Roger Dyke Posted July 4, 2020 Share Posted July 4, 2020 Hi All, A while ago I purchased a DYS D3542/6 - 1000kv motor but never used it. However, I've just installed it on my static rig to run it up and my findings were not as expected. It's spec. is supposed to be 555W, 38A, 1000kv, and 2 - 4S. Results using a 3S battery:- Prop 8x4 Volts 11.05 Amps 33.95 Watts 387 RPM 14000 ------------------------ Prop 9x6 Volts 10.65 Amps 51.97 Watts 573.2 RPM 12100 ----------------------- I'm inclined to think that the motor is either the 1250kv or the 1450kv version and has been put in the wrong box. The box is clearly identified in two places but the motor has no identification at all apart from the manufacturers label. What do you think or am I missing something? Quote Link to comment Share on other sites More sharing options...
PatMc Posted July 4, 2020 Share Posted July 4, 2020 IMO it looks like it;s the 1250kv version. It would be easy to verify by measuring the rpm & supplied voltage with no load. Use a couple of strips of self adhesive tape that are a contrasting colour to the motor body in order to measure the rpm. Dividing the rpm by the voltage will give the kv. Quote Link to comment Share on other sites More sharing options...
Peter Beeney Posted July 4, 2020 Share Posted July 4, 2020 Just measure the motor revs without a prop on, Roger, that will give you a reliable datum to base all your other measurements on. I usually do it with a 12V car battery, that’s a good constant voltage supply, the load current is minimal; and for the same reason a fully charged 3S is fine, very little voltage sag. Should be a ‘must do’ in every case case anyway. Hope this helps. PB Sorry Pat, you beat me to it… must be late… Edited By Peter Beeney on 04/07/2020 21:42:29 Edited By Peter Beeney on 04/07/2020 21:43:28 Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 4, 2020 Author Share Posted July 4, 2020 Hi Pat and Peter, Thank you both so much for your useful tips. I'll give it a go. Roger Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 Pat and Peter, Just for info. I have carried out the test with no prop as you suggested and the result was as follows:- Voltage: 11.98 RPM: 17300 So 17300/11.98 = 1440 So I take it that the motor is the 1450kv version. Not the 1000kv version as stated on the box. Thanks for your help. Roger Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted July 5, 2020 Share Posted July 5, 2020 If the no-load current is about 1A, that all matches up for a 1450kv and internal resistance of about 42mOhm. Quote Link to comment Share on other sites More sharing options...
Peter Beeney Posted July 5, 2020 Share Posted July 5, 2020 Hi Roger, I probably wasn’t that far behind you, I’d already guessed that the unloaded revs were in the 17,000 region; 17,285 to be precise. But that in turn is making me more than a trifle suspicious too. Those current consumption figures do tend to stand out from the crowd a little, 52 amps to drive a 9 x 6 on 3S?? Put that lump in your model and you’d flatten the battery in less than three and half minutes! ….And just how far is 52A out of spec. anyway? Can we now barbecue some sausages on the ESC? On the face of it, it appears you are getting an approximate 1,200rpm gain for a 22 ampere current flow increase. Based on this, to get to the sort of figures I might want to be looking at I think I might need to be looking for something like a 7 x 2 prop… Do you by chance have a link to that motor please? I can find the 1,000 and 1,250 ok but not the 1,450. Perhaps it’s gone into hiding, if so is there a reason for this I ask myself? Carry on dabbling, Roger, it’s all getting nicely interesting… PB Edited By Peter Beeney on 05/07/2020 12:15:24 Edited By Peter Beeney on 05/07/2020 12:17:35 Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 The no-load current was 4.5 Amps read back from the wattmeter when running full chat. 0 Amps read at idle. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted July 5, 2020 Share Posted July 5, 2020 Posted by Peter Beeney on 05/07/2020 12:14:17: Hi Roger, I probably wasn’t that far behind you, I’d already guessed that the unloaded revs were in the 17,000 region; 17,285 to be precise. But that in turn is making me more than a trifle suspicious too. Those current consumption figures do tend to stand out from the crowd a little, 52 amps to drive a 9 x 6 on 3S?? Put that lump in your model and you’d flatten the battery in less than three and half minutes! ….And just how far is 52A out of spec. anyway? Can we now barbecue some sausages on the ESC? On the face of it, it appears you are getting an approximate 1,200rpm gain for a 22 ampere current flow increase. Based on this, to get to the sort of figures I might want to be looking at I think I might need to be looking for something like a 7 x 2 prop… Do you by chance have a link to that motor please? I can find the 1,000 and 1,250 ok but not the 1,450. Perhaps it’s gone into hiding, if so is there a reason for this I ask myself? Carry on dabbling, Roger, it’s all getting nicely interesting… PB Edited By Peter Beeney on 05/07/2020 12:15:24 Edited By Peter Beeney on 05/07/2020 12:17:35 When it was in stock Quote Link to comment Share on other sites More sharing options...
