Is there a way to bend flex track into a specific diameter? I have some 8' and 9' pre-curved track, so if I need to bend some flex track that diameter I can eyeball the pre-curved track to try and match it. But if I want to make, say a 12' curve is there a way to determine how much bend to make? I'm using 5' long pieces of flex, so maybe if I measure the length of a straight line from one end to the other until it is X long? Any ideas?