Center the ball

[BrendAn]

Today I was playing with the position of the ball when flying straight.

I always need left rudder to keep the ball centred. Which I guess is normal. Now if I take my feet off the pedals the ball sits a about halfway over the line on the left. I took notice of the speed and it does not change. I thought I would lose some speed if it was yawing . And the other question is how are turn coordinators setup in relation to the aircraft or doesn't it matter.  

[Moneybox]

15 minutes ago, BrendAn said:

Today I was playing with the position of the ball when flying straight.

I always need left rudder to keep the ball centred. Which I guess is normal. Now if I take my feet off the pedals the ball sits a about halfway over the line on the left. I took notice of the speed and it does not change. I thought I would lose some speed if it was yawing . And the other question is how are turn coordinators setup in relation to the aircraft or doesn't it matter.  

I don't claim to know what I'm doing but it sounds like a job for a trim tab on that rudder?

[kgwilson]

Hands & feet off your aircraft should fly straight & level. If not it is not trimmed properly. Vertical trim is a central trim wheel attached via bungees to the centre stick and adjusts the whole stabilator.  I have no trim tabs at all & that was due to me being very fussy about side thrust and washout & making sure everything was balanced. Mt 3300A engine is offset 4 degrees which looks horrible with the cowl off & is 2 degrees more than recommended by Jabiru but exactly what designer Garry Morgan said when discussing engine positioning during my build.

 

A rudder trim tab is what you need.

[BrendAn]

27 minutes ago, kgwilson said:

Hands & feet off your aircraft should fly straight & level. If not it is not trimmed properly. Vertical trim is a central trim wheel attached via bungees to the centre stick and adjusts the whole stabilator.  I have no trim tabs at all & that was due to me being very fussy about side thrust and washout & making sure everything was balanced. Mt 3300A engine is offset 4 degrees which looks horrible with the cowl off & is 2 degrees more than recommended by Jabiru but exactly what designer Garry Morgan said when discussing engine positioning during my build.

 

A rudder trim tab is what you need.

Moneybox has the same idea as you. I think I will make one next weekend. Already has elevator trim tab 

 

Edited yesterday at 03:04 AM by BrendAn

[Blueadventures]

1 hour ago, BrendAn said:

Moneybox has the same idea as you. I think I will make one next weekend. Already has elevator trim tab 

 

Maybe send a message to Xair Ireland as they fly many models and should be a wealth of knowledge on the subject.  If you have any trouble pm me and I'll give you a personal contact over there.  Cheers.

[skippydiesel]

2 hours ago, BrendAn said:

Moneybox has the same idea as you. I think I will make one next weekend. Already has elevator trim tab 

 

Every aircraft I have flown had in cockpit elevator trim adjustment - does your comment (above) mean that you don't have this facility?

 

Again, every aircraft I have flown, requires changes to trim when speed changes - TO?/Climb, Cruise and in circuit Pre Landing and with Load changes (even fuel consumed).

 

Some of the aircraft had, in addition to elevator, aileron/rudder trim.

 

My current aircraft has in cockpit elevator trim and a very small fixed rudder trim (tab). In Cruise she flies straight & level (ball centered) without any hand/foot inputs. A little right rudder is require on TO/Climb.

 

As a result of recently carrying a 78kg adult passenger, I am in the planning process, to install a simple one way bungee cord, adjustable trim, for aileron & rudder to counter the effect of having such a "load" in the right seat.

 

Back to your aircraft - Some suggestions/observations:

• Before making any adjustment to flying surfaces be sure that you are starting from the kit/plans/manufacturer's advised settings for all flight control surfaces. Measurements may be in degree relative to a named location and or distance (inch/mm) to/from a certain point (eg spar).
• If fitted with a control stick/column, fix it in the vertical lateral plain (make a bracket with straps/Velcro) before aileron adjustment.
• Stick position for elevator adjustments should midway between full aft/forward.
• An adjustments to one flying surface will nearly always require adjustment to others.
• All adjustments should be small/incremental followed by a test flight to judge effect.

When I adjusted my aircraft lateral trim, I made careful (mental ) note of what inputs were required to have the ball centered during Cruise. 

In response to aileron correction I adjusted my flaps.

For Rudder, I cut several diffrent lengths of aluminium profile (see below from Bunnings Aero Space) fixed one piece at a time, using industrial double sided tape, to the trailing edge, mid span, of the rudder. Fix so that the crescent shape deflects the wind blast away from the direction of adjustment ie right rudder - tab on left side, trailing edge of crescent out. I only needed a tab that is about 50mm long

 

 

The white tape is just an aesthetic effect ie little fixing quality.

Hope this helps.

😈

[BrendAn]

4 hours ago, Blueadventures said:

Maybe send a message to Xair Ireland as they fly many models and should be a wealth of knowledge on the subject.  If you have any trouble pm me and I'll give you a personal contact over there.  Cheers.

This is my third xair. They are all the same.  What I was wondering though is when the ball is on the left side of the panel does it work exactly the same as if it is on the centre line. On any aircraft.

[BrendAn]

2 hours ago, skippydiesel said:

Every aircraft I have flown had in cockpit elevator trim adjustment - does your comment (above) mean that you don't have this facility?

 

Again, every aircraft I have flown, requires changes to trim when speed changes - TO?/Climb, Cruise and in circuit Pre Landing and with Load changes (even fuel consumed).

