Bench saw fence position when ripping

[brihol]

When I was at college they taught us that the fence should only be as far forward as the hook of the blade when ripping and well back when cross cutting.

Richard

One solution I've adopted when using a full length fence, which are often adjustable is to dial in just a fraction of "toe-out" ie the rear of the fence is about a millimetre further across than the front. It tends to mean you have to use a ruler to set the cutting distance from blade to fence, but I usually do that as a check anyway. The extra doesn't effect the passage of the wood through the blade but stops it binding on the rear of the blade - the principal cause of kickback
Brian

 

[Tarkin]

for anyone that hasnt see a kickback, this link shows an example...the guy is doing pretty much everything to provoke it, not a demo I would like to do!

http://www.metacafe.com/watch/910584/table_saw_kickback_demonstration/


Jeremy

Shudders! :shock:

As someone who is fortunate enough not to have had that happen to me, that was quite a spectacle. Sadly my cheapie table saw only has a very basic full length fence (Axminster job, with extruded ally top), so I always set the fence to be 2mm further away at the back of the blade than at the front, then stand at the non-blade side of the fence. I'm not a trained woodworker though, I've largely taught myself, and this has been my common sense derived method.

I have a block I add to the fence for crosscuts that sits way back from the blade, perhaps I should make a similar one for rips too. Thoughts anyone?

 

[Steve Maskery]

Tarkin
Have you considered making one of these?
http://www.youtube.com/watch?v=d7QXIN2X8-w

Cheers
Steve

 

[Digit]

Like a number of others on here I have a SIP TS. The fence has T slots built in so I have a paxolin sub fence that is slid back and forth to produce either a 'short' fence or a 'long' fence as required.

Roy.

 

[introuble!]

Steve,

"Tarkin
Have you considered making one of these?
http://www.youtube.com/watch?v=d7QXIN2X8-w

Cheers
Steve"

As someone whos new to all this i have to say thanks for all the info i've got from your you-tube vids so far One question though your still standing in the line of fire when you cut that, is the risk of kickback completely gone with your fence and are you not worried about the offcut flying back at you?

Im not trying to have a go it's just i have a triton work bench that scares the pineapples out of me!!!!

Thanks,

Dean

 

[llangatwgnedd]

so I have a paxolin sub fence that is slid back and forth to produce either a 'short' fence or a 'long' fence as required.

Where could I get a small piece of Paxolin from Roy?

 

[Steve Maskery]

HI
I do try to stand out of the way, and if you follow the line of the fence I think I am doing so there, too, although I'm the first to admit that the camera angle doesn't exactly help.

The point is that by removing the possibility of the fence pushing the timber into the rising part of the blade, the chance of kickback is greatly reduced. I'm not going to stick my neck out and say it is removed, but it's not something I worry about when using a short fence. I feel in control, I know the workpiece is not going to get trapped and can use all my concentration to keep my fingers out of the way and know I get the cut I want. Safely.
HTH
S

 

[Digit]

Where could I get a small piece of Paxolin from Roy?

Me if you fancy coming this way.

Roy.

 

[Tarkin]

Tarkin
Have you considered making one of these?
http://www.youtube.com/watch?v=d7QXIN2X8-w

Cheers
Steve

Thanks, Steve. Very interesting.

This is the kind of thing I was thinking about. I have something very similar for making crosscuts, but the way it secures means that it is held about 3" back form the leading edge of the blade. I think I'll make a new one that goes a little closer for rips...

Cheers,
Ewan.

 

[introuble!]

Thanks for your reply Steve and i take your point with camera angles and i realize that it depends your saw and on what your cutting too, your earlier post re wider boards for example. Will be making a short fence with a lip but i'll still stand behind the fence until i have much more experience than i do now.

Will start dropping hints for me Birthday prezzies :wink:

 

[ondablade]

No argument about the seriousness of kick back, but there can be practical problems with a short fence too.

First off there's a point nearing the end of the cut where there's not enough of the workpiece overlapping the short fence to be able to keep it guided parallel to the fence all that accurately.

