Having all parts printed now, I started the assembly. First stop: the M4 nylock nuts I have here are 4.88mm high whereas their slots in the cornerblocks allow only 4.68mm. Before I apply brute force persuasive taps with a hammer or a soldering iron to bring them home - would standard non-lock nuts do there as well?
Don’t use locknuts in the cornerblocks. Standard M4 nuts are 3.2mm thick.
Yeah I went with someone else’s metric part list and it looks like M3.5 are a much better fit. Sorry. I will go get some hardware this weekend and have a test fit. Sorry for the hassle. regular nuts should be fine though.
Franz, Vicious (still having problems to cal somebody Vicious… 
) - thanks.
Cheers,
Ulli
I had enough M4 square nuts laying around, which worked very fine.
Just drove myself nuts (lol) trying to figure this out. The only nuts that come with the kit are lock nuts.
My locknuts from the kit should fit.