Kapex is destroyed

i think there are plenty of ways to have an errant piece wood kick back from a miter saw.

my question is can a blade spinning at a max speed of 3400 rpm, fling a small piece of
wood hard enough to do damage to steel? force=mass*acceleration.

i know kick back can occur, but folks we are taking about magnesium case? it it possible
to generate the force to destroy a kapex? (sorry misalignment is not the same as destroy)

 
I have a Sawstop Industrial table saw. It is a big heavy machine with no discernible vibration. I always keep the wood still after making a cut until the blade comes to a complete stop. Yet, I still occasionally get a small cutoff violently bouncing around as the saw slows. Somehow, the cutoff contacts the blade and gets accelerated.  Most of the time the cutoff stays within the blade guard. I always stand so the cutoff won't come back at me if it does get kicked. I also wear good quality safety glasses for that reason.

If this can happen with a big heavy vibration free table saw, I could see it happen with a light weight mite saw.

I think keeping the Kapex head fully depressed and still until the blade stops reduces the chances of launching a flyer.
 
I really don't have a tremendous amount of experience with a SCMS, especially since getting my MFT's and ATF (now TS 55).  I can do just about anything with my TS 55 that I could do with SCMS (I no longer do trim moulding, my experience with that was many moons ago when we did it all by hand saws) or table saw.  Table saw has entered into the conversation I have watched small pieces creep towards the spinning teeth of my table saws as the saw was slowing down.  I never place any part of my body other than my hand or arm in the drect line of possible trajectory of a possible projectile.  I no longer have a table saw, but when I did have, I used a sled whenever possible.  If there were short, or very short cutoffs, they were carried well past the saw blade and I think I allowed blade to stop spinning before dealing with the little piece if i suspected danger.  I haven't used a table saw in nearly 20 years now, so i only think I had good habits.  The SCMS, I have not used enough to remember seeing a short wedge or square cutoff vibrating towards the blade after being cut.  It does make sense to me that such could happen.  The teeth are spinning towards the fence.  If there is a tiny piece of wood bouncing (vibration is a bouncing) around, and it happens to come against the blade, and the part of the blade it contacts happens to be a tooth, I am sure that piece will become a projectile. 

I remember my father's setup with his RAS. (It was in days before sliders became popular, or, I think, even invented) He worked with very miniature projects.  some of those projects had so fine parts they were no bigger than toothpicks.  He had his RAS set up with a worm gear drive so he could have absolute control of the saw head at all times. He also worked with very small blades and small teeth on the blades.  An 8" saw and used small 3 or 4 inch blades if necessary.  The few times I watched him, I never saw a kickback.  I guess he could take all day to run that saw thru one cut of a tiny piece of wood or metal.  He had a bout as much control of the RAS as he had with his machinist lathe.  I have never seen anybody else set up an RAS or SCMS that way.  It would be too costly time wise in carpentry and, i imagine, cabinetry to do so.
Tinker
 
So most scms do not have an electric brake? Really. Actually the kapex sends small pieces flying so easily that even before one can let go of the trigger let alone lift the head... Bam small pieces jammed up or wedged against the blade and zero throat plate. I will leave it at that. I just hope festool steps up and comes out with a better saw because eventually I would like a light, portable, small foot print, good dust collection saw just without the leaky arbor, kickbacks, silly safety switch and internal blade guard, flexible non flat base, and stiff miter table.
 
As a safety measure, I use the same technique as I do for the table saw.

I always position my body on the clamped side of the cut, and never have any body part in line with anything on the other side of the blade. I might take a quick look when starting the cut to insure that the blade is exactly on the kerf line, but then get out of the way. Even then, I always wear safety glasses, shoes, and a healthy dose of caution. Takes a little more time, but I still have all my fingers, and haven't needed stitches in 30+ years! [big grin]

And as Rick and others have stated, I wait for the blade to completely stop before raising the arm.  Even then, I have seen some 1/16th inch cutoffs fly...usually to the back side of the saw, but occasionally straight up. This is without a zero clearance...something I am rectifying as I write this. (Bought a Betterley ZC insert). The small cutoffs seem to fly when they get caught in the opening of base, and the ZC should eliminate that problem.

Cheers,
Frank
 
However I have used my Hitachi, I am sure the procedure has been habitual. I told of hitting a piece of T-channel.  That was a habitual thing as well.  I just grabbed a scrap out of the kindling box and needed it to be a little shorter.  I only saw three sides s I placed it on the saw table.  Luckily, i had clamped it tightly before making the cut.  The rest has been described.

As i have been reading all of the do's and don't's of this thread, one point has become very clear to me.  I don't mean to set an argument against those who argue whether to let the blade stop/or not wait for it to stop.  I am not trying to get into a chewing match.  It has also been mentioned that the blade should be totally down an, not mentioned specifically, forward all the way into the fence.  I never thought about it before this thread, but, it does make sense to my feeble mental mores.

