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  • July 22, 2024, 01:35:44 PM

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Author Topic: Endgame IV Build  (Read 193089 times)

Offline Mike Morrow

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Re: Endgame IV Build
« Reply #50 on: May 30, 2024, 06:15:04 AM »
Ken, thanks for doing the build thread. Most of it is more than I'm capable of but I always learn something new.

Mike

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Online Ken Culbertson

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Re: Endgame IV Build
« Reply #51 on: May 30, 2024, 03:34:44 PM »
I posted my flap "sealing" method in the open forum:

https://stunthanger.com/smf/open-forum/imbedded-flaps/msg673327/#msg673327

Ken
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If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC

Online Ken Culbertson

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Re: Endgame IV Build
« Reply #52 on: June 04, 2024, 06:06:02 PM »
After careful consideration I decided to bite the howitzer and redo the canard linkage using a reducing lever.  Making it was not easy.
 I had to raise the cockpit floor 1/8" and move the arming plug to the other side.  The lever is two pieces of .5mm carbon fiber sheet with a 3/16" hard balsa center. Ball links are a necessity because of the angles.  IT WORKED!  The canard now has an adjustment range of 5 to 35 degrees and by adding the reducing lever the pushrod angles are such that changing the throw does not change the center as much so I can easily adjust neutral.   On Endgame III I am not able to change the canard much without upsetting the inside/outside turn balance.

The wing is fitted to the fuselage but not glued in yet.  All the subassemblies except for the rudder are finished so it is time to start putting it together and cleaning it up.  The controls are super free.  Hard to believe that with the logarithmic with split flaps, a 5" bellcrank, two pushrods, 10 ball links and a reducing lever that the weight of the flaps is enough to move everything - and the flaps are pretty light!

I put everything on the scales to see where I am weight wise.  58oz including props and battery.  All that is missing is the rudder.  I figure that I will sand and the like for just about the weight of the rudder so that gives me 7oz to finish and still make 65oz.  It is a big plane with lots of power so a few ounces over is not going to temper my enthusiasm.

Ken
AMA 15382
If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC

Offline Lauri Malila

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Re: Endgame IV Build
« Reply #53 on: June 05, 2024, 09:53:22 AM »
Maybe I got something wrong from your pictures, but if you add such a lever between the bellcrank and canard horn, doesn't it reverse the movement..?
I think you'll need a logarithmic gadget for the canard, too. n~
L

Online Ken Culbertson

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Re: Endgame IV Build
« Reply #54 on: June 05, 2024, 12:38:22 PM »
Maybe I got something wrong from your pictures, but if you add such a lever between the bellcrank and canard horn, doesn't it reverse the movement..?
I think you'll need a logarithmic gadget for the canard, too. n~
L
The Canard is driven by the opposite side of the bellcrank from the flap pushrod.  It needs to be reversed so that the canard moves in the same direction as the flaps.  The lever also reduces the movement.  When I first hooked it up I had over 40 degrees of movement.  5 - 15 is about all it will need.

If I wanted to build a whole new fuselage I would couple it to the logarithmic instead of the bellcrank.

Ken
AMA 15382
If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC

Online Ken Culbertson

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Re: Endgame IV Build
« Reply #55 on: June 25, 2024, 04:42:12 PM »
First pic of it all in one place.  Almost half finished!

Ken

In case you are curious, or even if you aren't, the wing center section had to remain open to connect the rather elaborate control system and get all of the conduits for the wires going everywhere.  So, I glued the wing to the bottom of the fuselage and left the top planking off.  What I discovered doing it this way was having full access to the bellcrank with the wing glued into the fuselage is really cool.  Regardless of bellcrank size I make all of my control systems to go from neutral to full deflection with 1 1/2" of leadout movement.  That is 3" of wrist from full up to full down.  With it finally assembled I got to see if it all worked.  3" exactly!  Since I have a 5" bellcrank I was worried that I got the stops wrong.
« Last Edit: June 25, 2024, 05:05:25 PM by Ken Culbertson »
AMA 15382
If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC

Online Ken Culbertson

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Re: Endgame IV Build
« Reply #56 on: July 10, 2024, 02:27:42 PM »
This has been keeping me up at night.  First time twin and I have been told that the nacelles need to be as close to the wing as possible.  Don't ask me why because I don't know YET, I just trust the source.  So, by using state of the art reforming tools (Exacto #11), I reshaped the nacelles with the aft end of the motor 1/16" from the wing LE.  Nearly 1" closer. If this doesn't work I know where to send the bill.  LL~   I actually think they look better short.

Ken
AMA 15382
If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC


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