Non-through cuts, a "forbidden operation"?

[DennisCA]

Came upon this statement in an american forum

and my current tablesaw is a modern slider with riving knife and dust collection hood mounted on it, the riving knives in europe must extend above the blade so that you cannot make non- through cuts, a forbidden operation.

I am wondering if that really can be true? Isn't one of the main points and advantages of a riving knife that it can be used for non-through cuts? Sounds like this just transforms a riving knife into a tilting splitter. Surely modern saws aren't like this? One of the things I love about my old german saw is how I can do non through cuts and never have to remove the knife, it's just there.

I dunno it sounds to me like when americans say dado blades are illegal in europe, an incorrect statement but with some truth behind it.

 

[marcros]

incorrect. I suspect that the "truth" comes from the fact that most come with the guard attached to the riving knife from the factory, and to do through cuts the knife and guarding may need modifying to allow it (without needing to remove the knife to do so)

 

[Racers]

Mmmm see this thread.

table-saw-danger-t81629.html

Pete

 

[heimlaga]

This is how I have understood the matter:

There are plenty of daft Americans sueing machinery makers for any damage they have been able to inflict on themselves through any kind of possible missuse that the manufacturer hasn't thought of before and hence not forbidden. This is happening all the time and there are lawyers specializing in running this kind of lawsuits and there are always a certain percentage of cases where a judge or jury gets convinced that the victim did not know better.

Hence manufacturers are trying to protect themselves. In principle if you build a machine with a guard that makes the machine impossible to use without removing the guard then using the machine to cut wood will be an action that isn't recommended by the manufacturer and hence the manufacturer will be free from any responsibilities for accidents happening. Also every kind of use that you forbid and add a warning sticker against will not be your responsibility as a maker.
Various makers are trying to exploit this quirk in EU and particularly USA legislation by making guards that makes machines increasingly useless and adding stickers claiming that just about any use is forbidden.

The normal procedure undertaken by safety-minded owners of saws with that kind of riving knife mounted guard is to use a hacksaw to cut down the riving knife and then add an overhead guard just like yours. Then the maker's responsibility will be lost in the past but instead one gets a safe and useful table saw. In varois countries within EU such modifications may lead to various legal complications but I have won that battle against government so I know that here in Finland it is safe to do such modifications as long as the new guards are up to standards.

I was taught in vocational schools that cutting rebates and other thenching cuts on a table saw is allowed and reasonably safe but you must do it carefully and stay out of the path of a possible kickback. A kickback hitting you on your genitals may spell disaster to your fertility.

 

[woodiedonald]

I was told that a non through cut is more likely to bind on the blade and is more dangerous because you cant exactly see the path of the blade and could have a hand or something else in the way when you push the wood all the way through. Basically you shouldn't do it in industry but if its a home workshop you can do as you please.

 

[heimlaga]

In industry it is done all the time. Though I don't know what the inspectors say.

With an overhead guard it is very easy to keep one's hands a good distance away from the front end of the guard and consequently away from the cut line. On normal cuts one doesn't see the exact cut line beneath the guard so there is no difference at all except the slightly increased risk of the blade binding. Hence the riving knife should be in place. Push sticks are also important.
That is how our vocational school teacher taught us in 1999 or 2000.

 

[Phil Pascoe]

I can't see why it would be more likely to bind - how can it?

 

[condeesteso]

I don't know our local UK/European legislation regarding this, but I see tsaws in many pro shops set-up clearly to make blind cuts.
I admit my first thing with a tsaw is remove the hood and drop the riving knife just below the blade top.
Regardless of rules if I couldn't do blind cuts I would find my tablesaw considerably less useful.
Re binding, provided the stock is guided accurately (fence, slidding carriage etc) I see no greater risk of binding than with a through cut.
Re safety, to some extent a blind cut must be slightly safer as the stock acts as guard for the blade.
I do consider the tablesaw the most dangerous machine in the shop so I don't wish to appear cavalier about this... care and sense is necessary.

 

[Steve Maskery]

It's not that blind cuts are illegal or unsafe, they are not. The point is that they are so often carried out in in an unsafe manner.

