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Jan 22, 2015, 12:58 AM
Registered User
Lockey,

Reduce the angle of the canards by half and see how see handles it. But you really need to get you thrust angle sorted out. Or you definitely will need to move the batt forward. Check out your glide at the end in both vids. To die for!!!

In regards to the rudders, I have a F-35 that does the same thing when out of balance. You can graft additional area on the rudders, but I think you should be okay for now. Looked better!

Ksqm
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Jan 22, 2015, 01:34 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Thanks Aaron, I truly value your advice

Quote:
Check out your glide at the end in both vids. To die for!!!
Tell me about it ... it doesn't even look like it is going to stall eh !! and thats weighing over 900 grams

I tend to agree though ... still tail heavy, I will move the battery further forward (lucky still can) and go from there

Lockey
Jan 22, 2015, 01:50 AM
Registered User
Lockey,

Keep at it. You're getting there. Gotta knock of for the night/morning.

Ksqm
Jan 22, 2015, 02:57 AM
Tony Audsley Retired Locksmith
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Thread OP
Quote:
But you really need to get you thrust angle sorted out.
Can't do a lot about the trust tube angle mate, I think I will have to live with it (CHANGED IT ON THE PLANS) but I don't think half a degree will make a lot of difference

Hopefully the wind will be kind tomorrow and I can re-try with the battery further forward again, I will just have to put more Velco up front for the battery to hang on to

I also need to put some vent holes in the front (I have them all the way through the fuz ... the battery was getting quite warm

Lockey
Jan 22, 2015, 07:05 AM
Tony Audsley Retired Locksmith
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Thread OP
Did a little more to the hatch and made it so I can move the battery further forward

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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 ! :-)!
Not quite a day out with the models, but here is my shed, and I have 3 more in the car ... Gees, looking at the pics of my shed, I think I need to have a big tidy up

Most of the shots of the plane make it look very long and skinny so thought I would take a couple of shots of it from the top to show that its quite a chunky beast ... although it is quite long ... 1200 mm (around 4 ft long) and wing span is about 760 mm (30")

Lockey
Last edited by Lockey; Jan 22, 2015 at 07:30 AM.
Jan 22, 2015, 07:23 AM
Tony Audsley Retired Locksmith
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Thread OP
This is what I think the CG might have to be

Lockey
Jan 22, 2015, 11:35 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Took her out again today and guess what ... I took the wrong batteries (3's instead of 4"s) thought it lacked power when I launched it and just managed to keep her flying

I did seem to be more stable BUT still has that awful tendency to want to flip at the end of a roll ... all I can think is that it is something to do with when it is inverted ... I have never experienced this before

You can see what I mean at around 1.10 seconds into the video

Lockey

FS 2020 with 3's Battery (2 min 25 sec)
Jan 23, 2015, 12:50 AM
Registered User
Lockey,

Excuse me, but you are funny!!! Glad to see you've tamed the plane quite a bit. To fly like it does on minimum power, can't wait to see it again on 4S. I'm not going to be on long, gotta get up early in the morning. It's 12:50 am right now. Will have time to work on the Gripen tomorrow (later today), so expect to post pics. Keep at it!!! The FS-2020's next on my hit list.

Ksqm
Jan 23, 2015, 01:09 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Quote:
Originally Posted by ksqm
Lockey,

Excuse me, but you are funny!!! Glad to see you've tamed the plane quite a bit. To fly like it does on minimum power, can't wait to see it again on 4S. I'm not going to be on long, gotta get up early in the morning. It's 12:50 am right now. Will have time to work on the Gripen tomorrow (later today), so expect to post pics. Keep at it!!! The FS-2020's next on my hit list.

Ksqm
Thanks Ksqm ... but I would still like to find out what is causing the flip at the end of a roll

Look forward to seeing more of your build mate

Lockey
Jan 23, 2015, 09:29 AM
Tony Audsley Retired Locksmith
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Thread OP
I used the CG calculator and this was the result

Slight difference depending how I read the tip of the canard (only about 5 mm

I am probably on the money where I am now

Lockey
Last edited by Lockey; Jan 23, 2015 at 09:39 AM.
Jan 23, 2015, 10:06 AM
Retired CAD guy
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Since Sketchup works with surfaces and it probably has a CENTROID calculator for surfaces
I wonder how close the Centroid is to the Aerodynamic CG.

Nevermind

Here is my study - it's WAY off but there is no nose on this calc.

Sorry, just thinking out loud .....
Jan 23, 2015, 10:09 AM
Retired CAD guy
birdofplay's Avatar
I believe that your FLIP problem is Torque when there is very little if any
aerodynamic forces stabilizing the plane.
IE - top of slow loop yielding low speed and NO AIR over the surfaces while the motor is
screaming to get you over the top.

This is as opposed to Prop in slot planes.
Prop in Slot birds always have air over the elevons and I/we have gotten used to
getting away with murder at low speeds.


Bob
Jan 23, 2015, 07:29 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Quote:
Originally Posted by birdofplay
I believe that your FLIP problem is Torque when there is very little if any
aerodynamic forces stabilizing the plane.
IE - top of slow loop yielding low speed and NO AIR over the surfaces while the motor is
screaming to get you over the top.

This is as opposed to Prop in slot planes.
Prop in Slot birds always have air over the elevons and I/we have gotten used to
getting away with murder at low speeds.


Bob
Sorry to shoot your theory down in flames mate but both my Viggen and the Gripen are pushers (motor at the back) so no prop-wash over the surfaces and both fly well

Not sure Bob, the last video it was flying with a 3's battery and grossly underpowered and the loop was messy

The "flip" that concerns me it at the end of a roll (or as it comes out of being inverted) ... torque may play a part but I believe it is something to do with the tails ... this is the only thing different to any other delta

I have added a couple of lower fins to the underside of the tail ... we will see if this helps ... during my research on this one, I noticed that "some" similar planes have these

It may also be that my tails (vertical stabilisers) are at the wrong angle (too flat) and / or not big enough and not giving enough vertical support

Lockey
Last edited by Lockey; Jan 23, 2015 at 07:41 PM.
Jan 23, 2015, 08:03 PM
Retired CAD guy
birdofplay's Avatar
but but but

Pushers don't put any air over the surfaces either.

Soooo EDF or Pusher, ummmm errr oughta be similar ... yes / no ?

Oh well, you'll get it figured out.

Sure wish I had a Gulfstream, I'd come to Perth for a visit !
It's only 11,000 miles away

Bob
Last edited by birdofplay; Jan 23, 2015 at 08:16 PM.
Jan 23, 2015, 08:15 PM
Retired CAD guy
birdofplay's Avatar
ok ok ok ...
after I saw that airliner landing in the background of one of your recent videos.

I figured I could FIND your Flying Park on Google Earth without too much trouble.

Are you flying off of Turner rd up near Pierce ?

Or did I get choose the wrong airport ?

Bob

PS Maybe Middleton Park
Last edited by birdofplay; Jan 23, 2015 at 08:22 PM.


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