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Oct 26, 2020, 04:28 AM
Entropy is happening!
Jim.Thompson's Avatar
Yes, how is it going?
You have gone all quiet on us Bob.
Something we said?...........................
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Oct 26, 2020, 10:40 AM
Detail Freak
target's Avatar
Me maybe!
Oct 26, 2020, 01:32 PM
Entropy is happening!
Jim.Thompson's Avatar
I'm still hanging out for the "solved" part of this thread.
Oct 26, 2020, 11:29 PM
Detail Freak
target's Avatar
Solved but not executed maybe?
Oct 30, 2020, 04:14 AM
Registered User
fly2bob's Avatar
Thread OP
Okay okay here you go........

Quote:
Originally Posted by Jim.Thompson
I'm still hanging out for the "solved" part of this thread.
See excerpt from post #1 below in blue

Quote:
Originally Posted by fly2bob
.................EDIT OF THIS POST RE: THE SOLUTION TO THE PROBLEM IS BELOW IN RED..............

SIMI EDITTED: .......................

The programming for the JR radios assume your wing servo output shafts point toward the wingtips, the control arms stick out the bottom of the wing, which then connects to the control horn on the bottom of the control surface via a pushrod.

It also says the output shafts should also be on the TE side vs LE side, but I ran it through in my head, and since the rotational direction doesn't change there is no real difference. It would seem, the only difference is a shorter control rod.

Additionally, the manual states that the left aileron servo should be plugged into the ch 1 aileron port of the Rx, but I had found several sources that say - actually it's the right aileron servo that should go in that port. The left aileron then would go in the ch 5 gear port, left flap into ch 6 Aux 1, and the right flap into ch 7 Aux 2. Currently this is the channel ASSIGNMENT I have been using.

SIMI EDITTED: ........................
Although the output shafts point toward the wingtips like they're supposed to for my JR radio, and the control arms point down, the pushrods goes up through the wing at a shallow angle, and connects to the TOP of the control surfaces!


This resulted, I thought, in having to do some creative programming, using vastly unequaled numbers for some things like travel (throw) adjustment of some of the wing's servos.
I got it to fly 'okay', but wish deflection amounts were correct, and equal for both sides.
I was able to get all the features to work that I wanted, and it rolled fine to the right, but rolled very, very slowly to the left, and there were some other annoying things like for crow, where one flap would be down lower than the other, and as much as I tried to mess with the numbers, I couldn't get them to be equal, or the left control surfaces to have more deflection like the right.............................

Well............ as this thread continues, I wondered if since the control rods connect to the TOP of the control surfaces vs the bottom of the control surfaces, like the manual says they're supposed to, that it was a PUSHROD GEOMETRY vs SERVO ASSIGNMENT issue, and maybe it would solve my problem if I swapped which port (some of) the servos go into at the Rx, but it turned out not to be the case.
In the end, after trying it and not working, I reluctantly peeled off the circular vinyl servo covers to inspect what angle each servo's control arms was at.
This is revealed at the bottom of post #18 page 2.

If you looked at those results, you can see that the angles are all mixed up.............. ..

Regardless, what is needed to be done first is to get the left servo control arm angles to match the right side.
The control rods connect to the control arms using a metal clevis.
So the first thing I will try to do is to adjust the clevises on the left side of the wing to match the right.
If that doesn't work, then I'm going to have to somehow break loose servos in the left wing half, which are epoxied to the inside top of the skin, pull them out, reset the sub trims, and them reattach those right wing servo control arms so their angles match the right side.
Basically, the fact that the control rods connect to the top of the control surfaces vs the bottom, like it's supposed to, wasn't a servo assignment problem, but just a matter of reversing the servos, which is the way I already had it originally.

Target.........thank you for your edit of that one post.
I was already frustrated enough with this glider's setup from the improper install the previous owner did, that I don't need to be yelled at too. lol

I hope this will clear things up so as not to make this thread more of a "train wreck", as you described it, as I already have. lol

Well since it had been many days since I had touched it, I quickly double checked a couple of things.
1) I swapped the aileron servo plugs at the Rx again.
Yep, just as I remember.
The aileron's still go in the same correct direction, but the differential is reversed. So back to the way it was;
Rt. Ail. into the Ail. port &
Lt. Ail. into the Gear port.
Same with the flap servos.
2) I verified the servo arm angles matched what I wrote at the end of my #18 post on page 2.
Yup.

So after spending some time with it messing with some things,
I have good news.......................

