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: 38
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: 730
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
My Feedback: (92)
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,086
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: 38
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
My Feedback: (2)
 
underdw's Avatar
 
Join Date: Nov 2004
Location: Erie CO
Posts: 359
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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: 730
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: 730
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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: 50
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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: 38
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: 730
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

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
My Feedback: (92)
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,086
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Just look on Facebook for Tony Frackowiak.
TonyF is offline  
Reply With Quote
Old 12-27-2017, 08:59 PM
  #1812  
TonyF
My Feedback: (92)
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,086
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

The last few months I have been working with Mike Gaishin on some improvements and upgrades on the Contra V4. I have been very impressed working with Mike on his determination to keep the V4 Contra the best contra drive out there.

Mike has brought all of the gear fabrication in house including buying some new machinery to do this. This insures that he has complete control over the process. Mike has greatly improved the gears in the V4 and they are now available. I believe this gear upgrade is or will be available through F3A and the cost for all five of the gears is $200.

These gears have really smoothed out the V4 making it quieter with less vibration. Gone are the slight harmonics that might have existed with a V4. I am very impressed with the improvement in my V4's.
TonyF is offline  
Reply With Quote
Old 01-07-2018, 04:09 PM
  #1813  
PeterP
 
Join Date: Feb 2003
Location: Brisbane, AUSTRALIA
Posts: 464
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Does anyone happen to know what the gearing ratio is for the V4? I think it was 6.75:1 but would like it confirmed.

Mike has confirmed that the exact gear ratio is 1: 7.08 for the V4. for anyone that needs to know.

Last edited by PeterP; 01-14-2018 at 02:53 PM.
PeterP is offline  
Reply With Quote
Old 01-14-2018, 02:50 PM
  #1814  
PeterP
 
Join Date: Feb 2003
Location: Brisbane, AUSTRALIA
Posts: 464
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I have also had the opportunity to try out the new V4 gears which are now available and can confirm that they have transformed the drive. Very happy with the result now that the drive is super smooth and quiet.
PeterP is offline  
Reply With Quote
Old 01-23-2018, 08:02 AM
  #1815  
grotow
 
Join Date: Aug 2013
Posts: 38
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Anybody know the driver required to remove screws on Hacker C54?
grotow is offline  
Reply With Quote
Old 01-26-2018, 01:36 PM
  #1816  
Henning
 
Henning's Avatar
 
Join Date: Jul 2005
Location: Oslo, NORWAY
Posts: 200
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I flew for the first time today with the new upgrade gear set for the V4. What a difference. It is really quiet compare to the old gears. My flying buddy was flying with the V4 and old gear set and it sounded like two different propulsion systems.

Will the next generation gears be helical?


Br,
Henning
Henning is offline  
Reply With Quote
Old 01-26-2018, 06:55 PM
  #1817  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 730
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Henning View Post
I flew for the first time today with the new upgrade gear set for the V4. What a difference. It is really quiet compared to the old gears. My flying buddy was flying with the V4 and old gear set and it sounded like two different propulsion systems.

Will the next generation gears be helical?

Br,
Henning
Hey Henning,

The next gears probably won't be helical.

There are several things that contribute to quiet gears:

1/.. Tooth to tooth composite error
2/.. Total composite error
3/.. Tooth contact ratio
4/.. Tooth surface finish

The upgrade gearsets are cut in a single setup on a brand new Swiss CNC lathe. This means there is effectively no position tolerance between the center bore of the gears and the pitch circle diameter of the gear mesh, which is responsible for the total composite error. There is also almost no "clocking" error between the teeth as well, which causes tooth to tooth composite error.

The upgrade gearsets are also "lapped" as a matching set, which creates a very high-quality tooth surface finish.

Based on the inspection measurements Mike is now getting with the upgrade gears, the AGMA quality level is now 12 plus.

As far a tooth contact ratio is concerned, helical gears would help, however, the gear tooth profile was originally modified to maximize contact ratio and eliminate involute profile undercutting. (which can happen with pinion gears that have less than 17 teeth ...) This was done by radially shifting the pitch line of contact away from the pinion gear towards the planet gear.

This modification has given us most of the benefits that we could expect gain by using helical gears, so it probably doesn't make sense to increase manufacturing complexity by switching to them.