This opens the possibility of the end of the short fence becoming a fulcrum around which the workpiece rotates if it's not kept tight and parallel to the fence - levering the last part of it out into the leading edge of the blade. Not a safety risk per se as its cutting down, but it definitely risks damaging the workpiece.

A full length fence avoids this possibility by fully supporting the workpiece. The far end can also be clamped down if needed to avoid deflection.

What is a risk (albeit probably minimal if the fence finishes towards the centre of the blade - but more so if the fence ends very close to the leading/cutting edge of the blade) is that when the trailing edge of the workpiece clears the fence it becomes very possible in the resulting space to rotate it with the push stick/whatever so that the far end pivots out into contact with the trailing edge of the saw blade - creating a kick back risk.

The riving knife should prevent this causing a problem, but it's probably another argument for allowing the workpiece far enough forward to properly engage the riving knife before it clears the fence.

A full length fence avoids creating the space for the workpiece to rotate, but of course creates the risk we hear of all the time by providing a surface against which the workpiece can be nipped into the rising edge of the blade. But equipped with a properly set up riving knife maybe the risk isn't that high?

I've worked both ways without incident, but don't have the experience to make a call on the relative risks/benefits. But it seems to me that both have their pitfalls, and that there are fine details of set up and practice that matter in reducing risk and getting good results in both situations.

Despite these shortcomings the realpolitik of the environment the safety industry in this part of the world has created prevents serious discussion - it seems to be that if you are an employer you keep your head down and do as the ideology specifies or risk all.

What's clear despite this though is that there are so many people using so many full length fence systems on so many saws in the US that they can't be anything like as dodgy as the safety brigade over here likes to portray them to be.

How could it be the case, given that it's the most litigation inclined society in the world, and given makers (who often will happily fit guarding so restrictive in some cases as to make a tool almost unusable so you take it off and so assume liability) bending over backwards to avoid claims???

 

[Digit]

That Ian is why I use an adjustable short sub fence, by being able to slide it back and forth I can position it to give the safest result.

Roy.

 

[The Bear]

I don't have any experience of table saws other than my own, nor do I have any first hand experience of short fences. However my saw has an arrangement that is never mentioned whenever this discussion occurs. It has a full length rip fence which extends about 9 inches beyond the back edge of the top onto the rear extension table. The riving knife is about 9 inches front to back so keeps the cut open over a longer distance (think most are only a couple of inches?). The riving knife has 2 sets of sprung anti kick back teeth. As the work is pushed through, the teeth slide over the top. If it starts to kick back, they immediately dig in and stop it. I know that sounds like it might ruin your work but when sliding normally the teeth leave no marks. If it does kick back and the teeth dig in the mark they leave is tiny. I only remember them coming into action a couple of times but I am very happy with this set up. That is until someone tells me why i shoudn't be.

Mark

 

[ondablade]

I'd say if you find it works then it probably works Mark - at least until such time as you or somebody else figures out why not.

To paint a picture. There's set ups that work better than others, and the intelligent use of proven methods must reduce risk - but for my money there's none that is remotely fool proof. Just differing set ups, working styles and workpieces that when changed even slightly can in a flash take the situation from pretty safe to pretty dodgy.

Which means that (until somebody invents the answer to the -gormless- maiden's prayer) the safest set up of all must surely be informed caution and keeping the brain/awareness switched on - plus working hard on figuring stuff out.

Which is why the authoritarian/prescriptive 'you will xyz'/one size fits all style of 'safety' that we see so often must surely be the wrong approach. It has to encourage an unthinking approach - one which very understandably ('but you told me...') rapidly switches to the victimhood and the 'who do i sue' mentality when the inevitable does happen...

 

[moz]

Which is why the authoritarian/prescriptive 'you will xyz'/one size fits all style of 'safety' that we see so often must surely be the wrong approach.

Not really. It's all very well coming to conclusions based on anecdotes or what seems to make sense or I know best. The best H&S advice comes about through long and detailed study of serious accidents. In this context, that has been in favour of the short fence for a very long time. Better guarding, braking and good practice has seen a steady reduction in accidents which I see as a good thing. You may do what you like in your own workshop but I think you ought to be careful going out on a limb and giving contrary advice which may contribute to an accident. It's all very well saying the riving knife has it but the timber can begin to rise as soon as it passes the mid point. Kickback accidents have proved fatal, some involving penetration of the body akin to an arrow. With regard to you particular objection, I would say that not many woodworking procedures are completely skill free. The trick is to push the timber forward, not sideways. it's not that difficult.

