Hi guys. I'm David Theunissen based in the south of England. I maintain www.flyelectric.ukgateway.net and would like to thank Ken Myers for his inspiration...
Hello David I drew your attention on D-Calc concerning the chapter: "Prop" Given a prop in a list, given rpm you get the Power in Watt This calculator seems...
Welcome David. I'm afraid the trouble with your Croco data must have to do with your measurement. In the D-Calc sheet the I-Diff. numbers prove the results are...
Thanks Louis and Christian, Christian, when I enter Ralph's data without n0 I get very low I-Diff and 83.7% as you say. When I enter n0=7350 I get very large...
Hi David, low I-Diff. numbers do indicate accurate calculation. If the computed current at some differently loaded operating points is very near to the ...
Well, at least I'm not the only one! :-) I have checked my DVM and measuring technique with other DVMs and leads and get the same results within 0.1v. I can't...
Hello David Even if your tach gives 3000 on 50 Hz light, maybe it could have problems on a rotor or a propeller due to bouncing or not clean pulse train. Could...
I'll try natural light over the weekend and try to borrow another rev counter and clamp meter if a friend is not travelling. My clamp meter is 0-300A but...
Hi David I suggest that for no load current you use a DMM range 10 A to compare to your clamp-meter Did you spotted that Rm is measured at 41 milliohm and...
... What light source have you been using then? You will not get valid results using mains lighting, you need to use a dc sourced light (torch or led) or...
Hi Louis, Rm as computed by Drive Calculator is not the copper resistance. It is a dynamic resistance and a property of the system consisting of the ESC and ...
I am using torches but I also have some indirect ambient mains light. I don't expect this to be causing problems but I need to eliminate all possibilities. I...
Christian, I normally do my no load test first when the motor is cool. Should I do it last after running load tests to the motor is up to operating ...
Hi Christian Yes I agree that both ESC + brushless form a tight couple ESC has its "dynamic internal resistance" and motor too But total dynamic Rm is...
Hi David See my previous reply to Christian D-Calc is a very good speadsheet but it gives an "average" If you want a better accuracy simulation you have to...
... FYI, correct url is http://electrofly.free.fr (there's no www !) cheers anthony [Non-text portions of this message have been removed]...
anthony hubbard
pasmonadresse@...
Jan 13, 2006 2:56 pm
56
Does the No Load current Io actually change very much with motor temperature? I though this current was dependent upon the iron losses in the motor, and thus...
Hi Neil Io changes with voltage principally (following rpm) due to iron losses Temperature effect is not very important Louis ... Does the No Load current Io...
Neil, no load current changes with temperature because of several reasons. I know you are familiar with the basics, but I'll summarize it anyhow: As we all...
Hi again. I don't have a successful conclusion yet and testing is on hold while I reset my croc's magnets. They got such a fright at 1300W that some jumped...
Folks, my procedure for measuring prop rpm and no load rpm on my test stand are as follows. First the light source. I made a ¼ inch plywood u shaped holder...
Hi, I've been working on a project, and could use some N100W values for rough determination of necessary prop-size. To my disappointment there was no such...
Ich habe Messungen in den Antriebsrechner eingegeben. Ich habe dann festgestellt, dass der Wirkungsgrad relativ stark daneben liegt (5- 10%). Ich habe dann mit...
Hi the D-calc approach to estimate Rm is fine, but do not expect to be able to measure Rm with an Ohmmeter. Rm is a virtual resistance which is related to the...
Hello Peter The D-Calc approach of Rm is global and fine ... but not perfect Only due to temperature effect, Rm is variable as the load (and the current)...
For further assistance, please visit http://help.yahoo.com/help/us/groups/ From: Pete _ <petezx@...> To: D-calc@yahoogroups.com Subject: RE: [D-calc]...
Hi Peter I have no dynamometer bench, unfortunately. So I use D-Calc and also compare to my own calculations trying to take into account the temperature effect...
Hello Louis I have just calculated with D-calc and my equatins where a kns factor is added. I used my measurements and also some measuerments from Plettenberg ...
Having problems with message search?
Fill out this form to ensure your group is one of the first to be migrated to the new message search system.
