Electric Pattern Aircraft Discuss epowered pattern aircraft in this forum

Contra Rotating Propeller Drive for f3a 2m Pattern Planes

Reply
Old 10-07-2017, 06:00 AM
  #1801
grotow
 
Join Date: Aug 2013
Posts: 31
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Brenner,
I have been flying an Inspire the last couple of years and would like to try another airframe. What would you recommend for intermediate to advanced classes?


Gary
grotow is offline  
Reply With Quote
Old 10-07-2017, 09:32 AM
  #1802
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 726
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hey Gary,

I think the plane I'm flying now is a pretty good match for a Contra Drive, and will perform very well in the intermediate and advanced classes..

I am flying an Allure with a V4 Contra drive, a Jeti Mezon 90 ESC, and 5100 mah high voltage packs from f3aunlimited. I am also using 23" props, which requires me to use extra long Falcon landing gear.

I believe that the latest version of the Allure has had its landing gear redesigned and now they are stronger and longer, so the landing gear change probably isn't needed. My setup makes weight easily, but my packs only weight 1030g. With Thunderpower 5000 mah packs I am about 10g under 5kg.

This plane tracks very well, and has excellent yaw stability. I am also not using any mixing except for a slight downline mix. I can fly F17 with no problem, but the knife edge half loop requires me to add considerable power as I come down in order to maintain lift, and I have found planes that fly this maneuver better.

It snaps well, but the snap is slower than some of the planes that have Spark wings. I find that I typically get better snaps when I do them at reduced power because the snap isn't fast enough for the plane to maintain track at full power. Half throttle snaps work fine though. Doing two snaps opposite is a challenge because too much forward momentum is lost in the first snap if the plane is flying slow, and it's hard to maintain track if the plane is flying too fast..

These are only issues with the FAI F pattern, and planes that do these things better are going to have other compromises.

In its present form I think the Allure is an excellent choice for all classes up from intermediate to the f3a P pattern, and it is also an excellent match for the Contra.

Brenner ...
Brenner is offline  
Reply With Quote
Old 10-07-2017, 09:55 PM
  #1803
TonyF
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,080
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I can attest that the BJ Craft Agenda is another excellent choice. Before it I was also flying an Inspire and I wasn't sure anything would fly better than that. But the Agenda flies everything I have done with it very well. Mine is V4 powered but I have also seen this model fly very well with a V3. No issues with prop clearance with the stock landing gear. Also, no issues with weight as the airframe is quite light.

I have a build thread on the Agenda on my Facebook page.

Last edited by TonyF; 10-07-2017 at 09:58 PM.
TonyF is offline  
Reply With Quote
Old 10-08-2017, 03:31 AM
  #1804
grotow
 
Join Date: Aug 2013
Posts: 31
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Brenner,

Thanks for your input. It seems the Allure is no longer available and I would have to wait for the successor
Alchemy. Do you know if CK Aero offers a zero offset option for the contra?
grotow is offline  
Reply With Quote
Old 10-08-2017, 04:49 AM
  #1805
underdw
 
underdw's Avatar
 
Join Date: Nov 2004
Location: Erie CO
Posts: 357
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by grotow View Post
Brenner,

Thanks for your input. It seems the Allure is no longer available and I would have to wait for the successor
Alchemy. Do you know if CK Aero offers a zero offset option for the contra?
The Allure nose ring has only a very slight right thrust built into it. No need for a special fuse - just shim in a touch of left thrust for your contra.
underdw is offline  
Reply With Quote
Old 10-08-2017, 07:31 AM
  #1806
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 726
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hey Dan,

I forgot to talk about the nose of the Allure. It is pretty much set at almost zero degrees right thrust right from the factory.

The wing is non-adjustable, but whatever downthrust the nose has, it is correct because I installed my Contra so that it matches the nose, and all of the thrust angles worked out.

As far as trim is concerned, I have my CG from 1/8" to 3/16" behind the rear edge of the wing tube, and I trimmed out the adjustable stab to remove elevator trim.

The most critical thing was aligning the stab halves. I used a digital level, and I had to take a couple of tries before I got it right.

I don't have any extra air holes in the fuse, but my ESC is located directly under the rear of the motor where the motor fan can blow air directly on it. I highly recommend this. Before I did this I couldn't finish a flight before my ESC would cutout from over temperature.

The only other recommendation I have is to mount the batteries approximately inline with the thrust line so they don't adversely affect the vertical CG.

Brenner ...
Brenner is offline  
Reply With Quote
Old 10-08-2017, 07:33 AM
  #1807
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 726
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by grotow View Post
Brenner,

Thanks for your input. It seems the Allure is no longer available and I would have to wait for the successor
Alchemy. Do you know if CK Aero offers a zero offset option for the contra?
Hey Grotow,

If the Alchemy is a successor to the Allure, then I suspect that it will have all of the same characteristics. Drop a note to Bryan and ask him.

Brenner ...
Brenner is offline  
Reply With Quote
Old 10-09-2017, 12:15 AM
  #1808
willyuk
 
Join Date: Nov 2005
Location: , UNITED KINGDOM
Posts: 49
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by TonyF View Post
I can attest that the BJ Craft Agenda is another excellent choice. Before it I was also flying an Inspire and I wasn't sure anything would fly better than that. But the Agenda flies everything I have done with it very well. Mine is V4 powered but I have also seen this model fly very well with a V3. No issues with prop clearance with the stock landing gear. Also, no issues with weight as the airframe is quite light.

I have a build thread on the Agenda on my Facebook page.
Hi Tony,
can you let me know how best to find your facebook page? I would like to read your build thread

thankAl
willyuk is offline  
Reply With Quote
Old 10-10-2017, 07:01 AM
  #1809
grotow
 
Join Date: Aug 2013
Posts: 31
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Brenner,
This reply I received from Bryan "
Hi Gary The Alchemy and the Allure are still available The same price.You will be able to get one by December I think. Both models are set up mostly identical the Alchemy is just the latest progression of the design setup I used on the Allure. You can run any system you want ..Contra or single props Bryan CK Aero"
grotow is offline  
Reply With Quote
Old 10-10-2017, 07:03 AM
  #1810
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 726
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Quote:
Originally Posted by grotow View Post
Brenner,
This reply I received from Bryan "
Hi Gary The Alchemy and the Allure are still available The same price.You will be able to get one by December I think. Both models are set up mostly identical the Alchemy is just the latest progression of the design setup I used on the Allure. You can run any system you want ..Contra or single props Bryan CK Aero"
Thought so ...
Brenner is offline  
Reply With Quote
Old 10-12-2017, 04:53 PM
  #1811
TonyF
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,080
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Just look on Facebook for Tony Frackowiak.
TonyF is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

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



All times are GMT -8. The time now is 04:03 AM.