Rational "Crown Board" or "Coverboard
Not really required...But for completeness sake
The Grain should run along the longest dimension of any part.
Cutting of parts (all dimensions in mm).
Long sides of rim
Other rim parts
This item is identical in size and construction to the
"National Crown Board"
Use with rim downwards for bottom bee space or with the rim uppermost if top bee space is required.
The holes shown are to suite the standard
Porter Escape Holes
gives methods of cutting such holes. For normal use a single 33 mm central hole proves to be adequate.
9 mm plywood is specified owing to it's greater rigidity and freedom from warping. This durability outweighs the small cost saving of using thinner material.
9 mm is specified for the thickness of the rim material but commercial supplies are often of 8 mm thickness, using 8 mm is unlikely to cause any problems.
Assemble using a waterproof PVA type glue and 16 mm pins or staples.
If you wish to use this item in a system that uses bottom bee space, then add the
The version as drawn above is both simple and durable. If
is used on the rim and
is used on the main panel the item will give many years of good service.