Great points!
The base I have used is 12" x 20". Not very large. It is 5/8" solid steel plate so its pretty heavy. I feel no issues with tipping left to right, but I may add a few inches in the front to back dimension (the 12") to offset a slight tippyness. I could, for example push the machine over with a medium shove.
I appreciate the pedal input. I made on pedal already might as well figure out how to make another! Any thoughts on optimum sitting and standing heights for cylinder machines? Or typical heights? We mostly due small things (bags, purses, wallets) and imagine sitting a lot- I may add the ability to raise height if need be. As it is now it is about 37.5" to the feed dog from the floor.
Trying to get these pictures on....