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Hi there,am building a t/q but have no idea how to connect the potetiometer to the throttle levers because the lever travel on the boeing t/q is only 60 degrees and all I can find for sale are pots with around 300 degrees of travel which when connected would give me only 1/5 of the power setting when the throttle levers are at full forward position.how do builders get around this problem? any help please ,john
Hi Johncor,
We using gears, a big one (70 teeth) on the lever and a small one(20 teeth) on the pot.
That will give you a good ratio.
Best regards
Jan Geurtsen
For gears, get an old laser printer and disassemble it. Loads of neat parts to use for tq or other moving things
Hi John,
as already described you need to use gears.
To use the complete range you need to find a gear with the correct ratio. Here an example:
Lets assume you have a 280 deg pot and 60 deg lever travel.
the ratio would be 60/280 = 0.214. That is your target ratio. Lets assume you want to use a gear at the lever with 50 teeth.
Then you need a smaller gear for the pot (50t*0.214=10.7t). Since you wont find a gear with 10.7 teeth you could use one with 10 but that would exceed the travel of your pot since
your actual ratio would be 10/50=0.2. That means your pot would use 300 deg (60/0.2) for a lever travel of 60 deg. Thats to much since you have only 280 deg.
So you have to use a bigger gear for the pot. Lets try 12 teeth. 12/50=0.24 --> Now your pot would use 250 deg (60/0.24) for a lever travel of 60 deg. Which is close to your target.
I hope that helps you abit.
keep in mind that the travel of the pot has a tolerance. You should find it in the datasheet. For the max travel of the pot you should subtract the tolerance from the max travel value.
Cheers,
Rob
Thank's guys for the help,since i'm building the tq from scratch it would not make such a difference if the lever travel is a couple of degrees either side of 60 degrees.thank's again, john