wizsmaster
Moved On
If you want to look at it that way, It's a venturi build like an injector, placed before the needle wheel pump. :rofl:
Volcano club
- Thread starter tom obrecht
- Start date
moondoggy4
Team RC
Me three
Me three
Me three
I have spoke with Spazz about even a smaller skimmer then the 1240 something for a 120 reef, I know he is busy and it will tank alot of work to iron out the details but 120 to 180 is a poplar size tank so that being said maybe it would be worthwhile and give us little guy's a chance to be in the club also. :rollface:<a href=showthread.php?s=&postid=12947778#post12947778 target=_blank>Originally posted</a> by Rwinfrey
ok ok everyone to there corners.
WE meaning even HAN know Scott and his skimmers are top notch so cool it and lets all drool over Scotts big gigantic skimmers.I only wish he would make some luguna based smaller skimmer's ( I am begging you man) like you know for somthing like my 150 gallon and at 22cents a killowatt LOW WATTS.
Rwinfrey
New member
I keep bugging him to he told me that there will be somthing down the road but he just doesn't no what pump to go with.I really believe luguna is the future mainstay skimmer pump.I also believe it won't be long before the red dragon flow pumps are copied and become the main flow pump.
hahnmeister
In Memoriam
If the pump is force fed, you wouldnt even want a venturi on the pump intake... you would want it to flow as free as possible because injecting into a restriction would cause even more restriction for water to flow, and possibly even damage the pump. Maybe a valve on the inlet to be able to turn back the pump if the flow is more than needed, but a venturi is useless if the pump is force fed.
The Lagunas are the 'mainstay' for now... easily matching the performance of a dart... but the thing is, a dart should be able to go even further... in theory. It would need a custom volute and such, just like a Laguna as it becomes a Red Dragon or Airstar... but because it has an external motor, there is potential to go beyond what any 'mag-drive' or water cooled motor can do.
The weakness of a any water cooled motor is that there needs to be a space between the stators (the body), and the rotor (the magnet) for the plastic (to seal the motor from the water), as well as allow for enough water flow to keep the pump cool. This weakens the potential of the motor... since the closer the magnet to the stators, the more powerful and efficient the motor will be. Externals dont have this drawback... since they are air-cooled, the magnets and stators (windings) can be as close as possible... a hair's width if need be. This is why you dont see mag-drives over a certain size... the Laguna 4200 being one, and the Mag-Drive 36 being the other (of which I think the 36 and some other large mag's were discontinued because of problems with this). For Red Dragons, the magnet is swapped to lower the wattage, increase torque and power factor, etc... it also makes the water cooling area more restricted: the reason for the anti-lime loop.
The other option is to seal the entire motor, retaining the shaft seal, and run the whole unit underwater. The drawback is that you no longer have convective cooling for the motor on the inside, so you have to use a very intense cooling method for the outside of the motor or it will overheat... or use a very cool motor.
One way to make a cool motor is by making it DC. DC motors dont have phases or power factor, and tend to run very cool right off the bat (at the motor). This is where the Red Dragon 2 comes in. The downside is that the wattage that most people read is the RMS wattage, which is not the true power of a pump, but it is what matters for our utility bills. You can have a motor that only registers 40 watts RMS, but is really chugging down 100 watts of REAL power. DC motors dont have this... the RMS matches the VA (real) power, and so you cant 'cheat' the utility bill... so where you had a 40 watt RMS motor before to get 1000lph of air, with DC you may need 80 watts.... and on top of that, there is the problem of the power conversion... most AC/DC converters are going to lose at least 7-10% in converting from AC power to DC... often more (depends on how expensive/cheap you want to get). The other downside is that if its a shaft-drive DC motor, like the RD2s, the seals can go, just like the dart, and blow the whole thing.
So then you need a DC water cooled motor... back to water cooling, and all of its disadvantages, as well no more RMS power to fall back on. Its 50/50. I think for smaller skimmers, a mag-drive DC motor is the ideal... going from 20 to 40 watts isnt so big a deal to gain all the advantages of DC. For larger pumps, then you are talking a jump of 120 or 140 to 200 or even 300 watts to go DC!
Along the same lines as Klaus, I am looking into alternative magnet assemblies for the Laguna motors. Rather than just larger, I'm thinking that if some of these neodymium/NdFeB magnets, if protected properly, might make for a much stronger and efficient motor than the AC ones we have now. Wish me luck!
