When to start crate training and stop free feeding

I don't really like free feeding because it's harder to really tell if one of the dogs is "off its feed" and something is wrong.  Plus, since I use food in training quite a bit when I am teaching new behaviors, I like to be able to know when my dog is hungriest, thus time some of my training sessions so that I can use part of the ration as rewards when the dog is likely to be most motivated by that.

I suppose what I do is not true free feeding.  I know how much the dog eats per day and stop at a certain point (or encourage her to eat more).  But if I set down the bowl of food she doesn't run to it and eat it all like the adults.  I just leave it in the puppy pen until it's gone, or until I have to leave and then pick it up.  Currently she is getting kibble as training treats (otherwise she'd be eating like 50/50 food/treat!) so that's factored in.  I think part of it is how these pups are weened and fed up to nine weeks.  Each breeder has their own method.  They are used to a more "grazing" style of feeding.  Since they grow so fast it's not hard to tell if something's wrong, and the poop is always a great indicator.

Come to thing of it, my adults "graze" as well but are also fed a measured amount.

 I started crate training my newest pup the first night we got him. He put up a bit of a fuss, but you just have to ignore it. You'll learn quickly when your pup needs to use the bathroom or he's just wanting to get out. I give him something to chew on once he's in the crate to prevent him from whining too much and he's learned quickly that when he whines he won't get what he wants. If your pup needs to go outside and has been in the crate, wait for a break between the crying and then take her outside to use the bathroom then put her back in the crate. This is what I do with him at night.

I don't free feed him and personally I don't like the idea of that. He has a scheduled time for being fed three times a day, it makes it easier to know when they have to use the bathroom. 

Hopefully I've helped!