How to stop little fingers getting crushed in a trap door.?

http://www.chasmood.com/archi-dcc.htm

Here is a site that may have useful information.

I would suggest adding a handle of some sort to the bottom of the trap door. This will allow your son to close the door while not having his fingers in the way. A simple handle from the hardware store costs about 2 or 3 dollars. You can even use a small bit of rope, just so long as it is short enough to not be a choke hazard.

They make these hydraulic arms that slow down a closing door so it doesn't slam. I think they sell them at hardware stores. Or is that what you meant by door closer? You should try out various models that may support more weight than a model used for screen doors, which are typically very light, perhaps lighter than your trap door.

How about a 2x2 or 2x3 all the way around the edge to prevent fingers from being flat on the floor and or on the edge? Also a reminder to the kids to keep fingers away from outside.

Attach a handle of some sort, or make a small hole that can be used to hold the trap door.

Good luck! It sounds like your son will have a lot of fun!

If there's a safety risk, I would remove the door until you can find a better solution. You don't want your son to crush his fingers!

Easy! I am a mum...slow down the closer and put a cushion, like foam or soft rubber in place. :)