 

[wizard]

Do it all the time, knife just below blade overhead guard 2 push sticks 3hp motor 14” blade

 

[Tom MasterCraftsman]

I've been trenching on panel saws and radial arm saws all my working career, many workshops I've worked in we always took off the riving knife regardles of blade size ony really nessary for ripping timber when trenching you don't really pass the knife.
I have experienced many kick backs due to binding even with a knife on, gards knifes and hse is important but understanding you machine and what can happen is most important, even with a push stick you can get hurt with kick back.
On a table or panel saw and a radial arm saw kick back out due to the beds being out of true to each other causing the wood to drop or rise if not supported or bent or cupped timber and the cut closing on the blade causes binding and kick back, you should do your best to be aware of this and always position your self and your hands arms ect in a position where you won't be hurt. Rembering that you should be able to exorb the forse of kick back it it happens eg like jumping you bend your knees when landing. The same applies to all machines wood is a natural product and the stress of the grain is often relived when you cut though it causing it to bind or move whilst machining.
I've had many visits at places I've worked from hse the make dish a big thing about gards but on many machines the can be totally useless ,respect the machine and are always aware of what can happen and don't get complacent or lazy machinery can be safe and a joy to use. Something hse will never understand only experience will teach. Common sense always helps too hse not aware of that one either.

Stay safe, be aware and keep yourself out of harms way and touch wood you should be accident free!!

 

[Sgian Dubh]

I have experienced many kick backs due to binding even with a knife on, gards knifes and hse is important but understanding you machine and what can happen is most important, even with a push stick you can get hurt with kick back.

Stay safe, be aware and keep yourself out of harms way and touch wood you should be accident free!!

So, basically you're saying you've had many kickbacks, then talk a load of drivel about sloppy wood machining techniques, and close with a contradictory homily about staying safe and accident free ... after admitting you've experienced lots of, er, accidents.

You're not expecting anyone to take anything you said in your post seriously are you? Slainte.

 

[Tom MasterCraftsman]

I've only had one injury due to machining and it wasn't a kick back, the point I was making is if you understant what can happen respect your machinery you are less likley to be injured, If you are close enough to need a gard your to close!!! I'm not saying you shouldn't use gards you should.I'm making the point that most old school and experienced wood workers know haw to stay safe gards or not. A riving knife is only in use when the wood passes it, if trenching the wood needs to be wider than blade before it comes in use!! Eg a 50mm but of wood will only contact knife rafter making the cut!!
Be aware of the danger so you can avoid.

 

[Shrubby]

Richard Jones 1 - Tom Nil
I've just spent hours making partial cuts with a Shaw guard on the saw and a push-stick and push-block copied from Holz-BG
At no point was I impeded or slowed by safe working practises and still have 10 fingers
Matt

 

[Tom MasterCraftsman]

I just thought by explaining how I have experienced kick and how it can happen and how the knife is only really is in use on longer cuts it my help others avoid injury and kick back. Just trying to be helpful and share my experience of machining, i thought i made some valid points on understanding what causes kick back, I agree not using gards is sloppy, most accidents happen when being complacent and not being aware of the risks.

Tom.

 

[Tom MasterCraftsman]

I just read the post on table saw danger using a push stick, it's with a look!!

 

[PAC1]

If you look at the HSE website a riving knife is essential but does not need to be higher than the blade. If you are making a rebate or a groove on the table saw you need a Shaw Guard or other guard that will prevent the piece of wood going airborne and will keep your fingers and push stick away from the blade.

 

[Graham Orm]

I just read the post on table saw danger using a push stick, it's with a look!!

Thanks for the input Tom. Whether you're right or wrong, not everyone on here is aggressive with new members. Welcome and don't be put off.

I cut the top off my knife so that it's level with the top of the blade, allowing partial cuts. No problems so far. You always see a disclaimer on TV woodworking shows, saying that the guards were removed to help with filming, we all know this is BS and that the guards get in the way.

Every time you use the table saw you take a risk, guarded or not. The thing is to be permanently focused on safety, regardless of how simple the cut may be. I've experienced kick back once, the wood flew past my shoulder and embedded itself in a 9mm MDF panel on the wall behind me. When it happens you don't know about it until it's over it's that fast so reacting and getting out of the way isn't an option. I was shaking and stopped working for ten minutes. Then, as always I stood to the side of the blade, I believe this simple precaution saved me from a nasty injury.

"Have a good day, and let's be careful out there!" (Name the TV show).

 

[DennisCA]

If you look at the HSE website a riving knife is essential but does not need to be higher than the blade. If you are making a rebate or a groove on the table saw you need a Shaw Guard or other guard that will prevent the piece of wood going airborne and will keep your fingers and push stick away from the blade.

Whats a Shaw guard? Is this another name for the same system as a Boom Arm and SUVA that I need to add to my mental list of words for the same thing?

 

[Phil Pascoe]

I just read the post on table saw danger using a push stick, it's with a look!!

"it's with a look"?? :?