Replies

1. 
   jazzdogg | May 14, 2005 07:53pm | #1

   We got 2 of them at school this year. They've both been out-of-order for the entire semester because the gears on the blade-raising mechanisms destroyed themselves; I've heard that this is a widespread problem. Before this problem surfaced, we were happy with these saws - particularly the fact that, unlike American made saws, the splitter raises and lowers along with the blade.

   -Jazzdogg-

   Whether you think you can, or you think you can't, you're right.

1. 
   MarkRD | May 14, 2005 09:49pm | #2

   The splitter that raises and lowers with the blade is also called a riving knife. And can be found on one american made cabint saw, the SawStop.Mark

   Measure it with a micrometer, mark it with chalk, cut it with an ax.

   View Image

2. 
   migraine | May 14, 2005 11:04pm | #3

   With you/the school being so close to the main headquarters, are their any legal(small claims) that can be done to rectify the situation???  Baybe a suit for each one of the machines might be possible.  Are they trying to fix the problem??  Seam that a school would be a client that they would do anything to make it right.  Especially for someone that frequently posts on this website... 

   or are they blaming abuse on the students as a cause

1. 
   jazzdogg | May 15, 2005 02:52am | #4

   As I understand it, they've acknowledged the problem and are looking for a remedy - it affects more than just  our saws, and for all I know, could require changes in the manufacturing process or supply chain.

   They have made no attempt to place blame on the school or students, and are interesting in finding a remedy, but have to wait for systemic changes (a factory-supplied solution) that can be applied to all affected saws - not just ours.

   I believe they are fully aware of the damage to their reputations having these inoperable saws in front of staff and students for an entire semester and are sincerely interested in finding a solution.

   -Jazzdogg-

   Whether you think you can, or you think you can't, you're right.

    

   Edited 5/15/2005 12:49 am ET by jazzdogg

2. 
   DaveBarker | May 15, 2005 03:37am | #5

   Because a riving knife raises and lowers with the blade, it can be made to fit very close to the blade. This helps prevent kickback by not allowing wood to contact the back part of the blade.

   The "lowly" Ryobi BT3100 saw has a riving knife and it works quite well.

1. 
   macalex | May 15, 2005 07:02am | #6

   "So what is so special about the "riving knife" ... rising and lowering with the blade?"

   Also allows you to cut over the top of the blade without removing the riving knife - for grooving or ripping stock thicker than your max depth of cut.

   Keeping it tucked up tight behind the blade minimises opportunities for stock to catch on the knife after it has passed the blade as well.

   MalcolmNew Zealand  |  New Thinking0.06% of the world's people are Kiwis

3. 
   jazzdogg | May 15, 2005 07:46am | #7

   "This riving knife feature has been mentioned quite a few times here on Knots, but I cannot recall a single rational explanation for it."

   Metod,

   In a college woodworking environment, this feature enhances safety in numerous ways: since students do not have to remove the splitter, they don't have to remember to replace it; the splitter (riving knife) on the Laguna tablesaws is situated much closer to the blade, minimizing the possibility of the work nudging the blade and causing kickback (a smaller gap between the back of the blade and the front of the splitter); there are no anti-kickback pawls attached to the riving knife (as they typically are with removeable splitters), which makes it far easier and safer to rip thin stock because there's nothing protruding between the riving knife and the rip fence to inferfere with the use of a push stick.

   -Jazzdogg-

   Whether you think you can, or you think you can't, you're right.

4. 
   adastra | May 15, 2005 05:46pm | #8

   The times I've had problems with American splitters occurs when I'm ripping say an 1/4" off in a trimming cut. That 1/8" ripper sometimes will curl and wedge between the splitter and the stock and just have to stop and remove the bind.

   This is a problem if you are ripping 10' or 12' lengths and you are too far away from the machine to reach the power.

   So its happened enough that a splitter will figure into my decision but its such a rare feature its not make or break. But its another reason I'm leaning more towards Sawstop or a used Euro machine.

5. 
   dwright | May 15, 2005 07:27pm | #9

   Metod,

   I'm a hobbyist!  Taking extra time with every single cut to closely inspect the wood and go through a mental checklist certainly reduces the risk of injury.  It does not prevent injury though.  Most people who get cut do not think they were working unsafely.  There are other factors too.  I usually work alone, but I also have a 10 year old son who uses more of my tools every year.  Sometimes friends and coworkers work in the shop on projects.  Even without the brake the SawStop is a very nice saw.  My wife and I considered the issues carefully, and got a SawStop.  So far I think I made the right decision.  Based on earlier posts in this thread, I'm glad I didn't get a Laguna TS.

   You consider blade brake saws to be important to professionals but unneccessary for hobbyists.  I consider these saws to be essential (more then important) to professional and educational shops, and optional (advisable in some cases) for hobbyists.

   Best, Dave

6. 
   Peter36 | May 15, 2005 08:59pm | #10

   I guess you don't "need" bandaids either.

7. 
   adastra | May 16, 2005 02:44am | #11

   I guess I didn't make it too clear. The 1/8" ripper I'm talking about is the fall-off.

   Sometimes when making a trimming cut; say taking 1/4" off a 4" wide rough workpiece to get a 3.75" finish the fall-off will be free to react to any stresses in the piece. Sometimes the workpiece isn't parallel to begin with so what could be 1/8" fall-off at one end might taper to zero at some point during the rip. If you happen to start at the narrow end to trim then that fall-off piece (which is essentially a long taper with a knife edge) can wedge between the splitter during the rip causing a bind.

   If I'm ripping a non-parallel board I always start at the narrow end if I can as I don't like to have the feed pressure disappear while I'm in the middle of a cut. Nor do I like to have the fall-off shoot back (which happens occasionally with narrow fall-off) at me while I still have a workpiece between the fence and the blade.

   I hope that makes a little more sense.

   I won't be placing an order for a SawStop any time soon. But I agree that for a pro it seems more valuable as bills sometimes dictate you work longer than is safe. Fatigue is a big factor in accidents with professionals I believe. That and just the sheer number of opportunities a shop workweek presents for a mishap over the length of one's working life.

   Best regards.