Circular Saw q

[meow2222]

I've seen it said its safer to set the blade so it only protrudes 1/4" below the work.

IME this means any jam causes kickback, whereas with the blade fully out a jam just stalls the machine, pulling the workpiece toward the baseplate with no kickback. The times I've had to use the blade shallow I really dont like the way it handles, it can kick easily, and I dont see how that can be safer. It also means more forward force is needed to make progress, which doesnt strike me as adding to safety either.

Any input on this?

Oh - there was recently a thread with a link to various ways circular saws have caused accidents. I've googled for it but again goog doesnt seem to be returning it for some reason. Anyone recall the thread title?

NT

[Bob Mannix]

Yes. You need one of these!!

[Bob Mannix]

Or even one of these:

[Si]

In message , Bob Mannix writes

Looks very pricey, & having an 'aloominum' brake digging into your saw blades is surely going to shorten their life considerably.

[Andrew May]

Don't know about the blade but the brake is a one-shot item. I have a feeling that I have seen a cost of $200 a time mentioned. I suspect that that one fact alone would reduce accidents. It seems a perverse aspect of human nature that loosing $200 if one takes unnecessary risks is likely to have more effect then loosing a finger.

Andrew

[John Rumm]

I think it kills the blade stone dead - never mind shorten it! Better than lopping bits of you off though.

[mike]

I thought this had more to do with the angle at which the teeth meet the wood (and hence the cleaness of the cut) than safety. Is that not correct?

[dom]

I think this is probably more important on saw benches than handheld circular saws.

On a saw bench the crown guard should only have a smallish clearance above the timber being fed through. That reduces the chances of feeding in a finger, and of a kickback if the timber lifts off the table.

With a handheld circular saw, the guard retraction/return is automatic. Both hands are on the saw, so the chance of a finger interaction is small. Should the saw kick right out of the job, your stance and hold should minimise the chances of blade contact - and if that fails, the blade guard should close in time. However - only having a small part of the blade exposed below the job probably does reduce the chances of certain other types of blade contact accident. I do agree though, it makes many saws more awkward to hold.

[David in Normandy]

The thing NOT do do with a table saw is to remove the guard. I foolishly did this as the guard kept getting in the way with larger pieces of timber. However, one day the saw did a violent kickback. It was so violent it knocked the timber out of my hands and the entire table rocked onto it's back two legs, then rocked forward onto it's two front legs - presenting the unguarded circular saw blade straight towards my groin. Thankfully it rocked back upright again. Had it toppled or gone another couple of inches, well.... Closest I've come to a vasectomy - and a heart attack!

[Pete C]

Hi,

What tends to make a kickback occur on a circular saw or table saw?

Is it cutting green wood or poorly supported wood that pinches the blade?

cheers, Pete.

[dom]

I meant to add that with the largest saw bench I've used (Elliott,

600mm blade) the blade was usually left at it's maximum height, but a very good independent guard (not the kind attached to the riving knife) was always wound down close to the job.

I do deep ripping (aka trench cuts) on my own TS - but use a homemade Shaw (tunnel) guard to reduce the chances of blade contact. There rarely is a reason to have no guard at all (I've done it very occasionally when trimming an awkward piece that would foul on a crown guard)

[dom]

Several causes. Two common ones are the cut closing up behind the blade and pinching the rising back edge of the blade, and improper adjustment of the fence leading to pinching between fence and blade. Often compounded by dull/damaged blades, missing or incorrectly adjusted guards. Missing or incorrectly adjusted riving knives. Timbers not properly supported leading to twisting etc. Ploughing on regardless of warning signs (sudden increase in resistance to feed, saw slowing and labouring).

[David in Normandy]

I'd guess poorly supported timber i.e. not flat against the table, or presenting the timber to the saw too quickly. The thing is that when you get a kickback it is so fast you can't always tell what caused it. Bloody frightening though and potentially very dangerous. I seem to remember the particular kickback I refer to occurring when cross-cutting some 3 x 2" softwood.

Familiarity breeds contempt. I'd been working for months without the guard and found it easier to use the saw when handling large pieces of timber.

[Andy Hall]

Standing at the side is the way to avoid this.

[The Medway Handyman]

[The Medway Handyman]

I've always been told that you should adjust the saw so the gullet of the teeth just clears the thickness of the work piece. The theory being that the peripheral speed of the blade is highest at the very edge. This should give the best performance e.g. cleanest cut, maximum efficiency, less effort.

I've never had a circ saw kickback when doing this. Mind you, as they say; "For maximum control, hold the saw firmly with both hands after securing the workpiece".

I always use a circ saw with both hands just so I know where both are - away from the blade. And always stnd to one side of the cut line.

[Stuart Noble]

Great for ripping I imagine.

[Stuart Noble]

More to do with lack of weight in the bench. Either bolt it to the floor or put some sandbags on the base. It should be impossible to push over

[meow2222]

I dont get it... tip speed is the same wherever you put the blade.

Theyre vicious little buggers but so useful. Scariest moment so far was when a fence exploded. Yeah, it was that violent.

NT

[Andy Hall]

It is.

Even better is to clamp the material to a sliding table on the left of the blade and not to use the rip fence at all.