1) Though there is a Z-bend at the control arm end of the control rod (because there just isn't room for a clevis at that end), the control surface end of the control rod is threaded with a clevis, so they're adjustable.

2) I discovered the real culprit as to why I wasn't getting hardly any left up aileron throw.

Though I didn't see it at first, when I had disconnected the left aileron clevis for the 3rd time to unscrew it some more so that I could adjust the left aileron control arm more forward, via the subtrim, to match the angle of the right control horn, I saw the sub TE cavity at the last 1" of the wing, which is suppose to be hollow, filled with light weight spooge, which must have been from a wing tip repair before I bought it.

If you look the photo, IDK if you can see the difference in color between the end grained balsa & the white spooge after I dremeled it out, but it's just outboard of the blue tape I placed there so you can see it better.
My heart jumped with glee!
To verify, I reattached the clevis to the control horn, turn everything on, gave left stick aileron and noted it's restricted travel throw, just as it had been doing, but also the max angle the control arm was going.
Then I turned everything back off, disconnected the clevis again, turn it back on, and gave full left stick again, and what do you know, the servo arm went back much further towards the TE than before!
YAY!

3) The servos, though older (read 'vintage' lol), with a torque rating on the low side & could stand to be replaced with newer higher torque servos, are all tight with no slop or double neutral, and are in good condition.

I was very happy about this because I REALLY didn't want to try and rip them out with no reinforcement on the inside of the upper skin, and risk the outside of the upper skin tearing.

There is a tiny bit of slop on two of the control surfaces, but through careful inspection with a magnifying glass, it is from the hole of the servo arm the control rod goes through being just slightly too big that is causing it.
I will use a tiny drop of CA on it while constantly moving the stick and control surface so it doesn't freeze and lock up.
This should take care of the slop.

Though I still have some fine-tuning to do, the servo control arm angles are now about the same, I have plenty of left up aileron travel, and other surface deflections are getting more identical,
so I'm pretty happy.

Happy Holloween,
Bob
Last edited by fly2bob; Oct 30, 2020 at 04:23 AM.
Oct 30, 2020, 04:51 AM
Entropy is happening!
Jim.Thompson's Avatar

Properly solved now!


That is good news Bob!
And this is an actual solution!..................the excerpt from the first post you repeated in blue above hardly rates in that regard..................at least to my thinking.
You had us readers almost as confused as you were, but all is well that ends well.

One thing you will have learned now along the way, is how to recognise the sound of a stalled servo. This is important to know and be aware of when setting up any model. Mechanical and electronic rates must be adjusted when and if they do stall, to avoid this.
Or in this case, any obstruction, like the lump of splooge, should be removed to allow normal travel.

But..........you probably now realise all this without me saying!...............

Edit: the picture does not show me anything relating to the problem!
But, hey, who cares?

Jim.
Oct 30, 2020, 07:32 AM
Registered User
fly2bob's Avatar
Thread OP
Quote:
Originally Posted by Jim.Thompson
That is good news Bob!
And this is an actual solution!..................the excerpt from the first post you repeated in blue above hardly rates in that regard..................at least to my thinking.
You had us readers almost as confused as you were, but all is well that ends well.

One thing you will have learned now along the way, is how to recognise the sound of a stalled servo. This is important to know and be aware of when setting up any model. Mechanical and electronic rates must be adjusted when and if they do stall, to avoid this.
Or in this case, any obstruction, like the lump of splooge, should be removed to allow normal travel.

But..........you probably now realise all this without me saying!...............

Edit: the picture does not show me anything relating to the problem!
But, hey, who cares?

Jim.
Well all I meant by 'solved' was that it was discovered and verified that it wasn't a pushrod geometry vs. servo (Rx port) assignment problem after all. But you are right, I was confused, and stumped, and even though I didn't want to tear off those nice circular vinyl servo covers that were on there, I'm glad you guys pushed me do it because it was the next logical step.

Strange thing is, the servo didn't make
any sound when stalled & stopped by the spooge, I had no clue.

And yeah, I should have taken the picture with the spooge still in there. I was just so happy to have finally found what was causing my problem that I dremaled it out right away wanting to see it work better. Oh well.

Thanks again for the help guys, and sorry for the roller coaster ride.

E-ticket
Bob
Oct 30, 2020, 01:59 PM
Detail Freak
target's Avatar
Yeah, mechanical limiting is normally something you look for in initial installation, or after a repair.
Second hand planes I usually consider to be RTF- and that stands for Ready To Fix.
It is rare that I will leave a used plane exactly as I receive it, and taking off the servo covers is always a good idea if buying in person.

