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Old Oct 17, 2012, 10:02 PM
The Earth got in the way!
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Originally Posted by Dead View Post
Maybe someone should tell my ex wife this trick!
Puss in boots oooh cat (0 min 21 sec)
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Old Oct 18, 2012, 05:15 AM
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Australia, QLD, Ipswich
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Originally Posted by demonGti View Post
The PA linkages work just like they are intended. If you take the time to do them properly there is no need to adjust. Ok fair enough, the AMR need down trim on the elevator, but are you saying you trim your planes mechanically using adjustable linkages ... I think not
If I have the ability to yes I will. TBH I regret not fitting a threaded rod end on at least one end of the linkages on my Bandit. Like these http://shop.dubro.com/products/produ...n=recommended&

I like to have everything neutral physically and within the radio. Then have a fly and trim for straight and level, then adjust the linkages manually to try and remove as much radio trim as possible. As pointed out having trim/subtrim effects linearity as well as reduces control throw in the direction that trim has been applied.

It's much the same as trying to setup your largest throw rate setting up so that all your end points etc are out at there limits, you can do this by mechanically adjusting your linkage for the required throw or by using programmable servos. By having your endpoints at much less than about 100% ( using the fact that Futaba's max is 140%) you'll start to loose a noticeable amount of resolution.
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Old Oct 18, 2012, 05:24 AM
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United Kingdom, London
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Originally Posted by luke352 View Post
I
It's much the same as trying to setup your largest throw rate setting up so that all your end points etc are out at there limits, you can do this by mechanically adjusting your linkage for the required throw or by using programmable servos. By having your endpoints at much less than about 100% ( using the fact that Futaba's max is 140%) you'll start to loose a noticeable amount of resolution.
well, i cant recall about ultimate, but on every one of my other planes, my epa is around 100-120... because if i go mechanically 1 hole less on servo arm, than servo arm-control rod forms a straight line and im getting around half of required throw at 150% EPA...
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Old Oct 18, 2012, 08:25 AM
Precision Aerobatics Team
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South Africa, GP, Randburg
Joined Dec 2006
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Quote:
Originally Posted by luke352 View Post
If I have the ability to yes I will. TBH I regret not fitting a threaded rod end on at least one end of the linkages on my Bandit. Like these http://shop.dubro.com/products/produ...n=recommended&

I like to have everything neutral physically and within the radio. Then have a fly and trim for straight and level, then adjust the linkages manually to try and remove as much radio trim as possible. As pointed out having trim/subtrim effects linearity as well as reduces control throw in the direction that trim has been applied.

It's much the same as trying to setup your largest throw rate setting up so that all your end points etc are out at there limits, you can do this by mechanically adjusting your linkage for the required throw or by using programmable servos. By having your endpoints at much less than about 100% ( using the fact that Futaba's max is 140%) you'll start to loose a noticeable amount of resolution.
Luke, I was not referring to nor proposing anyone sets up their linkages hap hazardly and needing lots of trim/sub-trim to correct it. I'm talking about making up the control linkages as prescribed by PA using their hardware and recommended servos or similar. All i'm saying is if you take the time to do it properly, centre your servos accurately beforehand, choose a servo horn that sits as close to 90 as humanly possible (sometimes rotating the horn 180 is closer to 90) secure the control surface with tape at the neutral position, then proceed to make up the linkage it will be accurate enough that it will require none or maybe a click or two of trim.... and I am willing to bet that if you carefully follow procedure in the manual, no pilot will feel any difference between left or right. up or down. If at any stage you need to replace a daffy servo, you'll need to remove one end of the linkage anyway even if you've used adjustable ball links and threaded rods. So if the 'trim' with a new servo is slightly different its so easy to slice the heat shrink with a blade and redo one end of the stock linkage. Lets face it, you never need to bugger around with the linkages for any other reason than damage of some sort.
Please don't think that i'm trying to stop anyone from fitting whatever linkages they like tho their planes.... go ahead. I just don't think that it's necessary, and to give that impression to new PA model owners is just not right.
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Old Oct 18, 2012, 01:29 PM
They Call him Dead!
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I don't think anyone is trying to say that it is necessary. What we are trying to say is that we don't like their system, we prefer another system, and in our OPINION, it could be done better. If enough people AGREE with us (and that is an IF) then maybe PA will change.... but that s a BIG maybe....
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Old Oct 19, 2012, 07:35 PM
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TBH I'm not familiar with the system used on the AMR, only the setup used for the Bandit which once set is never adjustable again. I assumed the AMR was the same or similar. A system which could have been made much more user friendly by simply supplying 4 threaded couplers.
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Old Oct 20, 2012, 05:09 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
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Originally Posted by luke352 View Post
TBH I'm not familiar with the system used on the AMR, only the setup used for the Bandit which once set is never adjustable again. I assumed the AMR was the same or similar. A system which could have been made much more user friendly by simply supplying 4 threaded couplers.
Yep it's the same.

You put it very well.. with a little more though and only a couple of added grams PA could make it so much easier for the end user.

The standard pushrods do 'work', and once you have done a few you get the knack. I found the trick is to leave one end connection bound with thread but not CA'ed right until the point that everything is set up, plane fully assembled, radio programmed, servos centred. Then and only then, with all pushrod length adjustments made, hit those pushrods with CA and apply the heatshrink. That way you should get the length spot on and you only have to worry about flight trimming adjustment.

