Go Back  RCU Forums > RC Airplanes > Extreme Speed Prop Planes
Reload this Page >

Old Shrike back in the air today (tail wags)

Notices
Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Old Shrike back in the air today (tail wags)

Old 07-13-2008, 08:13 PM
  #1  
Blade-breaker
Senior Member
Thread Starter
My Feedback: (4)
 
Join Date: May 2008
Location: Austin, MN
Posts: 209
Likes: 0
Received 0 Likes on 0 Posts
Default Old Shrike back in the air today (tail wags)

My old Shrike 40 went for a few flights today. I unfortunately could not get the Rossi 53 on it to run correctly so I swaped it out for a O.S. 46 FX that I had on the bench. I ran a
11-6 prop and the plane moved out surprisingly fast.

My question is, when the plane is flying fast the tail of the plane wags side to side. It looks exactly how a plane with a rudder would look if you slightly went back and forth with the rudder while flying level. It does not seem to affect the way it flys. Ailerons and elevator work fine at any speed. It does look very goofy flying like that though.

Anyone have any suggestions?

Thanks
Ryan
Old 07-14-2008, 12:45 AM
  #2  
LGM Graphix
My Feedback: (22)
 
LGM Graphix's Avatar
 
Join Date: Apr 2003
Location: Abbotsford, BC, CANADA
Posts: 5,800
Received 59 Likes on 41 Posts
Default RE: Old Shrike back in the air today (tail wags)

My Shrike 40 did that as well, I added another piece of triangle stock to the fins on top of the stab to make them sturdier and the wag went away. I think it's caused by the fins flexing on the stab.
Old 07-14-2008, 09:14 AM
  #3  
nexxa
Senior Member
 
Join Date: Nov 2004
Location: Montreal, QC, CANADA
Posts: 165
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

Your plane is probably a little tail heavy.
Advance your CG a little bit, like 1/4 or 1/2 inch. The plane will come a little hotter on landing, but will be more stable at high speed.
I Have the same trouble with my little Wonder .10 when I put a OS.32 on it. Advancing the CG by 3/8, solve the stability problem.

Hope this help.
Old 07-14-2008, 09:44 AM
  #4  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

Ah, just write it off as Dutch Roll and act macho about it. [>:]
Old 07-14-2008, 06:53 PM
  #5  
Blade-breaker
Senior Member
Thread Starter
My Feedback: (4)
 
Join Date: May 2008
Location: Austin, MN
Posts: 209
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

Sounds like a plan. I will move the bat. forward some and give that a shot.

The CG is a good guess by the way. I do not have the plans for the plane any more. I just guessed.

Thanks
Old 12-29-2008, 01:02 AM
  #6  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

Have you carefully checked the alignment of each tail surface. If they're misaligned they could be fighting each other at speed. I'm currently building a Shrike 40 and am seriously considering modifying it with dual rudder control.
Old 12-30-2008, 05:59 AM
  #7  
gofastz
Member
 
gofastz's Avatar
 
Join Date: Nov 2006
Location: Callahan, FL
Posts: 87
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

I got to tell you that I have a OS 46 AX on mine running a Race Ultrathrust Muffler with a 10X6 APC and have had Doppler readings at 131 MPH.....It is a blast to fly and I also have a slight tail wiggle that doesn't bother me in flight.....Hand launch that baby and she is a breeze..... She just floats out and away she goes.... Removing the Landing gear really stepped up the speed.... Landings are very easy..... Sliding in to a nice stop..... I really like how easy the 46 is to run..... VERY DEPENDABLE!!!!! I think adding rudder control would be a mistake.... The weight factor alone would be a negitive.... Just my 2 cents......Gofastz...[8D]
Old 12-30-2008, 06:04 AM
  #8  
gofastz
Member
 
gofastz's Avatar
 
Join Date: Nov 2006
Location: Callahan, FL
Posts: 87
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

Oh, One last thing.....The Shrike 40 is becomming more and more rare to come across.....Which is a shame! It's a wonderful plane.....
Gofastz[:@]
Old 12-30-2008, 06:45 AM
  #9  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

Wow. 131 mph. That works out to about 23000 rpm. Do you think the 46 would really turn that fast? I do know from experience that radar speed measurements are notoriously unreliable, for a lot of reasons.
Old 12-30-2008, 11:05 AM
  #10  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

Gofastz, I hear what you're saying. Keep it simple! I'm at the building stage where I have to decide to add rudder or not. It would be an easy mod. There would be the extra weight of the servo, flexable control cable and linkages. I could save some weight by using a micro servo for throttle control. I have read on previous posts that people were putting extra weight in the tail, especially if the went with a .46 engine. So adding rudder control has the benefit of adding useful weight back there. I plan on using an OS 40 FSR with a Macs tuned pipe so the CG shouldn't be an issue.

It is a shame that Lanier discontinued the kit. However, I did save the plans, instructions and balsa sheets that the ribs popped out of.
Old 12-30-2008, 11:25 AM
  #11  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

Quikturn:

Would you be willing to get the plans copied at a printshop, trace the rib outlines onto paper and send them to me?

I'd pay for all of it. I'm kicking myself in the butt for not keeping the plans and rib outlines for the one I built several years ago.

Regards
Old 12-30-2008, 01:29 PM
  #12  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

Bob,

I just looked over everything. Let me see what I can do with this. I cut the plans somewhat. The top down view, side view and tail template are in seperate pieces now to ease the construction process. I can tape it back together or a print shop can work with it. All the balsa sheets are in tact except for the main fuselage sides. That can be seen on the plans anyway. The critical piece of info are the shape of the ribs.

