Bj episode straighten fuse

All types of precision flying including F3A and IMAC

Bj episode straighten fuse

Postby raptorheli2 on Fri Jul 18, 2014 9:12 pm

as a couple of people were asking on another thread-

My BJ craft Episode had a bad twist in the fuse/tail. the canaliser was the same but an easier fix.

First thing is first-how do you know you have a twist, well you buy yourself a self leveling cross laser.

the cheap ones are decent enough for our needs with 0.8mm accuracy. The better ones go upto 0.5mm and 0.3mm respectively.

I would suggest you get this with a cheap tripod (one for your digi camera will fit) http://www.screwfix.com/p/stanley-cubix ... evel/69712

or if you want to spend a bit more then this is ideal- http://www.tooled-up.com/product/bosch- ... od/170943/

unfortunately i don't have many before pics (impatient) but the canaliser and right hand stab was 9 and 11mm off respectively.

before.jpg


next up you need to level the plane using the laser on the very top or bottom of the wingtube and see how the laser looks on the rudder. it is hard to see in this pic but it was 2.5mm off from bottom right to top left.

level.jpg


now we add the fuse clamp now we know how much we need to twist the fuse- (sorry, forgot to take one with it on the plane). once my plane was in this clamp i closed the top of the clamp off with a bit of wood (not pictured) to keep pressure on the fuse.

jig.jpg


when the plane is in the clamp you need to twist the fuse, the easiest way to do it is the wingtube. put the tube in the plane and build it up on the side you need to twist. the other end of the wingtube i hung a small screw bucket on it with lead weight to keep the twist where i wanted it.

whilst in the clamp i heated the last 1/3rd of the fuse with a hairdryer and let it cool. i repeated this process a few times while slowing removing the twist on the wingtube. once i got it where i wanted it (in my case i needed to twist the fuse 15mm measured from the tip of the wingtube in order to get rid of the 2.5mm twist) i left the plane in the jig overnight.

now i was happy the fuse was straight (again level the plane with wingtube and check the vertical is in the middle of the rudder to check) i had to shim the right hand stab a little. a bit of 32nd ply done the trick-

after.jpg


and finally fixing the canaliser which was 9mm off-

canaliser.jpg


last thing was to measure the distance from the wing tips to the tail and the fin etc....FLY TIME.

i hope that helps others who may be in the same situation.

note the other episode in this pic had the same issues but the warp was the other way.

20140706_144257 (Medium).jpg

cheers
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Re: Bj episode straighten fuse

Postby -steves- on Sat Jul 19, 2014 6:34 am

Awesome information, well done that man. :clap:
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Postby Arun on Sat Jul 19, 2014 6:41 am

Thanks! Awesome write up...
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Re: Bj episode straighten fuse

Postby ChrisC on Sat Jul 19, 2014 2:54 pm

Excellent work! 8-)

There is a conspiracy theory though that futaba and JR have paid all the model manufacturers to build all their airframes bent. That way, people without the skills above are forced into buying expensive radios with all sorts of fancy mixes to get your plane flying straight again.

Just saying! ;)
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Re: Bj episode straighten fuse

Postby thomasdavid on Sun Jul 20, 2014 8:50 am

Interesting that you can do it with just heat from a hair dryer. I was expecting more destructive methods.

Are you going to do some f3a comps with it?
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Re: Bj episode straighten fuse

Postby -steves- on Sun Jul 20, 2014 9:44 am

thomasdavid wrote:Interesting that you can do it with just heat from a hair dryer. I was expecting more destructive methods.



That kinda makes you think what a day like Last Friday would do to it in direct sunlight at a field all day :shock: Scary stuff! :?
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Re: Re: Bj episode straighten fuse

Postby ChrisC on Sun Jul 20, 2014 10:27 am

-steves- wrote:
thomasdavid wrote:Interesting that you can do it with just heat from a hair dryer. I was expecting more destructive methods.



That kinda makes you think what a day like Last Friday would do to it in direct sunlight at a field all day :shock: Scary stuff! :?

I believe that's where the lyrics "let's twist again, like we did last summer" originated. Chubby checker was an avid aero modeller! :D

Apologies, no more terrible jokes from me. :)
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Re: Bj episode straighten fuse

Postby raptorheli2 on Thu Jul 24, 2014 9:45 pm

thomasdavid wrote:Interesting that you can do it with just heat from a hair dryer. I was expecting more destructive methods.

Are you going to do some f3a comps with it?


yes i'll be doing the scottish comps with it.

just got some wing adjusters to fit to it, it does weeeeird things in a bunt so need to play with incidence.

btw, when i say heat from a hairdryer, i got it as hot as you would want to keeping in mind the fuse is painted.

sunlight wouldn't do much unless you happened to have the fuse in the clamps and twisting it a LOT in the opposite direction and leave it for a few days :D

cheers
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