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Marc RC pilot

carbon push rod sticking advice

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Marc RC pilot
Posted (edited)

I got hold of a new Sunbird glider but the elevator push rod is quite seized up on the downwards phase of elevator. I tried carefully spraying some wd40 into rod/sleeve which helped a bit but still sticking.

Any advice on how I can best free it up please?

 

Thank you20190726_200007.thumb.jpg.ac5f1fa041d0fc158ac35ea0b9b07380.jpg

 

 

20190726_193550.jpg

Edited by Marc Sinclair
Had wrong model name/changed to correct one

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pete beadle

Hi Marc

Possibly dust if it's new.......

Your spray won't reach far enough into the pushrod outer to shift it

Try taking the fus round to your nearest garage and blast it with compressed air - turn your eyes away while you start doing this, as there will probably be a lot of (possibly toxic) dust being forced out, which your unprotected eyes won't like,  then try to  concentrate on the little gaps between the inner and outer of the pushrod - also try to force compressed air in from the openings in the rear of the fus too......

WD40 is good but the spray isn't ideal, it relies on the vapour to get the lubricant where you want it, you really need to stand the fus tail-down and try to get some liquid lubricant into the outer from the front

It would be best to remove the bellcrank assembly if that doesn't work, but I don't know if that is possible on the Sunbird

Good luck

Pete

BARCS1702

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heli_bee

Marc,

I have had similar issues with a Typhoon. It turned out to be some excess epoxy on the pushrod at the tail end of it.

I had to disconnect the clevis from the tail-plane bell-crank ( that was a keyhole surgery type of exercise) to be able to remove the pushrod.

The excess epoxy popped off easily enough and everything was fine after that - once I got the clevis re-attached of course.

Martin.

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Marc RC pilot

Thank you Pete and heli_bee for the good advice,

Yes the sunbird's crank is all pre-set up/fixed to bell- crank and dammed hard to even see let alone get to, but I think there might be an option for that keyhole surgery (lol HB).

Did you make a new hole of fin close to bell-crank to access it heli_bee?

We have a local garage so I got both options open to me and will try my luck with air compressor first, but it really seems stuck badly.  

The other one is ok but a little sticky and has I could remove it, I sprayed some wd40 from cockpit end and encouraged it down tube  working it with the carbon rod. I did notice some waxy looking stuff on push rod which I cleaned off as well. Seem to do the trick. I got the felling the elevator rod is in same but worse  state.

Will report back if/when I fix it.

 

Thanks again 

 

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Marc RC pilot
Posted (edited)

Tried compressor(with safety glasses, thx Pete) but n8o joy.

Key hole surgery will be next. There might be an option to get to it by removing the upright piece of wood that's in the fin as I do not want to cut any holes in fiberglass if I can avoid it.  

Also you might have noticed the wings have 4 servo trays but only 2 large ailerons cut out/working...I think it was a prototype or one of the first of it's kind. 

20190731_170612.thumb.jpg.81dec290bd4dce5e83100143f9eece6f.jpg20190731_170853_001.thumb.jpg.167c086ecaba8fa291b72a0627265640.jpg

 

 

Edited by Marc Sinclair
added pics

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pete beadle

Hi Marc

I hate to say it but it looks like there has been a repair done to the section of fin that contains the bellcrank bearing

Your "light-bulb x-ray" has revealed the edge of some chopped strand mat - immediately above the bellcrank slot - no manufacturer would leave the ends of a mat untrimmed like this - is it  new or has it been repaired before, do you know?.....

I thought it was odd when you described it as a sunshine glider.....I've never seen a Sunbird logo like this nor  with red and blue wavy lines at the other wingtip

More info needed:yes:

Regards

Pete

BARCS1702

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heli_bee

Ho Marc,

I cut away part of the wooden fin post to get to the bellcrank clevis. Easy to replace the wood later. What is not so easy is getting the pushrod back into the tube and connecting the clevis.

Good luck.

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Marc RC pilot
10 hours ago, pete beadle said:

Hi Marc

I hate to say it but it looks like there has been a repair done to the section of fin that contains the bellcrank bearing

Your "light-bulb x-ray" has revealed the edge of some chopped strand mat - immediately above the bellcrank slot - no manufacturer would leave the ends of a mat untrimmed like this - is it  new or has it been repaired before, do you know?.....

I thought it was odd when you described it as a sunshine glider.....I've never seen a Sunbird logo like this nor  with red and blue wavy lines at the other wingtip

More info needed:yes:

Regards

Pete

BARCS1702

Good morning Pete

 

Thanks for bringing that to my attention. It is new but I think it is a prototype Sunbird and it has been in a dry/sound storage for some time inside there protective bags.

I will get a definitive answer to the history of it soon and pass on to you. Beautiful kit and small enough for me to carry around with a my small backpack on my future treks/slope soaring initiation :) 

Apologies for getting the name wrong...Yes it is a Sunbird. Interesting about the logo etc will find out more for sure.  

Will post a few pics of underside/top of wings in min.

 

Cheers

 

Marc  

9 hours ago, heli_bee said:

Ho Marc,

I cut away part of the wooden fin post to get to the bellcrank clevis. Easy to replace the wood later. What is not so easy is getting the pushrod back into the tube and connecting the clevis.

Good luck.

You are a star heli_bee, thank you. Will get my surgical keyhole tools out.

btw, I had the opportunity to look at a new 2m Typhoon when I bought the Sunbird, and I must say it looked absolutely fantastic on all fronts! Someone had beaten me to the sale of it unfortunately. I would have taken it without thinking twice it was so nice.

 

Thx 

 

 

 

 

 

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Marc RC pilot

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Marc RC pilot

@pete beadle

Hi Pete

I asked previous owner and this Sunbird is the only full span aileron one made with a custom scheme and should roll extremely fast. 

