RnB Posted November 5, 2004 Report Share Posted November 5, 2004 This the 2000 Euro's version........ for my pumps Should I buy a large stepdown transformer off tradme then use 115V USA pumps.... I can get therse for $89 ish already with needle wheel impeller in them...... (postage extra) Or should I go Ehiem and cut a deal with someone...... Pies "raves" about ehiems and I agree but the already modified needle wheels have a lot of appeal, and $89usd is quite good too! Peter Quote Link to comment Share on other sites More sharing options...
Ira Posted November 5, 2004 Report Share Posted November 5, 2004 You could have a look at some DIY needlewheel options. I've seen ones using a chopped down bioball. Using a transformer is fine for low wattage stuff, but I kinda worry about losses with higher wattage. Anyone know what kind of efficiency the average transformer has? Quote Link to comment Share on other sites More sharing options...
RnB Posted November 5, 2004 Author Report Share Posted November 5, 2004 I am going to use flat sheet clear 10MM acrylic, this is 2400mm x 1200mm @ 215.22+gst trade... sides of the reaction chamber are going to be 800mm high by 300mm wide, it will give the reaction chamber 27% more volume then the big deltec but more importantly this will cost only $100 for the main chamber, be clear AND allow me to use standard flat through fittings which is going to make things SO much easier here is an interesting design made of flat acrylic http://www.reefcentral.com/forums/showthread.php?s=&threadid=371055 Quote Link to comment Share on other sites More sharing options...
Ira Posted November 5, 2004 Report Share Posted November 5, 2004 Once you make yours up, if it works well I might get you to build one for me too...Not quite so big though. Quote Link to comment Share on other sites More sharing options...
Brianemone Posted November 5, 2004 Report Share Posted November 5, 2004 ill take one twice the size for my nano Quote Link to comment Share on other sites More sharing options...
RnB Posted November 5, 2004 Author Report Share Posted November 5, 2004 IRA It is very likely that my first cut will be pretty much a copy of Pies skimmer..... simply because it will be quicker to get a two pump one built and in test..... and a little cheaper as well.... Could be a deal... I build you a skimmer and you help me build some tanks! Quote Link to comment Share on other sites More sharing options...
Warren Posted November 5, 2004 Report Share Posted November 5, 2004 Should I buy a large stepdown transformer off tradme then use 115V USA pumps.... I can get therse for $89 ish already with needle wheel impeller in them...... (postage extra) I wouldn't put a 115V 60Hz pump on to a 115V 50Hz mains. A stepdown trany won't change the frequency. By putting the same voltage but lower freq on the pump it will over flux it but 20% causing at least 44% more iron loss and higher copper loss in the motor. It may significantly reduce the life. The pump will also run at about 80% speed. Since pumps have a flow rate proportional to the speed cubed, you'll end up with much less flow as well - approx 51.2% flow rate... Quote Link to comment Share on other sites More sharing options...
Warren Posted November 5, 2004 Report Share Posted November 5, 2004 I am going to use flat sheet clear 10MM acrylic, this is 2400mm x 1200mm @ 215.22+gst trade... sides of the reaction chamber are going to be 800mm high by 300mm wide, it will give the reaction chamber 27% more volume then the big deltec but more importantly this will cost only $100 for the main chamber, be clear AND allow me to use standard flat through fittings which is going to make things SO much easier Have you used acrylic before? How are you going to glue it together? After being machined or cut, acrylic needs to be annealed before it is glued if you are using a hard glue (like Acrifix192). It's one of the best cheaper acrylic glues available. It has virtually no shrinkage and sets perfectly clear. It fills very well and looks just like the original acrylic. If you don't anneal the sheets first they will crack all round the joints. If you are going to just silicone it together there is no need to anneal. Quote Link to comment Share on other sites More sharing options...
RnB Posted November 8, 2004 Author Report Share Posted November 8, 2004 http://www.bayplastics.co.uk/product%20 ... ch(bending).htm found this on the annealing process..... Quote Link to comment Share on other sites More sharing options...
RnB Posted November 8, 2004 Author Report Share Posted November 8, 2004 starting to think North Shore Laser Cutting here, they can cut 10mm clear no probs, from a DXF file they can just setup and go..... (thanks for the lead Chimera!) That would be cool as they could cut out circullar shaps etc etc etc all the holes could be cut then just a glue job....... Quote Link to comment Share on other sites More sharing options...
Brianemone Posted November 8, 2004 Report Share Posted November 8, 2004 can they make me a cool fish tank?? Quote Link to comment Share on other sites More sharing options...
RnB Posted November 8, 2004 Author Report Share Posted November 8, 2004 Mass: approx. 530x530x980 mm current consumption per pump: approx.. 38 Watts of max. air achievement: approx.. 2800 Liter/Std. recommended aquarium size: approx.. 4500 litres number of skimer pumps: 4 flow rate: approx.. 2,800 litres of Std. Contact pipe (diameter): 300 mm foam pipe (diameter): 160 mm weight: approx.. 23 kg Quote Link to comment Share on other sites More sharing options...
RnB Posted November 8, 2004 Author Report Share Posted November 8, 2004 my tank is laser cut....... looking at it over the weekend gotme thinking but laser cutting was not open to ask questions...... The cool thing is once the DXF is done and they have tinkered... They could cut these things "on demand" this has an almost german precision engineering ring to it :lol: :lol: I think DIY has just got "A WHOLE LOT EASIER!" Quote Link to comment Share on other sites More sharing options...
