Eric Robson Posted November 22, 2020 Share Posted November 22, 2020 I recently bought 6 x MG 90S servos from Banggood ,I had a Futaba T-FHSS mono RX doing nothing so I set up and checked a servo, nothing happened on checking the other 5 none worked, I tried a Futaba servo it worked fine. Thinking to myself you only get what you pay for I will complain and see what happens. This morning out of curiosity I tried them on my Spektrum gear they all worked fine. Checked the Futaba nothing worked although a Hitech servo worked on the Futaba RX . I have a set of 35mh Futaba and set that up for the Banggood servos they all worked fine on the old Futaba set. Has anyone had a similar experience and put it down to faulty servos? Cheers Eric r. Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted November 22, 2020 Share Posted November 22, 2020 Strange one Eric. Mayne a digital v analog issue? Not sure though Gary Quote Link to comment Share on other sites More sharing options...
kevin b Posted November 22, 2020 Share Posted November 22, 2020 I had a strange problem a couple of months ago. Bought 10 metal gear servos from China. Tested them and 6 traveled to one end and burned out (literally, smoke and sparks). No problems with the seller though. After some consideration I came to the conclusion that they had been wired with 360 degree circuits and standard gear boxes ! I now have 6 spare gear boxes and cases for if I damage any. Quote Link to comment Share on other sites More sharing options...
i12fly Posted November 22, 2020 Share Posted November 22, 2020 Could it be a voltage issue? I bought 6x SG90 servos recently from BG as I just want cheap and cheerful in non critical application. Fitted them onto a servo tester and an old but charged NiMh 4.8v battery. None would work. Battery voltage OK off load >5v. Tried another 2 oldish batteries and the servos were OK. Put all on a cycling soak test and they work fine and centre well too. Conclude that the first battery was duff. In hindsight I ought to have connected it using a Y lead then I could have measured the voltage on load. Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted November 23, 2020 Author Share Posted November 23, 2020 Hi All, I used the same battery on all 3 sets, I also tried a 4 Max mini servo on the Futaba RX that worked OK too all the servos I tried were analogue, i even used a Y lead with different servos on the Futaba worked and the MG 90 did not. Very strange , Cheers Eric. Quote Link to comment Share on other sites More sharing options...
kc Posted November 23, 2020 Share Posted November 23, 2020 I wonder if you plugged them in the wrong way around in the Futaba? No 'Tab' on the side as normal Futaba so it's easy to reverse them. Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted November 23, 2020 Share Posted November 23, 2020 It could be that the MG90s need a stronger position signal than the other servos and that the Futaba receiver position signal isn't quite as strong as the other receivers. Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted November 23, 2020 Author Share Posted November 23, 2020 Good morning All, kc that was the first check I even put them in the wrong way to check they had not been wired wrong at the factory. Frank I tried another new Futaba RX straight from the box and it was just the same. the Spektrum works fine Still confused Eric. Quote Link to comment Share on other sites More sharing options...
