RE: servo screws
You need to determine what thread type/pitch is required . You can do that by going to a hardware store and trying different bolts until you get one to thread in or trying some from your parts bins/piles. It doesn't have to be the exact same head style. I've used capheads with a washer on some servos where I've lost the machine screw. If you don't have any hardware stores then try a bolt from another servo. Futaba arms are supposed to fit ACE servos so you could try a Futaba machine screw. If not then you can email ACE RC and give them the part number from my earlier post and buy them.