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It was me, the pump stayed but was close, and the motor had to be at the under side, if the suction cups wear out (we know they always do), the pump will slide.
BTW, thanks for your insight. I think you are right. When I modded with different props, I noticed when the motor was pushed to the limit, the flow reduced while the watt draw increased, must be slipping badly. But at certain working range the slipping effect has to be minimal, else the DC pumps can't have multiple speed settings. Although I think DC motors work differently than the AC ones. BTW I needed a few K4 parts had a little chat with Bruce at Hydor, a very nice guy. He said Hydor is coming out with a more powerful K pump, probably the same size as K4 but more flow. They also are working hard on controllers for the K pumps. BTW, my flow=100Xwatt math was not totally pulled out of a hat. I looked at all the AC stream pumps and their factory specs and came up with this simple rule of thumb, just to offer some clue if you can not or don't want to test the flow. Variables such as mentioned above, and others such as how big the opening and how restrictive are the slits too can influence the flow. Last edited by jacmyoung; 04/27/2007 at 06:28 PM. |
#160
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One of these days I'll find the time to play with these things again, I have many props to play with from the old RC boat racing days..
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Giancarlo Podio |
#161
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Duplicate post...
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Giancarlo Podio |
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I cant wait for the parts to star tthe upgrades.
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#163
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#164
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I know nothing about the Tunze nanostream, do they use brushless DC motors where the impeller is directly connected to the core or do they use a magnetic coupling from the DC shaft to the impeller/propeller? If they are using brushless DC motors then they work much in the same way as AC induction motors, the biggest difference is in the controller itself which simulates the AC sinewave by switching DC current between the coils...
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Giancarlo Podio |
#165
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I think it is the latter since they share the same propeller units with their similarly rated AC pumps.
I forgot to mention while I was talking to Bruce at Hydor he also showed me a prototype of their upcoming nano K pump the size of an AAA egg, rated 3.5W and 265gph if I remember correctly. |
#166
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bump. any more pics?
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#167
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The K4 motor will not turn an unmodded 3004. I tried it several times and i had to cut the prop down several times to get it to work. You have to cut in the neighborhood of 1/8" off the prop to get it to spin.
If there is anyone out there that has been able to get the 3004 to spin unmodded I would love to hear about it. If you do get the 3004 to spin unmodded, I would bet money you have the prop on backwards....... Medic found this out already
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-Kurt |
#168
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Hey....don't talk about me that way.....But I do have an un-modded one on the other one and it works. Come on over and check it out.....by the way, you can help me out set up the new system! LOL
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Rick |
#169
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Did you check the other un-modded prop and K4 how much watts they were drawing? I bet more than usual. Could be Hydor sent you a K4 with larger motor in it.
They did say they will release a bigger K pump, same size of K4 but more flow, so it is possible they sent you a prototype of the bigger motor by mistake? Of course I can be way off. |
#170
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I have no idea how you got it to work, but I will have to bring over one of my impellers some time and see what the difference is. I havent even had luck getting an MJ900 to turn that prop and that is a bigger motor than the K4.
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-Kurt |
#171
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Where would you get an MJ 1200 magnet if you didn't own a MaxiJet?
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Ryan My mom always told me to stay away from the reefer. |
#172
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"Beer is proof that God loves us and wants us to be happy." ~ Benjamin Franklin |
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You can also get them from Premium Aquatics; that is where I've gotten my last few. I forget, but I think they are around $8 a piece.
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Rick |
#174
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Not all MJ900 motors and magnets are exactly the same strength I have found. This depends on age of the motors/magnets as well as manufacturing inconsistencies. I have been able to get a MJ900 to spin a 3004 Dumas and another MJ900 wouldn't, go figure. If you trim the Dumas prop down just a hair this will help. D. |
#175
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Ryan My mom always told me to stay away from the reefer. |
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