But it could be made so much easier, and better.
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Old Oct 20, 2012, 05:32 AM
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South Africa, GP, Randburg
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Originally Posted by JetPlaneFlyer View Post
... easier, and better.
Is your opinion. That's great, I won't knock you on it Steve. Better for you and a handful of others maybe.
But to me the PA philosophy is that of 'lightness'. So if PA had to use hardware like everyone else.. heavier tail wheels, bulkier motor box, aluminium LG, more wood in the construction etc.... and steel threaded control rods with ball links, that weight quickly adds up and before you know it you'll flying an "x" brand plane. I don't know about you guys, but I happen to like the way my light PA planes fly and I appreciate the trouble they go to to make them that way.
I'm not bothered with a little extra work for a great flying plane.
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Old Oct 20, 2012, 08:15 AM
The Earth got in the way!
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United States, OH, Canal Winchester
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Old Oct 22, 2012, 07:10 AM
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Taiwan, 北市
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Hi all, I've maiden this great little plane and it flies great! But I'm having CG issues - I've shoved the stock battery as far forward as possible so that it's almost hitting the wall. Measuring with my fingers, I'm fairly certain the CG is in the 45-50 mm (definitely much more forward than the 57-60mm recommended range) and the plane still requires a lot of down elevator trim to fly level. On inverted, it still climbs slightly - not a lot, but enough to be annoying, as I'm used to planes diving a little inverted.

Other than the last resort of just taping dead weight to the cowling, is there anything I can do to further move the CG forward? Motor and ESC are both stock.

Thanks for any advice.

Best,
Kevin
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Old Oct 22, 2012, 07:32 AM
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South Africa, GP, Randburg
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Originally Posted by kchen95 View Post
Hi all, I've maiden this great little plane and it flies great! But I'm having CG issues - I've shoved the stock battery as far forward as possible so that it's almost hitting the wall. Measuring with my fingers, I'm fairly certain the CG is in the 45-50 mm (definitely much more forward than the 57-60mm recommended range) and the plane still requires a lot of down elevator trim to fly level. On inverted, it still climbs slightly - not a lot, but enough to be annoying, as I'm used to planes diving a little inverted.

Other than the last resort of just taping dead weight to the cowling, is there anything I can do to further move the CG forward? Motor and ESC are both stock.

Thanks for any advice.

Best,
Kevin
What servos are you using Kevin?
Are you flying with a spinner?
Is your tail wheel the stock one?

You can move your esc more forward inside the cowl if you haven't tried this already.

dG
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Old Oct 22, 2012, 07:39 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
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Quote:
Originally Posted by kchen95 View Post
Hi all, I've maiden this great little plane and it flies great! But I'm having CG issues - I've shoved the stock battery as far forward as possible so that it's almost hitting the wall. Measuring with my fingers, I'm fairly certain the CG is in the 45-50 mm (definitely much more forward than the 57-60mm recommended range) and the plane still requires a lot of down elevator trim to fly level. On inverted, it still climbs slightly - not a lot, but enough to be annoying, as I'm used to planes diving a little inverted.

Other than the last resort of just taping dead weight to the cowling, is there anything I can do to further move the CG forward? Motor and ESC are both stock.

Thanks for any advice.

Best,
Kevin
Kevin,
Bear in mind that the AMR always needs a lot of down elevator trim to fly level, it's just the way it is, it even mentions it in the manual.

But it shouldn't climb when inverted. Normally there is no problem getting the correct CG (which many find is way forward of the factory specified position). DemonGTI pretty much covered most of the reasons why you might be a bit tail heavy, i'm assuming you are using a 3s 2200mAh battery?
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Old Oct 22, 2012, 08:53 AM
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Everything is stock, including servos and tail wheel. I do have the spinner installed. Not sure if I can move the ESC any farther forward, since the air scoops are in the way - but I guess I can put it on top of the motor box?

Yeah it's just strange that the plane still climbs slightly when inverted, even with the CG now clearly way more forward than the 57-62.5MM - my best estimate is around 48-50mm. That's why I'm thinking of adding lead weight to the front of cowling, which obviously isn't ideal because this plane is supposed to be light

Kevin
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Old Oct 22, 2012, 09:53 AM
They Call him Dead!
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United States, SC, Pawleys Island
Joined Jul 2003
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PLEASE don't add weight. PA goes to ridiculous lengths to keep the weight down so that the planes fly the way they do. Can you turn your radio on so that the servos are all centered and take pics of the plane? Take side views of the stab and elevator as well as side views of the wing and ailerons. Also a pic of the entire side of the plane?

Also remove the cowl and take pics of the motor box from the side and from several different angles.

When you fly it, trim for level flight and then go vertical to high altitude. Point the plane STRAIGHT down and let it fall with power off. Be sure to be viewing plan from the side. Does it fall straight down? Does it pull to canopy? Does it pull to Landing Gear?
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Old Oct 22, 2012, 11:16 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
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Originally Posted by kchen95 View Post
Yeah it's just strange that the plane still climbs slightly when inverted, even with the CG now clearly way more forward than the 57-62.5MM - my best estimate is around 48-50mm.
Kevin,
I went on (and on) about the CG a few pages back. It seems to be subject of some dis pure as some swear by the factory 57- 60mm CG.
Personally I found the CG had to be in the 47-48mm range for neutral trim. Even at that you might find that it climbs a little when inverted with low throttle, but at about 75% power it should fly level. You will need to be closer to 45mm to get a trim that needs a hint of down when inverted.

Are you using especially light batteries by any chance? Mine balances at 47mm with the rear of the battery about 20mm from the back edge of the tray and the front of the battery maybe 20mm from the firewall.
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