Any reason why Festool ditched the riving knife for the TS 60?

[bwehman]

Obviously Festool considered this disadvantage when designing the tool and decided that the kickback sensor was the net-better way to go. To a lot of people it seems like a major oversight and a big step back. Any idea what the actual good reason might've been? Clearance issues in the body of the saw? Too complex? Lots of engineering for a niche problem? Trying to figure it out and wondering if anyone might know.

 

[peacefulandpatriotically]

Thanks for posting this question, I was just going to do the same.  Let's see what (if any) response we are given.

 

[jeh]

Other manufacturers such as Mafell do not use a riving knifes on their track saws so there is not an engineering need to have one. Removing it saves weight along with the cost of knife and any mounting hardware.

 

[Coen]

Good luck getting a to the point answer. Looking forward to it too.

Other manufacturers such as Mafell do not use a riving knifes on their track saws so there is not an engineering need to have one. Removing it safes weight along with the cost of knife and any mounting hardware.

Half the laptop manufacturers ditched the menu, scroll lock and pause/break keys from their keyboards. That doesn't mean there is no need for those keys. It's just going with the "current thing", reality be damned.

Mafell's sensor doesn't prevent the cut from closing on the rear of the blade and locking it up either.

I will say this again: a riving knife PREVENTS most of the kick backs from even taking place. A sensor only prevents a bloody outcome while also increasing the frequency of kickback in the first place...

For folks that removed the riving knife the sensor is a nice addition. If you cut particle board, MDF, plywood... the riving knife doesn't do anything anyway. For cutting real wood... stick the sensor where the sun doesn't shine and give me a riving knife.

 

[xedos]

Obviously Festool considered this disadvantage when designing the tool and decided that the kickback sensor was the net-better way to go. To a lot of people it seems like a major oversight and a big step back. Any idea what the actual good reason might've been? Clearance issues in the body of the saw? Too complex? Lots of engineering for a niche problem? Trying to figure it out and wondering if anyone might know.

Most likely because it's not necessary.

The materials typically cut with a scoring saw don't tend to close up on themselves. 

It's not an oversight - FT is very deliberate with their decisions - for better or worse.

 

[jonnyrocket]

My $0.02

Festool has two lines of track saws, the HK and the TS.  The TS product line is marketed as a “plunge saw” where the HK is more of a traditional non-plunge circular saw.

The strengths of the TS line over the HK is doing plunge cuts, where the biggest risk of kickbacks is at the beginning of the cut, or during the plunge. A riving knife does nothing to stop this kind of risk, but the new anti kickback technology absolutely does.

The HK on the other had is marketed as a Track Saw focused on cross cuts and rip cuts, and not plunge cuts. As such, the HK still has a riving knife.

 

[ChuckS]

A good reason why the TS60 doesn't have a riving knife...

so that a year later, they can release a new TS60R, a TS60 included with a riving knife!!! [tongue]

Without a riving knife, this six feet long 2" thick oak might not have gone through:

[attachimg=1]

 

[woodbutcherbower]

It's pretty well-known that Coen is the forum's resident riving knife Rottweiler. I bought one of the first TS60's to hit the UK, and I spent literally the entire first day with it trying to make it kick back. Wet green oak, kiln-dried oak, air-dried oak with warps, twists and bends in it and under massive tension, quarter-sawn inch-thick maple, Canadian redwood, air-dried sapele, inch-and-a-half thick walnut, Douglas fir .......... all ripped, not crosscut, and all prime candidates for cut closure. I even tried being really stupid and plunging a 12-tooth Panther rip blade quickly into wet stock.

I couldn't make a kickback happen. The slightest lift at the rear end of the saw triggers a dead stop to the motor.

 

[Mark Katz]

Most likely because it's not necessary.

The materials typically cut with a scoring saw don't tend to close up on themselves. 

It's not an oversight - FT is very deliberate with their decisions - for better or worse.

Well the TS saws are not scoring saws - maybe you meant sheet goods saws. But it is obvious that, while they're great for sheet goods, they're useful for other materials too. If they were only intended for sheet goods, why wood there be a TS 75 and a TS 60? A TS 55 would be adequate for any sheet good. For that matter, so would a TS35 or TS45.

 

[Crazyraceguy]

Most likely because it's not necessary.

The materials typically cut with a scoring saw don't tend to close up on themselves. 

It's not an oversight - FT is very deliberate with their decisions - for better or worse.

