Replies

1. 
   BruceS | May 18, 2008 06:28pm | #1

   What kind of blade are you using?? 

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S. 

    

1. 
   lumberjacques | May 18, 2008 07:49pm | #6

   freud 10" ultrafine crosscut, 80 tpi, part number tkr806 http://www.freud-tools.com/freudtktefco1.html

1. 
   BruceS | May 18, 2008 08:04pm | #7

   As the others have said.  Refresh the surface with MDF or particle board.  But I would go for a different blade also.  Freud LU80R010 HiATB 2degree Neg. hook, 80Tooth.

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S. 

    

   Edited 5/18/2008 1:06 pm ET by BruceS

2. 
   PADDYDAHAT | May 18, 2008 07:24pm | #2

   j, what type and size of stock? Are you using a blade with a negative rake on the teeth? Paddy

1. 
   mrbird90 | May 18, 2008 07:36pm | #3

   To prevent tear out on the bottom side of the stock, the table surface should only have a groove in it the exact width of the blade, this will go a long way to reduce tear out. I never have tear out on the top side. I replace the top surface with 1/4" plywood quite often.

1. 
   lumberjacques | May 18, 2008 07:44pm | #5

   i just changed the top, putting in a new 1" mdf to replace the much scored other surface

2. 
   lumberjacques | May 18, 2008 07:42pm | #4

   generally, hardwoods, such as oak, padouck, etc. sometimes softwood such as canadian pine and cypress.

1. 
   PADDYDAHAT | May 18, 2008 10:06pm | #8

   j, the stock is no prob but as Mr. Bird says ,that work surface needs to have a shallow kerf exactly the width of your thin kerf blade tooth. Think of it as a zero clearance support for the wood fibers. That 15 degree positive rake or hook angle on your blade teeth isn't the best either. Instead of trashing the top when it gets too cut up, just line the new top with a piece of hard-tempered- fiber board aka masonite and replace it when it wears. Let us know how you make out. Paddy

3. 
   oldusty | May 18, 2008 11:06pm | #9

      You don't really  say where the tear out is ? Sounds like the bottom right ?

           Try placing a sacrificial scrap of 1/4" material under , see if the cut improves .

              Take a framing square  , long side against the fence check the blade while pulling out the un plugged saw (osha approved) and see if the same tooth stays with the square line ,,, sight up higher on the fence against the blade to the square to check for heel or toe cut , it may still cut square but have a slight heel cut that can cause tear out .

       Some carriages have rods that like guides or tracks the head travels on them . Take a look if so some can be rotated to reveal fresh surfaces . Also bearings up there with some adjustment if you are lucky .

        Adjust the carriage head to right . Also the slot in the back against the fence can contribute to tear out on the back edge .

      Technic and the RAS are everything , they are fussy easily upset and not for everyone . Seems most shops nowadays use a  slider miter saw instead . I still use my RAS , but I'm totally old school .      

                    good  luck         dusty ,who has a Makita scms and loves it     

4. 
   HowardAcheson | May 19, 2008 01:44am | #10

   I have found that the number one reason for a poor cut is that the blade is skewed. That means that even though you may have aligned your arm to give you an exact 90 degree cut you may not have aligned you motor/blade assembly to be at 90 degrees to the arm. It's the same effect you have on a table saw if the blade is not parallel to the miter slot.

   To check for skew, use an accurate framing square. Place one arm into the angle between the fence and the tabletop. Place the other arm across the face of the blade being sure you do not touch the nut and washer on the arbor and that the square arm is between the teeth. In other words, you want the arm only touching the plate of the blade. The motor assembly should be place out the arm so the blade center is about 6-8 inches from the fence. What you are checking is the the arm of the square lays perfectly against the blade plate. If it doesn't, loosen the appropriate bolts and twist the motor assembly until the square's arm is touching evenly.

   Finally, while a negative hook angle is nice for a RAS, it certainly isn't necessary. Folks have be using the same blades used on tablesaws for many years before negative hook blades were developed. As long as your blade is sharp and appropriate for the cut you are making, it is fine.

   Howie.........
5. 
   Bolts | May 19, 2008 07:23am | #11

   The advice you have already received is pretty good have you checked your kerf adjustments after squaring up the saw to the arm.I use a dial indicator to line up the front and back of the blade using the motor trunions ,I have a RAS for 35 years never had you problem to that degree.Go back to basics and realign the saw and table us a sacrificial top on the table change it every so often should solve the problem.

   You can make it fool proof but not idiot proof