The Lagunas are the 'mainstay' for now... easily matching the performance of a dart... but the thing is, a dart should be able to go even further... in theory. It would need a custom volute and such, just like a Laguna as it becomes a Red Dragon or Airstar... but because it has an external motor, there is potential to go beyond what any 'mag-drive' or water cooled motor can do.
The weakness of a any water cooled motor is that there needs to be a space between the stators (the body), and the rotor (the magnet) for the plastic (to seal the motor from the water), as well as allow for enough water flow to keep the pump cool. This weakens the potential of the motor... since the closer the magnet to the stators, the more powerful and efficient the motor will be. Externals dont have this drawback... since they are air-cooled, the magnets and stators (windings) can be as close as possible... a hair's width if need be. This is why you dont see mag-drives over a certain size... the Laguna 4200 being one, and the Mag-Drive 36 being the other (of which I think the 36 and some other large mag's were discontinued because of problems with this). For Red Dragons, the magnet is swapped to lower the wattage, increase torque and power factor, etc... it also makes the water cooling area more restricted: the reason for the anti-lime loop.
The other option is to seal the entire motor, retaining the shaft seal, and run the whole unit underwater. The drawback is that you no longer have convective cooling for the motor on the inside, so you have to use a very intense cooling method for the outside of the motor or it will overheat... or use a very cool motor.
One way to make a cool motor is by making it DC. DC motors dont have phases or power factor, and tend to run very cool right off the bat (at the motor). This is where the Red Dragon 2 comes in. The downside is that the wattage that most people read is the RMS wattage, which is not the true power of a pump, but it is what matters for our utility bills. You can have a motor that only registers 40 watts RMS, but is really chugging down 100 watts of REAL power. DC motors dont have this... the RMS matches the VA (real) power, and so you cant 'cheat' the utility bill... so where you had a 40 watt RMS motor before to get 1000lph of air, with DC you may need 80 watts.... and on top of that, there is the problem of the power conversion... most AC/DC converters are going to lose at least 7-10% in converting from AC power to DC... often more (depends on how expensive/cheap you want to get). The other downside is that if its a shaft-drive DC motor, like the RD2s, the seals can go, just like the dart, and blow the whole thing.
So then you need a DC water cooled motor... back to water cooling, and all of its disadvantages, as well no more RMS power to fall back on. Its 50/50. I think for smaller skimmers, a mag-drive DC motor is the ideal... going from 20 to 40 watts isnt so big a deal to gain all the advantages of DC. For larger pumps, then you are talking a jump of 120 or 140 to 200 or even 300 watts to go DC!
Along the same lines as Klaus, I am looking into alternative magnet assemblies for the Laguna motors. Rather than just larger, I'm thinking that if some of these neodymium/NdFeB magnets, if protected properly, might make for a much stronger and efficient motor than the AC ones we have now. Wish me luck!
spazz
New member
i have to agree with you on this hann. skimmer pumps for the most part are converted flow pumps and there is some effecienty loss in there designs. i have found there is better ways to increase the air output to skimmers but it only works for very large skimmers. it is very hard and expensive to downsize an electric motor. i have looked at DC motors for needle wheel pumps but ran into the same problem. RMS. they make some very effecient converters buy yes there is still a loss in power. for people in places like california, florida and some areas of the northeast have super high electric costs. so every watt counts to those people. i think what really needs to be dome to make a super effecient pump is to design a new pump from the ground up. the problem there is cost. also the problem of the effecienty of mag drive pumps is the other problem. i agree that the gap between the magnet and the fields are too far apart and it looses too much of its effecienty. the other problem is mag drive pumps like iswaki and panworld pumps are not designed so they can be converted to a needle wheel pump.
the one thing that needs to be considered is if you have the gap between the fields and the magnet alot closer there might be a problem with calcium build up and then the pump might lock up. the heat from the pump can cause the calcium to lock the magnet up.
the one thing that needs to be considered is if you have the gap between the fields and the magnet alot closer there might be a problem with calcium build up and then the pump might lock up. the heat from the pump can cause the calcium to lock the magnet up.
hahnmeister
In Memoriam
ksed, perhaps you didnt read it right, but I didnt make any mistakes.
Spazz, well, thats where the additional cooling comes in for water cooled... on the Lagunas for instance, thats why the anti-lime loop is added as they get converted to Red Dragons. Thats one way that works, but by compensation, not by eliminating the problem. Im thinking that rather than use a larger magnet to 'bridge the gap', that a more powerful magnet might just be easier. The only problem is that some of the stronger magnets out there also dont mix with saltwater too well, so they need to be encased in something.
