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

First time flutter prob on Dust

Reply

Old 02-09-2003, 11:18 PM
  #1  
FlooredCOBRA
Senior Member
Thread Starter
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

Well today I finally flew my Dust after not flying it for a while. I totally forgot how fast these things really go. My nerves was shot as if it was the first time I ever flown the thing. And especially not warming up with another plane first after not flying it for a while.

Well I cranked it up and launched and got it up. I set my trims and got the feel for it again. I turned around and lined up with the runway and nailed it WOT. I dove down and then it got on the pipe. Nothing unusual here yet. I took it up pretty high and split-S into a dive at WOT still on pipe. The engine unloaded and as it came across the field. Then I heard that NASTY sound. The flutter. Out of all the times I have flown it I have never had this problem before until today. I could take it high as I can see it then WOT in a dive and never have a flutter problem. Just today for some reason it did. And even just flying level it did this.

Huge let down!

I am guessing that maybe the horns on my servo in time wore a larger hole or on the clevis wore a larger hole. I am not to sure yet. It might of been since it was so cold the covering had the drum effect on it. It only does it when the engine unloads though. Kind of weird, I can be on pipe and it will be OK but after it unloads its that nasty sound. I am not sure but it is a real let down having a dust and not being able to fly WOT.
FlooredCOBRA is offline  
Reply With Quote
Old 02-10-2003, 12:22 PM
  #2  
Cactus.
Senior Member
My Feedback: (1)
 
Cactus.'s Avatar
 
Join Date: Dec 2001
Location: CamborneCornwall, UNITED KINGDOM
Posts: 6,136
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

unballanced prop causeing frequency at just the right rpm to make the plane vibrate? servos hanging around for ages and the pot isnt accurate anymore and it wont hold center letting the surfaces move slightly?
then again it could be like mine one very windy day as i flew through the turbulence comming off the cliffs the whole plane drummed which it never does, got a few glances because it sounded like it exploded
Cactus. is offline  
Reply With Quote
Old 02-10-2003, 12:36 PM
  #3  
MMallory
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: South Plainfield, NJ
Posts: 1,148
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

Cold weather = more performance. It could simply be that your plane has never gone that fast.

Mark M.
MMallory is offline  
Reply With Quote
Old 02-10-2003, 10:11 PM
  #4  
FlooredCOBRA
Senior Member
Thread Starter
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

I was thinking the same thing also about the weather. On top of that it was fairly windy too. I am going to replace my servos anyhow with some stronger torque ones than what I have in it. I been meaning to do that anyways.

I just hope it goes away and ends up being weather or wind or something. I hate the fact that I cannot fly my DD WOT.. It totally kills the fun factor of it.

I am going to go over it and see what I come up with. Just odd out of all the other times I have flown it it has never gave me any problems.
FlooredCOBRA is offline  
Reply With Quote
Old 02-11-2003, 01:10 AM
  #5  
Dustflyer
My Feedback: (13)
 
Dustflyer's Avatar
 
Join Date: Dec 2001
Location: Abington, PA
Posts: 913
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Servos

Floored,

You didn't tell us what kind of servos or hardware you are using.

I had FMA coreless servos in my Dust when I first started out with the Jett FIRE 50. Things went fine for a while and then flutter started. Turned out I could wobble the servo arms back and forth almost an eighth of an inch even with the power on! The servos and/or bearings just gave out. After that I decided I'd never go back to cheap or "second tier" servos. I put a pair of JR 8101's in my Dust and the problem went away.

Nowadays I only use good JR or Futaba coreless servos in my airplanes. Dust designer Jeff Gilbert is a big fan of JR 4735's, something to keep in mind.

I am assuming you did a nice tight covering job with UltraCoat and have the pushrod guides installed.

Based on the experience I've had with my Dust I believe if you've got good servos and good hardware with no slop you should be free of flutter.
Dustflyer is offline  
Reply With Quote
Old 02-11-2003, 01:49 AM
  #6  
FlooredCOBRA
Senior Member
Thread Starter
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

I am running a 4.6 1000 mah pack with JR 507 with BB.

This is where my problem more than likely lies. Ever since I put the GRRT in nose I been meaning to change these servos but just have not done it yet. And now I think the cheap servos are now showing what happens with wrong set up.
FlooredCOBRA is offline  
Reply With Quote
Old 02-11-2003, 12:41 PM
  #7  
MMallory
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: South Plainfield, NJ
Posts: 1,148
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

507's???!?!?!?

YES, they are your problem! It's pure luck you haven't crashed before long before this.

Mark M.
MMallory is offline  
Reply With Quote
Old 02-11-2003, 08:05 PM
  #8  
FlooredCOBRA
Senior Member
Thread Starter
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

Yeah I know. Pretty crazy of me even flying it with these servos. I had these in there originally with the OS 46FX in nose. I had meant to change to better servos after I put my GRRT in it but just haven't yet.

I knew better about this just been to lazy to mess with it. Well now is a good time to swap out. And about to hit the HS right now and get 2 of them along with some other goodies while I am there.
FlooredCOBRA is offline  
Reply With Quote
Old 02-11-2003, 09:45 PM
  #9  
Cactus.
Senior Member
My Feedback: (1)
 
Cactus.'s Avatar
 
Join Date: Dec 2001
Location: CamborneCornwall, UNITED KINGDOM
Posts: 6,136
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

I've just got standard ballraced Futaba servos in mine, 4mm threaded pushrods with CF tube over that and compressed with nuts, MVVS 40 APC 9x7, looked at putting my GRRT in, but was harder than 4 bolts so i didnt bother.
My Outlaw is almost as fast, but has just 3003's on rather large surfaces. Maybe we dont get flutter in Cornwall? ? lol
Cactus. is offline  
Reply With Quote
Old 02-11-2003, 09:57 PM
  #10  
FlooredCOBRA
Senior Member
Thread Starter
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

I'm pretty sure it would with that GRRT in it.....lol
FlooredCOBRA is offline  
Reply With Quote
Old 02-11-2003, 10:03 PM
  #11  
Cactus.
Senior Member
My Feedback: (1)
 
Cactus.'s Avatar
 
Join Date: Dec 2001
Location: CamborneCornwall, UNITED KINGDOM
Posts: 6,136
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

couldn't be bothered, with the carb at the back i would of had to move the engine forward, drill two new holes, cut the rear of the mount out, and worse of all compleatly redo the throttle snake.
realising that was enough for me not to bother. esp as i'll have a Magnum by this time next week to play with and drop the GRRT into
Cactus. is offline  
Reply With Quote
Old 02-12-2003, 01:07 AM
  #12  
FlooredCOBRA
Senior Member
Thread Starter
 
Join Date: Aug 2002
Location: Hampton, GA
Posts: 1,551
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default First time flutter prob on Dust

your right. It does take some cutting of the mount also cutting out 2 slots for each needle on the sides.

But well worth it! just in case you decide to try it
FlooredCOBRA is offline  
Reply With Quote

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