Cutting down a riving knife.

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MJP

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Gents - I've bought a used Ryobi ETS-1525 (AKA Clarke CTS10D) table saw from a local woodworker. It has already been set up nicely, runs smoothly, cuts good and square. A nice enough saw for a beginner like myself. Now, I've just made a sled for it but I have one problem - the riving knife stand way above the blade so if I have the blade high up, the sled can't pass completely over it because the riving knife comes against the back stop, above where the blade cuts at its highest. It also means that I can't make concealed cuts for dados etc. The plastic guard has long been removed of course! I am thinking of cutting the riving knife down in height so that it is a millimetre or so below the top of the blade. As far as I can see, this won't negate the purpose of the riving knife, it will still keep the cut open. What is the general opinion? Is this a safe thing to do or am I missing a safety issue?
 
I have done exactly this as 90% of the time I am using a cross-cut sled on my saw.
Other than the absence of the crown guard (which can be replaced by something freestanding if you feel the need) it doesn't affect the safety at all (IMO).
 
Thanks pcb - It's good to have some confirmation that I'm OK doing this. OK then - let's get the disc cutter out.....
 
MJP":p4gqjxko said:
Thanks pcb - It's good to have some confirmation that I'm OK doing this. OK then - let's get the disc cutter out.....
hmm, I would wait for a few more replies - there are some who will disagree with me, worth waiting to hear what they have to say...
 
I would strongly suggest getting hold of a crown guard fairly soon and making use of it.They are mandated for industrial use for a good reason.You could also buy a suitable piece of steel for your other intended use and again I would suggest you make efforts to cover the top of the blade in some form as low flying knots are not fun things to encounter.
 
worn thumbs":3qzj8zpy said:
again I would suggest you make efforts to cover the top of the blade in some form as low flying knots are not fun things to encounter.
That's a good point, when using my saw minus crown guard I always wear one of these
 
I have seen a crosscut sled whereby it has a bit of perspex front to back about 6 inches wide to prevent the blade throwing anything at you, and cutting the tip off the riving knife won't hurt that at all.
 
I think the table saw has removed more body parts than almost any other machine (maybe the bandsaw has more fingers counted).
To be completely safe (SAFE, not worried about legal at this stage) the blade should be fully covered so that if you fell forwards for any reason you could not touch the spinning blade.

Anything you remove from the top of the blade is at your own risk. This is where the legal bit comes in. If any one else gets hurt by that blade, even if the blade isnt moving, you would be open to be sued for very big money.

So, what you do in your workshop when the door is closed aint nobody's business (nudge nudge wink wink) but if any one else has access, be extremely careful what you have on show.

Having said all that, if you are going to use a sled all the time and you leave the sled in place when the saw is not in use........
 
Thanks chaps. Being me of course, immediately after the first reply I went and cut off the top of my riving knife. Sled works great now, and a five-cut gave me a cumulative error of about 30 thou, good enough to begin with.
But the mention of a cover over the blade - I could fix a sheet of thick polycarbonate over the top centre of the sled, covering the blade. That's a nice idea. I'll do that.
 
A last comment:
Looking through ebay for suppliers of polycarbonate sheet to make a guard for my sled, it's clear that some of them don't know the difference between polycarbonate and acrylic. So looking for a more reliable source, I came across https://www.thepolycarbonatestore.co.uk/ who seem to be willing to supply small pieces, cut to order, for very reasonable prices. Looks like a good source to bookmark for machine guards.
 
Yes, that's another good site worth bookmarking. I see they do Tufnol too, which is useful for my other interest, which is amateur radio.
 
I am a firm advocate of the combination of a low riving knife and an overarm guard. That is the industrial way of doing things. The way we were taught in vocational school.
The only reason why few saws are fitted with overarm guards is that a piece of injection molded plastics held with one bolt to the riving knife is a lot cheaper to manufacture and once the ownes has removed it beacause it didn't work the maker is free from all responsibilities.
Unfortunately your saw may be a bit small for any comercially acvailable overarm guard.
 
heimlaga":18qbo41l said:
I am a firm advocate of the combination of a low riving knife and an overarm guard. That is the industrial way of doing things. The way we were taught in vocational school.
The only reason why few saws are fitted with overarm guards is that a piece of injection molded plastics held with one bolt to the riving knife is a lot cheaper to manufacture and once the ownes has removed it beacause it didn't work the maker is free from all responsibilities.
Unfortunately your saw may be a bit small for any comercially acvailable overarm guard.
Don't entirely agree. The guard attached to the riving knife has several big advantages; it stays close to and in line and height of adjustment with the blade so it's always well covered against accidental contact, it's very effective at stopping kick back - or kick up - where the blade lifts a piece and flings it like a sling shot, it has low profile and doesn't get in the way of line of sight. Also it's a lot simpler to set up, and cheaper, which means less likely to be left out of the operation.
I'm just guessing but it might be a later development as only moulded plastic will do as the material - you couldn't have metal that close to the blade as contact does occur occasionally, quite safely with the plastic.

So - answering the OP; there's place for both but the knife mounted guard gives highest degree of safety.

PS Steve Maskery did a video some time back showing the dangers of using a flimsy DIY overarm guard. The main hazard was that having it mounted from the side any contact with the blade or workpiece could immediately twist the guard around unpredictably. Steve's guard got flung forcibly off!
Knife mounted it's always dead in line.
 
Oddly enough I was thinking about this last night. I've ordered a couple of sheets of 5mm polycarbonate to make a cover guard for my sled which should make that reasonably safe, but I was thinking about the crown guard as well. I could buy another riving knife and fit the original crown guard to that of course (when I bought the saw the crown guard had been removed, but I do have it ) and change the knives when needed - but would I do it? So I was thinking about making some kind of Wadkin style guard - which I understand now is called an overarm guard. This could be bolted to the Ryobi stand upon which the saw sits and swivel over the blade when needed. I'm sure that this could be done with a few pieces of steel bar, sheet, angle, a bit of welding and some swearing. Interesting times.
 
MJP":uj0waozu said:
.... I could buy another riving knife and fit the original crown guard to that of course (when I bought the saw the crown guard had been removed, but I do have it ) and change the knives when needed - but would I do it? ...
You'd get into the habit after a few near misses. If you actually lost a finger you would become extra cautious about losing another one!
I'd definitely advise against a DIY over arm guard. In Steve's demo it got forcibly snatched so fast it was difficult to see how it had happened. More like an explosion!

PS and if you must use an uncovered blade always use two push sticks. Feels odd at first but becomes second nature and actually increases your dexterity and control. The standard pattern - not just any old stick. One in each hand at every possible opportunity! Make copies from mdf or ply, have them always around near the machine.

100237_xl.jpg
 
MJP":3iph4hz1 said:
Thanks Jacob. Could you give me a link to Steve's demo please?
Not sure where it is. A few years back - ask Steve?
 
Hey -I'm a newbie - who's Steve?

Steve- if you're reading this, can I have a link to the event that Jacob mentions please?
 

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