Well the TS saws are not scoring saws - maybe you meant sheet goods saws. But it is obvious that, while they're great for sheet goods, they're useful for other materials too. If they were only intended for sheet goods, why wood there be a TS 75 and a TS 60? A TS 55 would be adequate for any sheet good. For that matter, so would a TS35 or TS45.

He may be confused, thinking that all of the TS60 are the TSV version?

But, "sheet goods" doesn't necessarily mean thin. It's not an everyday thing, but I cut through double layers of 3/4" material often enough to matter. There is also the idea of bevel cuts, which changes cut depth dramatically.

 

[peacefulandpatriotically]

It's pretty well-known that Coen is the forum's resident riving knife Rottweiler. I bought one of the first TS60's to hit the UK, and I spent literally the entire first day with it trying to make it kick back. Wet green oak, kiln-dried oak, air-dried oak with warps, twists and bends in it and under massive tension, quarter-sawn inch-thick maple, Canadian redwood, air-dried sapele, inch-and-a-half thick walnut, Douglas fir .......... all ripped, not crosscut, and all prime candidates for cut closure. I even tried being really stupid and plunging a 12-tooth Panther rip blade quickly into wet stock.

I couldn't make a kickback happen. The slightest lift at the rear end of the saw triggers a dead stop to the motor.

Thanks for that feedback.  Out of curiousity, what did the wood look like when that electronic control is triggered?

Personally, the reason I would prefer a riving knife has nothing to do with kickback, for me its all about preserving the cut quality on the wood I am cutting (I use hard wood 99% of the time).  As we all know, you can be ripping a board of your favorite hard or softwood and all is going well when suddenly the wood starts closing up.  Similarly, when ripping boards whose thickness exceeds your max depth of cut, the wood has a tendency to want to close up against the blade.

Please correct me if I am wrong but even the slightest bit of un-expected pressure on the blade will result in a deformed cut.  How is an electronic "Kickback prevention" mechanism going to help me in these particular scenarios?  Isn't this similar to the idea that the highest performing table saws have the lowest levels of vibration, so that the edge on your newly-cut piece is as smooth as possible?

 

[woodbutcherbower]

[member=79298]peacefullyandpatriotically[/member] You’re completely correct in what you say. The few deliberate kickbacks I induced resulted in virtually no damage to the cut edge and only a tiny nick out of the rail’s splinter strip - the motor stops so, so quickly. The tiny resulting scrapes on the cut edge would easily have been removed by one very shallow pass of a low-angle block plane. FWIW - I’m old-school, and I’ve ALWAYS inserted wedges behind the blade whenever I suspect any chance of a cut closure. When I’ve occasionally encountered something closing up a heck of a lot - you can feel it because it’s also closing up on the riving knife, too. The second the saw starts to need any effort to push it - in goes a wedge.

 

[ChuckS]

Snip.The second the saw starts to need any effort to push it - in goes a wedge.

I've never used a track saw or circular saw on anything other than ply sheets. How do you wedge during a cut? Do you stop the saw and put the wedge in the open end, or put the wedge right behind the saw from the top surface while still ripping?

 

[Cheese]

How do you wedge during a cut? Do you stop the saw and put the wedge in the open end, or put the wedge right behind the saw from the top surface while still ripping?

I keep a couple of cedar shims (the stuff used for shimming jambs & windows) in the saw Systainer. When i pull out the saw, I pull out the shims.

 

[woodbutcherbower]

Snip.The second the saw starts to need any effort to push it - in goes a wedge.

I've never used a track saw or circular saw on anything other than ply sheets. How do you wedge during a cut? Do you stop the saw and put the wedge in the open end, or put the wedge right behind the saw from the top surface while still ripping?

It's pretty simple, Chuck. Keep the saw moving (even if you have to slow it right down) - because if you stop cutting, the chances are that when you stop the saw, remove the blade from the cut, move it back a few inches, then re-plunge - the tiniest, fractional movement or deviation will become visible on the cut edge. I cut my own wedges from oak offcuts, but there are also plastic ones commercially available. They need to be around 3" long x a minimum of 3/4" wide (wider is better if you have the material available), and taper from zero to around 1/2" thick - so we're talking longish, thin wedges. If you make them too thick, the wedge angle will be too steep and you'll only be able to get the very tip of it into the kerf - the objective is to have something which you can pop right in there quickly and easily, opening up the kerf with the smallest downwards push of the wedge - and yes, you put them in from the top, behind the saw. I’ve prepared a full photographic construction plan for you down below  [smile]