RnB Posted November 8, 2004 Author Report Share Posted November 8, 2004 Have decided to go with 240V pumps.... I really want the modified aquamedic's Ocean Runner 2500 units. Quote Link to comment Share on other sites More sharing options...
RnB Posted November 8, 2004 Author Report Share Posted November 8, 2004 Here is an online vid of 20mm acrylic being cut.... http://www.eurolaser.com/video/acrylics_foot.wmv pretty cool really..... different people telling me different things re the squareness of the cuts, going to get some offcuts and try it out.... this from another laser cutting company Acrylics are cut by "vaporisation". The absorbed laser radiation initiates a process which comes close to a physical phase change from solid to liquid to vapour with a remarkably low level of chemical degradation. The vapour, colourless with a distinctive smell, is highly inflammable and burns with a sooty flame. A gentle stream of pressurized air or nitrogen blows the vapour away from the cutting zone to prevent its ignition. It also dries the remaining liquid melt on the cut edge, creating a glossy, smooth, flame-polished like cutting edge. Quote Link to comment Share on other sites More sharing options...
RnB Posted November 9, 2004 Author Report Share Posted November 9, 2004 warren - it does seem that some pumps are rated 50 or 60hz, like Iwaki's MD External Pumps Widely used in the aquarium industry, these magnetic drive pumps have ceramic shafts and will pump a high volume of water at an extremely low price. Inlet/Outlets are 1" barb fittings. Not designed to run dry. Not UL-listed, CE-approved, pumps are 115V/50-60Hz. Six month warranty. but not Ehiem... so far as i can see, still this is not the hobby of freely exchanged information that I would like..... Have been advised that the drop in pump throughput will probably not be the 40% you mentioned tho, how did you come to this figure? Peter Quote Link to comment Share on other sites More sharing options...
Warren Posted November 10, 2004 Report Share Posted November 10, 2004 After a bit of research on some of the pumps available on the net it does look like they don't drop much in flow from 60-50Hz. The 40% drop will be accurate if the shaft speed drops to 80%. I expect the motor is designed primarily for 50Hz operation and runs a high slip at 60Hz so the shaft still rotates at a similar speed. The output on most pumps I looked at only goes up by 5-10% at 60Hz... There must also be enough iron in the pump for 50Hz operation as well. Quote Link to comment Share on other sites More sharing options...
RnB Posted November 10, 2004 Author Report Share Posted November 10, 2004 thats what i think as well... for some pumps.... Iwaki do not have seperate impeller assemblies for 50 or 60hz pumps just one build so they are safe IMHO from my pump labs at uni (how sad they where to an electronics engineer all that way back!) remind me that for a given pump design if you plot the output say LPM from say 5 rpm through to say 1800rpm then the curve will go up to the pump reaches maxium efficiency then begin to drop.... how flat the top would be would be a function of the design.. I am going to take a punt here that most pumps running on 60Hz in the US would run here at very near there max effiecincy..... I am thinking of running everything in my MAF room on 115V excpet the heaters and lights... that way I can just import any pump, controller etc etc etc from the us without hassle...... a big 5kva transformer unit is about $150-200 second hand and probably have a smaller one on stanby... I have a 2kva one for my treadmill already.... never had a problem with it and have done massive miles on it. It does not get very hot, so i am suspecting the losses are quite low as well..... Quote Link to comment Share on other sites More sharing options...
RnB Posted November 12, 2004 Author Report Share Posted November 12, 2004 It seems that the laser machine i went to look at will not achieve a suitable result straigh off, it is concave. It is because as the operater explained the laser beam diverges, they can change the focal length so the cut is square at the edges, but it is deeper in the middle. It is not suitable for direct glueing without jointing etc. It was a huge laser cutter, they where cutting 1/8inch thick steel with it when i saw it running..... I am going to see another machine to see if it can give a better result. Quote Link to comment Share on other sites More sharing options...
Ira Posted November 12, 2004 Report Share Posted November 12, 2004 Bugger. Quote Link to comment Share on other sites More sharing options...
lduncan Posted November 12, 2004 Report Share Posted November 12, 2004 You need someone with a water "laser" high pressure water cutter which doesn't diverge much. They can cut a sponge cake with these water jets without any visible divergace at the bottom of the cut. At the same time they can cut through 1.5" steel (from memory). Quite impressive. I'm sure they could use it on acrylic. Don't know who would have one here though. Layton Quote Link to comment Share on other sites More sharing options...
RnB Posted November 12, 2004 Author Report Share Posted November 12, 2004 that is exactly what a mate said... http://www.laserstream.co.nz seeing them monday Quote Link to comment Share on other sites More sharing options...
Warren Posted November 12, 2004 Report Share Posted November 12, 2004 Maybe ask them if it work hardens the material at the same time. Would be good if there's no need to anneal afterwards. Quote Link to comment Share on other sites More sharing options...
RnB Posted November 12, 2004 Author Report Share Posted November 12, 2004 lots of reef central acrylic gurus saying there is no need to anneal.... what is your experience of this comment Warren?b Quote Link to comment Share on other sites More sharing options...
Warren Posted November 12, 2004 Report Share Posted November 12, 2004 Unsure, I've always machined my acrylic parts. Every time I've tried to glue without annealing it cracks. I always anneal now as acrylic isn't cheap plus it's difficult to work with and takes a long time to machine. It may also be the glue I use. I like acrifix since it's so easy to use, has excellent filling properties and gives a melted together look. Do you know what glue they use? If it's soft like silicone then yes, no need to anneal... Quote Link to comment Share on other sites More sharing options...
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