Still, the disadvantage of DC remains... you cant play with the power factor to get a low RMS wattage. The 'advertized' wattage of 40 watts on an AC motor looks good even though its sort of cheating as the real power is much higher usually.
The best thing I have come up with so far is to simply enlarge the volute on any existing motor/pump to bring the flow and cooling characteristics of a two-phase mix to be similar in power needs to that of the single-phase/water function it had. Loss of head pressure isnt so big a deal, as these are needlewheels after all. Make the volute very enlarged to the point that the venturi is more like the original inlet than anything, with the motor running an even heavier flow bias. It seems darts have not reached this yet because they keep having overload/thermal problems.
When converting any motor to a needlewheel, the motor spins without the resistance it was designed for because there is air in the volute... this 2-phase mix allows the motor to 'slip' forward... often lowering the RMS, but the VA can rise. So, to gain back the resistance that the pump normally has, you have to add more air and water... and the best way is to enlarge the volute so the impeller has to do more 'work'. If you can enlarge the impeller, sometimes that is good as well, but usually, that means there will be 'sputter' problems at startup because then the larger impeller has to handle more water until there is air in the body. So keeping the impeller the same is the way to go usually... unless you start messing with the electronics. Maybe some sort of power factor correction circuit could be used on a dart, for instance, to get it operating back closer to spec when used as a needlewheel. This is the big advantage that Lagunas have, but it should be able to be put onto any external motor... sort of like a 'ballast' for a pump... giving it more power when starting to avoid sputter, then cutting it back right away as to not overload the motor and run the motor cooler with a higher power factor. Its either that, or magnets as far as going AC is concerned.
Spazz, well, thats where the additional cooling comes in for water cooled... on the Lagunas for instance, thats why the anti-lime loop is added as they get converted to Red Dragons. Thats one way that works, but by compensation, not by eliminating the problem. Im thinking that rather than use a larger magnet to 'bridge the gap', that a more powerful magnet might just be easier. The only problem is that some of the stronger magnets out there also dont mix with saltwater too well, so they need to be encased in something.
Still, the disadvantage of DC remains... you cant play with the power factor to get a low RMS wattage. The 'advertized' wattage of 40 watts on an AC motor looks good even though its sort of cheating as the real power is much higher usually.
The best thing I have come up with so far is to simply enlarge the volute on any existing motor/pump to bring the flow and cooling characteristics of a two-phase mix to be similar in power needs to that of the single-phase/water function it had. Loss of head pressure isnt so big a deal, as these are needlewheels after all. Make the volute very enlarged to the point that the venturi is more like the original inlet than anything, with the motor running an even heavier flow bias. It seems darts have not reached this yet because they keep having overload/thermal problems.
When converting any motor to a needlewheel, the motor spins without the resistance it was designed for because there is air in the volute... this 2-phase mix allows the motor to 'slip' forward... often lowering the RMS, but the VA can rise. So, to gain back the resistance that the pump normally has, you have to add more air and water... and the best way is to enlarge the volute so the impeller has to do more 'work'. If you can enlarge the impeller, sometimes that is good as well, but usually, that means there will be 'sputter' problems at startup because then the larger impeller has to handle more water until there is air in the body. So keeping the impeller the same is the way to go usually... unless you start messing with the electronics. Maybe some sort of power factor correction circuit could be used on a dart, for instance, to get it operating back closer to spec when used as a needlewheel. This is the big advantage that Lagunas have, but it should be able to be put onto any external motor... sort of like a 'ballast' for a pump... giving it more power when starting to avoid sputter, then cutting it back right away as to not overload the motor and run the motor cooler with a higher power factor. Its either that, or magnets as far as going AC is concerned.
I believe the new tunze circulation and needlewheel pumps use a neodymium impeller magnet. The flow and wattage are quite good, likely thanks to the strong magnet.
If done on a large enough scale to be cost effective, that would give laguna's yet another edge.
I am surprised nobody has made a custom volute for a dart.
If done on a large enough scale to be cost effective, that would give laguna's yet another edge.
