RCMF

Level 1 => Gliders & Gliding => Flat-Field => Topic started by: Bustergrunt on July 31, 2013, 19:36:00 pm

Title: Seagull KA8b airbrake installation
Post by: Bustergrunt on July 31, 2013, 19:36:00 pm
OMFG, how hard is it to install these flaming things...

Has anyone done it and can upload a pic to show me...please?
Title: Re: Seagull KA8b airbrake installation
Post by: FrankS on July 31, 2013, 20:22:41 pm
The ones in the Pilatus are every bit as hard to fit with the supplied hardware, I reviewed the Pilatus and as per the review I changed out the rods to use a threaded rod with a conventional clevis and Z bend, the Z bend on the servo arm and clevis at the airbrake, took a little setting up to get them both deploying level but once set they stayed set unlike the original stuff which was self adjusting every time you deployed them.

I've flown the Ka8 as well though, builder had similar problems with the airbrakes and had to change out the control rod, but it's do-able and they do fly really well.

Pictures of my Pilatus airbrake mods below

Title: Re: Seagull KA8b airbrake installation
Post by: Bustergrunt on July 31, 2013, 22:25:46 pm
Okay...round 2 tomorrow night...
Title: Re: Seagull KA8b airbrake installation
Post by: muffler on August 01, 2013, 08:18:55 am
Quote from: FrankS on July 31, 2013, 20:22:41 pm
The ones in the Pilatus are every bit as hard to fit with the supplied hardware, I reviewed the Pilatus and as per the review I changed out the rods to use a threaded rod with a conventional clevis and Z bend, the Z bend on the servo arm and clevis at the airbrake, took a little setting up to get them both deploying level but once set they stayed set unlike the original stuff which was self adjusting every time you deployed them.

I've flown the Ka8 as well though, builder had similar problems with the airbrakes and had to change out the control rod, but it's do-able and they do fly really well.

Pictures of my Pilatus airbrake mods below

Hi all,

I'm also now putting together a ka8b with my Dad & now having a look at the air brakes. On the Pilatus it looks as though the servo is in front of the air brake? On the ka8b the servo is behind which looks to me as though the geometry is wrong so when you get to a certain point in travel the servo won't be doing anything. It looks to me as though you need a different horn, one which will put the point at which you attach the clevis or z bend way in front of the hinge line?

Glad to hear they fly well.  :af :af

Regards
muffler

Title: Re: Seagull KA8b airbrake installation
Post by: Bustergrunt on August 04, 2013, 20:27:51 pm
What a palaver...I've spent a load of time on this and still can't get it right.

I'll try one more time with flexible snake inners as the 'rods' are binding etc...

Failing that it'll be a spoileron mix and taping these buggers up.
Title: Re: Seagull KA8b airbrake installation
Post by: ThrottleBender on August 04, 2013, 21:54:36 pm
I am sure you would find it much easier to put the servo under the spoiler.
Spoiler servo operation in RC glider (http://www.youtube.com/watch?v=JoAsw2ccfM0#ws)
Title: Re: Seagull KA8b airbrake installation
Post by: Bustergrunt on August 06, 2013, 20:41:57 pm
Sod it...I've taped over them until I can be bothered to make up some propper PCB horns that will give the correct 'geometry' to the movement.

Spoilerons mixed in now...not very scale but ... oh well....
Title: Re: Seagull KA8b airbrake installation
Post by: muffler on September 18, 2013, 11:08:00 am
Hi all,

Just about ready to test fly one of these, it will be tugged up.

For those that have flown it, have you kept with the recommended c of g & recommended control throws?

I had to add quite a lot of lead in the nose to achieve the recommended c of g, I suppose that's part & parcel of a traditional built glider? (I'm used to foamies!

Regards
muffler
Title: Re: Seagull KA8b airbrake installation
Post by: Bustergrunt on September 18, 2013, 17:45:09 pm
On the advice of a geezer, I added 1/16th packing to the LE of the tailplane...
Title: Re: Seagull KA8b airbrake installation
Post by: FrankS on September 19, 2013, 08:33:45 am
I balanced mine so it balanced slightly nose down at the recommended position in the manual and it flies very nicely at that. I didn't need to pack up the elevator leading edge.

It might be worth noting that Seagull did update the Pilatus, a fellow flier has got the earlier version and the differences we noted are

1) On the earlier version the cockpit area is just a butt joint to the fuselage and get get knocked off, on the later version the horizontal former runs through for additional strength
2) On the earlier version the wing bolt hatches are on top of the wing and below on the later

Not sure what other changes have been made, but 2) seems to be a way of spotting the earlier and later versions.
Title: Re: Seagull KA8b airbrake installation
Post by: selleri on October 01, 2013, 14:03:05 pm
Quote from: Bustergrunt on September 18, 2013, 17:45:09 pm
On the advice of a geezer, I added 1/16th packing to the LE of the tailplane...

I've got about 5mm under mine, the CG is at 65mm, aileron throws all you can get, same with rudder, can't remember the elevator throws but around 15-20mm. Nice plane!

(http://frettavefur.net/Forum/uploadpic/2013/1368575593_0.jpg)
Title: Re: Seagull KA8b airbrake installation
Post by: Bustergrunt on October 01, 2013, 18:42:46 pm
I now need a left wing....anyone got one?