Nickolas

Hi,

I have installed a pair of fairly new 9154 servos on my Proline (they had been used for about 10 flights on another model). When I set up the rods for the first time the model was inverted and I adjusted the rods and sub trims so that the ailerons are perfectly aligned with the trailing edges.

When I went to the field and placed the model in horizontal position the ailerons seemed to be beneath the trailing edge line due to gravity I suppose, so I used opposite sub trim to align them compared to the one used in inverted.

Is that common with these servos? Are they so sloppy enough to change the neutral positions of the moving surface depending on the model position?

What is your experience? CPLR and top Japanese pilots seem to be using them on ailerons, are their servos different from the ones provided to an average modeller like myself? I wonder if someone has spent hundreds of hours building a straight scratch built balsa wing like the Japanese flyers do, why would he use servos with such a big slop? I suppose this can "ruin" the the effect of the man hours spent for building a straight wing.


Looking forward to replies or comments,

Nikos

BERUSTY

My Feedback: (3)

9154 resolution...

Sounds like you may have connected the servo leads backwards...reversed the leads.

Rusty Dose
Team Futaba
Team YS Parts and Service

Nickolas

Sorry but is mehcanical issue, I have not connected the leads in reverse...

rcpattern

My Feedback: (45)

I have been flying them for almost 2 years in my black magic with ZERO slop. They are the tightest servos I've ever flown. I sent them back to Futaba for a routine service this winter and after all the flights, they were still as tight as day one. ( I love Merle Hyde's mounts).

When the radio is on are you able to physically move the servos the distance you described? If not, then it is not servo slop.

Arch

Rune

I have had several off this servoes (over 10) and every one off them have slop in the gears...... and also had some problem with pot.meters on them and always used Hyde mounts....

jrpav1

My Feedback: (17)

Nickolas,
Could you describe your linkage setup in more detail? Maybe a few pic's? Something doesn't sound right there. As you probably know, there are many things which can create a "sloppy" linkage: Excessive gear-train lash in the servo, a bad output bearing in the servo, excessive clearance in the control horns, etc. There could be something else besides the servo that's causing your problem. If you have some free time, you could remove the servo and attach the linkage securely to a piece of wood attached to the servo mounts. Then try to move the aileron back and forth. If it moves, you've got slop in the linkage. Don't assume because the linkages "look" tight that they are. As with any problem, try to "break it in half", then drill down to find the cause. Start by determining if it's the servo or the linkage - then look for the exact cause. I had a "mushy" elevator condition on one of my planes and it turned out it was the servo grommets. No one publishes the "hardness" (durometer) of their bushings but I can tell you that they're not all the same.

John Pavlick

Nickolas

Hi,

Thanks for the answers, Rune I think my servos are like yours, may be is the batch? I bought them from Germany.

John,

I use probably the best hardware available, which is Central Hobbies Carbon Pushrods with titanium ends MK-Kato hardware with ball bearing link ends. I don't think my system has slop. Slop comes from the servo head, everything has been checked with power on. Unfortunatelly the slop is due to servos. I have a spare gearset to check, may be it is the particular servo batch. Otherwise I will fly with sloppy servos...what else can I do?

It is a pitty though...

Nikos

jaycey

I think that unusual turbulance caused by non-fitting spats is putting excessive lateral forces on the carbon layup in those pushrods, causing resonance and subsequently premature wear of the gear train.

Solution...fit the spats, stand back and admire a much better looking model (you will soon forget about that slop)[8D]

Nickolas

Thank you very much for the scientific approach, unfortunatelly seems to complicated to apply it....

rcpattern

My Feedback: (45)

When the radio is turned on, can you physically move the surface, if so, how much? Or when you turned the plane over where the ailerons just down slightly, but they are still tight??