I am surprised nobody has made a custom volute for a dart.
spazz
New member
yes i agree with this. this is the reason i use a 2" output on the pumps. it decreases the resistance of the flow going through the plumbing. also i keep the output as short as possible. this reduces resistance too.
the overload thermal problems are only with the A O Smith motors. the ones that ues the baldor motors dont have that problem. i have never had one motor overheat on me.
this is not a problem with the baldor motors on the dart needle wheels. but the higher head heights i work with are not as easy to work with like other skimmers. most skimmers are right around 30" tall. the makes the head pressures alot easier to work with. im dealing with 48 inches. that added 18 inches really cuts down on the air intake. but i have been working on different venturi designs to work around that added height problem. i do loose about 5% between 30" tall and the full 48" of height. its a very time consumming thing go test out 6-8 different designs and then all the different angles that you can make for a venturi.
right now i feel the dart needle wheel works ok. but i feel there is room for improvment. i plan to start some different design to test some time this fall. there is some ideas that i have to improve bubble shear and increase the air intake to the pump. alot of this has to due with pin size and RPM's. any RPM can be used but the wheel needs to be tuned to that RPM and that head height. you can make any needle wheel work as long as you have a starting point and work your way past that point.that way you can find the most effecient head height for that wheel. then you have to work your way up to the desired head height you need that wheel to perform properly at.
the big problem i see with the laguna pumps is the conversion. it is costly to amke the housings and special designed bearigns needed to replace the center shafts. it would be cheaper and less work to have a special mold made for the darts so its built for a larger output. the rest of the pumps is just fine. it might be nice to have some better bearings in the motor that have less resistance. i wish ceramic ball bearings were cheaper. they have alot less resistance than steel all bearings. they also dont react to salt water. but to have ceramic berrings in a motor like that is an extra $300. and i dont feel it is really worth the added costs.
spazz
New member
its just a matter of time before this is done. also newer and better designed wheels will be comming as time goes on. also more uneque designs and more effecient designs that produce smaller bubbls that will dwell longer and remove more from the water becasue of there longer dwell time. the person who can make bubbles that are so small that you almost cant see them with the naked eye will be the one who can produce the best skimmer pumps. alot of this has to do with the materials used for impellors. mesh wheels are evolving at a rapid pace but are not perfect becasue they streach out or get clogged up. newer more aproprate materials will replace that mesh and improve the output of these pumps. but it takes time and money to test all the different designs and find the right one that lasts years not months. and does not need to be cleaned as often.
JCTewks
In Memoriam
Scott, It really is not THAT costly to mfr new volutes for the laguna's...and there is ABSOLUTELY no need for new bearings or shafts or anything on the Laguna 1500 and up models. Klaus has new impellers made because the volute He is using is too small to get the air that he wants out of the pump. So, instead of making larger volutes (relatively inexpenxive), Klaus has new impellers made (VERY pricey, and the larger magnet requires the "anti-lime bypass" cooling loop). Laguna's should be modded more to the specs of the ATB Airstars instead of people looking at RD as the almighty, all knowing, must be the best, will even clean your house it's so expensive pump. IMO, Just because Klaus was the first to use the Laguna does not mean that He uses the best design...invention is always followed by refinement!!!
You can completely retro a laguna for the cost of the pump plus $100 or less (depending on if you want fance RED volutes
)!!
spazz
New member
<a href=showthread.php?s=&postid=12963343#post12963343 target=_blank>Originally posted</a> by JCTewks
Scott, It really is not THAT costly to mfr new volutes for the laguna's...and there is ABSOLUTELY no need for new bearings or shafts or anything on the Laguna 1500 and up models. Klaus has new impellers made because the volute He is using is too small to get the air that he wants out of the pump. So, instead of making larger volutes (relatively inexpenxive), Klaus has new impellers made (VERY pricey, and the larger magnet requires the "anti-lime bypass" cooling loop). Laguna's should be modded more to the specs of the ATB Airstars instead of people looking at RD as the almighty, all knowing, must be the best, will even clean your house it's so expensive pump. IMO, Just because Klaus was the first to use the Laguna does not mean that He uses the best design...invention is always followed by refinement!!!
You can completely retro a laguna for the cost of the pump plus $100 or less (depending on if you want fance RED volutes
yes i have to agree with that. but when i was refering to bigger votives i mentfor the dart pumps more than the laguna pumps. i really dont want to mess with the laguna's becasue there is 2-3 different people working on them. i want to work on refining the dart to make it perform better than what it is currently doing. i feel this pump has some potential that needs to be unlocked. and it can be done very easily and cost effectivly.
spazz
New member
<a href=showthread.php?s=&postid=12963343#post12963343 target=_blank>Originally posted</a> by JCTewks
Scott, It really is not THAT costly to mfr new volutes for the laguna's...and there is ABSOLUTELY no need for new bearings or shafts or anything on the Laguna 1500 and up models. Klaus has new impellers made because the volute He is using is too small to get the air that he wants out of the pump. So, instead of making larger volutes (relatively inexpenxive), Klaus has new impellers made (VERY pricey, and the larger magnet requires the "anti-lime bypass" cooling loop). Laguna's should be modded more to the specs of the ATB Airstars instead of people looking at RD as the almighty, all knowing, must be the best, will even clean your house it's so expensive pump. IMO, Just because Klaus was the first to use the Laguna does not mean that He uses the best design...invention is always followed by refinement!!!