Dickw Posted July 5, 2020 Share Posted July 5, 2020 Is it this motor? Dick Denis is quicker! Edited By Dickw on 05/07/2020 12:26:28 Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 Hi Peter, Your thoughts are interesting. The more I look into it, the more it seems that the market for this motor is probably for quads and drones (with small fast props etc.). Of course, I maybe wrong (again). I didn't purchase it from there, but below is the link to the DYS website showing the motor D3542/4 - 1450kv. **LINK** Roger Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 Hi Dick, Yes, the 1000kv one was the one it was supposed to be and what it says on the box. I think it is exactly the same as the Turnigy D3542 series (but re-badged). Flash Hobby also badge them. Edited By Roger Dyke on 05/07/2020 12:42:07 Quote Link to comment Share on other sites More sharing options...
Dickw Posted July 5, 2020 Share Posted July 5, 2020 I don't know about quads and drones, but that 1450 motor would suit a faster model - perhaps something like a simple pylon racer type. MotoCalc agrees that it would be around 52 amps on a 9x6 and 3s static, dropping to the mid 40amps in the air. If you fly full throttle all the time run perhaps time would be a bit short, but if you throttle back a bit once in the air and only use full throttle for a few aerobatics you should get 5min plus flights. Only thing is, your 'on load' rpm figures look a bit lower than I would have expected. Dick Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 Hi Dick, Thanks for your info. It will probably go back in the box now as my older years don't really lend themselves to the punch holes in the sky set. Nowadays I'm more of a tootler. Good to find out what it was though. Even if it wasn't my intended purchase. Roger Quote Link to comment Share on other sites More sharing options...
Dickw Posted July 5, 2020 Share Posted July 5, 2020 Hi Roger Nothing wrong with tootling, I do a fair bit of that myself these days . Mind you, I do like to have power available for take off, loops etc., and getting myself out of trouble. As an example, a data log of one plane last week shows a current draw of 43 amps at take off, but most of the flight was at part throttle using less than 20 amps - tootling even! Dick Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted July 5, 2020 Share Posted July 5, 2020 I've seen your tootling Dick - anything up to 7 kW bursts of less than 2 seconds with 100 mph vertical climbs. Measured figures, not wildly optimistic estimates... Tootling? Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 Hi Denis, Sorry, I accidentally missed you out. It was in stock around 6th May a couple of months back. Roger Edited By Roger Dyke on 05/07/2020 17:11:45 Quote Link to comment Share on other sites More sharing options...
Dickw Posted July 5, 2020 Share Posted July 5, 2020 Posted by Martin Harris on 05/07/2020 15:40:08: I've seen your tootling Dick - anything up to 7 kW bursts of less than 2 seconds with 100 mph vertical climbs. Measured figures, not wildly optimistic estimates... Tootling? OK, so I like a bit of variety - but even that could be described as tootling when I slow it down and go thermal hunting. Dick Quote Link to comment Share on other sites More sharing options...
Mike T Posted July 5, 2020 Share Posted July 5, 2020 Mis-labelling problems apart, I have to say I do like those DYS motors, particularly the gold anodized ones, where typically, size-for-size, the shafts are thicker than other makes' equivalents. In addition to being stronger, its easier to get a good fit/grip with a collet. Quote Link to comment Share on other sites More sharing options...
Roger Dyke Posted July 5, 2020 Author Share Posted July 5, 2020 Hi Mike, I quite like the look of them too and on the sizes that I use, do like the 5.00mm shaft which is 4.00mm on a number of others. Quote Link to comment Share on other sites More sharing options...
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