HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 19, 2012, 10:44 PM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
I found a video with someone showing a much better roll rate with the Cirrus. At ~5:30 it does a good enough roll to make me X off any need to increase it.

I still haven't started on the build yet, I have some more finish work. Now I do see a reason to leave the gear legs longer than scale. These small low wing planes have the wing close enough to the ground to act like an air hockey puck or worse a bounce oscillation can easily start as with another low wing Cherokee I have. I did see a guy at the club with a .40 low wing generic airplane that bounce oscillated on him every time he lands.


http://www.youtube.com/watch?annotat...&v=v3tvPBim9dg
Chophop is online now Find More Posts by Chophop
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 20, 2012, 01:41 PM
More Motors, More Fun... :-)
nioa's Avatar
Phoenix, AZ
Joined Jan 2008
692 Posts
Quote:
Originally Posted by nioa View Post
.....Just when you think you have fixed it, that demon [nose gear failure] pokes up again. Maybe I'll just make a tail dragger out of it!
Quote:
Originally Posted by alexjschauer View Post
No that would ruin it!!! Wash your mouth!!!!
Lol.....
Well OK, I don't like the taste of soap so I didn't turn it into a tail dragger.

I finally got some time to experiment, and removed the stock nose gear. I drilled out the stock arm and mount and installed a Dubro 5/32" gear wire with a Dubro lite tire. The "spring" in the gear wire forces the nose of the plane plane to sit higher then I wanted, but it was close enough for a test flight. I used 2-56 rod on the steering control arm to the steering servo to make it stronger then the small wire I had. I also added some washout to the ailerons.

It's like a new airplane. I had some very nice flights this morning. First time I didn't actually have something happen to the gear for a change. The washout seemed to help the plane with its nasty tendency to drop a wing suddenly and without warning. Landings and takeoffs are much better. I can come in much slower now, more safely. It still "jumps up" a bit, when it hits a bump in the asphalt, but I find it more manageable now. Unfortunately, the scale "look" of the nose gear is gone, but in its place, is a plane I can actually fly (and it does fly great!) without having to repair it after every flight.

Nick
nioa is offline Find More Posts by nioa
RCG Plus Member
Latest blog entry: VQ Models T-34 Mentor 61.4"...
Reply With Quote
Old Aug 20, 2012, 02:09 PM
Registered User
Alex Schauer's Avatar
United States, MN, North Mankato
Joined Feb 2011
4,665 Posts
I should do that.
Very tempting.....

Pictures would be much appreciated!
Alex Schauer is offline Find More Posts by Alex Schauer
Reply With Quote
Old Aug 20, 2012, 02:36 PM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
I figured out an easy way to keep the nose gear kick from damaging servos.

Make the nose wheel push rod hole at the servo arm connector large enough that the rod easily pushes back-forth. Use or make two locking collars like on the wheels, that fit on the control rod. Push a collar on then a spring. Now push the rod through the arm connector hole. Put a second spring on the rod, then the 2nd locking collar. The servo arm connector will be in the middle between the two springs.

Now do not lock the rod in the servo arm connector, it is supposed to slide. To set the nose gear center, adjust the locking collars and put enough spring tension on to hold the wheel firm enough to steer. When I can, I'll show a photo, but after I make one. Still tied up on the other plane, I hoped to have it done yesterday.

I have done several nose gear to tail dragger conversions. They were the answer. I'll give this nose gear a try, but when on grass, it's always the same story. I love this plane for it's body, not it's wheels.
Chophop is online now Find More Posts by Chophop
Reply With Quote
Old Aug 21, 2012, 02:33 PM
More Motors, More Fun... :-)
nioa's Avatar
Phoenix, AZ
Joined Jan 2008
692 Posts
Name: SR22-0032.jpg
Views: 72
Size: 145.4 KB
Description: Here is the Dubro standard gear with a 2 inch Dubro wheel.

Here is the Dubro gear. The spring location brings the nose up a bit too much, but for the test flight it was acceptable. Now that I know it flies better, I will fabricate a better gear. I am not going to attempt to try to bend the 5/32" wire, so I will use a Dubro E/Z Adjust Axle.

Name: EZAdjustAxle.gif
Views: 69
Size: 23.8 KB
Description: Dubro E/Z Adjust Axle

The top of the nose gear, shows two arms, the original arm I left in place because I was too lazy to remove it for testing. Now that I have done the flights, I will take it apart and set it up right.

Name: SR22-0035.jpg
Views: 115
Size: 130.4 KB
Description: Topside nose gear.

Here is the washout added to the ailerons on both sides.

Name: SR22-0034.jpg
Views: 142
Size: 69.2 KB
Description: Some aileron washout.
nioa is offline Find More Posts by nioa
RCG Plus Member
Latest blog entry: VQ Models T-34 Mentor 61.4"...
Reply With Quote
Old Aug 21, 2012, 06:25 PM
Retired and Lovin' it!
United States, KY, Sturgis
Joined Jul 2007
2,523 Posts
Looks like washin, not washout. Washout would raise the trailing edge of the aileron.

Tony
tpfing is online now Find More Posts by tpfing
RCG Plus Member
Latest blog entry: North Las Vegas 1971
Reply With Quote
Old Aug 22, 2012, 12:22 PM
More Motors, More Fun... :-)
nioa's Avatar
Phoenix, AZ
Joined Jan 2008
692 Posts
You're right. Does work though, helps keep the stall a bit higher. Makes inverted flight very tough though. But this is not the kind of plane that I like to fly inverted, it just looks too strange!

