Andy-H Posted July 7, 2023 Share Posted July 7, 2023 I bought a couple of new Hitec HS82MG servos last year at a show. Testing them on the bench with my Spektrum NX radio, they seem very noisy compared with other servos I have, even when no arm connected. They operate quickly but seem to move imprecisely when moving the stick, vibrate slightly and make a buzzing noise. Only happens when moving the stick. It’s almost as though they can’t quite work out where to stop. I attached a 2mm rod to a servo arm as an extended pointer, and this shows up a slight vibration during the movement. The buzzing can be replicated by putting a bit of load on the servo arm by hand. I tried loosening the servo case screws in case they were over-tight but that didn’t make any difference. I took this up with the retailer who consulted J Perkins, but all they seemed to suggest was the servos were older models and best switch to digital servos. Is this a common issue or have I just picked up a couple of duff examples ? This model of servo seems to be well thought of from what I’ve seen elsewhere on the forum. Quote Link to comment Share on other sites More sharing options...
John Lee Posted July 7, 2023 Share Posted July 7, 2023 I use a lot of these without issue. Check that you Tx frame rate is set at 22ms frame rate for these analog servos. 1 Quote Link to comment Share on other sites More sharing options...
MattyB Posted July 7, 2023 Share Posted July 7, 2023 (edited) Highly likely to be a frame rate issue - should be easily solved by setting the right mode at the TX, very poor that the retailer did not suggest this. http://www.indyrcsouth.org/forum/index.php?topic=2866.0 Edited July 7, 2023 by MattyB Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted July 7, 2023 Share Posted July 7, 2023 22 minutes ago, John Lee said: I use a lot of these without issue. Check that you Tx frame rate is set at 22ms frame rate for these analog servos. Likewise - lots of Hitec Mg82s in use in my models with Spektrum DX9 and DX7 and never had that problem. Quote Link to comment Share on other sites More sharing options...
Andy-H Posted July 7, 2023 Author Share Posted July 7, 2023 In fairness, they did suggest I check this, which I did and it is set at 22ms as default. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted July 7, 2023 Share Posted July 7, 2023 (edited) What rx battery are you using? I also have a few of these in use with spektrum tx and rx with no problems. Edited July 7, 2023 by Nigel R Quote Link to comment Share on other sites More sharing options...
2.4g Shaun Posted July 7, 2023 Share Posted July 7, 2023 Andy, Have you tried the servos with a servo tester or different manufacture of radio to take your Spectrum tx out of the equation. Shaun. 1 Quote Link to comment Share on other sites More sharing options...
Andy-H Posted July 7, 2023 Author Share Posted July 7, 2023 Nigel, battery used was both 4x new AA dry cell and also tried powering via ESC/lipo. Shaun, Good idea to try a servo tester. Interestingly, on the auto sweep function, they work reasonably smoothly. However, if I then switch to auto centring, they go to centre then wiggle briefly before going back to centre. I’ve noticed they also occasionally buzz/vibrate briefly afterwards. All suggests there’s some slight hesitancy when moving to a new position. Unfortunately, I have no other radio to compare. what I might do is connect them to the servo tester and run the auto sweep function for half an hour in case they need bedding in. Andy Quote Link to comment Share on other sites More sharing options...
2.4g Shaun Posted July 7, 2023 Share Posted July 7, 2023 It sounds like the servos are the problem . Unusual as I've used quite a number over the years and had no issues with excellent reliability. Looks like you've been very unlucky. Quote Link to comment Share on other sites More sharing options...
steve too Posted July 8, 2023 Share Posted July 8, 2023 What receiver are you using and does it have the latest firmware? There was a bug in some Spektrum receivers that meant that they ran their outputs at 11ms even when told 22ms during bind and some Hitec analogs don't like 11ms. Quote Link to comment Share on other sites More sharing options...
Andy-H Posted July 8, 2023 Author Share Posted July 8, 2023 On the bench I’ve been using an AR620. Was updated last year but I’ll check whether there might have been another update since. Will also try us8ng a different receiver. Thanks for all of the suggestions. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted July 8, 2023 Share Posted July 8, 2023 11 hours ago, Andy-H said: Nigel, battery used was both 4x new AA dry cell and also tried powering via ESC/lipo. Shaun, Good idea to try a servo tester. Interestingly, on the auto sweep function, they work reasonably smoothly. However, if I then switch to auto centring, they go to centre then wiggle briefly before going back to centre. I’ve noticed they also occasionally buzz/vibrate briefly afterwards. All suggests there’s some slight hesitancy when moving to a new position. Unfortunately, I have no other radio to compare. what I might do is connect them to the servo tester and run the auto sweep function for half an hour in case they need bedding in. Andy I wouldn't waste your time putting unnecessary wear on your new servos. My advice to you would be to find a mate who runs another brand of radio and test them on that. Still the same? then my money would go on the servos (very, very unusual, but not unknown as I found with a similar fault many years ago with some new and expensive micro servos on my old 35meg Futaba gear) - However, If they run perfectly well on different gear, then it's likely to be some weird incompatibility with the Spektrum outfit. Presumably all your other servos that you use with your Spekky gear work normally? Quote Link to comment Share on other sites More sharing options...
Andy-H Posted July 8, 2023 Author Share Posted July 8, 2023 Yes, the others(futaba, bigger hitec units, emax, etronix) are all fine. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted July 8, 2023 Share Posted July 8, 2023 I guess all you can do is try them on another brand of radio to see if they work correctly or not. How useful the result will be, I'm not sure - they don't work with your Spekky radio and that's that - you've checked frame rate and power supply and gone through a logical process of substitution etc so I'm not sure what else you can do without more sophisticated testing techniques to nail exactly what is going on - if you can be bothered. 99.9% of the time our gear is plug/play/forget and doesn't require any knowledge of electronics to get it working - maybe you've just been unlucky this time. The advice from your retailer and distributor wasn't exactly very helpful. Quote Link to comment Share on other sites More sharing options...
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