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Jan 20, 2015, 07:24 AM
Retired CAD guy
birdofplay's Avatar
I'm liking this one too.
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Jan 20, 2015, 08:55 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Sat on my workbench, it looks quite big so I thought I would compare it with the Gripen JAS 39 ... here they are side by side

Just had a thought .... I have forgotten to install the servos for the elevons ... bugger

Lockey
Last edited by Lockey; Jan 20, 2015 at 09:06 AM.
Jan 20, 2015, 09:14 AM
Retired CAD guy
birdofplay's Avatar
Is everyone in Perth as invigorated as you,
or do you have all the oxygen from Shark Bay piped directly into your shop ?

On a Calm day You will have to take all your planes out and Photo the group !

Be sure to bring a WIDE ANGEL lens ! :-)
Jan 20, 2015, 09:18 AM
Registered User
Lockey,

LOL!!! Happens to the best of us. But since yo have the top off, keep it off 'til you're able to run up the EDF. That's to make sure you're ducts don't collapse on ya. I'd advance the throttle VERY slowly, looking for signs of stress. If need be, you can reinforce the ducts with strips of fiber glass or carbon fiber tow CA'd on them. Space the strips about every 2" or so. But believe me, it is worth the work.

Ksqm
Jan 20, 2015, 07:09 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Quote:
Originally Posted by ksqm
Lockey,

LOL!!! Happens to the best of us. But since yo have the top off, keep it off 'til you're able to run up the EDF. That's to make sure you're ducts don't collapse on ya. I'd advance the throttle VERY slowly, looking for signs of stress. If need be, you can reinforce the ducts with strips of fiber glass or carbon fiber tow CA'd on them. Space the strips about every 2" or so. But believe me, it is worth the work.

Ksqm
I already tested the fan Aaron, I ran it up to make sure it was running the right way and to test the thrust .. all seemed to be OK ... AND ... the top is already glued on

Thanks Bob, I guess I must enjoy building more than I enjoy flying oh ...

That said ... it would most certainly be a lot easier to build as a pusher than as an EDF

Lockey
Last edited by Lockey; Jan 20, 2015 at 08:06 PM.
Jan 21, 2015, 03:32 AM
Tony Audsley Retired Locksmith
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Thread OP
Did a little more to the build today, seems to slow down at this point as most of the work is fiddly

I have tried a 2200 / 4s battery and it seems to balance easily with the battery under the canards, seems I won't have to move it to the forward compartment

I don't have a smaller 4's battery but I guess a smaller battery could move into the forward section to balance

Lockey
Last edited by Lockey; Jan 21, 2015 at 05:18 AM.
Jan 21, 2015, 06:30 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Ready for maiden ... all up weight with 2200 / 4s battery is 912 grams

Not sure yet how I am going to launch it ???

Lockey
Last edited by Lockey; Jan 21, 2015 at 06:54 AM.
Jan 21, 2015, 07:37 AM
Registered User
Looks great cant wait to see it fly.
Jan 21, 2015, 08:36 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
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Quote:
Originally Posted by Loco1
Looks great cant wait to see it fly.
Cheers Kev, wish you were here to hand launch it for me mate ... tomorrow around 11 -12 am they reckon wind is low

Lockey
Jan 21, 2015, 08:45 AM
Registered User
I have to agree with Loco1, it looks marvelous! I'm still collecting parts to start the build but hobby time is scarce...
Jan 21, 2015, 08:52 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Quote:
Originally Posted by kalleman
I have to agree with Loco1, it looks marvelous! I'm still collecting parts to start the build but hobby time is scarce...
Don't worry mate, when you get time ... its great been retired (semi retired anyway) only down side is getting old

She certainly is a bit of a strange looking beast eh ... hope I have the CG in the right place ... I am not sure how much lift the body (fuselage) will contribute

Lockey
Last edited by Lockey; Jan 21, 2015 at 09:03 AM.
Jan 21, 2015, 10:13 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
EDIT:

I maidened her yesterday and BOY oh BOY I was lucky to bring her home in one piece

It was doing some really strange things, seemed to fly OK at full throttle but as soon as I went to a lower throttle she was a handful

I am pretty sure that it was tail heavy and I moved the battery forward for the second flight and then forward some more ... and I think it needs to go even further forward

Last flight I was about one and a half inches further forward than I started and still seemed a little tail heavy

I couldn’t move the battery any further forward as the Velcro that holds the battery in place wasn’t forward enough

Lockey

FS 2020 Maiden Flight (2 min 59 sec)


FS 2020 Second Flight (3 min 3 sec)
Last edited by Lockey; Jan 22, 2015 at 07:26 PM.
Jan 21, 2015, 11:40 PM
Registered User
Lockey,

Just to clarify, you where moving the batt to the rear of the plane, to counter it being tail heavy? That is the tail of the plane was dropping in you? If tali heavy, move the batt forward.

Next I would check the thrust line. It would seem tail heavy, if your thrust tube is pointing up. If your thrust tube is not to the end of the tail cone, the tail cone could be causing the problem.

You can also check the alignment of the rudders. If the rear of the rudder is closer to the center line than the front, you have built in tail down nose up attitude. Also, how are the canards set? Traditionally, you want a degree or two, le up te down, so they stall before the main wing. You could go with zero incidence, move batt forward and try again.

The glide just before landing flair was pretty good. Where you providing any control inputs? Was power on at all? That made me think your thrust line was the culprit. Keep at it. Beautiful plane.

Ksqm
Jan 22, 2015, 12:11 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Quote:
Just to clarify, you where moving the batt to the rear of the plane, to counter it being tail heavy? That is the tail of the plane was dropping in you? If tali heavy, move the batt forward.
Yes mate, was moving the battery forward

Quote:
Next I would check the thrust line. It would seem tail heavy, if your thrust tube is pointing up. If your thrust tube is not to the end of the tail cone, the tail cone could be causing the problem.
Thrust tube is at zero, and th runs all the way through to the end of the tail cone ... EDIT ... just checked the drawings and it looks like the thrust tube is pointing up slightly ... about 4 mm at the back, which equates to 0.6 degrees (just over half a degree)

Quote:
You can also check the alignment of the rudders. If the rear of the rudder is closer to the center line than the front, you have built in tail down nose up attitude. Also, how are the canards set? Traditionally, you want a degree or two, le up te down, so they stall before the main wing. You could go with zero incidence, move batt forward and try again.
As far as I know, the rudders are parallel ( this was the reason for designing the rear end this way ... to keep the tails at the correct angle and position) and the canards are at a positive angle ... front up about 5 degrees (similar to the Gripen)

Quote:
The glide just before landing flair was pretty good. Where you providing any control inputs? Was power on at all?
If you look at the glide on the fist landing in the second video, you will see it was just hanging there BUT it didn't stall and the second landing in the second video it was a better glide (battery moved forward) both landings were power off

Notice also, at the end of th roll (17 seconds in on the second video) it flipped very quick and wanted to roll further until I brought it back

I will be moving the battery further forward, couldn't move it any further today as I had no way of holding it in position

The other thing I did wonder was ... if the rudders (vertical tail fins) were big enough ??

Please check out the second video, I moved the battery forward on the first flight in the video and further again in the second flight in the video

Lockey
Last edited by Lockey; Jan 22, 2015 at 12:36 AM.


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