Replies

1. 
   BlueEnamel | Dec 04, 2002 05:18am | #1

   Ron,

   I use a 40T Freud Diablo thin kerf 7-1/4" blade w/stablizers in conjunction w/ a jig similar to a crosscut sled on my TS. I use it to cut stringing for inlay work. It seems to work well. If you set it up to cut an exact 90 degree then by adding angled inserts/fences at 15, 30, 45, 60, 75, etc. degrees to it, you can cut the angles exact and be able to repeat them.

   You do have to be very precise when making the jig and angle blocks, but it pays off in the long run. I use 1/2 or 3/4 MDF for the base. One of the recent FWW issues had Steve Latta make a set of sleds. Mine is of similar construction, but not as large, since the stock is usually less than 1/4" thick. Also, the smaller blade + the MDF thickness reduces the total thickness you can cut.

   For wood for the fences, I'd use poplar or mahogany, and orient the grain so that any seasonal movement does not affect the reference face(s) of the jig. Same for the angle blocks. If you're going to use the jig for a long while, or for a bunch of pieces, you may want to make a separate jig for each angle. I'm not sure which is the better option.

   I also use similar jigs for making burr puzzles and other interlocking puzzles.

   I hope that helps,

   -- Blue

1. 
   Ron | Dec 05, 2002 01:20am | #2

   Thanks, I was hoping you would say you use you miter saw,I have so many pieces and so many angles.I have been working on a set up to try my miter saw,I hope to give it a test run this weekend.Its one of those things that you think about and you have to do it just to put your mind at ease.Its nice to have your input just in case I'm unsucessful.I have the issue that you mentioned and I have read the article again.Thanks for you help. Ron

2. 
   BG | Dec 05, 2002 02:06am | #3

   Blueenamel,

   it appears Ron is all set to go...do you mind if I ask a somewhat related question?

   I was just slicing up some quartersawn 3" maple into 1/2x3x30" strips/boards.  The TS is brand new. I'm getting burning on the fall away board.  That is, not the board between the saw and fense, but the other side.  I'm using a thin kerf 30 T Freud.  Do you think I need to go down to 24T..or maybe the blade is warped?  The TS seems okay...any thoughts?  Thanks

1. 
   johnhardy | Dec 05, 2002 03:08am | #4

   Typically, it's good practice (IMO) to have the fence not exactly parallel to the blade. If you have the back side a few thousandths wider than the front you don't bet burning on the piece between the blade and the fence.

   What this can do, however, is cause blade marks or burning on the "fall away" piece (as you found out). If you could check the set of your fence, it might be too far away from parallel. That's first. The other thing you could try is building a jig so that you force the "fall away" piece away from the blade. I'm not talking about lots of tension here, but something that would bend it away from the blade. Of course, this wouldn't work well if the cut off piece were 6 inches wide, but for thin strips it should work well.

   John

1. 
   BG | Dec 05, 2002 05:19am | #5

   john,

   Thanks, I'll check the fense again.  When I first set it up I attempted parralell...with the tought of opening it up a bit after testing....I'll measure again.

2. 
   BlueEnamel | Dec 05, 2002 07:30am | #6

   BG,

   The suggestions that johnhardy recommends should cure the problem. He's right on with the cause of the burning.

   Another possibility is that since the maple is 3" thick, it probably isn't totally dry on the interior of the wood. Assuming the wood was dried to hardwood standards, on thicker pieces of wood, typically 12/4 and over, the interior of the wood isn't as dry as would be expected. Now when the wood is cut, a new surface of the wood is exposed that has a higher moisture content than the outer surface. That plus the heat of the blade can cause the strip to warp inward or outward, depending on the grain and moisture gradient.

   Also, if you're cutting wood with tension in it, the wood may move as the saw kerf releases the tension and allows the wood to move so that the tension is minimized. In extreme cases, this can cause the wood on the waste side of the blade to move up and over the piece near the fence.

   I hope this helps,

   -- Blue

1. 
   BG | Dec 05, 2002 01:44pm | #7

   Bluesnamel,

   I haven't been back down to the shop since John's message to check on his suggestions ...darn cold.

   This stock is leftovers from my workbench project a few months ago.  I think the mositure is okay, but the tension release in the wood is a definite maybe. These particular pieces were cut from a larger twisted, cuped piece which I tried to salvage some good parts from.

   I've burned wood before...so this is not a new skill for me...lol. What is a little unusual is that its on the ouside(fall away) piece and the burned surface is very shiny and sooty...usually, the burn is into the wood, this, on the other hand, is dusty and on the surface. 

   Oh well, I'm not going for a PhD. here, I'll learn what I can and move on.  I'll look at the alignment of the fense and think about wood tension.  thanks

1. 
   johnhardy | Dec 05, 2002 07:16pm | #8

   A simple way to test the fence is to do the following:

   Unplug the saw. Safety first.

   Raise the blade up to full height. This gives you the most distance between the leading and trailing edges of the blade.

   Take a short piece of stock that has absolutely parallel sides and place it between the near edge of the blade and the fence so that when you move the piece of wood the blade moves ever so slightly. You don't want a tight fit here.

   Now take the piece of wood and place it (same orientation of the wood ... same edge against the fence, same edge on top, etc.) between the fence and the trailing edge of the blade. If you get the same movement of the blade you are parallel, which is what you really do not want. You'd like to have a folded dollar bill slip between the wood and the fence be about the distance to do this.

   Of course, the best way to do this is to use a dial caliper set up, but I haven't gotten there yet. Using something like the above gives you the right amount of "opening", and you can obviously play with the amount to get the best results for your saw.

   John 

2. 
   BG | Dec 05, 2002 09:26pm | #9

   John,

   Thanks, I'll try that...can you break a $10...lol

   I got one of those magnetic base measuring devices with the dial and point, etc.  to test within .001 tollerance..it came with the saw as a free gift.  Can't quite figure out how to use it yet...

3. 
   johnhardy | Dec 05, 2002 09:39pm | #10

   You can use a modification of the same technique to test to see whether the blade is parallel to the miter gauge slot. But this time you want the blade to be the same distance, front and rear, from the slot, so that it is truly parallel.

   Take your miter gauge (I'm assuming it moves without slop, because this counts) and place it in a position so that a block clamped to the gauge (set for 90 degrees) barely touches the blade at the front. Without unclamping the block, move the miter gauge to the back of the saw blade and see is the blade touches with the same "pressure" or distance. Note that for this one you should use the same sawtooth on the blade that you used for the front test. You'll need to rotate the blade by hand. This discounts any runout in the blade.

   To be totally accurate, you should also use the same sawtooth for the other test I described earlier.

   John

4. 
   BG | Dec 06, 2002 12:10am | #11

   John,

   The other issue might be the fense.  I was reading anothers experience with setting up a Grizz and the Fox Classic fense.  The fense has those thick sheets of plastic...he needed to plane his to get them flat. 

   BG