I have recently discovered that the £26.99 mitre
saw I purchased for B&Q isn't much use for
anything wider than 7cm, which I would have
found out if I had read the box more carefully.

It`s not really the full answer but I modified the blade guard on my similar
cheapo mitre saw so that it`s able to cut a few exta cms.( but not as much as
13cm)

A previous answer to a similar question said that the cheapo sliding saw
versions( eg B&Q ) worked up to around 285/300mm ( 1 foot) but the sliding
action wasn`t very good.( rather stiffish)

HTH

Chas