Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

thrustline more negative or down.

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Kolb-List
View previous topic :: View next topic  
Author Message
phcpilot



Joined: 24 May 2016
Posts: 16

PostPosted: Fri Oct 08, 2021 5:16 am    Post subject: thrustline more negative or down. Reply with quote

Re Chics question:

"Will that adversely effect thrust angle and if so, in whatway? Thanks, Chic"

Chic, it is not a case of "adverse" effect.
Giving a pusher engine down thrust increases the nose up force so that less up elevator is required as you increase power. If that's a good effect for you as it was for me then it's not adverse, it's beneficial.
I think most Pilots would prefer to have the plane nose up when they applied power and this is how to do it.
 It all depends on what you want.
Peter.


- The Matronics Kolb-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List
Back to top
View user's profile Send private message
Richard Pike



Joined: 09 Jan 2006
Posts: 1649
Location: Blountville, Tennessee

PostPosted: Fri Oct 08, 2021 1:47 pm    Post subject: Re: thrustline more negative or down. Reply with quote

Tomorrow is WUFI - https://www.facebook.com/groups/1663741873840700/permalink/3007887912759416
and as soon as I get done with my part of work day at church, I plan to go fly and participate.
As part of tomorrow's flight, I plan to have a camera alongside the airplane aimed at the horizontal stab & elevator.
I am really curious to find out where the elevator is at cruise.
I am thinking that you ought to be able to tell if your engine thrust line is optimal by how much up or down elevator you have to use while in level flight.
If your thrust angle is correct, then your elevator ought to be inline with the stab.
To the extent that you have to have either up or down elevator, then your thrust line needs to be adjusted.
Feedback?


- The Matronics Kolb-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Jerry-TS-MkII



Joined: 23 Aug 2017
Posts: 78
Location: Indiana

PostPosted: Fri Oct 08, 2021 2:36 pm    Post subject: thrustline more negative or down. Reply with quote

Richard..
I thought the tail helped to establish the angle of attack, which
dictates the Co of Lift, which varies with your airspeed. The DC-3 used
a 23015 airfoil which had basically zero pitching moment over it's AoA
range.. but just about every other airfoil has a pitching moment that
varies with the AoA. Add more weight, and your AoA changes then too.
And the tail is compensating for all of that, as it varies. If your
extra HP airplane flies faster, you need less angle of attack to
maintain level flight, which means the nose will be down.. until you
slow it up. Otherwise, you need to remove the wing and change it's
angle relative to the fuse/stabilizer. All of that varies over the
speed, weight, altitude envelope, and the length of gear legs when it
comes to flaring, etc. I could be wrong. If you run your camera, pick
several different cruise speeds. I would expect to see each one
producing different elevator angle. I'd set the trim to 0.. so that it
doesn't affect your notes. Will be interesting to hear of the results.

On 2021-10-08 5:47 pm, Richard Pike wrote:
Quote:

<thegreybaron(at)charter.net>

Tomorrow is WUFI -
https://www.facebook.com/groups/1663741873840700/permalink/3007887912759416
and as soon as I get done with my part of work day at church, I plan
to go fly and participate.
As part of tomorrow's flight, I plan to have a camera alongside the
airplane aimed at the horizontal stab & elevator.
I am really curious to find out where the elevator is at cruise.
I am thinking that you ought to be able to tell if your engine thrust
line is optimal by how much up or down elevator you have to use while
in level flight.
If your thrust angle is correct, then your elevator ought to be inline
with the stab.
To the extent that you have to have either up or down elevator, then
your thrust line needs to be adjusted.
Feedback?

--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace
really is amazing.




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=503491#503491








- The Matronics Kolb-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List
Back to top
View user's profile Send private message
Richard Pike



Joined: 09 Jan 2006
Posts: 1649
Location: Blountville, Tennessee

PostPosted: Sun Oct 10, 2021 6:18 pm    Post subject: Re: thrustline more negative or down. Reply with quote

Flew yesterday evening and again tonight, perfect conditions, took some pictures, got my head on straight about my engine/gearbox/prop setup. Here's how:
Yesterday's flight I set out to film the horizontal stab/elevator at 5000, 52k, 54k, 56k, 58k, & 6k rpm.
The elevator at 5k & 5200 rpm was slightly down - 1st pic.
At 5600 - 6k it was in line - 2nd pic.
Thinking about the effect of going from the B box/electric starter & Ivo, to an E box w/electric starter & Warp Drive - I am thinking I moved about 5-7 pounds of weight rearward about 24".
So now - with moderate thrust at 5-5200 rpm, the slightly rearward CG requires drooping the elevators a hair, at higher speeds/more thrust, everything is about where it needs to be.
Along with that, tonight I gave it a real workout, cranking and banking, rapid throttle inputs, back to zero throttle while cranking and banking, a lot of aggressive maneuvering, and it felt really good.
Then I set the throttle at 5400, which works out to about 60 mph, and just flew around until it go so dark I had to land. 3rd pic
Greaser. Life is good.
Quit worrying about it and just go fly.


- The Matronics Kolb-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Kolb-List



5000rpm (Medium).jpg
 Description:
 Filesize:  174.46 KB
 Viewed:  896 Time(s)

5000rpm (Medium).jpg



6000rpm (Medium).jpg
 Description:
 Filesize:  169.22 KB
 Viewed:  896 Time(s)

6000rpm (Medium).jpg



20211010_190212 (Medium).jpg
 Description:
 Filesize:  63.74 KB
 Viewed:  896 Time(s)

20211010_190212 (Medium).jpg



_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Kolb-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group