[Hallicrafters] rotor-mast

[Jack Schrader]

Anyone have a suggestion as to how I can secure the mast going up to my 7 element beam more securely to my ham IV rotor. I know that someone ( I can't afford it) sells a device for this purpose but thought I could use
something else, like rough sandpaper, to increase the friction between the mast and the rotor.

I also could use a portable drill and drill through the top of the rotor and then through the mast but the mast is 
1 1/2" galv. pipe and the going would be tough.

Any suggestions?

73 Jack