HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Yesterday, 03:04 PM
PA Team Pilot
kohersh's Avatar
United States, FL, West Palm Beach
Joined Apr 2011
786 Posts
Kfuchs, what are you using to measure your deflection?

2 likely suspects come to mind, and not knowing your building or flying experience and knowledge I'll throw the most common pitfalls out there for you

The first cause that comes to mind is usually the linkage geometry being incorrect, meaning the control surface is not at zero degrees/neutral while the servo arm is at 90 degrees to the case (with the minimum usage of subtrim possible.)
Excessive amounts of subtrim limit the throw in one direction, this produces the opposite effect on the surfaces throw in the other direction, so it has too much one way and not enough the other as your experienceing. The remedy here is to verify the arm is on the correct spline with the least amount of sub trim possible (or as one of the Russian PA pilots has done, to use a circular servo arm as the mount for the CF extensions you should buy with the kit, that way there is always zero subtrim-but that's a lot of work if not absolutely necessary)

The last likely thing that comes to mind is that the control horn in the surfaces was not fully seated when the glue set, which would alter the geometry and produce a differential like that.

As camoy said however the effect will not be crippling for you. This is not a fast airplane, it rolls pretty good for its shape and airspeed but its not a fast roller either (compared to other PA models). Extreme deflections actually slow the rolls down as it acts much like brake. Most of the time you'll only be asking for that last 10 degrees of throw when the plane is post stall where the braking effect is negligible but the additional throw is needed to divert the propwash and create enough lift for the surfaces to be effective with minimal forward airspeed. Yes you'll miss it but not as much as if it were on the tail..
If you can post a pic or two of the setup with the surfaces neutral, so we can also see the link and arm, that will be helpful
kohersh is offline Find More Posts by kohersh
RCG Plus Member
Sign up now
to remove ads between posts
Old Yesterday, 11:39 PM
Registered User
South Africa, GP, Midrand
Joined Jan 2014
10 Posts
Hi Kohersh

I have not yet glued in the CF rods between the servo and the aileron horn.

I am using the template supplied in the kit to measure at the tip, and I have also used a protractor on the tip to find the exact difference. The issue is the gap between the wing trailing edge and the aileron leading edge. The gap was set measuring in one direction only. The leading edge of the problematic aileron is almost square on the one edge and slightly rounded on the other. The aileron that's ok have its leading edge slightly rounded on both edges. The square side now only deflects to 35 degrees, while the slightly round side provides 45 degrees.

I wil have to remove the covering sealing the gap, cut off the CA hinges and put in new hinges next to the old ones. This time deflecting the aileron in the direction where the square leading edge meets the trailing edge of the wing ( and check it to the other side as well).

I need to decide if this is the way forward, since I will have more work once if have glued in the CF push rods and realize I can not live with the deflection. At this stage it's going to mean a new pushrod as well.

I do own an Addy, and it's done 118 flights. 50 degrees up and down on the ailerons.
Kfuchs is online now Find More Posts by Kfuchs
Reply With Quote
Old Today, 12:30 AM
PA Team Pilot
kohersh's Avatar
United States, FL, West Palm Beach
Joined Apr 2011
786 Posts
Hmm, so your saying that the wood being squared corner is obstructing the deflection of the surface?

If I understand right it deflects to 45 in one direction and on the same ail to 35 the opposite direction. So why not remove your gap covering strip and either crush the fibers that make up that squared off corner (making it rounde with something like a cooled iron) and then cover over it from that side, or use a hobby knife and chamfer the square corner to the same effect. Seal the covering with an iron and then install the gap seal over it. Beats removing the aileron all together.
FWIW the 'official PA method' is to only measure one side. I initially made my how to video showing both sides measured and was asked to change it, reason being it left more opportunity for a mistakenly overlarge gap.
Thanks for the reply and sorry your having trouble. Thats a good number of flights on the Addy! sounds like you enjoy that plane
kohersh is offline Find More Posts by kohersh
RCG Plus Member
Old Today, 03:53 AM
If it has wings it will fly...
ckleanth's Avatar
United Kingdom, England, Birmingham
Joined Mar 2011
1,904 Posts
TBH, do it properly first time. I'd cut the hinges take the control surface off, get a few new cf hinges, make new holes and do it again.
my adx elevator is going to have that done when I get some free time.
ckleanth is online now Find More Posts by ckleanth
Reply With Quote
Old Today, 05:59 AM
Thumbs are overrated.
Poffertjesporem's Avatar
The Netherlands, NB, Sint-Michielsgestel
Joined Nov 2014
99 Posts
@ chleanth,

IF you make slots in the fuse,, you can get 72 degrees up and 61 down elevator deflection, while using the stok control rod
Poffertjesporem is online now Find More Posts by Poffertjesporem
Reply With Quote
Old Today, 07:23 AM
PA Team Pilot
kohersh's Avatar
United States, FL, West Palm Beach
Joined Apr 2011
786 Posts
72 degrees, woah! Holy speed brake batman!
kohersh is offline Find More Posts by kohersh
RCG Plus Member
Old Today, 07:26 AM
Registered User
South Africa, GP, Midrand
Joined Jan 2014
10 Posts
Yes, looks like I did a better explanation the second time

I will look at the option of rounding the one edge. Will the strip that's sealing the gap , stick again if I remove it. It's going to be a pain to find the exact colour transparent covering here in South Africa.

