The importance of practising what one preaches

[siggy_7]

Yes but you are not really supposed to do anything other than "severing" cuts on a TS.

This is precisely the sort of thing I meant when I said that some people are in denial about reality. The fact is that lots of people use their table saws for non-severing cuts. I am not defending the plethora of bad practice promoted by some amateurs online, but there are lots of examples where table saws are used in this manner. The main examples that come to mind are cutting box joints and tenons. Both of these cuts are often made on the table saw, and the type of riving knife with crown guard attached prevents it. Manufacturers like Incra will even sell you jigs specifically designed to do these singular tasks; these manufacturers have to comply with the safety standards of the regulatory environment in which they sell. So if the UK government says it's ok for Incra to sell you a box joint jig, you should recognise that people are going to buy that jig and use it even if you don't think it's a safe/sensible thing to do. As removal/re-fitting of the over-tall RK is a right pain on most if not all saws, this inconvenience is a substantial short-coming of this type of guard, and something more flexible is needed (i.e. an overhead guard rigidly supported, but not attached to the saw assembly).

 

[Jacob]

..... As removal/re-fitting of the over-tall RK is a right pain on most if not all saws,

No prob on mine (Mini max combi) I just slide the table forwards and there are two nuts. 30 secs maximum.

this inconvenience is a substantial short-coming of this type of guard, ....

It's a trade off - on the other hand it's a very effective guard - much better than the suva type and relatively fool proof - it stays close to the blade and moves with the adjustment. It's just about indestructible. I doubt there have been many finger accidents with the crown guard in place.
And of course when cutting slots/housings over the blade arguably you don't need a guard so much as the blade isn't extended far and is partially covered by the work piece, as long as you use push sticks and drop the blade down as soon as out of use.
There are some very daft gadgets out there Many of them just too clever by half. All the non crown guard type have the same inherent fault; they can be wrongly adjusted i.e. they are not fool proof!
They nearly all have a second fault in that they are mounted from the side so accidental contact with the blade will skew them over and jam them tight. To avoid this they have to have plenty of space around - sometimes wide enough to get your hand in too close, particularly if wrongly adjusted in the first place.

PS I lifted this picture from the net. It looks just like my Minimax except this one has only one nut. Even quicker!

 

[PAC1]

It is a trade off. A crown guard can be wrongly adjusted for instance if you do not wind the bade down as low as possible part of the blade can be exposed. A suva provides a complete cover for the blade when it is spinning but not cutting wood whereas a crown guard leaves the sides and back exposed. It is also possible for a crown guard to touch the blade and unless very well fixed to the RK be pulled off. A suva probably gives better dust control as it encloses the blade. My crown guard sometimes acts more like a chute to ensure I swallow the maximum amount of dust and is useless when trimming boards to width as it cannot capture dust going sideways.
They both have pros and cons

 

[Jacob]

..It is also possible for a crown guard to touch the blade and unless very well fixed to the RK be pulled off. ...

Hmm, not really - it's mounted very rigidly in line and behind - if it touches the blade it'll just lose a bit of material. That's why they can be set so close to the blade. You'd have to swipe it with a hammer to get anything worse to happen.

 

[PAC1]

..It is also possible for a crown guard to touch the blade and unless very well fixed to the RK be pulled off. ...

Hmm, not really - it's mounted very rigidly in line and behind - if it touches the blade it'll just lose a bit of material. That's why they can be set so close to the blade. You'd have to swipe it with a hammer to get anything worse to happen.

A very rigidly mounted suva and a very rigidly mounted crown guard will be equal to the task. But a less rigid crown guard and a less rigid suva will cause problems. I have seen less rigid crown guards. for instance on my Felder the supplied crown guard is attached to the RK by a bolt as per yours but the RK has an open ended slot in the top of it rather than hole to fit the bolt thus with the best will in the world rigid is not a phrase I would use to describe the connection. The theory is the light crown guard detaches rather than dragging the RK onto the blade. I can also remove the Crown Guard in seconds for when I lower the blade below the table. But as a safety device it is not what you expect from Felder.
You can get a suva that attaches to the RK rather than fixed by some side extended arm. Potentially best of both worlds

 

[siggy_7]

As removal/re-fitting of the over-tall RK is a right pain on most if not all saws,

No prob on mine (Mini max combi) I just slide the table forwards and there are two nuts. 30 secs maximum.

