Hitec 925

[antsis]

Has anyone had experience with this servo? When I bought my Raptor 60, it had the hitec 925 servo on the rudder. I had a CSM SL560 gyro installed and wanted to use the super servo feature, so swapped the 5925 digi off the Super Sport, with the 925 0n the R60.

The R60 had its maiden flight on sat and is an beautiful machine. However, the super sport was sluggish in the turns. I checked the tail rotor for movement and the gyro, a GY240, was working fine. Eventually just grabbed the servo arm and found that it had no strength when under load.

Anyone had a similar experience?

Ant

[Raptorite]

Hi Ant,

If the rudder control appears to be sluggish in the turns, it usuallly means either there isnt enough movement in the control mechanism, or more likely in this case the servo simply isn't strong enough to move the tail.

I am not familiar with the 925 but I would suggest it be changed for something more appropriate to rudder usage, the CSM 560 pairs up pretty well with a choice of Futaba 9253 or 9254 or a JR 8700G.

Out of those three, my choice would be the Futaba 9254 as it is one of if not the best tail servo currently on the market.

Cheers,

Pete.

[antsis]

Pete

I'm using the 560 on my R60 with the Hitec 5925 digi and it seems to be fine. I'm having a few niggles with tail wag, but have been reducing the headspeec which seems to be working.

The 925 was on the super sport with the gy240 and this was very sluggish. For the moment, I will stick a 9001 on it, but am planning to to get rid of this heli and get a second R60.

Ant

[Raptorite]

Hi Ant,

If you are able to sort out a tail wag by playing with the headspeed it suggests there is something out of balance or true somewhere.

The ideal headspeed for a R60 is around 1800rpm, so if you find that in order to get rid of that tail wag you end up with a headspeed less than that, there is something wrong somewhere.

In stock form the R60 comes with only 1 bearing support for the tube drive inside the boom, which the manual suggests should be placed in the middle of the boom. When I first built my R60 about 3 years ago I also had a tail wag. I found that with mine the tube drive out of the box wasnt perfectly true and therefore was the culprit. I added a second support bearing and spaced them out equally inside the boom. This solved the problem.

Since then and after many a crash with the R60 I have also found 90% of the tube drives supplied as spare parts also to be slightly out of true, so it is well worth adding that second support bearing as it gives you a far more rigid and more importantly true tube drive.

Cheers,

Pete.

[antsis]

tail wag

Pete

When we originally tested the R60, the gyro was set to 60% and there wasn't any breeze at all. It had a slight wiggle and I reduced the gain to 56%. This seemed to solve the tail wag, but I still thought the headspeed was a little high.(no tacho to check). The next time I took it out, itwas quite windy and as soon as I got to hover throttle, the tail was all over the place and I ended up reducing the gain right down to 33%. I didn't feel right about this, so reset the gyro and then reduced the headspeed. The gyro gain is now around 52% and it's solid. Unfortunately, can't guess what the headspeed is, but the heli doesn't lag in response or power.

I checked the bearing on the tube drive and it is smack in the middle. I'll go with your suggestion and slip another one in and see if that helps.

Ant

[Raptorite]

Hi Ant,

From what you have just said it seems to me that you may well benefit from moving the ball on the servo arm in by 1 hole. This will mean you can get the gain up without having unnecessary tail wag.

Give that a try too and see how you get on.

Cheers,

Pete.