HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 01, 2007, 11:20 AM
Registered User
Joined Nov 2004
3,159 Posts
From the picture it seems that the aft portion of the rotor is directly in the propwash. This blade will be getting significantly increased airflow and therefore lift. If you are rotating CCW then this is going to give you a left roll.
my guess is that if you get the rotor up out of the propwash this will diminish.
I could guess that when you slow down with power on, this effect could get stronger.
What happens with the power off completely? Does the need for right trim go away? If so, it may be telling you that the prop blast is affecting the rotor.
There is a possibility that the prop blast is creating negative twist in the aft blade. This would add to the left roll problem.
mickey
mnowell129 is offline Find More Posts by mnowell129
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 01, 2007, 11:58 AM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
969 Posts
Mickey,

For whatever the reason, there just don't appear to be any significant requirements for lateral trim with the latest flexible rotor, whereas I think that most of the effects that you refer to were present when I was using the previous stiff rotor. I have to confess that I never tried taking the power completely off with the stiff rotor except just before landing, and the stick was already fully over to the right anyway.

Al
alfoot is online now Find More Posts by alfoot
Reply With Quote
Old Jan 01, 2007, 12:27 PM
Registered User
Joined Nov 2004
3,159 Posts
I see. The stiff rotor was the one with the trim problem. I missed that somehow. A rigid rotor does change the phase lag so asymmetric velocity does create a roll component to the retreating blade. In this case to the left. This would explain the need for right trim.

I'm guessing that you needed some down trim when you switched to the flexible rotor as well?

mick
mnowell129 is offline Find More Posts by mnowell129
Reply With Quote
Old Jan 02, 2007, 06:27 AM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
969 Posts
Hi,

Just a clarification - the Monotwirl flies well with the latest standard of rotor (this is the one that is part of the magazine article if it ever appears ) as I hope you can see in the second movie.

I have not noticed any change in the pitch trim either so, through a bit of development, a LOT of education via the great autogyro theory threads on RCGroups, and a fair bit of luck, the Monotwirl seems to go reasonably well.

Al
alfoot is online now Find More Posts by alfoot
Reply With Quote
Old Jan 21, 2007, 10:58 AM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
969 Posts
Hi,

No sign of the Monotwirl in the latest (February 2007) RCM&E I'm afraid. I think that I will give it one more month and then I might find an alternative method of getting it to the enthusiasts on this forum (if you would like) .

Al
alfoot is online now Find More Posts by alfoot
Reply With Quote
Old Jan 21, 2007, 09:31 PM
skumgummi dave
Gresham, OR.
Joined Mar 2004
1,766 Posts
Al:

Yes please. We would like. Am also excited to hear more details on the Quadra Twirl.....

Thanks; Dave
foamdave is online now Find More Posts by foamdave
Reply With Quote
Old Feb 06, 2007, 01:38 PM
Registered User
St. Louis, MO
Joined Oct 2002
2,523 Posts
YEAH the Monotwirl is coming!!!!!
KenP is offline Find More Posts by KenP
Reply With Quote
Old Mar 10, 2007, 07:08 AM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
969 Posts
Hi,

Just to keep you all updated, I got a response to the email I sent to the editor of the RCM&E in early February.

It said "We will publish it-eventually!! Keep sending me pics of the new stuff. Always very interesting."

So I hope it will not be too much longer.

Al
alfoot is online now Find More Posts by alfoot
Reply With Quote
Old Mar 11, 2007, 04:44 PM
Registered User
St. Louis, MO
Joined Oct 2002
2,523 Posts
I have always wondered you do want blade flex in flight correct?
KenP is offline Find More Posts by KenP
Reply With Quote
Old Oct 16, 2007, 02:34 PM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
969 Posts
Monotwirl Free Plan - November 2007 Quiet and Electric Flight International

Hi,

It's been a long time coming (changed publisher), but I've just been informed that the Monotwirl will feature as a free plan in the November 2007 Quiet and Electric Flight International.

You can check out some of the details of the magazine here:-

http://www.qefimagazine.com/issue/issue.aspx?cid=3903

I see also that Inter-Ex will be covered.

Al
alfoot is online now Find More Posts by alfoot
Reply With Quote
Old Oct 16, 2007, 05:55 PM
Registered User
JochenK's Avatar
Joined Jan 2005
1,286 Posts
Al,

thank you for the information. I'll have to see if I can find a copy over here.

Jochen
JochenK is offline Find More Posts by JochenK
Reply With Quote
Old Oct 17, 2007, 02:37 AM
Restricted User
StephanB's Avatar
Frankfurt-region, Germany
Joined Mar 2003
1,450 Posts
Quote:
Originally Posted by JochenK
Al,

thank you for the information. I'll have to see if I can find a copy over here.

Jochen
Jochen,
i failed earlier, no Q&EFI to find at the usual sources, even not at intl.book/mag dealers at FRA airport or frankfurt central station.
Stephan
StephanB is online now Find More Posts by StephanB
Reply With Quote
Old Oct 17, 2007, 02:57 AM
Registered User
JochenK's Avatar
Joined Jan 2005
1,286 Posts
Stephan,

it looks as if you can order it here:
https://ssl.topackt.com/modellsport....schriften.html

Jochen
JochenK is offline Find More Posts by JochenK
Reply With Quote
Old Dec 03, 2007, 10:17 AM
Registered User
Joined Jun 2003
67 Posts
I have no AutoGyro experience and I have made one from the QEFI plan but had trouble launching, it just dives staright into the deck, snapping the nose off (now fixed). I want to try again, whats the best way to launch. I realise it needs to beinto wind, had a friend do a little run with it and blades spun up quite nicely. What i have noted is that the model needs to be held at a fairly steep angle to get the blades spinning, bit likle the 2nd video at the start of this thread. Friend then sort of leveled the fuselage before releasing but the blades slowed dramtically, hence the crash.

Could this be a problem with the angle of the rotor assembly, pretty sure (blades have enough negative pitch on them)? Is this just normal behaviour of an AG and I need to release at the steep angle required to spin the blades up? Do i need full power and a bag of up elevator or anything like that?

thanks,

Scott.
scoot is offline Find More Posts by scoot
Reply With Quote
Old Dec 03, 2007, 01:03 PM
Keep it simple
alfoot's Avatar
Salisbury,England
Joined Jan 2005
969 Posts
Hi Scott,

Sorry to hear that you are having problems.

I've found that the best way to launch is to tilt the autogyro well back, nose into wind, and wait until the rotor is spinning well. If there is little or no wind, you will need to jog or run to get the rotor spinning. As for power setting, it's best to have more rather than less throttle, and then launch with the nose high, as per the movie. You should be able to "feel" the rotor generating lift before you launch.

I assume that you have checked the C of G and all of the angles are as per the plan, and that the weight is within the range.

Hope this helps, please let us know of your progress.

Al
alfoot is online now Find More Posts by alfoot
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Stevens G480 Video now up! skyyking Parkflyers 24 Apr 21, 2004 08:25 PM
The EdgeRC Pocket Combat Twin video is now up!!! birdofprey Parkflyers 6 Jul 31, 2003 08:31 PM
Interesting site with early bird video clips Ian Easton Scale Kit/Scratch Built 0 Jul 25, 2002 12:19 PM
Tomcat video now ready to view bipeflyer Electric Ducted Fan Jet Talk 43 Jul 24, 2002 07:04 PM