Benson Blade tracking bars

[Gyro28866]

Does anyone have a set of plans to build or photos to look at; to gather info to be able to build a set of blade tracking bars for a set of Benson blades. looking for been there done that oops, from someone. so I do repeat the same trials.
Thanks.

[Jazzenjohn]

I made some bars to help set the blade pitch on my Bensens. The way I did it was to take some 1" square aluminum stock (massive overkill, it was just that I had it laying around) and drilled holes to allow it to be clamped over the bolts on the pitch blocks. I made them 14.3" long from the pitch pivot to the end, blued the ends and scribed lines for 1, 1.5, and 2 degrees of pitch. I clamp them onto the 2 pitch blocks with some quick clamps. It makes setting the pitch accurately very easy and quick. I didn't get a tremendous improvement but I got a small one. Its biggest feature is that it's quick, and if you're not careful you can be way off using the scribed lines on the pitch block itself, but it's darn near impossible to be off using the bars. If I remember correctly the sin of 1 degree times 14.3 is pretty close to .25" so 1 deg is 1/4" up from even, 1.5 deg is 3/8 up and 2 deg. is 1/2" up from even.

[Gyro28866]

Thanks John.
I built a set of tracking bars, your measurements are dead on.
Thanks alot.
David

[Jazzenjohn]

Glad to help. I think I usually set them at 1.5 degree up from even. You can also use the same trick to set your adjustable prop pitch accurately by doing the same thing but instead of the Al. bar, use a laser shining on the ground.

[Gyro28866]

I tried using 1 1/2 degree and had a little hop at 45 to 50 mph.
reset back to 1 degree - smooth as silk - all airspeeds,
I did not exceed 75mph indicated in a decending turn which I leveled off about 50 agl above the runway. all smooth