DIY 10mm König Eyepiece

Just a quick question,

I'm thinking of making a 50mm eyepiece for a Bresser Messier 10inch dob,  do think this would work?

Many thanks

Mark

Markie, a 50mm eyepiece in an f5 telescope like your dob gives an exit pupil of 10mm, which is vastly too big, probably big enough to see the central obstruction. Try making an eyepiece of around 30-35mm focal length.