I was given this used saw. Went to cut a piece of timber with it but as soon as the blade touched the wood the blade stopped rotating. Turned it off and checked. The blade can be rotated by hand. How do I tighten up the blade? When I try to tighten the central nut the whole spindle seems to turn. On my angle grinder there are 2 flat sides on the spindle to stop it rotating when changing blades but I can see no such on the saw. Any help appreciated.
It is an older saw with no pin. Instead I have put a piece of wood in the saw and held the teeth of the blade down on it. The spindle still turns when I try to tighten.
OK, the blade is locked, the securing nut is fine, the spindle turns,
It sounds as though there's a spacer missing.
The securing nut goes over the blade and holds it tight by friction. What might be happening is that the nut reaches the end of the spindle thread BEFORE it comes into secure contact with the blade.
There is often a spacer (perhaps missing in this case). The spacer simply "bulks out" the blade, effectively making it a bit thicker.
Thick enough to allow the nut to sit tight to the blade before it runs out of spindle thread.
These saw blades come in different thicknesses. A thick blade may have been fitted in the past, allowing the nut to tighten on the blade. If that blade was replaced with a thinner one, an additional spacing washer may be needed between the nut and the blade, just as Builder points out. Sometimes when a saw manufacturer's thinner blade is bought, it comes supplied with this spacer, in case it's needed.
must just add, we have one we bought from B&Q 16 years ago, has cut miles of wood, we built decking, timbered out the garage, cut the wood studding to insulate 3 rooms in the house, completely re-did the kitchen,bulit door frames, clad the bathroom, built hen houses etc. same blade, and it still cuts and mitres perfectly. wonderful tool.
Mine has a special washer that allows for slightly different blade thicknesses. It is a thick one with a 'sunken' middle to fit over the shaft, so it is actually the outer ring of the special washer that holds the blade in place. Maybe yours is supposed to have one too and is missing, it sounds like it.