Replies

1. 
   Dave45 | Dec 13, 2009 06:15pm | #1

   I'm no machinest, but couldn't you mount a blade on the arbor, install the table, and make whatever tweaks are necessary to get the blade square to the table surface and the miter slot parallel with the blade?

2. 
   JeffHeath | Dec 13, 2009 06:45pm | #2

   1. Have cast iron top on saw, close to correct in position.
   2. Mount blade on arbor.
   3. Color ONE tooth with marker, so it's visible and easily identifiable.
   4. MAKE SURE SAW IS UNPLUGGED. THIS SHOULD HAVE BEEN FIRST!
   5. Rotate blade so colored tooth is at front with blade raised all the way up.
   6. Measure distance from colored tooth to miter slot using ACCURATE measuring steel rule, not a tape measure.
   7. Rotate colored tooth to back of blade opening.
   8. Measure again. The distance at the back of throat opening needs to be equal to the front of throat opening.
   9. Tap saw top at front left or back left with rubber mallet to adjust until both measurements are equal.
   10. Tighten top, and check again to be sure nothing moved.

3. 
   RalphBarker | Dec 13, 2009 06:56pm | #3

   I'd add a step to Jeff's list - run a dial indicator against the blade while slowly rotating the blade by hand to make sure the blade is true on the arbor.

   Well, two steps. I'd also verify the measurements to both miter tracks, just to verify that the tracks are parallel, too.

1. 
   Dave45 | Dec 13, 2009 08:48pm | #4

   He'll also need to check that the blade is square (perpendicular) with the table surface. I would do this with a good macinest square, or a drawing triangle.The dial indicator is also a good idea to check arbor runout.

1. 
   Jammersix | Dec 14, 2009 03:42am | #5

   Thanks for the suggestions, guys, I see I should have written with far more clarity.I've checked the runout of the arbor, it's as close to dead on as anything I've ever seen.I'm looking to get the table set square to the blade, much closer than with a ruler. I'd like to get it down to within a couple thousandths, if I can, so I'm trying to figure out how to mount my dial indicator accurately in the slots.I've played with mounting it on half of one of my old sleds, I don't know that I trust that.More suggestions?

1. 
   Dave45 | Dec 14, 2009 05:10am | #6

   By "square to the blade", are you talking about the blade being 90* to the table surface, or the miter slot being parallel to the blade.I check for miter slot parallel using a piece of 1" aluminum square tube (longer than the miter slot) laid next to (and touching) the blade teeth. Then I take measurements with a machinest scale between the square tube and one edge of the miter slot at the ends of the miter slot. Using the ends of the miter slot gives you a long enough distance to find small differences that might get lost if you only measure at the blade teeth. If I'm within 1/32", I call it good.

1. 
   Jammersix | Dec 14, 2009 05:50am | #7

   Miter slots parallel to the blade.And that's one of the things I was looking for, a way to multiply the error!Thank you!I've been screwing around with a dial indicator and a base, but that's limited to the width of the blade at most, and more like 8 inches.Thinking about this, I could even get REAL jazzy, and go with three screws at appropriate distances in three pieces of wood, and make the error as big as I want it!

2. 
   Jammersix | Dec 14, 2009 07:13am | #8

   Okay, from the theory bin for guys who drink too much coffee and think too much:I'm thinking of putting together a set of straightedges, using the method described in "Leveling The Tables With A Shop Made Test Bar", by John White, in the article here:https://www.finewoodworking.com/fwnpdf/011142038.pdf(You'll need to be a subscriber to see it.)Now, I realize that this is way, way overkill, but I like theoretical applications.If I were to get completely carried away, and decide that I want The Most Accurate Tablesaw Alignment In Washington State, it seems to me that the thing to do is magnify the error until it's so big even a blind guy like me can measure it.So, if I set up a set of these shop made sticks, say, 50 inches long, and if I merely changed the location of the center screw to bear on the appropriate thing, (One set made to bear on the blade, and one on the miter slots...), I'd come up with something like this:--Three bearing points on each stick, however:The end bearing point and the center bearing point on the "blade" stick would need to be about 8 or 9 inches apart, so that both bear on the blade.The end bearing point and the center bearing point on the miter slot stick would need to be just inside the table width, so they both bear on the miter slot, as far apart as possible.The "other" end would be where I'd measure the distance.Then, if I decided that I wanted one or two thousandths to the safety side, it's straight multiplication. A two thousandths difference is ten thousandth at fifty inches. which is much bigger, but still pretty small.Point is, I could magnify the error simply by increasing the length of the sticks, in increments of whatever the layout between the bearing points of the blade stick is. I'll probably use something like 9 inches, so it'll be multiples of nine.Then I'll go across the street, to make my measurement. :)Anyone see problems?