Brenner ...
Brenner is offline  
Reply With Quote
Old 01-28-2018, 05:33 PM
  #1818  
vbortone
My Feedback: (2)
 
Join Date: Apr 2004
Location: Olathe, KS
Posts: 641
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Wahoooo. Pure mechanical engineering.
vbortone is offline  
Reply With Quote
Old 07-16-2018, 01:54 AM
  #1819  
bem
My Feedback: (1)
 
Join Date: Feb 2009
Location: SWEDEN
Posts: 1,568
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hi,
It was a while since anyting was written in this thread.
Brenner:
Can you give the latest update what is going on with Your Contra drive development and present status (V4) and plannned enhancements (V5?) in near and perhaps longer into the future? And what is the present maintenence interval on the latest version of Your Contra drive (I can read on F3A Unlimited website 200 flights then regrease of gearbox is needed).
Do You know anyone flying a BJ Craft "AJ Element" with a V4 Contra?

/Bo

Last edited by bem; 07-16-2018 at 02:07 AM.
bem is offline  
Reply With Quote
Old 07-16-2018, 02:51 AM
  #1820  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 730
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hey Bem,

Here in USA there are many people who fly the Element with a V4 Ccontra Drive. The person I know the best is me.

The Element works very well with a Contra Drive. The Element has a huge rudder fin, which makes it very stable in Yaw. Also, the V4 Conta Drive is about 12mm shorter than the Adverun Drive, so it is not necessary to cut the nose back like you have to do with the Adverun Drive.

However, In my experience the nose angle in the Element was molded wrong, so you will need to adjust it with a disk sander if you want the Contra to match properly.

As far as future V4 development is concerned, the focus at the moment is maintaining consistent manufacturing quality so that every Drive that is sold works flawlessly. We want to build a reputation as the Drive that just runs.

Right now there is very little that we can think of to offer as an improvement. The all-up weight of the Drive is actually less than most single prop systems. The package size is also less than most single prop setups as well.

Also, the new gear sets have reduced the sound to the point were it is pretty much comparable with single prop setups. I am currently at the USA NATs, and the V4 sound quality is noticeably better than the latest Adverun even with helical gears.

Maintenance is currently about 1cc of grease every 200 flights. However, I am testing to see how long we can stretch this out. Last year I got about 500 flights before I regreased it, and I think I could have gotten more.

The actual regressing operation is also very convenient because all you need to do is remove the front spinner and inject grease through the hollow drive shaft.

Over greasing can be an issue if too much grease is applied. We are working on changing the user manual to make this easier to understand.

If the Drive is not overgreased it remains bone dry on the outside.

Right now we are doing a lot of work on the manual to make care and maintenance as clear and as easy as possible, and as far as future development are concerned, we welcome suggestions.

Brenner...

Brenner is offline  
Reply With Quote
Old 07-16-2018, 03:27 AM
  #1821  
bem
My Feedback: (1)
 
Join Date: Feb 2009
Location: SWEDEN
Posts: 1,568
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Thanks Brenner, good answer, as usual.
Do You happen to know what Contra Andrew Jesky is using in his AJ Element? I saw a photo from WC 2017 where he had a decal on the side of his Element plane and it was "AVR XS" so I suppose he used Adverun Contra at WC 2017? He do not use Brenner Contra V4 - right?

/Bo

AJ Element (Andrew Jesky) at WC F3A 2017:
bem is offline  
Reply With Quote
Old 07-16-2018, 03:42 AM
  #1822  
ltc
My Feedback: (3)
 
Join Date: Mar 2010
Location: Mendon, MA
Posts: 902
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Bo
in the picture you posted, that looks like an Adverrun, based on the spinner looking like CF rather than (anodized) aluminum plus it looks like here are small screws on the back of the rear spinner, something the Brenner doesnít use
ltc is online now  
Reply With Quote
Old 07-16-2018, 04:01 AM
  #1823  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 730
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hey Bem,

Andrew used an Adverun at the last worlds.

This year heís using a Q80 13xs. Iím watching him unpack an Oxai Accuracy right now.

If anyone has any questions for him, I can ask him for you.

Brenner...
Brenner is offline  
Reply With Quote
Old 07-16-2018, 04:06 AM
  #1824  
Brenner
Thread Starter
 
Join Date: Jul 2007
Location: Bridgman, MI
Posts: 730
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

By the way, Jason Shulman, and Joseph Szurr are the two team USA pilots who flew the V4 Contra. (and are still flying V4 Drives..)

Andrew likes to change a lot so itís hard to know what heíll be flying year to year.

Brenner...
Brenner 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