Passing timber diagonally over saw blade to create curve ?

[tool613]

Personally I'm not keen on fences that short, by using a sliding sub fence on the full length fence I can adjust for different blade diameters, to ac as a gauge when cross cutting repeat lengths etc.
In other words, the best of both worlds.

I have two plates for the PK. One i Added a through fence to cut sheet and guide jigs like the tenoning jig you see in the back ground. I have a short fence for riping on this saw if i need to change the long fence out. I have a large 14" belted saw with more depth of cut than the PK with its 18" blade for ripping with a power feeder(the best crown guard push stick made) :lol: . Then there the general 10" saw with a bessy fence. Man can not live with one saw alone :lol: What i find remarkable is the oldest(the PK) has the best safety features of them all.

jack

 

[Digit]

Nice!

Roy.

 

[TheTiddles]

I've done it, making a tunnel guard over the blade with bits of MDF etc... it's not going to kick-back and I'm stood 2' from the blade taking of 2mm at a time so relatively safe. Is it a recommended practice, of course not, but can it be done safely, yes, with a lot of care. In general do people use that level of care? Not in my opinion.

 

[andersonec]

...it is completely safe.

Wrong, end of. The tablesaur is an inherently UNsafe machine and any machining operation that entails the removal of the crown guard and riving knife only makes it more so, which is why this sort of thing is a complete 'no go' area in any professional 'shop in the UK. What the 'murricans get up to, with a rather more cavalier approach to elfn'safety, is to me at least, beyond belief. One of the main reasons why I never look at FWW 'cos if I did, it wouldn't do the old BP any good - Rob

You edited out the first sentence in my post which was "As with any other machining task, it is as safe as you make it and cove cutting on the table saw can be made as safe as any other table saw cut".

I don't know if you use a table saw cross-cut sled but these also require the removal of the guard and riving knife.

Here is one Americano who explains about 'kickback' properly and speaks some sense about saw safety...http://www.dailymotion.com/video/x7d2vt ... _lifestyle

Andy

 

[SammyQ]

It's not often I want to take issue with the Rob Stoakleys of this world, but I feel I must simply remind everyone that the much respected Bob Wearing went so far as to publish a geometric derivation - based on saw blade dimensions - to work out the approach angle for cove cutting on a" tablesaur".

Now, both Roberts, if memory serves me right, 'did time' in a classroom? The place with the most potential for statistic creation? How can we have two diametrically opposed views from two such eminent practitioners of our hobby?....Oh yes! What do you do for a living, Aled?

Just sayin'....I'm reminded of removing a feline's outer integument, ways to effect same.....

Sam

 

[Steve Maskery]

I don't know if you use a table saw cross-cut sled but these also require the removal of the guard and riving knife.

Andy
That's not quite the point, though, is it?
For cross-cutting, the RK is pretty irrelevant anyway, as the wood is usually severed before it reaches the RK, and in any case, the RK is to mitigate the negative effects of ripping, not cross-cutting.
And when you use a x-cut sled, it has its own integral guard. So whilst the ripping guard may be absent, the blade is still guarded.

You do use different guards for different operations, don't you?

S

 

[Digit]

One other point I would like to raise here. Most of my cross cutting has no need of the maximum cut, so most of my cross cutting is done with a smaller, cross cutting blade.
Why a smaller blade? TPI.
A 10 inch blade with, for example, 60 teeth, has one tooth per 1/2 inch, more or less.
An 8 inch dia blade with 60 teeth has, roughly, 25% more teeth to the inch.

Roy.

 

[andersonec]

I don't know if you use a table saw cross-cut sled but these also require the removal of the guard and riving knife.

Andy
That's not quite the point, though, is it?
For cross-cutting, the RK is pretty irrelevant anyway, as the wood is usually severed before it reaches the RK, and in any case, the RK is to mitigate the negative effects of ripping, not cross-cutting.
And when you use a x-cut sled, it has its own integral guard. So whilst the ripping guard may be absent, the blade is still guarded.

