circular saw

[Fred]

Hello,

Some years ago I bought a green bosch circular saw from a well know DIY shop (why do people here call them sheds?). It's been fine for occasional DIY use. In all that time, I've never changed the blade. Silly question: how do I know when it's time to change it?

I've been having some problems lately with the guard. When I cut, the guard lifts as it should until I'm halfway into the wood but then it won't lift any further so the saw cannot advance. If I lift the guard with the finger tab, it frees it, and thereafter it will continue to lift on its own and I can continue sawing. What does this mean? Does something need oiling or replacing? The instructions don't really help in this regard.

Thanks.

[Frank Erskine]

It probably just needs a good clean to get rid of bits of sawdust in the guard mechanism.

[George]

Odd that,you're halfway into the wood and you cannot go any further? I'd of though if the guard has lifted and you're well into cutting the wood the guard cannot stop you from proceeding. Could be your blade teeth have become blunt and its putting strain on the motor? is there scorching signs on the blade?chec that the blades securing bolt is tight?does the guard run freely in open and close mode ie can you move it with your hand?

[David in Normandy]

I had a similar symptom with my Wickes circular saw. The cause was the blade guide was slightly bent behind the blade, so the blade would cut into the wood up until the guide reached the wood - it was missing the groove and hitting the wood to the side of it. Took a while before the penny dropped because you can't really inspect the saw while it is running.

[Stuart Noble]

Sounds like the lower part of the guard is catching the front edge of the workpiece. It's happened occasionally on all the circular saws I've ever used. Chopsaws usually have a plastic wheel to ride more easily over a square edge

[dom]

That's the riving knife. It's there to stop the material closing up behind the cut and pinching the blade. Bent riving knife - bad.

[Frank Erskine]

Another possibility is that the blade is worn or has lost its set, so that the kerf is jamming on the riving knife - this coiuld give the apparent symptom of the guard jamming. Take the blade to the saw doctor!

[David in Normandy]

I just bent mine back into position. It only needed bending very slightly to fix the problem. Been fine since.

[dom]

.

Whilst I've taken really good handsaws, and stuff like planer blades to the saw doctor - do people really do that with small circular saw blades - particularly hobbyist ones?

[Pete Verdon]

I wouldn't. Even if I knew a saw doctor, I think for my PPP circular saw I'd just be picking up a new blade from B & Q.

Pete

[George]

Wouldn't it be cheaper buying the saw. ;-)

[Steve Firth]

A few months back I needed a pair of ear defenders, some goggles and dust masks. It was cheaper to buy a B&Q PPP set of all of the above with a 185mm circular saw blade than it was to buy them separately. Of course now I have a blade that doesn't fit anything I own, but I think eBay will take care of that problem.

[The Medway Handyman]

I've found this happens in two instances;

In timber of a certain thickness where the guard catches under timber. Try adjusting the depth of cut so the edge of the guard touches the edge of the wood & doesn't go under it.

When I've been cutting timber supported on a couple of battens. The guard edge touches the floor/bench first.