Nick
nioa is offline Find More Posts by nioa
RCG Plus Member
Latest blog entry: VQ Models T-34 Mentor 61.4"...
Reply With Quote
Old Aug 23, 2012, 10:28 AM
Retired and Lovin' it!
United States, KY, Sturgis
Joined Jul 2007
2,523 Posts
Nick, have you tried it the other way, ie, washout? I'm curious as I have one that I have not yet flown. I bought it a year or so ago and decided right away that it needed flaps. I have stripped the covering off the wing and resized the ailerons, added the outboard leading edge extensions but got hung up on building the 'fowler flaps' and hung it up and not finished it. Hopefullly, I'll get my interest back before too long and finish it.

Tony
tpfing is online now Find More Posts by tpfing
RCG Plus Member
Latest blog entry: North Las Vegas 1971
Reply With Quote
Old Aug 23, 2012, 12:52 PM
More Motors, More Fun... :-)
nioa's Avatar
Phoenix, AZ
Joined Jan 2008
692 Posts
I have not tried it the other way, Tony.

It worked, so I was satisfied. Please let us know how your flap mods work out. (I call mine micro-flaps )

I started experimenting with this because the plane would suddenly drop a wing at relatively good flying speeds on stall tests with the stock plane setup. With the aileron washin the plane was able to slow down much better, then just mush ahead. It surprised me, actually, how effective this one small change was.

For those thinking of trying it, I want to remind them that very little offset is needed. More is not better, and have plenty of altitude for tests. Great thing is, It doesn't cost anything, so give it a try, and see if it works for you.

Nick
nioa is offline Find More Posts by nioa
RCG Plus Member
Latest blog entry: VQ Models T-34 Mentor 61.4"...
Reply With Quote
Old Aug 27, 2012, 12:15 AM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
Finally got into the build. Most of it was spent, 3 hours, cleaning CA from the ailerons. They used far too much, it had run along an inch or more past some of the hinges. So I had to carefully scrape it out. Got the deflection force down to about 50 grams force to deflect 30* or so.
I'm using HS-65HB's so I guess the stiffness will not load the servos much but will at least help prevent flutter. The rest of the build went by the numbers and very fast. Still deciding between the 80g 1100 kv 275 watt or 100g 1000 kv 400w. I think the Power Up 480+ will be more efficient with the APC E 10x7, the 3530-11 is at max.

This plane seems heavy for such a small wing, but it sure looks like it will be fast. I'll have enough room to land it. I already had the motors in the parets bin, waiting for a plane, or else would have used the Rimfire motor and eliminated any guessing games.

Not complete yet, I just got up to the hstab install today.
Chophop is online now Find More Posts by Chophop
Reply With Quote
Old Aug 27, 2012, 02:48 PM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
Coming along nice now. This thing has me wondering how a full scale Cirrus owner can keep from making a proud fool of himself. I wish I had one like this in a 60 or larger, wow.
Chophop is online now Find More Posts by Chophop
Reply With Quote
Old Aug 27, 2012, 04:49 PM
Registered User
Alex Schauer's Avatar
United States, MN, North Mankato
Joined Feb 2011
4,665 Posts
KMP makes a gasser...very tempting.
Alex Schauer is offline Find More Posts by Alex Schauer
Reply With Quote
Old Aug 27, 2012, 06:26 PM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
I tested the motor and it sure is nice, no resonance with the airframe, it sounds like a million bux. Just have a few things left, then some extended ground tests, I just threw a magnet on the 54 inch Cessna so I want to be sure. I only ground tested for thrust and heat then flew it. The one time I didn't do the runups I got bitten. No big deal, no damage, I reglued the magnets with red loctite and they ain't coming back out, or it seems, by my attempts to pry them out.
Chophop is online now Find More Posts by Chophop
Reply With Quote
Old Aug 29, 2012, 02:45 PM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
Here's the nose gear shock absorber. Two 3mm stops, 2 ball point pen springs, and a slightly oversized servo rod stop hol. I mean only overbore it enough to allow the rod to slide back-forth without binding. Do not use the rod stop screw, it is supposed to slide.

Just set the nose gear straight, install, and adjust the springs to have enough tension to steer without flexing the springs. Best to glue the stops in place after finding the suitable tension. Or if they come loose you will loose nose gear steering.

Now if landing with the nose wheel cocked for x-wind etc., it will not jam the servo and strip gearsunless it's one terrible hit. I used an SG-90 because they are said to easily strip gears and the arm spline. I want to test this.
Chophop is online now Find More Posts by Chophop
Reply With Quote
Old Aug 29, 2012, 08:11 PM
Laugh NOT at King Tupitos
Chophop's Avatar
Pleasant Valley Modelport
Joined Sep 2006
8,715 Posts
Oh well, nice try. I did some testing and with the springs I have, if it hits with the nose wheel turned, it can allow it to turn farther and may cause a tipover. So, it would have worked with a taildragger but it looks like I'll need an HS-82MG and solid rod, in other words, scrap this idea for now.
Chophop is online now Find More Posts by Chophop
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
For Sale KMP Cirrus SR 22 ARF Kit (NEW IN BOX) JuanRodriguez Aircraft - Fuel - Airplanes (FS/W) 1 Jan 17, 2010 07:37 PM
Discussion Looking for plan or any draw of layout of CIRRUS SR22 airplanee RafalM The Builders Workshop 6 May 03, 2008 08:26 AM
Discussion Converting a Cirrus SR22 by KMP Keith43221 Sport Planes 4 Nov 05, 2006 01:30 PM
Discussion Cirrus SR22-G2 Keith43221 Giant Scale Airplanes 0 Nov 04, 2006 12:16 PM