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        Question Seagul 3 meter KA8-B

#1 hondaboy92hatch Apr 13, 2012 05:25 PM

Seagul 3 meter KA8-B
 
Hi guys,
I am about to buy a 3 meter Seagull KA8. I am wanting to know if the c/g is right on and what servos you guys you are useing in it? I plan to get it in two weeks.

Thanks for any help.
Joe

#2 Seadog Apr 13, 2012 05:56 PM

As far as I have seen, the Seagull Ka8 is 3m and the Phoenix Ka8 is 3.5m or 6.0m. Which one have you got your sights set on?

Dave Smith

#3 Big Nuts 181 Apr 13, 2012 06:36 PM

Hi Joe with regard to servos for the two smaller ka8 HS 81mgs have been quite adequate so far, as to the 6 meter HS 645mg on aileron/elevator with hs705bb on rudder and tow release. These are the servos myself and a mate have been running on our ka8's. Regarding CofG all planes started out at 33% and adjusted to suit flying styles till they felt rite.

Enjoy your new model they fly superbly.

#4 hondaboy92hatch Apr 13, 2012 07:09 PM

Quote:

Originally Posted by Seadog (Post 21322793)
As far as I have seen, the Seagull Ka8 is 3m and the Phoenix Ka8 is 3.5m or 6.0m. Which one have you got your sights set on?

Dave Smith

Hi Dave,
I am looking at the 118 inch ws one. I wrked late last night and did the calculation wrong. I am just wondering if the c/g is roght on as I want to get it put it together and hope to fly at the aerotow event at brooks field in Salem OR

#5 hondaboy92hatch Apr 13, 2012 07:11 PM

Quote:

Originally Posted by Big Nuts 181 (Post 21323123)
Hi Joe with regard to servos for the two smaller ka8 HS 81mgs have been quite adequate so far, as to the 6 meter HS 645mg on aileron/elevator with hs705bb on rudder and tow release. These are the servos myself and a mate have been running on our ka8's. Regarding CofG all planes started out at 33% and adjusted to suit flying styles till they felt rite.

Enjoy your new model they fly superbly.

Thanks for your info.

#6 roknhs Apr 13, 2012 09:19 PM

I just got one from Horizon.........haven't built it yet but, I've looked it over and fitted the pieces together. It will build very light......no doubt the battery has to be in the nose to get close to CG..........not sure the battery will be enough to get it to balance. I would hate to stuff lead in the nose but it might need some. With the tow release set up, there isn't a lot of room in the nose to work with. I'm sure the AUW ready to fly will be less than 7lbs...........not bad for a 10ft wing. The plane is actually built quite well for the money. I was pleased with it.

#7 Big Nuts 181 Apr 14, 2012 04:53 AM

Make up a 5 cell sub c RX pack, then you would have some usefull weight.

#8 roknhs Apr 14, 2012 10:50 AM

Hey BNuts,
Agreed. Heavier battery would do it. I'm using 2300mah A123..........if one isn't sufficient I could use two..........overkill I know but, I do hate lead.

#9 Seadog Apr 14, 2012 06:10 PM

C of G
 
Don't want to contradict Rossco, because he has a ton of experience, (but I'm about to do so) regarding CG on this aircraft, but as the Ka6, Ka8, ASK18, etc. all have a straight leading edge with a swept-forward trailing edge, the effect is that of a swept-forward wing. In other words, the C of G is further forward than it would be on a wing where the spar sticks out at 90 degrees from the fuselage and the tip rib is nicely in line with the root rib. I've seen a couple of scary maiden flights on ASK-18's where they were balanced at 33% because that is the rule-of-thumb, and it is close to unworkable. For the forward swept wing, I would start at about 28% and work back as you fly the plane and become comfortable with it. Nose heavy works....tail heavy potentially becomes a bag of balsa.

Try this CG calculator when you get your plane:

http://adamone.rchomepage.com/cg2_calc.htm

CG is not a function of airfoil, it is a function of planform, and this will give you a head start on a successful first flight.

Just sayin'.......

Dave Smith

#10 hondaboy92hatch Apr 14, 2012 07:30 PM

Thanks for the help guys I appreciate it.

Joe

#11 Big Nuts 181 Apr 14, 2012 07:42 PM

Sorry I didn't explain that very well 33% of average chord, root and tip but on my ka8 mine is balanced at about 33%. 28% is a good safe starting point though.

#12 tinkrerpilot Apr 18, 2012 07:03 AM

Just got one from Horizon Hobby also. Picked up the white one. Been eying this over on the U.K. site of flea bay. Cost was just astounding to get it over here in the U.S. Finally someone had them here.
Couple of quick questions for you guys. Anyone using micros in the wings and full size in the fuselage, or is it micros all the way around? The instruction show something like HS425BB for rudder and elevator.

Also, has anyone thought about adding blade type spoilers over the standard flip style spoilers? Reasons for either?

Over all the kit looks very well made. Finish is great so far. will keep along for any other news or ideas.
Thanks.

tink

#13 stephen Damon Apr 18, 2012 09:11 PM

Look up seagull ka and add Damian, as he has blog on plane

#14 Damian Couzoff Apr 19, 2012 05:53 AM

Quote:

Originally Posted by hondaboy92hatch (Post 21322549)
Hi guys,
I am about to buy a 4 meter Seagull KA8. I am wanting to know if the c/g is right on and what servos you guys you are useing in it? I plan to get it in two weeks.

Thanks for any help.
Joe

Hi joe,l have the centre of gravity at the recommended centre of gravity-being 60mm.The instructions have a 10mm margin fore and aft of 60mm.As far as servos go,just use two standard servos (HS 422 deluxe) in the cockpit for rudder and elevator control,and trim the servo tray by a couple of millimetres to fit them.I used HS 82 MG for the ailerons.I also fitted 250mm electric spoilers.I have flown mine off the slope,over 20 flights now,and it could do with a ballast box located in the fuse at the centre of gravity,but if you are only going to aerotow it,a ballast box would obviously not be required.Overall,its a good value for money model,and i enjoy flying it,regards damian:popcorn:

#15 tinkrerpilot Apr 19, 2012 06:54 AM

Thanks Damian! Kinda figured it out and have servos on order. When they get here, it will be time to put this one together. Looking forward to some aerotow this summer. Pretty much a straight forward install and setup.


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