Ken

Thanks for the prompt and comprehensive answer. It all seems clear but there is one question. Please will you confirm that the metal inserts have the 'flat bit' at the bottom and not at the top ?

I've been doing electric parkflyers for about six months and am now build a nitro trainer. So, there is much to learn. Thanks for the kind offer of additional assistance. With people like you and P C (and all the others too numerous to mention) around I'm sure that there will be decent answers for my (anticipated further questions). Of course, I'm not against doing forum searched first LOL