Hi Dai
I have not changed over to wfp yet, and have just finished my trolley (building my own) I also have the unger poles, and have also used waste pipe to hold my pole, but what I did was to cut 4'' of waste pipe down its lengh to create a strip of waste pipe, I then riveted this to the bottom of my pipe to stop my pole going all the way through, I don't know if it will have the same affect as you have, but I think after reading your thread, I might have saved myself a few new ends for my pole, many thanks