It is such fun and a great lesson for kids.
Here in Texas I do the same thing with my hand crank machines. I create a bunch of 2 patches that can be sewn together to make a 4 patch quilt square the visitors can take with them. I just let the kids turn the crank to avoid liability issues and they are excited. The boys especially like watching the bobbin move back and are interested in the mechanics of it all. As a project for in-between times, I sew 5 inch squares together to make a quilt top and when finished I will set it up so visitors can help tie it. I done this for over 10 years at Texas historic sites and it has been great fun. This is such a great way for kids to develop an interest and understanding of history and people who made this nation.