John

 

[Ironballs]

I know what you're saying Ian about constantly thinking, but John is right with what he says. You won't eliminate all kick back with a short fence, but you do greatly reduce the risks, I've had kick back twice, one time was using a long fence and the other was when cutting some thick timber that decided to bind on before it got to the riving knife - that was when the thinking ahead approach worked and I was able to kill the saw whilst hanging on to the wood (though having a foot operated emergency stop would have been better).

Like with any problem, address the root cause and not the symptom, going to a short fence addresses the root cause - for most cases, you still need to be prepared for the that stressed timber waiting to twist.

It's also worth remembering that the table saw in rip mode is one of the first power tools in the prep stage that you bring the timber to, in other words ultimate accuracy is not what you should be aiming for here; so you don't need a full length fence.

 

[mtr1]

If I'm ripping sawn timber on my saw I have a short fence as this is the safest way to rip timber. If you take a look at these dedicated rip saws there is a common theme.

I have used this type 1000s of times, usually a 24" wadkin, I was taught by a wood machinist who had been in the trade for 45yrs,and still had all his fingers. If the timber starts binding before it gets to the riving knife simply draw back and re-cut(as suggested already by Sim). When we used to rip timber on one of these ripsaws, if the timber was binding it usually took two, one to push the timber in and one to bang a wedge in at the back. I have ripped 10" timber this way and it is the safest way to do it, I am talking about dimensioning stock at the first stage of course.

 

[ondablade]

Thanks guys, no problem. I'm not even remotely arguing to reduce how seriously we think of kickback. I've likewise been careful not to make recommendations John, and am not about to do so - i don't have the experience to do that.

Nor am i advocating some sort of free for all - and as before it'd be daft not to take on board proven methods.

What i am taking a tilt at though is the prescriptive/authoritarian/no discussion/just do it my way approach to safety (or anything else to do with behaviours for that matter) - because while it's the knee jerk response of most of us, it's been proven time and again that it creates a counterproductive (opposing whatever you are seeking to bring about) mindlessness. (the management/psychological term is 'learned helplessness')

It's one of the greatest problems facing our societies today - being the reason why authoritarian bureaucracies typically turn intelligent people into mindless automatons. Another example is the 'computer says' phenomenon. Googling the term will bring up a gazillion articles on the topic.

Beyond that though it seems to me that serious questions have to be asked when makers in the world's largest woodworking equipment market chooses to sell equipment fitted with full length fences.

The answer to this apparent conflict in views is surely in the detail. More to the point - when mindlessness has the ability to make pretty much any method we care to imagine unsafe it makes the approach to promoting safety at least as important as the technical methods...

 

[moz]

What i am taking a tilt at though is the prescriptive/authoritative/no discussion/just do it my way approach to safety/quote]

I don't think it's authoritative. It's just a question of stacking the odds in your favour or against you, based on plenty of previous evidence. For anyone running a pro workshop with employees it does become prescriptive in effect. Imagine the scenario where some employee has had a large lump of timber fired into his knackers at 100mph. Good luck convincing H&S or a court that that full length fence was an attempt to overcome 'learned helplessness'. Good habits applied consistently really are the best protection.

John

 

[Jake]

Beyond that though it seems to me that serious questions have to be asked when makers in the world's largest woodworking equipment market chooses to sell equipment fitted with full length fences

US safety standards are generally decades behind European ones. It isn't because they have thought through all the dangers and decided full length is safer - they just haven't got as far as thinking about it at all and are just selling stuff that was designed in the 1950s and barely changed since.

The US market seems to be changing and basic features such as short auxiliary fences are being sold as additional value added safety features. That says more than the fact that loads are sold without such basic features.

The argument that they are litigious so must have good safety standards is completely fallacious. Go and look at their industrial injury stats and you will see they are far worse than ours (expressedper thousand or whatever workers).