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Sep 12, 2020, 08:42 PM
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radfordc's Avatar
Quote:
Originally Posted by darmar
Did I miss it or there is no single word mentioned about balancing full flying elevators on the shaft? Doubt it FW did it at the factory. Itís a must for any model with full stabs regrdless of size. This way load on servos is much less at higher speeds.
Mass balancing of control surfaces is done to prevent flutter. It does not reduce the aerodynamic loads on the servo.

https://www.faa.gov/documentLibrary/...C23-629-1b.pdf
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Sep 12, 2020, 09:46 PM
He builds stuff. :)
Pepperpete's Avatar
Not sure who said it but someone mentioned they don't care if the servo's are barely up to the task. Either you have way too much money to burn, you don't care at all about safety, or are just nuts.

The issue I have isn't how Motion is handling it. It's how they say "oh it's fine...but just in case here's more work on a 1000 aircraft, and make sure you thank us for the free upgrade". Weak servo's in these jets has been an issue for YEARS. Like why is this STILL going on? I'd pay extra to know it's not going to fall out of the sky.

These planes should be tested PAST the tolerance they claim. They mention developing larger servo's because of the F-18 issue so why were they not included right out the gate. This isn't Motion, it's Freewing. I'm sure it will all be resolved but after this many models, how is it such a capable company still can't get the most basic many years long concerns dealt with.
Sep 12, 2020, 10:23 PM
Registered User
edwen303's Avatar
Quote:
Originally Posted by darmar
Did I miss it or there is no single word mentioned about balancing full flying elevators on the shaft? Doubt it FW did it at the factory. It’s a must for any model with full stabs regrdless of size. This way load on servos is much less at higher speeds.
Btw this feature is built in by design in real Mig by positioning the pivot line on the CG of flying surface.
Absolutely! Post #1121 and 1123 addressed this.

Pepperpete: If you check price for Freewing 17 g servo for 90mm F-16 etc, it is in the same league as Corona 238MG from Hobbyking with twice the torque. So not sure it is the driven by cost or else. Like I mentioned, the reliability of elevator, engine, and receiver are THE most essential for a flying fixed wing rc model.

Guess Freewing should have really given a warning in the manual: "IT IS ESSENTIAL TO PLACE ELEVATOR ROD TO THE MIDDLE HOLE OF SERVO ARM, failure to do might likely cause a crash, etc". Nowadays I rarely read the manual of a flying model except for cg, so such note if existed might get skipped anyway.

Boy I swear HK had 238mg servos as of yesterday, now it is all out of stock in USA warehouse, you guys acted fast
Last edited by edwen303; Sep 12, 2020 at 10:51 PM.
Sep 12, 2020, 10:42 PM
Registered User
edwen303's Avatar
mass balancing for Mig-29 elevator?
In manual (https://cdn.shopify.com/s/files/1/10...serManual2.pdf), Page 2 and 4 shows the location of pivot, the area in front of the pivot is less than HALF of the area behind the pivot. Unless there is factory weight on the front, the elevator appears not balanced. Also the larger area behind pivot will demand higher torque on the servo in flight, IMO.
Sep 12, 2020, 11:50 PM
Registered User
Quote:
Originally Posted by radfordc
Mass balancing of control surfaces is done to prevent flutter. It does not reduce the aerodynamic loads on the servo.

https://www.faa.gov/documentLibrary/...C23-629-1b.pdf
Either way oversized servo is a must.
Sep 13, 2020, 12:11 AM
Registered RC NUT!
The Snake's Avatar
Quote:
Originally Posted by edwen303
Absolutely! Post #1121 and 1123 addressed this.

Pepperpete: If you check price for Freewing 17 g servo for 90mm F-16 etc, it is in the same league as Corona 238MG from Hobbyking with twice the torque. So not sure it is the driven by cost or else. Like I mentioned, the reliability of elevator, engine, and receiver are THE most essential for a flying fixed wing rc model.

Guess Freewing should have really given a warning in the manual: "IT IS ESSENTIAL TO PLACE ELEVATOR ROD TO THE MIDDLE HOLE OF SERVO ARM, failure to do might likely cause a crash, etc". Nowadays I rarely read the manual of a flying model except for cg, so such note if existed might get skipped anyway.

Boy I swear HK had 238mg servos as of yesterday, now it is all out of stock in USA warehouse, you guys acted fast
i agree that we should pass it on and i have seen many times that more details should be on the user manual!
Sep 13, 2020, 12:24 AM
Registered User
fredmdbud's Avatar
Quote:
Originally Posted by radfordc
Mass balancing of control surfaces is done to prevent flutter. It does not reduce the aerodynamic loads on the servo.

https://www.faa.gov/documentLibrary/...C23-629-1b.pdf
"Mass balancing" is a terrible term, and misleading - the more accurate term should be "critical mass damping", as elevator flutter Is similar to wing flutter, i.e. a harmonic resonance/oscillation.
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Sep 13, 2020, 12:37 AM
Registered User
mshagg2's Avatar
At the recommended location on the servo horn the front of the elevator *almost* touches the outside of the vertical stab at 100% of output (i.e. 2000ms). In the outermost servo hole it visibly and audibly grinds on the vertical stab.