You can completely retro a laguna for the cost of the pump plus $100 or less (depending on if you want fance RED volutes
yes i have to agree with that. but when i was refering to bigger votives i mentfor the dart pumps more than the laguna pumps. i really dont want to mess with the laguna's becasue there is 2-3 different people working on them. i want to work on refining the dart to make it perform better than what it is currently doing. i feel this pump has some potential that needs to be unlocked. and it can be done very easily and cost effectivly.
JCTewks
In Memoriam
I agree that there is some HUGE potential for the Dart.
Maybe you could just rig up a "test" volute out of a huge block of acrylic or PVC and go at it with a router to see what volute internal volume and dimensios will work best
I like Jon's idea of a "chip" similiar to the Laguna that gives a boost in startup torque and maintains PF.
Have you seen the titanium meshwheels that Klaus developed? I don't think they went into any US skimmers, but neat anyway...here's a link to a pic of them http://aquarien-anlagenbau.de/index.php/cPath/6
Maybe you could just rig up a "test" volute out of a huge block of acrylic or PVC and go at it with a router to see what volute internal volume and dimensios will work best
I like Jon's idea of a "chip" similiar to the Laguna that gives a boost in startup torque and maintains PF.
Have you seen the titanium meshwheels that Klaus developed? I don't think they went into any US skimmers, but neat anyway...here's a link to a pic of them http://aquarien-anlagenbau.de/index.php/cPath/6
wizsmaster
Moved On
whatever happened the the titanium wheels in the US? i remember klaus posting abotu them, but they never made it here in the end, did they?
pdelcast
New member
Dude -- I'm afraid you have a few things wrong...
DC motors work by converting the DC to AC either by using brushes or by using a synchronous controller. So there isn't any real difference between DC and AC motors. No rotary motors use pure DC as a power source. (well, actually homopolar motors use pure DC, but they are extremely rare, and very very poor efficiency.)
RMS wattage is real wattage. It is essentially the integral of the power function over the time domain. VA is NOT the real wattage -- you have them backwards. VA (when talking about AC wattage) is a generalized mean (OR peak power -- which isn't the same as watts, which is a measurement of energy usage)- - less accurate than a true RMS measurement. RMS wattage works with sinusoidal, square, multiphase ... you name it. VA only works with DC or Sinusoidal currents. A lot of people use simplified RMS calculations -- and get VA instead (which is incorrect) -- the proper RMS calculations return TRUE average power by a varying load.
The most efficient widely available current motor designs are DC Permanent magnet brushless (where the controller converts DC to three phase AC synchronously with motor rotation.) Efficiencies on those types of motor typically exceed 90% -- BUT, copper rotor induction motors are very close (85-87%), and don't have the AC-DC conversion efficiency losses.
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one thing -
The metal mesh wheels for RE are not titanium but actually Hastelloy C. I dont recall why Klaus abandoned the Ti wheels, but it has some ductility limits and may not accomodate a small radius of curvature for his 'loops'.
Hastelloy is an extremely corrosion resistant alloy with good mechanical properties. It is a nickel based alloy with ~15% Chrome and 15% Moly. Very good stuff and very costly. The density is higher than Ti, but i think it meets the intent. I have some really nice hastelloy mesh (looks like metal enkamat). I just do not have a pump to try it out on for the moment.
Scott - I have not tried it (I dont even own a dart) but couldnt you just use a large diameter PVC pipe to make an enlarged Dart wet end?
The metal mesh wheels for RE are not titanium but actually Hastelloy C. I dont recall why Klaus abandoned the Ti wheels, but it has some ductility limits and may not accomodate a small radius of curvature for his 'loops'.
Hastelloy is an extremely corrosion resistant alloy with good mechanical properties. It is a nickel based alloy with ~15% Chrome and 15% Moly. Very good stuff and very costly. The density is higher than Ti, but i think it meets the intent. I have some really nice hastelloy mesh (looks like metal enkamat). I just do not have a pump to try it out on for the moment.
Scott - I have not tried it (I dont even own a dart) but couldnt you just use a large diameter PVC pipe to make an enlarged Dart wet end?
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