H9 ASH 31 build, notes and questions

[BryanB]

I got the parts out of the box and started the model as per the manual. My kit is A11.

My first question is for either Ali or Stephane since they have completed models.

The end hole at the end of the servo arms included with the A7050's is at 20mm. Is this the correct hole distance to use for the ailerons? It's not stated in the manual.




Servo arm rod distance from center at servo per the manual.

Flap servo arm distance is stated as 10mm

Rudder servo arm distance is stated as 13mm

Elevator servo arm distance is stated as 10mm

[BryanB]

Two other items of note.

The servo rods included for the ailerons are long at 45mm. They will need to be cut down to about 25-30mm to make the shown completed control arm length.



Per the post above, the new aileron servo covers are more than just flat plates with a faring to cover the rod. IF, you use the supplied A7050 servo arms and use the last hole at 20mm these new covers will not fit as per the photo.

[Tom]

Well.....it’s really pretty simple.....cut the arm back so it fits the cover. As far as the push rods go.....find all of them and compare them all side by side to see which go where and then make the call to cut them to fit. I haven’t broached servo install yet because I’m still waiting on the servos to get here! At the end of the day you just need to make what parts are given work.

[Mark Stone]

My servo arms ended up at 10mm long with about 85% of servo movement. 8mm would have been perfect but the push rod rubs on the rear wing surface when the ailerion was at maximum up defection.
I also had to relieve the bottom wing skin about 3mm to clear the horn to achieve the recommended maxium down deflection.

Would have almost been worth making a wedge shaped packer to go under the servo mount to lift it a little higher,

The servo covers could have been left a little larger so that you could adjust the alignment if required, mine are about on the small side, even with square corners drop into the recess.

Inner panels tomorrow, I'm putting full sized servos in on mine they just fit.

Mark

[mtnbiker63]

I'm 90% done with kit B15, just need to do what you are doing now. A couple of questions. Did you use the supplied screws to hold down the servo on the outer wings? Have you mounted your inner wings to the fuselage yet? I don't have huge hands, but I just don't see a way to screw on the nuts for the trailing edge of the inner wings.

I found all the lengths for the pushrods to be wrong and not by a little either. Also, the two holes that mount the horizontal stabilizer where off just a smidge. But I finally got it to go.

[BryanB]

Well.....it’s really pretty simple.....cut the arm back so it fits the cover. As far as the push rods go.....find all of them and compare them all side by side to see which go where and then make the call to cut them to fit. I haven’t broached servo install yet because I’m still waiting on the servos to get here! At the end of the day you just need to make what parts are given work.

Tom, I appreciate you trying to help but you didn't answer the single question I asked.

My servo arms ended up at 10mm long with about 85% of servo movement. 8mm would have been perfect but the push rod rubs on the rear wing surface when the ailerion was at maximum up defection.
I also had to relieve the bottom wing skin about 3mm to clear the horn to achieve the recommended maxium down deflection.

Would have almost been worth making a wedge shaped packer to go under the servo mount to lift it a little higher,

The servo covers could have been left a little larger so that you could adjust the alignment if required, mine are about on the small side, even with square corners drop into the recess.

Inner panels tomorrow, I'm putting full sized servos in on mine they just fit.

Mark

Mark, control deflection geometry was what I was concerned with before cutting down the servo arm. Think I'll grab some scrap G10 and make new flat covers like the manual shows and leave the arms full length.

[Tom]

Tom, I appreciate you trying to help but you didn't answer the single question I asked.

Um......did you not end up cutting down the servo horn so it fit the cover? You’re welcome.

[MarnochS]

Hi Bryan,

From two of the Demo ASH-31 at the Horizon AeroTow, one has the aileron configured as the manual states ( no cover ), the other uses a shorter servo arm length and corresponding shorter aileron horn ( cover )
.

Practically, just make the alieron horn long enough to clear the cover and the same with the servo horn . Optimally the best mechanical advantage would be to use the shortest servo horn possible. This also allows more servo arm travel which means better control surface centering.

[edfmaniac]

If the servo arm length is a problem, just cut it down, but you'll have to alter the arm length on the control surface as well to maintain range of motion in the surface. LDS linkages, the high end systems being installed on the more expensive gliders, use impossibly short levers on both ends of the control rod/link. It works the same as long levers if they are the same length, or have the same ratio, on each end.

After reading some literature on drag induced by these types of external devices on the wing, I'd be opting for LDS mounting systems with the money I've saved on the kit.

[BryanB]

Vic, those are cool.

[BryanB]

Hi Bryan,

From two of the Demo ASH-31 at the Horizon AeroTow, one has the aileron configured as the manual states ( no cover ), the other uses a shorter servo arm length and corresponding shorter aileron horn ( cover )
.

Practically, just make the alieron horn long enough to clear the cover and the same with the servo horn . Optimally the best mechanical advantage would be to use the shortest servo horn possible. This also allows more servo arm travel which means better control surface centering.

Good stuff. I guess if I have to I can fire up the vacuum former and make a new enclosed cover out of styrene if I need extra arm length to get the desired control throws without interfering with the wing itself for up aileron. Guess I'll start modding and see what I come with and post the results.
Do you know if the one with the cover was Ali's or Stephanes?

[ARUP]

Push your cover into some clay then deepen the 'groove' in the clay. Put some glass cloth and epoxy onto this and let it cure then trim to fit. Paint. Weeeeeeeeeeeee!

[French1]

Brian,

the one I flew with was the one on left with the slot on the servo cover.

I don't know yet what I will do on the one I received, but my intend is to use the cover as it protect the servo arm. During the flying season, I broke one of the tip servo control arm when I packed it...

Stéphane

[Mark Stone]

The kit comes with much shorter brass horns than either of the two models in the pictures so your servo arms also can be shorter.

[mtnbiker63]

Here is my solution for the trailing edge wing bolts. I need to shorten the bolt to around 35mm and find a bolt with a flat head so I can hand tighten them. But I was able to attach this one and spin it using both hands.

[BryanB]

I went after the aileron install and want to pass along a few things with my install.

The first thing I had to do was drill out the hole in the brass aileron horn so that the supplied clevis would fit.
I used a #51 drill (.067") which made for a snug fit.




The next thing was to cut down the control rod. I cut mine to 30mm which is a little long but will work.




After ruining one servo arm I cut another to the 2nd hole from center which is about 14mm. This length gives clearance with the servo cover. I did not use the rubber servo mounts.




With the recommended maximum control surface throw for the aileron the second hole also gives clearance with the wing in max. UP aileron.



Think I'm happy with this install so far.

[mtnbiker63]

I'm having trouble with the rudder servo. When I power up the receiver, all the control surfaces move except the rudder. If I grab it, I can't move it by hand. So the servo is receiving power. If I force it a bit, then I'll get full rudder control and the servo is working great.

Any idea to what is going on?

[lenb]

sounds like the servo has a bad spot on the motor/pot
Try using sub trim to move the centering point of the servo and see if it works.
I would certainly send the servo in for repair