trim lever

12 posts in this topic

Posted (edited)

 

WARNING!   WARNING!  WARNING!  make sure you read my post from 11/7/21 if you are thinking about coping this.  It could jam up your elevator if it's pulled into the wrong position.   

Hi guys..  I have electric trim on my Kitfox 4, but it moves slow.  It helps to use plenty of trim on that plane when on final approach, so I rigged up a bungee to pull from the seat truss to the joystick.  That worked, and was much faster, but I revisited that system and came up with a lever much like the Avid trim uses.  It does mount on the joystick however.  I'm thinking I will move it to the front of the stick, but it works fine as is.  There is a piece of leather between the lever and the mounting bracket to give friction so the lever stays where you put it.  This does just give nose up trim, but I have the electric trim for cruise or nose down, although a bit of flaperon will give nose down as well.  I will keep playing with it, and maybe shorten up the lever a bit, it's about 4 1/2" from the pivot, and the part hooking to the bungee is about 3 1/2".  It did work good though on the landings I used it with so far.  JImChuk

 

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Edited by 1avidflyer
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Posted

Nice Version2 improvement Jim!

I'd make one like that - but If I had fancy trim like that then I would have one less excuse for bad landings...  and now you have no excuses so I think I'm in a good position here ;) 

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Posted


Very clever Jim. Looks great.

 

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Posted


Very clever Jim. Looks great.

 

Actually I saw someone else had used a bike shift lever on their joystick, and a cable from it pulled on a spring.  That gave me this idea, and I also kind of copied the Avid trim lever with the leather washer.  So I can't take all the credit.   JImChuk

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Posted

Nicely done! 

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Posted

WARNING!  WARNING!  WARNING.  This afternoon I went for a flight and on my second landing when I was slowing up and started to raise the nose, the elevator was jammed.  I think it was my trim lever was pulled back to far, and the arm that pulls on the bungee cord was hitting the seat.  I jerked the stick side ways and back and on about the fourth try, it let loose.  I think I had forward stick, but was afraid to use it if I Iost the neutral elevator position I was able to have.  I'm going to make a stop that will limit the travel of the trim lever so that can't happen again.  I'm also going to take everything apart from stick to elevator to make sure it wasn't something else.  A half hour before this, I had landed at a friends grass strip, and forgot to move the trim lever back to normal flight after landing with it in trim mode.  When I took off, it started to climb to much, and I right away pushed the trim to neutral setting.  I probably pushed it way further then normal and set myself up for the exciting finish of the flight.  It all ended ok, but was hairy for a bit.  So if anyone liked my trim system and want to copy it, make sure you have some kind of stop to keep it from jambing the controls.   

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Posted

My friend is installing your version of the trim in his KF IV, He doesn’t have it tested yet.  If the wind ever backs off here for a day or two he can get it tweaked, I’ll let you know.

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Posted

Make sure he has a stop on it to prevent it from doing what mine did.  JImChuk

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Posted

simple things can be real spooky sometimes glad you are ok.

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Posted

Yes he read your post and I’ll make sure he sees your stop.  Thanks Jim. 

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Posted

After thousands of ours in Avid B and MK4 I finally install electric trim.

Bought a linear actuator from Amazon and it worked well but too fast, so I bought a motor controller where I can control the width of a square wave to slow the actuator.

Before, I could always trim in cruise with a little flaperon but on landing with full flaps a higher stick force was needed.  Works great. 

On my model B I just had a spring from the seat carry through to the lower part of the stick. Then on final I would just slide one end of the spring up the stick.

John M

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Posted

I used to use a bungee tied to the seat truss and wrapped around the joy stick. Pulling it up would put more back pressure on the stick.  This trim lever is real nice as far as I'm concerned. Instant on and just the right amount for landing trim.  

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