I would buy one too.

A friend of mine takes a piece of PVC pipe the size of the patty he wants and cuts it in half down the length. Then puts plastic wrap in one half and fills with sausage and wraps the plastic wrap over it and then the top half of PVC and clamps. Into the freezer for a few hours then cuts with his slicer. Just another idea.

I would say your cooking temperature was too high and you melted the fat out of the sausage. Can you post your cooking process and temperatures?

Did you ice water bath them to cool after cooking? I have had luck with this helping.