Freewing Mig 29 - Elevator pushrod recommended vs outermost hole (0 min 24 sec)


(relax the channel isnt monetised lol)
Sep 13, 2020, 01:06 AM
Lee Liddle
Knife Liddle's Avatar
Quote:
Originally Posted by Pepperpete
Not sure who said it but someone mentioned they don't care if the servo's are barely up to the task. Either you have way too much money to burn, you don't care at all about safety, or are just nuts.
I said something like that. You can take your pick as to which problem I have lol. But, if you had asked for clarification I would have said....
My point is that even if I would have known at the time that the elevator servos would need to be replaced and possibly at my own expense, I still would have ordered the jet because imo at $640 greenbacks shipped to my door, it's still an amazing value. In fact I would probably pay that for an ARF-Plus version. But that's just me.
Sep 13, 2020, 01:10 AM
Lee Liddle
Knife Liddle's Avatar
Just ordered a pair of these from Amazon. They'll be here Monday. I'll have to use an Aux channel to reverse one of them.

https://www.amazon.com/dp/B00ORM3KWC..._ODBxFbG09TVM3
Sep 13, 2020, 05:02 AM
Registered User
janmb's Avatar
Quote:
Originally Posted by raydar
https://www.youtube.com/watch?v=8yDE...xk&app=desktop


Well it fly's well and looks damn good in the air so I am sure it will be well loved when the niggles are sorted.

He notes that he was 80% elevator pinned on landing when nose heavy, I would not be comfortable landing and reaching full elevator with nothing to spare so will be making sure I don't go infront of Freewings CG mark for more authority and as mentioned above less stress on the tail.
Well, Ryan usually ruins every models capabilities by flying them ridiculously nose heavy, so should definitely judge that aspect of any model based on his videos.
Sep 13, 2020, 05:06 AM
Registered User
janmb's Avatar
Quote:
Originally Posted by Doug Cronkhite
Just as an FYI.. using the outer hole on the servo arm reduces leverage to the surface by over 20% compared to just 1 hole further in (the FW recommended location btw)

Ideally, you should max out your ATV or Travel adjustment, and then use the closest hole to the servo that will give you the throw NEEDED, not max throw possible. Of the 5 FW jets I've owned, NONE have needed the 'high' rate throw recommended. People need to learn to setup their airplanes for maximum mechanical advantage and servo resolution.
Big +1!

Always make the servo to surface gearing as low as possible. You want as much physical servo travel as possible.
Sep 13, 2020, 05:11 AM
Registered User
janmb's Avatar
Quote:
Originally Posted by Evan D
I'm flying mine tomorrow. I think I've done all I can to have a good flight.

Curious how many of the nay sayers on her even have one? I know C601 has his for sale.

Also flying my MiG 17 tomorrow...
Try to not be so damn defense all the time. No need for that.

The nay sayers are just cautious, and care enough to want you and others to avoid mishaps. For which you should be grateful, rather than jumping in the trenches.

Exactly what is the relevance of whether or not posters have/have ordered the model themselves?
Sep 13, 2020, 05:15 AM
Registered User
janmb's Avatar
Quote:
Originally Posted by darmar
Did I miss it or there is no single word mentioned about balancing full flying elevators on the shaft? Doubt it FW did it at the factory. It’s a must for any model with full stabs regrdless of size. This way load on servos is much less at higher speeds.
Btw this feature is built in by design in real Mig by positioning the pivot line on the CG of flying surface.
Balancing in terms of CG matters virtually not at all. mass is NOT where the loads come from.

If you are concerned about balancing your tailerons, you should worry about aerodynamics, not mass. And once you start looking at where the pivot point would need to be in order to achieve aerodynamic balance, you will quickly realize that being well behind the end of the fuselage and not possible what so ever.


Quote:
Originally Posted by radfordc
Mass balancing of control surfaces is done to prevent flutter. It does not reduce the aerodynamic loads on the servo.
This!


Quote:
Originally Posted by edwen303
mass balancing for Mig-29 elevator?
In manual (https://cdn.shopify.com/s/files/1/10...serManual2.pdf), Page 2 and 4 shows the location of pivot, the area in front of the pivot is less than HALF of the area behind the pivot. Unless there is factory weight on the front, the elevator appears not balanced. Also the larger area behind pivot will demand higher torque on the servo in flight, IMO.
They are far from balanced, nor does it really matter as long as we are talking about mass. Balancing the mass is certainly possible, but doesn't help servo loads one little bit.
Sep 13, 2020, 07:32 AM
Retired US Navy
Evan D's Avatar
Just so you know I don't answer your posts. I find your posts mostly toxic.



Quote:
Originally Posted by janmb
Try to not be so damn defense all the time. No need for that.

The nay sayers are just cautious, and care enough to want you and others to avoid mishaps. For which you should be grateful, rather than jumping in the trenches.

Exactly what is the relevance of whether or not posters have/have ordered the model themselves?


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