What I usually do is to scatter a bunch of them on the bench at regular intervals so you always have one close at hand. The number of wedges you'll need to use is determined solely by the tendency of the timber to close up on you, and how long your cut's going to be. I've cut boards where it was closing up after a foot of cut. As I said - you can feel this happening as well as seeing it. So as you move along, keep your eye on the kerf and just feel how the saw moves. As soon as you see any movement on the kerf, or you feel the saw starting to struggle or bind - pop in a wedge 6" behind the saw, press it down into the kerf until you see that it's opened up the cut line again - and keep sawing. The objective of using 3" wedges which taper from zero to 1/2" is that just a small downwards wedge press is enough to open the kerf up nicely (and we're only talking 2.2mm or 1.8mm on TS55's), so it's super-easy to do.

Then just keep repeating the process if necessary as you move along the cut. If it's a horrible, difficult piece of material, you might end up putting a dozen wedges in on a long cut. Hope that helps !!

Kevin

View attachment 1

 

[mino]

To OP:
Marketing.
Maffel was claiming a riving-knife-less saw is better ... and they won the "battle" in the youtu-verse.

... FWIW - I’m old-school, and I’ve ALWAYS inserted wedges behind the blade whenever I suspect any chance of a cut closure. When I’ve occasionally encountered something closing up a heck of a lot - you can feel it because it’s also closing up on the riving knife, too. The second the saw starts to need any effort to push it - in goes a wedge.

So you effectively agree with Coen that a missing riving knife is a downgrade - which you are used to compensate for.  [wink]

A TS 55 R or a TSC 55 ... with a 2.1 mm riving knife and a 2.2 blade ... the only thing needed for perfect cut is to push a bit more. No additional skill, no wedge, not saw stopping possibly affecting the cut. No need to plane a cut surface .. just my experience.

That said, not all riving knifes are made equal.
Friend's ATF 55 in a Basis 1A/T module does not work anywhere close as good. The riving knife is only 1.9 mm with 2.5 mm blades. Too narrow to help with cut quality.

I think the folks which "do not miss" the riving knife generally made their opinion with saws that did not have it thick-enough or did not use blades with consistent thickness matching the knife. Then those which learned the hard way to not rely on the saw solving the wood closing issue for them..

Those who appreciate it - and are able to notice it - are probably too few for Festool to matter. Such is life. Besides, makes TS 55 Rs that little bit cheaper.
[smile]

 

[woodbutcherbower]

The only thing needed for perfect cut is to push a bit more. Just make sure you have good accident insurance.

Fixed that for you.

 

[ChuckS]

It's pretty simple, Chuck. Keep the saw moving (even if you have to slow it right down) Snip.
Kevin

View attachment 1

Thanks for your explanation of how wedging is done, and the visual is, of course, always a great help in any woodworking discussions. Thanks for taking the time, Kevin. Those who don't have a riving knife on their track or circular saws should benefit from your detailed notes.

I have many uses of wedges and shims  (such as for clamping, thickness planing and disassembling) in my shop, and I keep a box of them of various sizes - both shop-made and store-bought, including these:
https://www.leevalley.com/en-ca/sho...MI-76_1MST_wIVIxh9Ch2kmAOcEAQYASABEgKp_fD_BwE
https://www.leevalley.com/en-ca/shop/hardware/feet/levellers/40070-break-away-wedges?item=00S2050

When double-faced taping proves too strong for two boards to separate, a thin wooden wedge is often the life-saver.

 

[Crazyraceguy]

The wooden wedge is a very common technique, which has been around a long time, for all kinds of cuts.
The Streibig vertical panel saw that we use in the solid surface department actually came with a pair of Beech wedges. There is a riving knife on the saw head itself, but a 12' long panel standing on it's side, rather than laying flat, naturally wants to close the kerf because of gravity.

 

[Coen]

It's pretty well-known that Coen is the forum's resident riving knife Rottweiler. I bought one of the first TS60's to hit the UK, and I spent literally the entire first day with it trying to make it kick back. Wet green oak, kiln-dried oak, air-dried oak with warps, twists and bends in it and under massive tension, quarter-sawn inch-thick maple, Canadian redwood, air-dried sapele, inch-and-a-half thick walnut, Douglas fir .......... all ripped, not crosscut, and all prime candidates for cut closure. I even tried being really stupid and plunging a 12-tooth Panther rip blade quickly into wet stock.

I couldn't make a kickback happen. The slightest lift at the rear end of the saw triggers a dead stop to the motor.

Lol, So you did get kickback, just no bloody outcome.

The higher rpm of the TS60 also helps btw.