McG 6969 Posted November 28, 2017 Author Share Posted November 28, 2017 Hi again, I just finalized my motor test bench today. So, really happy with the progress as it will be used for the forthcoming Vicomte's tests as well. That was before I realized I had already been soldering some XT60 connectors to the wattmeter... So, I just have to produce some XT30 to XT60 'interfaces' next. One for the 'source' side and one for the 'load' side as well... ... and of course trying not to mix up the female and male sides for both. Anybody aware of the double left fuselage build?... Hakuna matata Chris BRU - BE / CTR Interfaces Control Quote Link to comment Share on other sites More sharing options...
Andy G. Posted November 30, 2017 Share Posted November 30, 2017 Anybody aware of the double left fuselage build?... Hakuna matata Chris BRU - BE / CTR Interfaces Control Double left fuselage build??? Ha! You're looking at the guy that once built THREE right hand wings! .. :P Quote Link to comment Share on other sites More sharing options...
John Robertson 3 Posted November 30, 2017 Share Posted November 30, 2017 And a 2-piece wing with 1 pop-up spoiler on the upper right, perfectly balanced by 1 pop-down spoiler on the upper left! Who . . . Me? Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted November 30, 2017 Author Share Posted November 30, 2017 Hey guys, Well, Andy. Let's just hope you were building a Fokker Dr.1 then... ... please don't worry, John. If people ask silly questions, just pretend it is a prototype wing for some 'perfect & accurate' low speed rolls... And meanwhile, this apprentice is still struggling with his electric connections... Hakuna matata Chris BRU - BE / CTR SuperWings Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 1, 2017 Author Share Posted December 1, 2017 Hello if there is still someone out there, I know electrical stuff isn’t really my ‘thing’. I don’t mean the cutting, denuding and connecting or soldering the bits together. No, not at all. What has brought me in semi-panic several times in full size stuff was just to connect all the bits together and finally power those wired or PCB circuits up… Now my connections/interfaces are done and ‘sourced’ to my wattmeter in 2S… … and for 3S. So far, no ‘magic smoke’… Let’s hope for the best when connecting the ‘load’ part of it. Hakuna matata Chris BRU - BE / CTR Smoke Control Quote Link to comment Share on other sites More sharing options...
onetenor Posted December 1, 2017 Share Posted December 1, 2017 Well said Chris (*) BTW where did you get motors for 4.80 Euros? Sorry no Euro symbol on my comp. John Quote Link to comment Share on other sites More sharing options...
Steven S Posted December 1, 2017 Share Posted December 1, 2017 Still here Chris. I was going to make my own test stand also, after reading the article in the magazine last year, but ended up buying these components from our friends at Banggod. I did make my own 3cell to 2 cell adaptor though. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 2, 2017 Author Share Posted December 2, 2017 Thanks for visiting, gentlemen. @ John > my XDD 2212 motors come from our Eastern friends aka Banggood, see here. They're even 5 euro-cent cheaper now. I can't really understand how they can manage get them free shipped to Europe at that kind of money. @ Steven > well, mine looks indeed very 'agricultural' compared to your 'blingy' thrust stand. But then it's made of scrap bits and some free 'stainless steel' (Yesss !) bearings from high-tech drawer sliders. The luggage scale belongs to The LotH, so, let's be discrete about it. By the way, are you satisfied with it? Hakuna matata Chris BRU - BE / CTR Thrust Control Quote Link to comment Share on other sites More sharing options...
Steven S Posted December 2, 2017 Share Posted December 2, 2017 It seems work quite well for comparing propellers in grams or ozs, but yours should also, maybe better, as you can test your luggage scale with a known weight. I get a good readout and can compare many props on the same motor, but have no way to know if the thrust reading [of 854 grams] is true. I run my different props on each motor and have set up a spreadsheet with the results. Edited By Steven Shaw on 02/12/2017 16:10:25 Quote Link to comment Share on other sites More sharing options...
