I put sticky velcro on the bottom of the pedal and it holds it to the carpet. If you don't have carpet there is a product call stay pedal that you can get, under $20.00 at Joann's or Hancocks, cheaper with a coupon. It's basically a mat that the velcro will stick to-----
I too have a 6600 and I learned to use the stop/start button and don't even use the foot pedal. It was ackward at first but once you get the hang of it,----wonderful-----
I have fibromyalgia, bursitis in my hips and sciatia so this has been a life saver for my back and hips----Give it a shot and don't give up----