Hi, Essie!
Welcome to MLMF
I do NOT know very much about electric mowers other than how well they do for maintaining smaller lots and yards. I believe I understand the problem you're having and it may be something as simple as finding a flat spot for the cap screw to tighten against. I can't confirm this but I did look around for online help.
Perhaps this may lead to someone (like talking to a real person) from this LINK: Black & Decker Tools | 19" Electric LAWNHOG. If you scroll down the site they do offer How To videos and maybe even email help....
Let us know if it doesn't and we'll try something else...
Welcome to MLMF
I do NOT know very much about electric mowers other than how well they do for maintaining smaller lots and yards. I believe I understand the problem you're having and it may be something as simple as finding a flat spot for the cap screw to tighten against. I can't confirm this but I did look around for online help.
Perhaps this may lead to someone (like talking to a real person) from this LINK: Black & Decker Tools | 19" Electric LAWNHOG. If you scroll down the site they do offer How To videos and maybe even email help....
Let us know if it doesn't and we'll try something else...