Steven S Posted December 2, 2017 Share Posted December 2, 2017 BTW - this is the Banggood link **LINK** It's a well built piece of kit, but your homebuilt version will do just as well. As far as I can see the trust readings are good for comparing different prop outputs and the luggage scale should do that function just as well. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 3, 2017 Author Share Posted December 3, 2017 Hi Steven, Thanks for the link at BG, but I had been looking at it some time back. I don't really know if my DIY thrust thingie will be able to do the job precisely. The point of interest isn't to have a 'certified installation', but as you say, to be able to compare results. Anyhow, the static thrust than can be measured is only a guidance as the thrust in flight will be different ie. 'higher'. I only did incorporate the luggage scale as I had it laying around, as IMHO the wattmeter is a lot more valid to check the admissible up to the extreme values for your components. For sure I'll be doing some multiple prop tests with one type motor, doing the same with a different motor, etc... Excel is our friend, young man... Hakuna matata Chris BRU - BE / CTR Excel Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 4, 2017 Author Share Posted December 4, 2017 Hi again, I went on with powering up the test bench and connected the 'load' side as well and obtained... no smoke at all. As I forgot to load the Lipos, sitting at +/- 50% charge for the small ones, I only had a brief test on 2S. The 3S battery being at 60%, I went for a short run to check the rotation direction of the motor. Everything fine but the motor only starts to turn at around 1200µs while the range of the servo tester is from 800 to 2200µs. Is there something wrong? Is this some kind of 'calibration' issue? I've been reading about throttle calibration with a Tx, but is it of application here with a servo tester? And, if so, I do I manage it? Could some angel-like forumite enlighten my darkness here, please? ... Hakuna matata Chris BRU - BE / CTR Angel Control Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted December 4, 2017 Share Posted December 4, 2017 The more knowledgeable will chip in, although I thought you would need to "span" the ESC to the RX or servo tester. Without prop set TX/servo tester to full speed, then power the ESC up. Then set TX/servo tester to min speed the ESC should bleep to confirm its set and armed. PS I noticed that your test rig has quite a large fontal area that the prop wash will be pushing against that might affect static thrust readings on a small prop set up PPS I don't think you can compare thrust values along the throttle curve (even if its linear) unless you can guarantee different ESC's perform the same way and a different prop will change the mid point speed anyway...Totally out of my league here!... Question for another post! Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 4, 2017 Author Share Posted December 4, 2017 Posted by Chris Walby on 04/12/2017 11:58:39: The more knowledgeable will chip in, although I thought you would need to "span" the ESC to the RX or servo tester. Without prop set TX/servo tester to full speed, then power the ESC up. Then set TX/servo tester to min speed the ESC should bleep to confirm its set and armed. Thank you for jumping in with some advice, Chris. As it is my intention to spend a few hours at La Grotte this afternoon, I will give my Lipos a full charge and give it a try following your method. I think to remember it was the same I had been reading for a Tx/Rx 'calibration' of the ESC, but didn't know if it could/should be applied to a servo tester. Regarding the "frontal surface", I do realize it could be very close to a Warp Radial, very 'agricultural', in fact... But I just built the scale in as I had it laying around. Not so sure at the moment to even use later as I prefer to compare the figures from the wattmeter. And don't worry, I won't blame you for any 'magical smoke', the hardware is just part of my 'college/study' budget... Thanks again, young man. Hakuna matata Chris BRU - BE / CTR Calibration Control Quote Link to comment Share on other sites More sharing options...
Steven S Posted December 4, 2017 Share Posted December 4, 2017 I had no trouble with my servo tester. Complete control through the full RPM range. It's wired up as you see in the first picture and I've used it with both a 30 and 40 Amp ESC. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 4, 2017 Author Share Posted December 4, 2017 Yippieyeah… no magic smoke at all at La Grotte. First thing I did was to charge the 2S & 3S Lipos. Then I tried with a Skywalker 15A instead of the 20A but got the same kind of result… ppfff. I checked the settings with the program card and afterwards I calibrated the 20A following Chris W’s advice… and everything worked correctly. Results with a 8x4,3 prop were 7,5A and 56W on 2S, while a draw of 11A gave 125W on 3S. I guess my 20A ESC is a bit OTT, but then it’s only 2g heavier than the 15A. The Frenchies use a 7X4 on 3S with their 2205 motor. I’ll test that too later. But meanwhile, no worries, I’ll start very gently with 2S. @ Steven > my connections are very the same but my ESCs come right out the ‘bag’. I guess you were just very lucky with the calibration of your ESCs or they had been used before and calibrated with your Tx? ... A very chuffed apprentice learned a few more things today. Thanks again both. Hakuna matata Chris BRU - BE / CTR Amps Control Edited By McG 6969 on 04/12/2017 19:27:13 Quote Link to comment Share on other sites More sharing options...
