CNC router machined plywood supers

Hi guys,

I’m looking into putting my experience as a CAD draftsman and also my experience from a previous job as a CNC router programmer/machinist into practise by making some supers to house my new flow frames. I’m trying to save a few bob whilst giving me something to do. I’m looking at getting a 2400x1200 sheet of 19mm marine grade plywood and machining as many supers as I can out of .
I can design the box in 3D software used in the cabinetmaking industry and simply send this through to the flat bed CNC for machining. It will include all the cut outs for observation windows, tool insertions etc etc just like the boxes flow sells. The only thing I will do different is that instead of doing the fingers joints I am planning to do a tongue and groove joints combined with screw and glue.

My questions are-

  1. Can anyone comment on the success of plywood used for hive boxes? I am planning to paint the outsides of the plywood with some exterior paint.
  2. I am getting some contradicting dimensions for what size to make these 8 frame boxes from. The flow team in their details for modifying langstroths says the internal measurement are 310mm x 465mm x 245mm high. Am I good to proceed with these internal measurements or does someone have something to add or correct here.
  3. What are the correct rebate dimensions on the box ends that the frames sit on. Is the depth to this rebate working to maintain a certain size gap from the top of the box to the top of the frame?

Any help much appreciated
Dale

There is a lot more at play with hive measurements than people first realise. Your major constraints are the langstroth frame size, the width of the Hoffman edges and the space from the bottom board (or super below). Other things to consider are that the frame stays at the end of the box are rebated to allow bee space between the frame end bar and the end of the box (a measurement often overlooked by people closing this space or using ‘rails’ for the frame stays).

I personally think the 310mm internal width for 8 frame is wrong, but it seems to be ‘standard’ regardless. The flow 8 frame seems slightly wider than this (315 from memory).

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Perhaps the measurements you want are here: http://www.dave-cushman.net/bee/lang.html

When the plywood is free it’s definitely worth it. When you have to buy it, I’d rather have solid wood. It lasts better.

I’m using leftover plywood for boxes also. You don’t want any of the end ply exposed on the corners. I’m using miter joints with dovetail keys on mine.

Using CNC you might be able to get more creative and use blind dovetail miters or tongue and groove miter.

Another very cool option that will extend the life of the box is to cut mitres through all but the last ply, which is then folded giving you a continuous layer of wood around 3 of the joints.

Here’s a link to a single piece of wood miter: http://www.popularmechanics.com/home/interior-projects/a15537/cut-makes-building-drawers-super-easy/

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