I have been having trouble with my extractor moving around the garage floor for years
So I put some wheels on it after a suggestion on this site and it helped dramatically the extractor would just dance around all over the shed and occasionally crash in to stuff.
Last week when I was extracting, I accidentally left a large lid off a 20 Kilogram honey bucket on the ground(Right way Up). I also moved the extractor and ONE wheel went up onto the lid.
I started the extractor and to my amazement this rogue wheel on the lid just sat there and the extractor simply moved around a little on the lid but basically it just sat there.
The rim of the lid guided the wheel and kept it in place. It made my day,I hope this might help someone else who is fighting their extractor.
Cheers
Steve