Asked — Edited

Hdd Servos And Iotiny

I know there has been issues with using the 360 deg servos with the iOTiny but I now have burned out 2 HDD servos using the iOTiny... Both were not under any load whatsoever just holding a position... Magic smoke both times.. Both only lasted 5 minutes with the iOTiny.... Should I try a third? FYI battery being used is a 7.2V Tenergy NiMH...

Anyone else using HDD servos with the ioTiny without issues? And is this just incredibly bad luck on my part? User-inserted image

User-inserted image


Upgrade to ARC Pro

Discover the limitless potential of robot programming with Synthiam ARC Pro – where innovation and creativity meet seamlessly.


@RichardR, I have used 7 of the hdd servos with one ioTiny since November with no burnouts. I use a power supply @ 6v.


Ok... maybe bad luck I guess... Right now I am trying a 3rd one as an experiment...


For this particular servo (in the picture) it turns out it was the motor that burned out which caused the fet to fry...


The IoTiny wasn’t the reason for the 360 servos being damaged. It was the 360 servos damaging themselves due to a very slight pwm timing difference between the IoTiny and ezb. The IoTiny isn’t at fault for that scenario you recall. It was the 360 servos that had a faulty component. The manufacturer of our 360 servo had changed the spec - we had it fixed last year :)


Hello Richard R, I started on a new project a while back, and I use the EZ-B IoTiny with a HDD EZ Robot servo with good results and no issues. It is powered by a Turnigy 2.2 Li-po 2 cell battery. I did have an issue with an older NI-MH battery pack (that had good voltage) but made all my older HD servos jump around and act strange. When I powered that same robot with a different battery, it worked fine. Steve S



I did some testing this morning. I plugged an IoTiny into a fully charged 7.4V LiPo battery and I had 2 HDD servos holding position for 20+ minutes. I also put the servos through their paces for a while. In either case I had no issues.

Is your 7.2V NiMH battery perhaps a 9.6V? Is there anything else hooked up to your IoTiny that could cause an issue?


Do you remember when you purchased those HDD servos? They shouldn't be able to be damaged - let alone with nothing connected to them. They should shut-down with too much load. I'm wondering what batch they're from


@Jeremie... You know me man... The batteries are 7.2v nimh...

@DJ... They are probably from one of the first batches of HDD produced... It was the motors that failed (which overload) the fet on both of those servos... Saying that the 3rd servo seems to be doing fine..


Guys this is not a big deal... Just feedback for reference.... I have used many hdd servos without any issues... I just found it odd that 2 burned up back to back when i was using them with the ioTiny...


That sounds about right. The hdd’s underwent a few slight changes between batches at the beginning. There’s a slight chance those first batch versions had a worn motor/gear and popped the fet - rather than shutting down.

United Kingdom

@RR, I haven’t had the same issue with the HDD with a IoTiny, BUT did experience one of 12 HDD’s that jittered a while back, which I believe was an issue with a batch from the early ones!