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Jan 05, 2020, 11:01 AM
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Nice video, thanks!
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Jan 29, 2020, 05:19 PM
Keep it simple
alfoot's Avatar
Hi all,

This is what you get when the windspeed doubles when you get airborne. The little RPG coped though!!

Enjoy,

Al

Als RPG autogyro windy day (5 min 34 sec)
Feb 28, 2020, 11:37 AM
BigTradioman's Avatar
Backwards flying go! A well sorted RPG that one.
Feb 28, 2020, 11:48 AM
BigTradioman's Avatar
Quote:
Originally Posted by Jburrill
Looking for some ideas on flying these, and there seems to be lots of expertise reflected in this thread. I recently finished a Panther (Rich Harris design). The maiden flight was a successful lift off, but I let it get too far downwind and hard to see, and it crashed hard, breaking the fuselage in two. It is now repaired, and I tried again but can't seem to get it airborne. The rotor spins up in the wind, but seems to slow down once I start down the runway. When it comes to a stop, the rotor is spinning fine, but apparently not fast enough to lift it. Restrained on grass, it spins up to give that swishing sound, but won't move forward, so I did consider larger wheels. Should the rotor be tilted ahead or back to get it to spin up, or kept fairy flat? Any ideas would be welcome. I have never seen anyone fly one of these except in videos, but I would sure like to get it going well.

John
Go with Chrisís advice plus some more doís and doníts: in the neutral elevator stick position the rotor should be tilted back by about 5 degrees from horizontal. Check you hang angle is about 15 to 18 degrees. After a repair itís easy to get tail heavy. Itís like moving the cg back on a fixed wing. If your blades are stopping check the hub bearing is free. A sticking rotor hub will kill the lift. Donít try and fly without doing test hops up to about 1 meter. This will help,you work out what trims are needed. Most Panthers I have flown have ROG with no back stick once the blades are up to speed.
Sep 21, 2021, 03:57 AM
It's all in the Blades!
SafeLandings's Avatar
Thread OP
Thought this one may be of interest?
I was having a clear out last year and came across the bulkhead assembly off my prototype Mantis, it seemed a shame to bin it so I started to knock a fuselage pod up using scraps of wood etc.
The idea behind this model is that with all of the pushers I have built the CG is generally low where the boom can get in the way of the prop as we try to align the thrustline up with the CG . To get around this in the past I have lowered or shaped booms to give enough clearance. For a change I decided to try a boom on the top, in theory it would be just as strong as a conventional set up as long as the mast is rigid enough.
To help with a higher CG further I extended the boom forward of the mast and mounted the rudder servo there.
The model was finally finished a few weeks ago in readiness for a small get together where I hoped to maiden. On completion of the model I found that my CG had moved further up but was a little too high for my prop selection, I decided to prop it down and crank the motor so that its thrustline still ran just above the CG.

Things didnt go to well on its maiden but I managed to get it down in one piece, things got worse until I realised I was adding left rudder trim rather than right. Once my error was spotted she was away and flying quite well until I opened the throttle. This created rudder flutter as its forward speed increased, again I was lucky enough to save it as the rudder detached itself.
Luckily for me our mate Steve brings most of his workshop to our meets and he just happened to have some wire trace and ferrals so I could change my nylon pull pull rods (I was in a rush!) to more substantial ones . This did the trick after several flights on the 3 blade set up I switched to 2 blades.
I managed to grab a bit of video in both configurations, here it is flying on 3 blades (2 blades to follow)

Rc pusher Autogyro test flight no3 (2 min 50 sec)


A little more fine tuning is needed but I am pleased with the results so far.

Rich
Sep 21, 2021, 05:48 AM
Registered User
britinoz's Avatar
Rich
That is just about as good as they get....... Nice looking model with a pretty snappy flight .
Chris...
Sep 21, 2021, 08:29 PM
The 1st Sofaman
Sofaman NJ's Avatar
Amazing design and flight!!! Well done Rich!
Sep 23, 2021, 01:53 PM
It's all in the Blades!
SafeLandings's Avatar
Thread OP
Cheers guys,

Will add some decor to it now that I know it flies, surprised the cranked thrust line worked, must be the kack of horizontal stab.

Rich
Oct 02, 2021, 09:43 AM
It's all in the Blades!
SafeLandings's Avatar
Thread OP
As promised a video of the model fitted with 2 blades, these are Panther blades. There are no tip weights added but they are around the 69-70gram mark, I will try with a heavier weighted set when I get chance.
It does a great spin to the left, the more the throttle is increased the faster it gets until it almost catches the blades up. Nearly bit me!

RC autogyro flying on 2 blades (2 min 22 sec)
Oct 02, 2021, 08:02 PM
Registered User
britinoz's Avatar
How to you fix the rudder flutter prob?..because to me, that open bottom looks very vulnerable.
Chris...
Oct 03, 2021, 03:13 PM
It's all in the Blades!
SafeLandings's Avatar
Thread OP
Chris,

Flutter was caused by me using nylon fishing line in my closed loop rudder control. This was changed to wire trace and it completely eliminated the issue as it was only rudder related. The mast has been strengthened to take the top boom so not a lot of flex there.
There would have to be quite a pitch for the rudder to touch the ground. If it did the you will the depron rudder is lower than the fin post so it should just push it away or snap it off.
You can also see the thrust angle of the motor on one of the shots .

Rich
Oct 03, 2021, 03:19 PM
It's all in the Blades!
SafeLandings's Avatar
Thread OP
Photos
Oct 03, 2021, 07:23 PM
Registered User
britinoz's Avatar
Got it Rich.....good thinking on this design.....a winner.
Chris...


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