Give me some time and I'll get it together for you. Heck, I could put together profesional looking plans if I won't get in trouble with Lanier.

Joe
Old 12-30-2008, 01:33 PM
  #13  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

I think on something like that, as long as you weren't making a profit, you'd be all right. If you like, I could check with Hobbico/Tower Hobbies to see what they say about it.
Old 12-30-2008, 02:31 PM
  #14  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

Not necessary as I'm just trying to help out fellow modelers.

The reason I kept all this is to build a modified Shike from scatch. A twin boom high tail to be exact.

Now that I'm looking at all this some details will be lost like some former shapes and spar cutouts on the ribs.
Old 12-30-2008, 03:21 PM
  #15  
gofastz
Member
 
gofastz's Avatar
 
Join Date: Nov 2006
Location: Callahan, FL
Posts: 87
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

Mustang fever: Wow. 131 mph. That works out to about 23000 rpm. Do you think the 46 would really turn that fast? I do know from experience that radar speed measurements are notoriously unreliable, for a lot of reasons.

Why would call me out like this ...... Must of got sticks and rocks in your Xmas stocking... Here's the spread sheet figures from Doppler.... Freq.coming 1830...Freq.going 1299 at 72 degrees comes to 130.9 MPH....Octave 6 shows 15176 RPM.....It was a while ago that I recorded the run.....If I can find it I will post the video and wave file.....If I have incorrectly plug in to the spread sheet method please feel free to correct me....WaveOscope also confirmed these figures...... To conclude, I remember we were running test with the wing shadow speed indicator system that is mounted to the plane.....That speed was also confirmed with that system....Gofastz
Old 12-30-2008, 04:17 PM
  #16  
daven
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,456
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

We routinely get 125-130mph with a draggier Q500 style plane, that motor, and stock muffler (baffle removed). Measured by radar, and telemetry for several years. I don't doubt his 131 mph claim one bit at all.

I can't explain, although there was a thread about how a plane could travel at a speed higher than its projected speed based on rpm and pitch a while back.
Old 12-30-2008, 07:59 PM
  #17  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

Mustang Fever,

FedEx Kinkos want $7.50 to scan the Shike 40 to a PDF file and $12.50 to copy it. Not sure what it would cost to ship in a mailing tube yet. You might want to check with your LHS first because a while back I ordered Ultra Sport 40 plans at just over $9.

As for the ribs and instruction booklet, I can scan those into a TIF file and email those to you. Let me know what you want to do.

Joe
Old 12-30-2008, 10:12 PM
  #18  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

Joe:

Sounds good to me. I don't know if using a mailing tube is necessary- I've gotten plans both ways and they all seemed to work. Your call, tho. Shoot me a PM when you know the total, and I'll send you a check. Zipcode 49601
Old 12-31-2008, 01:08 PM
  #19  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

I've even got all the specs written up on this bird:

OS 35AX (very light compared to BB 46s, should make balancing much easier and the vertical stronger)

Two HiTec Mighty Mini BB MGs for elevator and ailerons. Lighter, smaller, and more powerful than a lot of standard servos.

For visibility, I'm going to use the same color scheme I used on the bird below, a 50% electric Mikulasko Arrow. Coverite neon red, which comes out the brightest orange around, and Ultracote white.
Attached Thumbnails Click image for larger version

Name:	Zx70611.jpg
Views:	8
Size:	106.0 KB
ID:	1100198  
Old 12-31-2008, 04:46 PM
  #20  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

That's a nice looking model Mustang Fever.

Mine will get a trim scheme like the Ultra Sport 40, metallic blue w/white starburst stripes on top and a black/white invasion stripe on the bottom.

I'd add some pictures showing rudder mods to a Shrike but I can't seem to see the pictures once they're uploaded. With dual rudders, you can make adjustments to align both surfaces and I think that would eliminate this tail wag phenomenon.
Attached Thumbnails Click image for larger version

Name:	Us54233.jpg
Views:	8
Size:	51.3 KB
ID:	1100332   Click image for larger version

Name:	Kf12248.jpg
Views:	10
Size:	38.3 KB
ID:	1100333  
Old 12-31-2008, 04:47 PM
  #21  
Quikturn
My Feedback: (12)
 
Quikturn's Avatar
 
Join Date: Jan 2008
Location: West Des Moines, IA
Posts: 933
Received 6 Likes on 6 Posts
Default RE: Old Shrike back in the air today (tail wags)

Whoa! Look at all the pictures now.

Sorry guys. First time I added pictures.
Old 12-31-2008, 05:15 PM
  #22  
daven
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,456
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

No problems, I fixed it.
Old 12-31-2008, 06:29 PM
  #23  
Mustang Fever
Senior Member
My Feedback: (2)
 
Mustang Fever's Avatar
 
Join Date: Nov 2003
Location: Cadillac, MI
Posts: 3,225
Likes: 0
Received 1 Like on 1 Post
Default RE: Old Shrike back in the air today (tail wags)

Thanks, Quikturn

Are those Sullivan push cables? That's what I plan to use on a 65" PBY Catalina flying boat I'm currently building, for all the controls. How do you like them? I didn't realized how good they are until I accidentally ordered and used one on a throttle cable setup. Much better than standard cables.
Old 01-05-2009, 02:20 PM
  #24  
johnc1go
Senior Member
My Feedback: (9)
 
Join Date: Dec 2002
Location: South Bend, IN
Posts: 145
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Old Shrike back in the air today (tail wags)

Just my two cents, but it sounds like your engine is overpropped if you're trying for speed. Have you tried a 10-7/8 or even a 9-7 with your .46ax? It's been my experience that for speed I need revs and to get revs I have to use props of smaller diameters and steeper pitches.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.