Cheers

 

Marc 

 

 

 

 

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SilentPilot

Sunbirds are a real PITA. Let me save you the heartache, bung some servos in it and post it my way, you'll thank me for it someday 


Tony 😛  

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pete beadle

Hi Mark

I don't understand why the previous owner says the Sunbird rolls faster with "only" one aileron each side......that arrangement was what we had to suffer in the 70's and 80's because we didn't have the ability to drive 4 servo wings with the 4 channel trannies we used to have then.......the 4 servo arrangement greatly increased the roll rate as only the tip ailerons were providing the roll, without the drag of the absent, unuseable flaps, it's one of the most basic advantages that the 4 servo wing provides!:yes::thumbsup:

Regards

Pete

BARCS1702

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Marc RC pilot

lol Tony, thanks for thinking of my mental health :D

Makes sense what you Say Pete...I got a small modelling jigsaw for the flaps.... 😃 

 

Cheers

 

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SilentPilot

I have two Sunbirds, one glider and one e-glider.
The roll rate is blurry fast with the flaps backing up the ailerons (roughly 50%). I wouldn't want it to roll any quicker :D

 

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pete beadle

Hi SP

So, get a bigger one! I much prefer slow, precise, axial rolls to "twinkle" rolls personally:yes::)

Both the Sunbird and the Typhoon have elliptical wingtips. designed for assisting sudden changes of direction, both are relatively heavy in standard trim, great in high windspeeds but not so good when the wind drops.

One of the worst unintended manouvres I ever saw at Ivinghoe was a chap flying a Typhoon in high wind when the "Ivinghoe Sink" came through.......being a beginner he did everything wrong, starting with pulling in full up-elevator, and transitioning into the flat spin that quickly became a vertical dive, and finished when the plane hit the ground, and soon after, the  throwing of his tranny after it, which bounced off the slope, started to come to pieces in the air, and arced out from the slope edge, apparently trying to find the same  last resting place of the scattered wreckage of the Typhoon below..........and in deathly and complete silence ......... I never, ever, want to see anything like that again.....and hopefully never will......:(:no:

Yes, lovely planes, but heavy!

Regards

Pete

BARCS 1702

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SilentPilot

I've found the Sunbird responds well to a little Camber across the trailing edge. It can soar in quite low winds  :)
When the wind gets up I swap the Sunbird for my Minivec!

As for a bigger version... I'd love one, but alas I don't think there is one out there.
My Redshift is nice though!


Tony

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Marc RC pilot
8 hours ago, pete beadle said:

One of the worst unintended manouvres I ever saw at Ivinghoe was a chap flying a Typhoon in high wind when the "Ivinghoe Sink" came through.......being a beginner he did everything wrong, starting with pulling in full up-elevator, and transitioning into the flat spin that quickly became a vertical dive, and finished when the plane hit the ground, and soon after, the  throwing of his tranny after it, which bounced off the slope, started to come to pieces in the air, and arced out from the slope edge, apparently trying to find the same  last resting place of the scattered wreckage of the Typhoon below..........and in deathly and complete silence ......... I never, ever, want to see anything like that again.....and hopefully never will......:(:no:

lol Pete....What an absolute  nightmare scenario...The "...and in deathly and complete silence..." really set the scene/got me mate :D. Nice one. 

I guess us male-of-the-species are burdened with excess testosterone which for many is hard to control...Especially when trying to deal with understanding flight/having some control with it (slope bouncing tranny etc ) :) .

Big Leo (my early/all-time heroes) put it well: "For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return."

Or imagine the mind set/guts of being Otto Lilienthal in 1848...

 

Tally Ho! 

 

 

 

 

 

 

 

 

 

 

 

 

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Zim

Hey all

I'm the previous owner of the Sunbird 🙂 it was made as an experiment towards the end of my time as owner of SlopeRacer. We wanted to create a Sunbird which cost as little as possible to fit out. Having had really positive experiences in the past with two servo wing versions of the X-models Miniblade, I decided to try this idea with RCRCM. The aileron chord is a little larger than a regular Sunbird, in addition to having more span. The scheme is a one off that we were going to go with, but after I sold SlopeRacer, sadly this concept wasn't acted upon.

Pete, the extra size is needed as these ailerons need to not only provide roll control, but also provide solid braking as spoilerons. The fact that the wings carry only two servos now and not four, allied to less wiring running through there, along with the big surfaces means that absolutely no question, this thing will roll like a drill!

I can guarantee that there are no repairs to the tail, Pete 🙂 but I will acknowledge that RCRCM could have tidied up that layup in the tail, no question!

Now, MARC - reading through this has jogged my memory! Absolutely right - remove a section of the balsa fin post with a scalpel to give access. Very easy to do. Rotate the bell crank right up to give access to the clevis, pop it off and clean up the rod. I just couldn't remember it when I saw you! Just be patient with popping off the clevis. You don't want to slip and punch a hole in the skin!

Cheers

Z

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Marc RC pilot

An amazing/fascinating  bit of experimental Sunbird/design history there Zim! Thx for sharing it m8.

Also thank you for rod/clevis advice, should be relatively straight forwards and will defo mind not to puncture things (one of my genetic skills-sets it seems..) 

I wasn't sure if I could program flaperons into Sunbird, sounds good as she looks like a slippery flying-fish. :) 

 

 

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SilentPilot

The Sunbird is an amazing little glider. I've raced mine, aerobated it and chased thermals with it.

I do mean to add a belly hook. I'd love to see how it goes up my bungee!

What transmitter do you use? I can send you my .SPM file if you use Spektrum, it has loads of mixes to get the best out of it :)

Just wish it had a ballast tube fitted.

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