i personally use dowels and screws where you have a divider above to cover a screw head if its 12mm then no6x2" screws and a 3mm drill
15mm no8x2" screw with 4mm pilot
then the next level 2 or 3 --8mm x 35-40mm dowels to miss the screwheads by at least 1mm
this method allows you to individually dowel the dividers then screw into each divider
mark up all shelves with the center line off every divider on both sides except the top and bottom then just the inside face
use several dividers to mark up the ends lay one end on its back mark the bottom thickness at the bottom in this case 18mm square across then lay a divider on the line covering 90% off the pencil line draw a line and whilst holding firm place another divider end on and mark to give you next shelve height repeat till the top
then back to back flat on the surface transfer to the other end
dry fit the outside components and rebate the back
number the shelves out off sight and dry dowel to both sides then disassemble
start with the bottom shelve flat attach dividers using dowel then screws then dowels as suggested above check on each level for gaps and tap with a hammer and protective block
once you up to second shelve lay on face when locating the dividers with the dowel pins but make sure your surface is 100% flat otherwise you will have a mismatch iff the divider is in a slight hollow as it will be forward off the face
you then stand it up again for the screws then face down for the next row off dividers
you finish with the ends glued on but checking its as square as possible as soon after assembly as possible
clear as mudd ehhh
15mm no8x2" screw with 4mm pilot
then the next level 2 or 3 --8mm x 35-40mm dowels to miss the screwheads by at least 1mm
this method allows you to individually dowel the dividers then screw into each divider
mark up all shelves with the center line off every divider on both sides except the top and bottom then just the inside face
use several dividers to mark up the ends lay one end on its back mark the bottom thickness at the bottom in this case 18mm square across then lay a divider on the line covering 90% off the pencil line draw a line and whilst holding firm place another divider end on and mark to give you next shelve height repeat till the top
then back to back flat on the surface transfer to the other end
dry fit the outside components and rebate the back
number the shelves out off sight and dry dowel to both sides then disassemble
start with the bottom shelve flat attach dividers using dowel then screws then dowels as suggested above check on each level for gaps and tap with a hammer and protective block
once you up to second shelve lay on face when locating the dividers with the dowel pins but make sure your surface is 100% flat otherwise you will have a mismatch iff the divider is in a slight hollow as it will be forward off the face
you then stand it up again for the screws then face down for the next row off dividers
you finish with the ends glued on but checking its as square as possible as soon after assembly as possible
clear as mudd ehhh