Mounted and measured the length of the flapperon, marked the wing with masking tape. Used Dremel cut the wing at the masking tape. Sanded it down until the flapperon slot in the wing tip was even with the masking tape and then re-mounted the flapperon and re-measured (purposely tried to only make the flapperon fit, then once installed, I could accurately measure the gap. Pipestrel recommends 3mm. I measured 2.5mm (I can always take off more) to the edge of my applied masking tape and then took it apart, ground down the wing tip until even with the tape. Re-assemble flapperon. Measured movement up and down. Pipistrel says you need 33 degrees down and 28 degrees up. Calculated the amount the flapperon has to move to get that angle, measured and was short. I held the flapperon at the end of it's travel, Gave it a soft blow to mark were it was hitting the hing and took apart and ground out the areas were I could see the hit mark. Repeated this until I achieved the desired deflection
