Both the Swienty and MB appear to have the same demensions with 5mm top bee space and this applies to both wooden and plastic frames I have used.
The bottom bee space is 5mm with the plastic frames and 2mm with the wooden ones (Th*****) so taking 3mm from the runners may not.
Seen them running together in Denmark and they are NOT the same. The PH ones, as sold by MB are very different in how high the frames sit. They indeed were so close to the flush roof, and worse, if a normal one was sitting on top, there was inadequate beeway and they waxed and/or propolise them together, and the other way round make a mess of ladder comb. Great was the gnashing of teeth.
Checking the bee space at the bottom may just tell you about variations in the frames. Some of the plastic frames are moulded for the North American standard size for a Lang. deep, and some are moulded for an Aus/NZ size, and little cognisance is paid to this. Aus NZ frames are made slightly less deep than the usual international standard as, for historical reasons due to availability of very close in size wood, the were made with boxes just a coupe of mm less deep, and the length of the side bars trimmed by that much too so as to fit. I raise this as some of the plastic frames sold in the UK ARE made in NZ and are the short size. If you ever acquire some Aus or NZ boxes, and have not stated that they are for the European/North American size, they turn up a little too short for our frames and also bottom bee space. I went out to check some of our stuff in store after the previous post and indeed in the newest ones (the mould was rebuilt about 2009 due it wearing out) the point made is partially true, though the frames we have made to our own spec with UK/European thickness lugs sitting on the runners still sit at a proper height allowing adequate bee circulation space, the USA frames are a little higher in the box and do result in a split bee space and some issue getting over the top of the frames under a flush roof or feeder base..
Making the boxes non standard for the market they are in is really an unneccessary modification, with the main thought being to tie you in to that design.
In the referred to thread earlier mention is made of why are they made for Dadant frames but are a Langstroth box? Well, what is called in the UK a Dadant frame is not really called that anywhere else. It is normally called a medium depth, and called Dadant depth in the UK as it IS the same depth as a Dadant shallow. Internationally actual Langstroth shallows are a relatively unusual box, normally used for cut comb. Langstroth boxes are in 5 standard sizes, shallow, medium or Illinois, intermediate, standard deep, jumbo deep. The two common sizes are the medium and the standard deep. Hence the moulds are made primarily to make the mediums and the standards though some also do the jumbo. Thus, in the UK, you will be advised to get Dadant frames for the supers, as they are actually mediums not shallows.