   Edited 12/13/2009 11:14 pm by Jammersix

3. 
   AlanWS | Dec 14, 2009 07:32am | #9

   The problem with your approach is that it assumes the plate of the blade is perfect. You will amplify those errors too. The usual way to measure in such a way as to be independent of blade is to measure from one spot on the blade while that's rotated to the front, then again from the same blade spot while it's rotated to the back. In White's book (highly recommended) he describes using for this a dial indicator mounted on a block of wood that is clamped to your miter gauge. But he does extend the "blade" by simply using a piece of wood that can be rotated front to back, extending further than does the blade in each direction. Be careful to measure to the same spot on the wood, and it does not even need to be straight.Here's a link to John White's book, which describes this and many other things including those test bars you mention.
   http://www.amazon.com/Care-Repair-Shop-Machines-White/dp/156158424X/ref=sr_1_1?ie=UTF8&s=books&qid=1260764922&sr=8-1

   Edited 12/13/2009 11:34 pm by AlanWS

4. 
   Jammersix | Dec 14, 2009 07:48am | #10

   Ah!Thanks for the link!John, you've made another sale. :)

5. 
   Jammersix | Dec 16, 2009 04:11pm | #15

   Alan, thank you for the recommendation.

   I'm a carpenter, not a machinist, ("I'm a carpenter, Jim, not a doctor!") and I depend on machines to do what they're supposed to do!

   Thanks again!

6. 
   Dave45 | Dec 14, 2009 08:15am | #13

   Don't overthink this thing, Jammer. It's a woodworking tool, not a tool and die machine. - lolHow often have you seen a machinest push or pull a piece of metal by hand like we do a piece of wood?If you use my little trick and can get within 1/32", you'll generate more error just due to uneven force as you push the workpiece thru the blade.

4. 
   Don01 | Dec 14, 2009 07:48am | #11

   These tips will be of use once you get it reassembled.

   Don

1. 
   Don01 | Dec 14, 2009 07:53am | #12

   This should have the file

5. 
   Jammersix | Dec 16, 2009 04:08pm | #14

   A follow up- John, I bought your book, Amazon delivered it overnight, and I took one look at your solution and thought "well, duh..."

   Been wrapped around the axle so tight that I lost sight of the forest behind all the trees.

   At $15, or whatever it was, and with the "equipment" from Rockler for this one task running over $120, I figure the rest of the information in the book is free, and that I still owe you quite a bit!

   Thanks for writing the book, John!

6. 
   JohnWW | Dec 20, 2009 05:04pm | #16

   I apologize for not having responded earlier, I didn't see the post, I'm still learning how to use this new system.

   Here is how I now set up saws, and it is a matter of touch rather than hearing:

   With all of the top attachment bolts loose, install one of the saw's original metal throat plates in the top and raise the blade to full height while shifting the top around to get the blade approximately centered in the slot. Once the top is centered up, tighten one of the corner bolts so that it is snug but the top can still be pivoted on the tightened bolt with moderate taps on the top's edge with a mallet. The remaining bolts should be just barely finger tight.

   If the blade is at full height against the upper stop, drop it a fraction of an inch, sometimes being tight against the height stop will skew the arbor a bit and throw off the aligning process.

   Next mark a tooth on the saw blade so that you won't lose track of it as you go from checking the alignment in the front and then the back.

   For the next step you will need a strip of wood approximately 3/4" by 2" by around 15" long with the ends cut square. Hold the strip against your miter gauge and slide it against the blade so it touches the marked tooth at the infeed side. Using your free hand rock the blade back and forth a fraction of an inch so the tooth scrapes against the end of the strip. Shift the position of the strip to get the tooth to scrape lightly, then lock the strip in place against the miter gauge with a small clamp. Even if you have trouble hearing the tooth moving against the wood you should be able to easily feel it scraping through your sense of touch.

   Now rotate the blade so the marked tooth is at the outfeed end of the table and move the miter gauge forward until the marked tooth can again touch the wood strip, as before rocking the blade a bit to get a feel for how hard the tooth is bearing against the end of the strip. Now you can adjust the table to get the contact at the front and the back to feel the same and you will be aligned.

   I often don't even bother with clamping the strip in place, just using my hand to hold the strip against the fence as I shift from front to back. Skipping the clamp will make the process go faster.

   Hope this helps,

1. 
   Jammersix | Dec 20, 2009 06:54pm | #17

   Thanks, John.

   I know what you mean about a new forum. :)

   What made you decide to switch from the method you describe in your book?