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Main => Builders Discussions => Topic started by: Steve A on March 30, 2010, 09:50:48 AM

Title: Pressure to push levers(?)
Post by: Steve A on March 30, 2010, 09:50:48 AM
While im waiting for various items to arrive to finish my throttle, or at least make it usable, I have not been able to help myself from sitting with it pushing the power levers back and forth lol, i mounted the levers very kindly donated by Jack on a 12mm central spindle/axle and used a combination of large nylon and steel washers plus nyloc nuts. This method has worked great for getting good friction and the levers feel strong when pushed back and forth, and by loosening or tightening the nyloc nuts i can adjust the stiffness (?) Enough waffle, my question is:
How many pounds of force is required to push by hand real throttles forwards?
I was thinking i could adjust mine with the aid of a sprung scale ( like what fishermen use ) and get them approximately feeling like the real thing.

Thanks Steve
Title: Re: Pressure to push levers(?)
Post by: jackpilot on March 30, 2010, 12:04:43 PM
Tough question.
I think from memory that Mike told me 6 pounds, I may be off.
Rule of thumb.
As hard as you like, as long as you are able to make fine adjustments without having to go back and forth to reach the desired point.

Tip, to estimate the right torque/feel move the two levers together as you have to overcome about twice each lever friction.
Probably someone will jump in with a better answer.
JP
Title: Re: Pressure to push levers(?)
Post by: DarrylH on March 30, 2010, 05:26:00 PM
I can't comment directly on airliners but in general and (in my opinion having flown lights, and some high performance):

1. Depends whether the throttle is spring or mechanically loaded to "closing". If so you want a good dose of friction.

2. Depends on the sort of flying you are doing. Long cruise you want tight friction. Jaunting around sight seeing you may have it more loose.

3. Aerobatics, tight enough to not move around, loose enough so that you can use your fine motor contol for small adjustments.

4. At the end of each flight friction nuts and oil tank caps should be tightened as much as humanly possible (with grips preferably) because it ensures that the next pilot's  inconvenience is  maximised.... ;D

That is the reason most aircraft have pilot adjustable friction nuts. I assume with auto throttles witn servos may differ greatly


Darryl
Title: Re: Pressure to push levers(?)
Post by: Boeing Skunk Works on March 30, 2010, 05:44:55 PM
I may still have that spec that was sent to me from a Boeing maintenance manual. However, it's stored on an out of service computer at the moment. Still works, just not being used.

I am going to be using this computer again in the near future and when I get it out of mothball I'll see if it's still on the drive.
Title: Re: Pressure to push levers(?)
Post by: Steve A on March 31, 2010, 10:04:39 AM
Thanks Guys, It would be interesting to know exactly but for now i have set them at about 5lbs as this feels nice when im pushing/pulling, I have had to put a small bag of sand in the base of the stand as a weight because i cannot screw down the throttle and it trys to tip when i use it lol