kc Posted November 23, 2020 Share Posted November 23, 2020 To me it seems possible that the fit of the pins into RX is the likely problem as it's always tricky with such tiny Rx we have now. Perhaps the casing prevents being fully inserted. I would also say double and triple check you did actually reverse the plug in the socket! Its so fiddly its easy to fit them back the same ( wrong ) way..... ( I have done it! ) Nobody else seems ever to have mentioned electronic incompatibility despite lots of rumours of fake servos being sold. I noted that at one time MG90S were sold as Tower Pro while later the illustration just showed MG90S. But the ones I bought from Banggood were marked Tower Pro. Are your marked Tower Pro? Complaining to Banggood should result in replacement etc as they are quite good about such things. For instance I complained that my six MG90S did not arrive, they asked me to wait a while to see if they turned up and when they didnt arrive Banggood sent a new set which duly arrived. Followed by the original set in the next post! I reported it and they asked me to return the extras but I said I prefer you to invoice me for the extra set. Duly invoiced and all the servos were checked on a servo tester and worked OK. I must say I have not tried these MG90S in a Futaba Rx though. Frankly it's not worth risking dodgy servos in a model so complain or scrap them. Edited By kc on 23/11/2020 13:59:59 Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted November 23, 2020 Share Posted November 23, 2020 Posted by Eric Robson on 23/11/2020 10:00:03: Good morning All, kc that was the first check I even put them in the wrong way to check they had not been wired wrong at the factory. Frank I tried another new Futaba RX straight from the box and it was just the same. the Spektrum works fine Still confused Eric. Eric it could be a function of the chip that Futaba use puts out a slightly weaker position signal than the chip used by Spektrum. Not a problem for Futaba (or other brand) servos that are OK with this, but maybe the MG 90s servos need a bit more. BTW are these Tower Pro servos, I bought some servos off Banggood, MG966 I think, and they were not labeled Tower Pro, I don't think they were sold as Tower Pro either but sort of implied they were identical. They didn't prove to be very good, starting to twitch after a short period in use on a model with a Laser 150. The other servos a mix of Futaba 3003s and Savox have all been fine. Quote Link to comment Share on other sites More sharing options...
Gary Murphy 1 Posted November 23, 2020 Share Posted November 23, 2020 Something similar, had bought 25kg JX brand servo`s from ebay and really pleased with them. This was from different vendors depending who had in stock and delivery time,all from China. Then the last one sounded different when testing,then a close look showed it was not as good quality. Minor differences .So it was either a knock off most likely. But the originals were very good for the money Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted November 23, 2020 Author Share Posted November 23, 2020 Hi again , kc the RX is on the bench so it is easy to fit the plugs in I have used a Futaba extension lead to save messing about with the RX still no joy, Futaba, Hitech, and 4Max servos work no problem with the Futaba RX the fact they work with Spektrum indicates they are OK . Frank I did recognise them as Tower pro copies they even may be from the same source as I am not sure if Tower pro is still trading. I had no intensions of using them for any thing other than small foamies and when I get too old to fly they can be used to operate points and signals on an 0 gauge railway layout I was building while looking after my wife who passed away last year. I I must add this is a new model Futaba RX brought out I was told to keep abreast of the Spektrum economy RX's I have 4 of them 2 in regular use with no issues and 2 for my lockdown projects Thanks to all for your input Eric. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 26, 2021 Share Posted February 26, 2021 A bit late but just browsing through this topic I see that people have bought so called Tower Pro MG90`s. Unless you buy these from the Servo Shop they are going to be poor copies as I found out. There is an inherent fault in this range of servos in that the `sprung` clip providing a connection to the pot centre is of inferior quality and frequently does not make contact at all, resulting in the servo running to one end and burning out. Hi Tec use the same idea but with proper phosphor bronze. Another problem is that if you stop one with your finger it will not restart until the Tx stick is moved. Fantastic spec. on these which is why I bought a couple of types but the best place for them is the bin. Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted July 2, 2021 Share Posted July 2, 2021 Thisis a handy article comparing genuine TowerPro, clone and fake servos. It also describes how to recognise each and the failings of the counterfeit ones.Clone & Fake TowerPro Servos It does seem strange that anyone would bother to set up to manufacture a relatively complex item such as a servo, which sells for around £1 to £2 and then get it wrong. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 2, 2021 Share Posted July 2, 2021 Thanks for that, I shall check the ones I have consigned to the scrap box against the pics. I think that the others in question are the MG60Rs but will check that too. Shame to tarnish the name, and the spec of the genuine ones is very impressive. Will come back tomorrow with the result. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 3, 2021 Share Posted July 3, 2021 Just had a look and my 90s ones are indeed fakes. Also looked at my MG16Rs (not 60R as I said above) but they only have a label on top so cannot tell. When I got these I put one on a pair of drag brakes and it drove to one end and burned out due to the pot connection problem, but not knowing this at the time I replaced it with similar, which has given sterling service for many years, lucky with that one I suppose. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.