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Pietenpol-List: Engine thrustline offset

Posted: Fri Oct 23, 1998 12:48 pm
by matronics
Original Posted By: Michael Brusilow
Usually the measurment of "an inch" is taken at the prop end of the crankfrom center. I built my mount square and shimmed with washers at the mountattach point.Flies great. I also added 1/2" offset at the front edge of the verticalfin.Steve e.-----Original Message-----Greg CardinalSent: Friday, October 23, 1998 12:22 PMSubject: Pietenpol-List: Engine thrustline offsetI'm starting to think about the A-65 motor mount and would like tohear from builders who have completed and flown their planes.Did you build in any offset to the thrustline?Plans show some downward thrust but no offset to the right.I know some people build it in but I don't know how much.One experienced builder says "Down 1 inch and to the right 1 inch."That's fine until you think about the angle of offset.If shims are used at the motor mount to engine case connection toachieve 1" the angle is greater than if you used a pivot point fartheraft.So, the questions are:1. How much offset did you build in?2. How did you achieve your offset?3. How does it fly?Thanks,Greg Cardinal in Minneapolis________________________________________________________________________________

Pietenpol-List: Engine thrustline offset

Posted: Fri Oct 23, 1998 1:21 pm
by matronics
Original Posted By: Michael Brusilow
I'm starting to think about the A-65 motor mount and would like tohear from builders who have completed and flown their planes.Did you build in any offset to the thrustline? Plans show some downward thrust but no offset to the right.I know some people build it in but I don't know how much.One experienced builder says "Down 1 inch and to the right 1 inch."That's fine until you think about the angle of offset. If shims are used at the motor mount to engine case connection toachieve 1" the angle is greater than if you used a pivot point fartheraft.So, the questions are:1. How much offset did you build in?2. How did you achieve your offset?3. How does it fly?Thanks,Greg Cardinal in Minneapolis________________________________________________________________________________

Pietenpol-List: Re: Engine thrustline offset

Posted: Mon Oct 26, 1998 8:47 am
by matronics
Original Posted By: Michael D Cuy
>So, the questions are:>>1. How much offset did you build in?Greg- I tried to build in a degree or two off set andabout 1/2" downthrust into my jig. Final result is thatI had to use washers behind the motor mount to getit close to the above figures. It hardly has any offsetor downthrust and flies just fine. I do need a little moreright rudder on climb out though than I should require.>2. How did you achieve your offset?>3. How does it fly?>>Thanks,>Greg Cardinal in Minneapolis>>________________________________________________________________________________