So I had another go at these today. Easy as pie. At the risk of sounding stupid, but for the benefit of any others like me ..... the grease is not an optional extra. Plus, a good dollop of grease on the spring and ball bearing stops the little sucker from bouncing all over the garage floor.
Only negative comment so far is I reckon I’ll be up to Bunnings for some star washers. With the supplied flat washers the nut wants to come loose with the opening and locking of the blades.
We are heading to Gladstone this week so I’ll get to try them out.