If the spinning teeth are all the way forward beyond the fence and buried deep as possible into the zero clearance part of the saw table, any scrap cannot possibly get jammed into the fence or even come into contact with the blade teeth.  Now, I don't know if the backside of the teeth can have a collision with the piece of scrap that has been cut off.  The rest that i am describing, I think is true.  I don't know for sure, but it seems to make sense to me.
Tinker
 
I always let Kapex stop before lifting blade but still get the odd offcut flying around. It is worse when cutting mitres, was cutting some small moulding last week and every piece shot off as soon as the blade cut through it. Have had a few offcuts wedge in the guard but never any damage.
 
I always let the blade stop and at full depth and still have projectiles.  I am going to check the modification that was stated earlier in this thread and see if that helps.  I like the way the handle is set up because I can operate the saw in an almost identical grip to when I am using a hand saw.  As a result I can actually watch the off cuts and you can sometimes see them  start to move towards the back of the blade and when that happens I move to the opposite side of the saw because things are going flying.
JJ
 
In a production environment there is not time to let the blade stop between cuts, Yes it will mostly eliminate the kick back but in over 30 years in the trade Ive never damaged any other saw from a kickback, the worst I've had was a slightly buckled blade.

But i think most other saws are metal or aluminium at the back end not plastic
 
SittingElf said:
There are numerous instructions to wait for the blade to finish braking before lifting the arm once through the cut.

Hmm... interesting.

I have a different brand of miter saw, but that said, I've always completely lifted the blade out of the material before letting go of the trigger so that the blade didn't even begin to slow down until it was no longer in contact.  I never even thought about trying to stop the blade within the material after the cut...

The only time it stops within the material is if it does so on its own (when I don't want it to) - and that is quite rare for that saw.
 
the only time i've had problems like this is when the clamped piece is not clamped down or I haven't got a sufficient support on end of timber, even with this and the few pieces of offcuts that have snagged and flew backwards the most serious only caused the boot to come off,
 
I'm late getting to this thread.  Back in Post 11 MavDog talks about mechanically lowering the blade, if I read his post correctly.  How do you do that?

Thanks,
Dr.D
 
Thanks.  I think I found it; when I clicked on the photo in the referenced post, the photo disappeared, but went to inspect my saw and identified a silver hex nut in front of and to the right of the miter release gizmo.
 
Well here's the update. Amazon was awesome! I had a new saw show up last Monday along with a shipping label. That was three days after the blow up including two weekend days. Can't say enough about how great it was handled. Now on to the new saw....

I unpacked it and got it mounted to my stand. The first thing I did was lower the blade to cut position and observed how far down it went into the insert while slid to the back of the rails. The blade/saw head was not even close to low enough to clear the fence. I then adjusted the screw near the slide lock knob so the blade/saw head dropped lower into the insert until it cleared the fence when miter is set at 60 deg. I have made hundreds of cuts in the last week with this setup and haven't had a single bullet fly. I can honestly say this saw is awesome! Thanks for all the thoughts and responses!
 
Glad to hear the adjustment has made a difference. I definitely noticed a big difference as soon as I made it.
 
I'm not sure why there are so many people saying this has been handled poorly by Festool. There have been multiple comments on this thread after a Festool Employee said the tool was within the 30 day trial period and he could contact Amazon about replacing it. It seems like he will be getting a brand new saw.
 
MavDog said:
[member=19075]DrD[/member] Here is the link I posted above for instructions on making the adjustment.  http://festoolownersgroup.com/festool-tools-accessories/kapex-%27depth-of-cut%27-adjustment/

Thanks for the update.  My Kapex was good to go out of the box, but it looks like you got BOTH of yours not set up right at the factory.  This seems to have been occurring even back in 2007 when the above link was first posted.  I'm thinking that this depth of cut adjustment screw should be mentioned in the Festool manuals both in the initial setup check and in the troubleshooting guide.
 
teocaf said:
MavDog said:
[member=19075]DrD[/member] Here is the link I posted above for instructions on making the adjustment.  http://festoolownersgroup.com/festool-tools-accessories/kapex-%27depth-of-cut%27-adjustment/

Thanks for the update.  My Kapex was good to go out of the box, but it looks like you got BOTH of yours not set up right at the factory.  This seems to have been occurring even back in 2007 when the above link was first posted.  I'm thinking that this depth of cut adjustment screw should be mentioned in the Festool manuals both in the initial setup check and in the troubleshooting guide.
Totally agree. This adjustment was definitely the issue and should be listed in the owners manuals. Again thanks MavDog for the link.
 
jimmy986 said:
I'm not sure why there are so many people saying this has been handled poorly by Festool. There have been multiple comments on this thread after a Festool Employee said the tool was within the 30 day trial period and he could contact Amazon about replacing it. It seems like he will be getting a brand new saw.

Because if you go back and read the very first post - you will see that Festool tried to blame TetonStorm and that he had been using the saw incorrectly...  They wanted to teach him how to properly use the saw instead of stepping up to the plate and making it right

AMAZON is the one who came through for him.  They have the best Customer Service in the business and why I always try to buy from them
 
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