Thanks for all the suggestions.
Kfuchs is online now Find More Posts by Kfuchs
Reply With Quote
Old Today, 07:57 AM
Thumbs are overrated.
Poffertjesporem's Avatar
The Netherlands, NB, Sint-Michielsgestel
Joined Nov 2014
99 Posts
@kohersh

I'm still working on my elevator geometry, my target is 85 degrees up, and 71 degrees down as the down motion is limited bye the stucture.

http://www.rcgroups.com/forums/showthread.php?t=2351213
Poffertjesporem is online now Find More Posts by Poffertjesporem
Reply With Quote
Old Today, 08:53 AM
If it has wings it will fly...
ckleanth's Avatar
United Kingdom, England, Birmingham
Joined Mar 2011
1,904 Posts
Quote:
Originally Posted by Poffertjesporem View Post
@ chleanth,

IF you make slots in the fuse,, you can get 72 degrees up and 61 down elevator deflection, while using the stok control rod
I'm getting that sort of range in my ef extra 48 and this is what I intend for the adx to be able to do..
my plan is to taper the square edged control surface connection to have a nice and consistent angle so that the control surface will freely move at those angles. (yes its a covering strip/fix and recover job but I'm hoping to be able to just strip the edges that I will work on.
ckleanth is online now Find More Posts by ckleanth
Reply With Quote
Old Today, 09:30 AM
PA Team Pilot
kohersh's Avatar
United States, FL, West Palm Beach
Joined Apr 2011
786 Posts
I am in NO way saying that sort of travel is something to avoid, not at all it can be wildly fun. The PA planes don't get to that range as its really only use able for tumbling maneuvers and the trade off is in resolution on every other rate.
I found it interesting that in one of the magazines last year there was a aerobatic specific article written by 1st US RC flight school about how double beveling the LE edge of the control surfaces (how most mfgs get to those extreme throws) was the 'old school' way of doing things. and that the air flow is more disrupted by it. I'm going from memory and think the wife pitched my copy, Anyone else see that article or care to comment on it?
kohersh is offline Find More Posts by kohersh
RCG Plus Member
Old Today, 09:32 AM
PA Team Pilot
kohersh's Avatar
United States, FL, West Palm Beach
Joined Apr 2011
786 Posts
Quote:
Originally Posted by Kfuchs View Post
Yes, looks like I did a better explanation the second time

Will the strip that's sealing the gap , stick again if I remove it. It's going to be a pain to find the exact colour transparent covering here in South Africa.

Thanks for all the suggestions.
ehhh, your best bet would be to heat it to remove it, its not easy no. You could check with rcg user 'demon GTi', he's a PA stick and also is in SA, he may have some covering. Hey I sold a quad to a SA guy and he told me something about it being difficult to get hobby parts there, whats up with that?
kohersh is offline Find More Posts by kohersh
RCG Plus Member
Last edited by kohersh; Today at 09:45 AM.
Reply With Quote
Old Today, 10:32 AM
Precision Aerobatics Team
demonGti's Avatar
South Africa, GP, Randburg
Joined Dec 2006
2,091 Posts
Quote:
Originally Posted by kohersh View Post
ehhh, your best bet would be to heat it to remove it, its not easy no. You could check with rcg user 'demon GTi', he's a PA stick and also is in SA, he may have some covering. Hey I sold a quad to a SA guy and he told me something about it being difficult to get hobby parts there, whats up with that?
I've PM'ed him. Lets see if I can help from my side.
demonGti is offline Find More Posts by demonGti
Reply With Quote
Old Today, 11:54 AM
Registered User
South Africa, GP, Midrand
Joined Jan 2014
10 Posts
Thx Kohersh, I will chat to demonGti.

I appreciate the help and kindness.
Kfuchs is online now Find More Posts by Kfuchs
Reply With Quote
Old Today, 12:40 PM
Thumbs are overrated.
Poffertjesporem's Avatar
The Netherlands, NB, Sint-Michielsgestel
Joined Nov 2014
99 Posts
Quote:
I am in NO way saying that sort of travel is something to avoid, not at all it can be wildly fun. The PA planes don't get to that range as its really only use able for tumbling maneuvers and the trade off is in resolution on every other rate.
I found it interesting that in one of the magazines last year there was a aerobatic specific article written by 1st US RC flight school about how double beveling the LE edge of the control surfaces (how most mfgs get to those extreme throws) was the 'old school' way of doing things. and that the air flow is more disrupted by it. I'm going from memory and think the wife pitched my copy, Anyone else see that article or care to comment on it?
I made a bend in the control rod to make the big deflection posible(81 up 66 down), now the end point setting is at 102%, and my resolution is increassed (using stok control horn and cf extention arm) Ill post an tutorial here when i replace my test rod with quallity parts.

I did not read the artilce but the boundery layer does not like interferance. Some small vortex generators will counter the boundery layer seperation. I caste of the addy x i expect an vg of 3mm high wil do the job( the vg's on the wing are out of scale but do wonders in preventing tips stalls ).
Poffertjesporem is online now Find More Posts by Poffertjesporem
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Precision Aerobatics 58" Extra MX Official Roll Out Thread **New Video** hercdriver7777 3D Flying 5492 Yesterday 05:25 PM
New Product Precision Aerobatics Addiction X rcbirk21 3D Flying 235 Sep 01, 2014 08:10 AM
Wanted Addiction by Precision Aerobatics youace Aircraft - Electric - Airplanes (FS/W) 1 Mar 10, 2010 09:00 PM
Video Precision Aerobatics Addiction 3D Video hercdriver7777 Electric Plane Talk 13 Dec 26, 2009 11:35 AM
Discussion Precision Aerobatics Addiction -Aussie Made flying video dingfix Australia 26 Dec 02, 2007 04:38 PM