 

Some of the aircraft had, in addition to elevator, aileron/rudder trim.

 

My current aircraft has in cockpit elevator trim and a very small fixed rudder trim (tab). In Cruise she flies straight & level (ball centered) without any hand/foot inputs. A little right rudder is require on TO/Climb.

 

As a result of recently carrying a 78kg adult passenger, I am in the planning process, to install a simple one way bungee cord, adjustable trim, for aileron & rudder to counter the effect of having such a "load" in the right seat.

 

Back to your aircraft - Some suggestions/observations:

• Before making any adjustment to flying surfaces be sure that you are starting from the kit/plans/manufacturer's advised settings for all flight control surfaces. Measurements may be in degree relative to a named location and or distance (inch/mm) to/from a certain point (eg spar).
• If fitted with a control stick/column, fix it in the vertical lateral plain (make a bracket with straps/Velcro) before aileron adjustment.
• Stick position for elevator adjustments should midway between full aft/forward.
• An adjustments to one flying surface will nearly always require adjustment to others.
• All adjustments should be small/incremental followed by a test flight to judge effect.

When I adjusted my aircraft lateral trim, I made careful (mental ) note of what inputs were required to have the ball centered during Cruise. 

In response to aileron correction I adjusted my flaps.

For Rudder, I cut several diffrent lengths of aluminium profile (see below from Bunnings Aero Space) fixed one piece at a time, using industrial double sided tape, to the trailing edge, mid span, of the rudder. Fix so that the crescent shape deflects the wind blast away from the direction of adjustment ie right rudder - tab on left side, trailing edge of crescent out. I only needed a tab that is about 50mm long

 

 

The white tape is just an aesthetic effect ie little fixing quality.

Hope this helps.

😈

All xairs have adjustable elevator trim. I am talking yaw/rudder. 

What I am saying is if I take my feet off the rudder pedals it flies exactly the same with no loss of speed and the ball sits slightly off center, so is the turn coordinator out a bit.

[BrendAn]

A rudder trim tab is a good idea but I want to know the ball is correct first.

How are they aligned when fitted.

[skippydiesel]

 

You should be able to check that the ball is giving accurate information on the ground.

 

Use a known acurate builders level (same bubble reading when level reversed)  place across cockpit, lift undercarriage to to level fuselage. Your ball should be centered - if not instrument may need adjustment.

 

In theory, if the aircraft is in balanced flight it should not matter where the ball is located (left, centre, right of cockpit) the ball will be centered.

 

No matter your perception,that the aircrafts performance remains consistent, if ball allowed to "drift", aerodynamically the aircraft will be less efficient.

 

Yaw can be produced/controlled by aileron and /or rudder.

 

This is why I said - "An adjustments to one flying surface will nearly always require adjustment to others."

 

When you are in Cruise, what rudder & aileron inputs are required to get the ball centered? If just rudder -attache a temporary trim tab to the rudder. Size & location, your best guess, unless you can view other identical aircraft that may already have trim fitted.

 

Once optimum, rudder tab size, location, arrived at you may find that in Cruise the aircraft tends to consistently, slowly "slide" (wing drop) in one direction. If flaps can be independently adjusted, you may be able to counter this drop by either raising/lowering one flap. If flaps not independently adjustable, a little more rudder trim may be helpful.😈

[BrendAn]

2 minutes ago, skippydiesel said:

 

You should be able to check that the ball is giving accurate information on the ground.

 

Use a known acurate builders level (same bubble reading when level reversed)  place across cockpit, lift undercarriage to to level fuselage. Your ball should be centered - if not instrument may need adjustment.

 

In theory, if the aircraft is in balanced flight it should not matter where the ball is located (left, centre, right of cockpit) the ball will be centered.

 

No matter your perception,that the aircrafts performance remains consistent, if ball allowed to "drift", aerodynamically the aircraft will be less efficient.

 

Yaw can be produced/controlled by aileron and /or rudder.

 

This is why I said - "An adjustments to one flying surface will nearly always require adjustment to others."

 

When you are in Cruise, what rudder & aileron inputs are required to get the ball centered? If just rudder -attache a temporary trim tab to the rudder. Size & location, your best guess, unless you can view other identical aircraft that may already have trim fitted.

 

Once optimum, rudder tab size, location, arrived at you may find that in Cruise the aircraft tends to consistently, slowly "slide" (wing drop) in one direction. If flaps can be independently adjusted, you may be able to counter this drop by either raising/lowering one flap. If flaps not independently adjustable, a little more rudder trim may be helpful.😈

The more I think about the more I think the ball is the problem. Will do as you said and check it before anything else. It's not even a big problem anyway. Would be nice to fix it though.

[skippydiesel]

16 hours ago, BrendAn said:

The more I think about the more I think the ball is the problem. Will do as you said and check it before anything else. It's not even a big problem anyway. Would be nice to fix it though.

 

I recently went through a stage of thinking my electronic ball (Dynon Skyview) was not responding quickly enough and may be inaccurate.

 

I purchased a stand alone slip ball (see below). I carefully leveled, in the lateral plain, my aircraft, using several builders  & an electronic digital level (to reduce chance of  instrument error). I then very carefully stuck, with double sided tape, the slip ball to the panel, ball centered, just above the Dynon.

 

Turns out the Dynon was spot on all the time.😈

 

Edited 1 hour ago by skippydiesel