Riving knives/splitters and such

[Mike]

Let's just say, for the sake of argument, that someone had decided (all safety concerns duly noted) that they were never, ever going to use the blade guard/splitter assembly that came with their table saw. Wouldn't it be possible to take the splitter, and with a little creative work with an angle grinder, reduce it to something resembling a riving knife?

Of course this would depend upon the mounting setup of the particular saw, but so long as the front part of the splitter mounted securely to the saw, this should work, right?

[marc rosen]

Hey Mike, It would work as a splitter only but not as a riving knife. I had a similar discussion with two woodworkers at a local hardwood dealer and we concluded that the importance of the riving knife is that it keeps the same distance from the blade regardless of blade height and it not protrude above the height of the blade. (The latter is for convenience and not for anti-kickback reasons.) Like most table saws, the splitter is only close to the blade when the blade is highest. I'm not familiar with most riving knife saws but the one's I've seen mount the knife on the trunion/arbor mount/ height adjustment doo- hickey (fill in the proper term) so the knife moves with the blade. Marc

[Doug Miller]

*Resembling* a riving knife, certainly.

What benefit do you hope to derive from doing this?

Depends on how you define "work". One key difference is that a true riving knife moves up and down as the blade is raised and lowered, whereas a splitter does not -- and hence your intended faux-riving knife won't either. In other words, you'll still have to remove it to cut grooves, dados, or rabbets.

And you'll have no blade guard, unless you buy (or build) an over-arm guard of some sort.

Seems to me that your plan combines the disadvantages of both setups, with few (if any) of the advantages of either.

[Mike]

Yeah, I suppose that's true - I was looking at this as a slightly better option than nothing at all. Most blade guard/splitters on new saws are such crap that they are not worth using (yes, that's debatable, and I wasn't looking to start that discussion...) Maybe I'd be better to phrase this as taking a splitter that would otherwise never get used, and reducing it to something smaller/more elegant that would still serve to prevent a workpiece from pinching behind the blade. A better, although not free, implementation of this would be one of the table inserts that has a small splitter.

Lately, I've been seeing a bunch of saws that have a 'riving knife', but one that does not move up/down along with the blade. From what I've read, new model saws are going to be required to have a riving knife in order to get UL listing. I wonder if the fixed position knives are an inexpensive way to comply with the new UL regulation.

[Larry]

"Len" wrote in news:M7swl.17616$ [e-mail]:

Not trying to hijack the thread but... Just got a subscription to Wood magazine given to me by a friend. Reading this months Q&A at the back, Wood magazine did a quick check of their equipment and *none* of their machines were UL approved. Two thirds of ther equipment had *no* certification.

This question came about because a woodworker in NC had an electrician add a circuit for an air cleaner and the inspector would not let him install the device because of a lack of UL cert.

Larry

[Leon]

IIRC all saws have to have this standard by a certain future date.

[Nova]

What type is inspector? I've never know an electrical inspector to get involve with that is going to be plugged into an outlet.

[Steve Turner]

What kind of saw do you have? Most of the stock "splitters" I've seen are made of metal that's much thinner than the blade, and that doesn't really do a hell of a lot to prevent binding when the wood is coming back together behind the cut. A good splitter or riving knife really needs to be a RCH shy of the actual blade thickness to be safe and effective.

[Larry]

Nova wrote in news:_Vswl.970$6%. [e-mail]:

Apparently the electrical inspector. The homeowner hired the electrician to install the air cleaner, including the installation of the new circuit.

[Len]

: > And you'll have no blade guard, unless you buy (or build) an over-arm guard of : > some sort. : >

: > Seems to me that your plan combines the disadvantages of both setups, with few : > (if any) of the advantages of either. : : Yeah, I suppose that's true - I was looking at this as a slightly : better option than nothing at all. Most blade guard/splitters on new : saws are such crap that they are not worth using (yes, that's : debatable, and I wasn't looking to start that discussion...) Maybe I'd : be better to phrase this as taking a splitter that would otherwise : never get used, and reducing it to something smaller/more elegant that : would still serve to prevent a workpiece from pinching behind the : blade. A better, although not free, implementation of this would be : one of the table inserts that has a small splitter. : : Lately, I've been seeing a bunch of saws that have a 'riving knife', : but one that does not move up/down along with the blade. From what : I've read, new model saws are going to be required to have a riving : knife in order to get UL listing. I wonder if the fixed position : knives are an inexpensive way to comply with the new UL regulation.

If it's "fixed position", then it's not a riving knife and shouldn't meet UL, or anyone else's, standards for the way a riving knife is supposed to work.

Len

[Larry Blanchard]

I knew there was another reason I liked my antique Delta where the table goes up and down instead of the blade. Now where can I fasten my homemade riving knife? Hmmmm....

[SonomaProducts.com]

[LRod]

Just as a nit picking point of interest, UL does not "approve." The laboratory was instituted by a consortium of insurers to test products for which they would accept liablilty to ensure they had a certain level of safety. Thus "Underwriters" and "Laboratories."

They test products to verify that they meet a certain standard of insulation or other safety concerns and publish those meeting the appropriate standards on a list. Hence, the proper phrase is "UL Listed."

Back to lurking.

[clare]

Not plugged in, but definitely on a hard-wire.

[Ed Pawlowski]

That is why the inspector should never be called for a single line like that. Or have him inspect the line and wire in the appliance later.

[10x]

Actually, back in my teaching days, I used to teach measurement increments down to the LRCH level :-)

Joe aka 10x

[Jim Weisgram]

Should work. There's the "Shark splitter" that goes with the "Shark guard" that does something like what you describe.

[Steve Turner]

splitters on my Unisaw that are similar the one shown in those photos. But mine are better. :-)

[Martin H. Eastburn]

To get UL - you have to send SEVERAL machines to them. They run destructive and non-destructive testing on then and test against known documentations they have on like equipment.

Big company or tiny product - no real issue. How about taking the first three off a line and saying bye bye - with money and time and not see a penny. You might get cleared - you might get a list of things to fix and re-submit.

Mart> >

[Markem]

Or you change as to what you want from UL. I worked in the explosive environment lab in North brook. Gould submitted a motor with lead which barely met the current requirements of the motor it did not pass as it was a bit hot for a grain elevator environment. They did not resubmit the motor.

Mark