You do use different guards for different operations, don't you?

S

Steve,
That's exactly the point I'm trying to make, when cross-cutting the work is carried past the blade at a constant 90 deg and will not twist onto the back of the blade and this is why we do not cross cut by hand, we all know what the consequences of that operation would be.
When cove cutting there is no ripping cut and the wood cannot pinch onto the blade or be pushed sideways into the back of the blade and as it passes over the top of the blade while it is guided both sides, the blade is completely covered, admittedly it is uncovered when the cut is finished but we must remember the blade will only be, at it's highest, approx 10mm above the table top but I am sure some sort of cover, maybe a box-type effort, could be placed over the work to cover the blade once the cut is complete.

What I am trying to say is the actual cutting of a cove itself, like any other operation on the table saw, if carried out correctly, with the necessary guides and guards in place, is inherently safe, if other day to day cutting on the table saw is inherently 'unsafe' (which it would be if carried out incorrectly) then we really shouldn't be using the machine at all.

On the subject of unguarded cutty stuff, we must look at other machines which, when the cut is finished, eg band saw, router table, the spinning blade/cutter is unguarded once the cut is made and if making a groove in a piece of wood on a router table, the cutter could be quite far from the fence and standing proud in the centre of the table spinning away with a killer grin on it's face, one false move and you have a red router table, much the same in principle.

Andy

 

[woodbloke]

You edited out the first sentence in my post which was "As with any other machining task, it is as safe as you make it and cove cutting on the table saw can be made as safe as any other table saw cut".

I don't know if you use a table saw cross-cut sled but these also require the removal of the guard and riving knife.

Andy

What we do in our own 'shops is entirely up to us, as is the number of mangled digits we also end with at the end of the day. The default position is that this sort of practice has been outlawed in the trade for many years...it simply can't be done, or even attempted. The removal of the RK and crown guard is also illegal in a 'pro shop, much as makers I've worked with have wanted to remove it. When they queried it, the answer from the boss was always a flat 'no'...or words to that effect :-"

On my own saw, the original crown guard supplied with the machine has been replaced with a sprung loaded Suva guard which completey encloses the blade and slams shut once the cut has been completed:

...so that although it's not impossible to get fingers close the blade, it makes it a lot harder

Do I remove the RK and guard? I did once upon a time some years ago before I saw the error of my ways, in fact there isn't a machined groove in my tablesaur now to fit a sled of any description, so Xcutting is done using the slider on the saw...so why do I need to use a sled? I don't, because there are other ways of doing the job which are safer

As many here know, I submit a lot of work to F&C and if any dubious practices were included in an article, it certainly wouldn't see the light of day on the bookshelves in WHS, nor for that matter will you ever see the use of a Xcut sled in the magazine and to the best of my knowledge, no pics of said devices have ever been published (and I have every copy) - Rob

 

[GrahamH]

Flipping through a old (very old?) 1950's The Woodworker and it shows this practice for forming coves.

I think it shows a fence either side, though I can't remember if it shows a bridge piece, if I get time I'll scan it in.

 

[katellwood]

this guy has taken this technique to the enth degree, hands up who's tried this

http://videos.americanwoodworker.com/vi ... merican-Wo

 

[Racers]

Hi,

Hands up? only if you have some left :shock:

What a boring looking bowl, all that work for that, and that’s the only shape you can do.
How many useless ways of using a table saw can they come up with?


Pete

 

[AndyT]

+1

Utterly pointless.

 

[Hudson Carpentry]

Nope. My RAS came with official instructions on how to hollow a bowl using the RAS but I see nothing but trouble on that one so haven't thought anymore on that one.

 

[dickm]

An old friend, now sadly deceased, tried the same trick with his RAS to hollow the bowl of a spoon. It was fortunate he lived not too far from A&E.....
His nurse wife was rather put out when she came home shortly after the event to a message asking if she could find the missing bits of digit among the sawdust in case they could be sewed back on. They couldn't.