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  #1  
Old 11-28-2005, 11:51 AM
TX7A TX7A is offline
 
Join Date: Feb 2005
Location: Abilene, TX
Posts: 725
Default Manual Elevator Trim Knob Location

I will be installing the manual elevator trim. I would like to do something different to eliminate the half loop that the cable makes up to the fuel selector cover where it mounts. I am considering routing the cable through the tunnel cover & making a bracket/cover to mount the handle to. The trim knob would be slightly aft of the fuel selector handle and would be operated "back-handed". I've simulated this by placing the knob in the proposed position & sitting in the seat just to see how it "feels". It doesn't seem awkward and I'm sure I could get use to it.

My question:
Has anyone done/seen this? If so...got a picture?
Does anyone see a problem with doing this sort of install? (interference, etc.)

I've searched the archives for this particular idea, but have yet to see anything about it.

FWIW, I've seen a trim knob mounted on the sidewall & don't like that much either. And no electric trim for me.

Thanks for any ideas on this.
Sam
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  #2  
Old 11-28-2005, 03:24 PM
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hevansrv7a hevansrv7a is offline
 
Join Date: Jul 2005
Location: Detroit, MI
Posts: 1,587
Question Manual Trim Knob Alternate Location

Sam,
I'm trying to deal with a problem of locating that knob caused by adding the electric pump for FI. I would like to see a picture of what you are planning. I couldn't figure out where you were planning to put it. Remember the "off" position for the fuel selector is pointing straight aft - I think. What means "backhanded"? Thanks.
hevansrv7a
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  #3  
Old 11-28-2005, 08:24 PM
TX7A TX7A is offline
 
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Location: Abilene, TX
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Default

Quote:
Originally Posted by hevansrv7a
Sam,
I'm trying to deal with a problem of locating that knob caused by adding the electric pump for FI. I would like to see a picture of what you are planning. I couldn't figure out where you were planning to put it. Remember the "off" position for the fuel selector is pointing straight aft - I think. What means "backhanded"? Thanks.
hevansrv7a
hevansrv7a,
I'll have to post the picture tomorrow.
The position of the knob assembly will be lying along the inclined portion of the F-739/F-740 forward seat floor, between the seats. Some sort of bracket/cover assembly would need to be made to attach the handle assembly to. I don't see that as a problem though.
"Backhanded" (to me) means that the palm of your hand will be facing aft as you turn the trim knob, rather than forward as in the standard setup. The knob would be about 3 or 4 inches aft of the fuel selector and doesn't look like it would interfere.

Sam
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  #4  
Old 11-29-2005, 02:01 PM
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hevansrv7a hevansrv7a is offline
 
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Location: Detroit, MI
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Default Backhanded

"The position of the knob assembly will be lying along the inclined portion of the F-739/F-740 forward seat floor, between the seats. Some sort of bracket/cover assembly would need to be made to attach the handle assembly to."

That's clever. It also gives me an idea I will pursue at the shop tomorrow. What about just going vertical in the center, just aft of the spar instead of going through the spar? I wonder if the angle is too tight? One drawback would be preventing the use of a center arm rest or console. My friend's Mooney has the trim between the seats, down low.

Thanks.
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  #5  
Old 11-29-2005, 02:16 PM
arffguy arffguy is offline
 
Join Date: Jan 2005
Location: Elk Grove, CA
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Default

Quote:
Originally Posted by 7A_@ABI

My question:
Has anyone done/seen this? If so...got a picture?

I've searched the archives for this particular idea, but have yet to see anything about it.
Sam, I think you would probably be the first one to try this.
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RV-6A wings/fuselage
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  #6  
Old 11-29-2005, 03:22 PM
sf3543 sf3543 is offline
 
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Location: San Antonio, TX
Posts: 1,024
Default

If the manual cable is too long as a result of your new configuration, you could either create a loop in it back in the fuselage cone, if it is long enough, or just leave the extra cable in a half loop back there. You should have planty of room to do this, but just make sure you have it fastened down so it doesn't flop around. (A straight run is nice, but not necessary.)
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  #7  
Old 11-29-2005, 04:13 PM
RivetDriver01 RivetDriver01 is offline
 
Join Date: Aug 2005
Location: Neptune Beach, FL
Posts: 10
Default RV-6 Manual Trim Install

Here's a photo of my "backhanded" installation.





The install was complicated even further by competing for space with the Aileron trim control. The aileron trim knob is 1.5 in diameter and is hollowed out for the threaded portion of the Elevator trim control to pass through. The excess cable is rolled behind the aft baggage bulkhead.

The positioning seems natural and I don't think the reverse turning will be a problem.

-Mel
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  #8  
Old 11-29-2005, 08:00 PM
TX7A TX7A is offline
 
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Location: Abilene, TX
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Default Manual Trim Knob Location

RivetDriver01,

That's it! That's the idea I had in mind.
I also wondered about the trim mechanisim and if it would interfere. I appreciate any more suggestions regarding this setup. I'm leaning towards this concept.
Thanks again for the pic rivetdriver01.
Sam

ps
Here's a link to a pic of my basic thought on the location.

http://img518.imageshack.us/my.php?i...imknob25nx.jpg
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  #9  
Old 11-29-2005, 09:46 PM
arffguy arffguy is offline
 
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Location: Elk Grove, CA
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Default

Oops. Spoke too soon. Guess you are not the first Sam. Good job Mel. I also like the new aileron trim knob. Gotta love this site.
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RV-6A wings/fuselage
RV-3 empennage (extra thanks to Mr. Zilik)
RV-4 Plans only S/N 2938
Cessna 152
Elk Grove, CA
VAF #744 Exempt but paid anyway
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  #10  
Old 11-30-2005, 03:31 PM
RivetDriver01 RivetDriver01 is offline
 
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Location: Neptune Beach, FL
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Default Thanks for the positive comments!

It's really pretty straightforward to install. The only comment I have is to position it as far forward as you feel comfortable. This will allow you to keep the knob assembly centered with the tunnel and have enough space to bend the upper part of the cable to attach to the side of the floor rib. That cable doesn't like sharp bends!

The aileron trim knob took a lot of trail and error fitting, along with equal amounts of filing with a die grinder. It's not CNC quality, but that's what the cover plate is for...

I'll try to round up (or take) a couple more pictures of the components.

-Mel
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