Were you able to re-subtrim the flap servo, to the same arm angle as the other, and adjust the linkage?
If so, after you get it as close to perfect as possible, wick a tiny amount of thin CA into the clevis threads, to eliminate the slop there. And same at the clevis pin/horn, and servo arm/L bend linkage.
Doing the above properly will leave only servo gear slop.

Don't be surprised if the servos on the flaps need different end point adjustments to give same throws on the flaps. You might assume that the flap horns on a molded factory produced glider are placed identically to the hinge line. This assumption would many times be WRONG! Especially in older early moldies.

R,
Target
Oct 30, 2020, 06:08 PM
Registered User
fly2bob's Avatar
Thread OP
Good points.............will do.

I have the print out of the factory recommended control surface throws & settings, as well as the same from Daryl Perkins when he flew his at the WC. Daryl's throws were quite a bit more than the factory throws, and since I like a touchy set up, I can now have throws more like Daryl's.

Both only suggest 45-55 degrees of down flap for crow probably because that's about as much deflection as you can get out of them because of the control rod connecting to the top of the control surface vs it connecting to the bottom.

As I said, I still have some messing around to do with the settings to fine-tune them, but so far I've been able to get 48 degrees of down flap out of the left flap, and will be able to adjust the right flap to match using the Travel Adjustment for Aux2. Curious that the left flap doesn't have such an adjustment though. Yes I am still on the 8103. The way I figured it, is that if I can get it just the way I want it, or as close to it as I can on the 8103, a Tx that I am very familiar with, then I should just be able to feed in similar numbers to the 9303 while learning how to do so.

Bob
Last edited by fly2bob; Oct 30, 2020 at 06:14 PM.
Oct 30, 2020, 10:22 PM
Detail Freak
target's Avatar
If it were me, I would try to get as much down flap as possible (up to about 75*) and skip any aileron deflection.
If you aren't landing in a rotor area, landing with added flaps to a thermal mode works really well. Stall speed is lower with the wing cambered, you just have to use more or even ALL differential in the ailerons when landing, so you don't stall the already cambered wing (just like in real gliders).

R,
Target
Oct 31, 2020, 07:43 AM
Mark LSF # 3792
Target is correct landing with a little camber in the ailerons can limit stalls when landing. Just be careful not to use too much since it will reduce roll response. Also, Target I like your definition of RTF. I too rarely fly a second hand airplane untouched.
Oct 31, 2020, 01:09 PM
Detail Freak
target's Avatar
We are brothers from different mothers!
Oct 31, 2020, 07:04 PM
Registered User
fly2bob's Avatar
Thread OP
Quote:
Originally Posted by target
If it were me, I would try to get as much down flap as possible (up to about 75*) and skip any aileron deflection.
If you aren't landing in a rotor area, landing with added flaps to a thermal mode works really well. Stall speed is lower with the wing cambered, you just have to use more or even ALL differential in the ailerons when landing, so you don't stall the already cambered wing (just like in real gliders).

R,
Target
Have to go to work soon, but tomorrow I'll see what I can do to get some more down flap throw for crow and get back with the results.

Bob
Oct 31, 2020, 07:35 PM
Detail Freak
target's Avatar
Quote:
Originally Posted by fly2bob
Have to go to work soon, but tomorrow I'll see what I can do to get some more down flap throw for crow and get back with the results.

Bob
Just say "no" to crow!
Landing mode. I know that is what you mean. But crow generally means up ailerons coupled to down flaps.
Don't eat crow, Bob!

I hope all this minor tuning helps. It should, depending on what your radio is capable of. Camber changing is a huge deal, IMO. But you need accurate surface positioning. And separate trim in all flight modes. Some radios have a checkbox for that separate trim. You need elevator trim to follow the wing TE with camber changes (only a lot less movement).

FYI, the elevator compensation you should be mixing in your landing mode, is more down elevator throw at the beginning of the throttle stick pull down, than at the end (assuming you can get more flap down). After about 40-45* down flap, you stop adding lift, and start adding more drag. That is where you add only a bit more down compensation normally. And that is why more flap is so desirable. If you can get about 60* down, you will be golden.

R,
Target
Oct 31, 2020, 07:43 PM
Entropy is happening!
Jim.Thompson's Avatar
That reads about right Target, based on my limited experience.


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