Steven S Posted December 4, 2017 Share Posted December 4, 2017 Chris - It sounds like you are testing an 8x4, 3 blade prop. don't know why, but when I have compared 2 and 3 bladed props of the same diameter and pitch, the 2 bladed ones are always better, by about 20% Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 5, 2017 Author Share Posted December 5, 2017 Hi Steven, No, it's a simple 2 blade prop with a diameter of 8" and a pitch of 4,3". Don't ask me why that strange ',3' figure. They are from BG as well at the insane investment of around €3,45... for 5 pieces ! And amazingly 4 of them were perfectly balanced, only one needing a tiny bit of attention. I have some 'slow fly' props for another project and they are 9x47SF which obviously should be a little slower than a 9x5. Not sure if one (me !) could ever 'feel' the difference. Hakuna matata Chris BRU - BE / CTR Budget Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 6, 2017 Author Share Posted December 6, 2017 Hi everybody, I guess I should bring out some apologies now. I'm afraid I did discover a new addiction being MBT - ie Motor Bench Testing. I did spend a few hours at La Grotte, just charging and discharging batteries and running motors and props. Even without taking notes for that holy Excel projection. I'm really going to try to be more productive during the next sessions... Did I mention 'trying'? Hakuna matata Chris BRU - BE / CTR MBT Control Quote Link to comment Share on other sites More sharing options...
Steven S Posted December 6, 2017 Share Posted December 6, 2017 It is quite addictive isn't it. I've gathered quite a collection of props since I set up my test stand. Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 7, 2017 Author Share Posted December 7, 2017 Absolutely & totally addictive, Steven. I can hardly stop myself buying a couple more motors and having a drawer full of props. But now, as I checked the ChtiCat powertrain, I can go on with trying to have all that stuff 'talking' to the 'old' DX6i. Wish me luck, gents. Hakuna matata Chris BRU - BE / CTR Bind Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 8, 2017 Author Share Posted December 8, 2017 Hi again, Very wisely, I managed to get away from the motor test bench and went for the ‘binding’ process. I have a lightweight Redcon 6ch DSMX/2 receiver intended to take duty in the ChtiCat, so I went for my first ever binding to the DX6i Tx. Rx connected with ESC throttle wire & rudder servo, Rx powered with the same 2S, LED flashing, Tx power on with ‘Trainer’ switch on, LED static after a while… connected. Rudder servo moves properly, throttle does… nothing. Oops. Disconnect everything, set up again… rudder works, motor not at all. Did I kill my motor already? Disconnect again, followed by a bench test with still the same ESC… and motor works perfectly. Back to the Spektrum manual, nothing ‘weird’ to read… momentito, I have another Redcon Rx. Procedure starts again with the other Rx but with the same strange results. Believe it or not, but I manage to remain as ‘stoic’ as an Egyptian mummie. Well, ‘close to’. Back to the first Rx and then by the grace of the Upper Squadron Leader, I decide to connect my only 3S 850mAh Lipo and to try that… and it works, right away ! … But then, even better, when I decide to use it back on the 2S (with a bit of recharge in the meantime), it works perfectly as well. Very strange all that… and not that sure I’m totally ready for these ‘special’ RC discoveries. Hakuna matata Chris BRU - BE / CTR Weirdness Control Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted December 10, 2017 Author Share Posted December 10, 2017 Hello everybody, We had a first snow carpet here in Central Belgium today and I don't think I will be able to 'glide' the ChtiCat outdoors very soon now. I went to La Grotte anyhow to get a bit more experience with my electrical stuff and binding procedures. As I was quite pleased that I finally got the motor working, it seems now that I have to 're-bind' each time after I've been 'disconnecting' things. Powering on the Tx, than the Rx, doesn't make it work. If I redo the binding process, it works fine afterwards. Any ideas of what I'm doing wrong, please? Hakuna matata Chris BRU - BE / CTR Bind Control Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 10, 2017 Share Posted December 10, 2017 Bind plug left in after binding. It will start up in bind mode if you power up with a bind plug in. Quote Link to comment Share on other sites More sharing options...
Paul C. Posted December 10, 2017 Share Posted December 10, 2017 Hi Chris, no experience with the red con rx but just wondering if you are removing the bind plug after you have bound the tx to rx. Pleased to say that I have not encountered this problem with my dx8 😯 Paul. Quote Link to comment Share on other sites More sharing options...
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