Good for you! If only all saws were the same. On my Record, taking the knife off is equally fast - a single 16mm nut. It's very easy to drop the nut and washers into the dust collection guard of course, but aside from that it's easy. Putting it back on is a bit of a faff without dropping the bits. What takes an age is re-aligning the RK. Mine has three grub screws that control alignment - so as soon as you tighten the nut, it changes the alignment. You then have to slacken off the nut enough to make an adjustment, tighten up again, slacken adjust tighten etc... It's a pig of a job, principally because the process of tightening the nut changes the alignment. So even if you had it perfectly aligned, in the process of taking it off and back on again you really struggle to get it aligned properly without making some adjustment. This style of RK is even worse because of how wide they are at the top - this makes alignment with the blade as viewed from above even more critical. What's the difference between the thickness of an RK and a blade kerf - 0.6, maybe 0.8mm? Trying to get a knife aligned over an 80mm height and 100+mm length is a nightmare. All in all, I hate the RK on my saw with a passion and anything I can do to avoid having to alter the adjustment or remove it I will. Hence the attraction of a guard not supported on the riving knife. With other saws of course, your mileage may vary.

^ My nemesis of table saw adjustment.

 

[Jacob]

As removal/re-fitting of the over-tall RK is a right pain on most if not all saws,

No prob on mine (Mini max combi) I just slide the table forwards and there are two nuts. 30 secs maximum.

Good for you! If only all saws were the same. On my Record, taking the knife off is equally fast - a single 16mm nut. It's very easy to drop the nut and washers into the dust collection guard of course, but aside from that it's easy. Putting it back on is a bit of a faff without dropping the bits. What takes an age is re-aligning the RK. Mine has three grub screws that control alignment - so as soon as you tighten the nut, it changes the alignment. You then have to slacken off the nut enough to make an adjustment, tighten up again, slacken adjust tighten etc... It's a pig of a job, principally because the process of tightening the nut changes the alignment. So even if you had it perfectly aligned, in the process of taking it off and back on again you really struggle to get it aligned properly without making some adjustment. This style of RK is even worse because of how wide they are at the top - this makes alignment with the blade as viewed from above even more critical. What's the difference between the thickness of an RK and a blade kerf - 0.6, maybe 0.8mm? Trying to get a knife aligned over an 80mm height and 100+mm length is a nightmare. All in all, I hate the RK on my saw with a passion and anything I can do to avoid having to alter the adjustment or remove it I will. Hence the attraction of a guard not supported on the riving knife. With other saws of course, your mileage may vary.

^ My nemesis of table saw adjustment.

Bad design. It needs two nuts then it's dead easy - you just hold it in place and tighten the nuts.

 

[blackrodd]

I googled 'shaw guard' and came up with all sorts, including this, which looks like it would withstand significant abuse from flying bits and would be quick to adjust.

That is the original and genuine shaw guard, easy to set up and use.
The wooden pressure blocks that you see, are secured with spring steel strips to the main frame and being slotted at the end, helps getting the ideal pressure.
The cutters, or wobble saw etc, are behind the guard, wouldn't be any good to be on either the left or right hand sides.
Regards Rodders

 

[siggy_7]

Bad design. It needs two nuts then it's dead easy - you just hold it in place and tighten the nuts.

How do you adjust the alignment then? Shims?

 

[Jacob]

Bad design. It needs two nuts then it's dead easy - you just hold it in place and tighten the nuts.

How do you adjust the alignment then? Shims?

Non needed on mine. It just drops on to its bolts. Factory set though I expect I could alter it if I had to. I can set it a smidgin higher if the crown guard is too low for the depth of cut. There are two settings for the guard - if you have a scoring blade installed it'll go forwards to cover it.

PS my riving knife has a slot - I don't need to remove the nuts n bolts - just loosen them to get it off, finger tighten to keep them in place if I'm not putting it back.
I think yours are difficult because the machine maker is trying to tell you something i.e. don't do it!