Drying Pears, Apples, Green Beans and Sweet Potatoes

I'm trying several things in the dehydrator today: pears, apples, green beans, sweet potatoes.

Apples and Pears: Core, cut some with and some without skin. Store cored fruit in lemon water. Cut ~1/8" thick. Sprinkle with cinnamon (next time try brushing with some vanilla, then sprinkle with cinnamon). Dry at 135 F for 7 hours. Turned over at 4 1/2 hours. A bit rubbery, but almost done. Too thin, though, curling up like a bit.

Green beans: chop off ends, mix with 1 t. sunflower oil, sprinkle with salt. Dry at 135 F for 8.5 hours.

Sweet potatoes: sliced 1/8", to 1/2 sprinkled with cinnamon, to 1/2 coated with sunflower oil and sprinkled with sea salt.

Overall, disappointed that they aren't crispier.