Can't believe how lucky I was today

[Stanley Speel]

A couple of days ago I crashed my 600efl - I didn't hit throttle hold - it was 100% my fault I pushed the collective stick forward instead of hitting throttle hold during a flip! I thought I was very lucky with the damage - just broken blades and chipped canopy... I replaced the mainshaft just to be safe.

So today I got it all fixed up and took it out to fly. For the first couple of minutes things were great - loved the way the edge blades held on tictocks and more aggressive flips. Then I went on to do some rainbows and I noticed a slight tilt to the left which then corrected itself. I thought nothing of it and continued with some flips with pitch changes. Then suddenly the heli tipped to the left and forward quite aggressively, so I hit throttle hold and just about managed to bring it down with the remaining headspeed.

Checking the heli afterwards I noticed that one of the aileron servos had stripped and I could move it by hand, although it would return to its previous position when I let go. It definitely wasn't like that before so I can only think that one tooth had stripped which was caused by the crash and throughout the flight some of the other teeth stripped too as a result of this.

Throughout the flight at points I was flying pretty close to me and quite low down with the sideways rainbows and inverted hovering - I am so lucky that the servo didn't give way then...600s pick up speed really quickly. From now on after every crash I'm going to take apart the servos to check for stripped gears and not just rely on the absence of a clicking noise!

[cjcj1949]

You might find its the motor. One of my servos would work when the servo motor was in most positions but not all. Damaged commutator. Easy to fix if I could find a spare motor. I had trouble in flight, landed, all servos worked, took off and crashed on landing.

[Stanley Speel]

You might find its the motor. One of my servos would work when the servo motor was in most positions but not all. Damaged commutator. Easy to fix if I could find a spare motor. I had trouble in flight, landed, all servos worked, took off and crashed on landing.

I'm going to replace the whole servo to be safe. I will take the servo apart later today and see what I find. Also after the flying the servo did sound stripped whereas before it sounded fine.

[cjcj1949]

I thought mine was stripped to begin with, but no feel of stripped gears. It's only a possibility.

[Snaaakeey]

You might find its the motor. One of my servos would work when the servo motor was in most positions but not all. Damaged commutator. Easy to fix if I could find a spare motor. I had trouble in flight, landed, all servos worked, took off and crashed on landing.

I had this on a tail servo after a crash. Tail worked fine but at a certain range of motion ( full right rudder sort of area) the torque all but disappeared! I hadnt had any tail blow outs though.

[Vikki]

I use a X5 or higher jeweller's loupe to examine the gears. I don't trust eyesight alone. I had one that was really odd. It crunched, or didn't depending how it felt. Couldn't see anything with the naked eye but at X5 magnification I could see that part of one metal tooth was chipped and the debris was down between the teeth. I cleared it away and it seemed ok but I'm not daft, I wasn't risking it so replaced £10 worth of metal gears

Better safe than sorry

[Stanley Speel]

Re: Can't believe how lucky I was today

I think I've found the problem and its a weird one. No gears were stripped, but one gear (the one that is turned by the servo motor) had separated in two... and the inner bit could spin with some force! How is this normally held in?

See the pics below



Sent from my GT-I9100 using Tapatalk 2

[nitros]

Can't believe how lucky I was today

I got on my 450 all the cyclic sound and move(stuck) stripped, but I check them they seems fine. What should I do?

[Vikki]

That's a press fit. The little teeth lock the inner against moving under normal circumstances and the inner stays put because it's shoulder is ever so slightly larger than the hole in the outer. There's a name for the kind of fit and I'm not thinking interference fit. Swaged? There's a nut we use here, same technique. Hank bush!

[waveydavey]

I think I've found the problem and its a weird one. No gears were stripped, but one gear (the one that is turned by the servo motor) had separated in two... and the inner bit could spin with some force! How is this normally held in?

See the pics below



Sent from my GT-I9100 using Tapatalk 2

We've had the same thing on 610's a number of times, the gear, the brasss one is a push fit into the larger one. I did report it on here but got told I was scaremongering. Glad the heli is okay.

[cjcj1949]

Should be fixable. I think I'd rather use one I'd glued or soldered than 1 that hadn't failed yet. Looks like they've either made the servo too powerful for the mechanical fit or have a quality problem. It isn't a high tech super accurate part. Perhaps it wasn't pushed in properly (pressed). Or the metal is too weak to hold the small gear. I think I'd check any 610s I had. Slow araldite should fix it, and heat it as well to get the araldite held in. Then see if it holds when the servo is briefly stalled at max volts.

[Stanley Speel]

Should be fixable. I think I'd rather use one I'd glued or soldered than 1 that hadn't failed yet. Looks like they've either made the servo too powerful for the mechanical fit or have a quality problem. It isn't a high tech super accurate part. Perhaps it wasn't pushed in properly (pressed). Or the metal is too weak to hold the small gear. I think I'd check any 610s I had. Slow araldite should fix it, and heat it as well to get the araldite held in. Then see if it holds when the servo is briefly stalled at max volts.

I've just replaced it with a spare one I found from a broken DS620 gear set I had. I am pretty sure (and hoping) that it failed as a result of my crash a couple of days ago. However I am going to be thoroughly testing the other DS610s in there before flying it again!

[waveydavey]

I'm afraid we have had them fail in flight Stan, it certainly seems like a quality issue. I've been using 610's for a couple of years and never had the problem but I've seen 3 others fail like yours. When did you buy them, the ones that failed were all earlier in the year bought around Springtime

[Stanley Speel]

I'm afraid we have had them fail in flight Stan, it certainly seems like a quality issue. I've been using 610's for a couple of years and never had the problem but I've seen 3 others fail like yours. When did you buy them, the ones that failed were all earlier in the year bought around Springtime

Mine came from fast-lads as part of the 600EFL supercombo in late december 2011.

[waveydavey]

Maybe the same batch then Stan