Hi I am building a super box to fit my seven flow frames and require the length of the over hang section at the back of the frame in mm. This is important to ensure the adjustment screw functions properly. Please see attached photo.
I only modified a Langstroth box. It has a 3/8" frame rabbet on each end and with standard frames that leaves 1/8" of slop or 1/16" extra space on each end. I didn’t check that carefully but I think it was the same extra space with the flow frames.
3/8" is around 9.5mm I will ensure I allow for some minor adjustment.
I have built a super to house my 7 flow frames that will sit directly on top of a National Brood Box.