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Thread: TS tune up - HELP Please - long post

  1. #1

    Unhappy TS tune up - HELP Please - long post

    Hi all,

    hope everyone had a good weekend!

    Well, the in-laws came into town yesterday so I got a little time in the garage (aka - the shop). Decided I'd fine tune the saw to prepare for my first "real" furniture project as everything to now has been for the shop or outdoors. I checked squareness of miter slot to the blade, squared the miter guage using my engineer square, checked blade parallel to slot, and finally the fence was squared.

    When I went to make a test cut I just crosscut a 1x3 piece of oak w/factory edge. After cut I put the two pieces side by side w/one side inverted to check for squareness. Unfortunately it is not. Went back to check blade and it seems good.

    What I'm suspecting at this point is the belts or casters. The reason i'm suspecting this and not the arbor is that I've been succesful with the test cut method mentioned above before. After sitting there and trying to figure out what may have happened I thought of the Zero Clearance Plate I installed last week. During the initial saw through of the plate I had a 2x4 of Fir clamped above the plate to hold it down. As I was slowly raising the blade the plate began to smoke from the friction and so I stopped the saw right in the middle of the plate and the 2x4 (I know , I know). I'm suspecting that this may be the cause of the problem. While I can't detect any runout on the blade by checking the same tooth on the front and back I suspect that when the blade is running at full speed there may be a little play or wobble. At the same time, the blade is still contacting the zero plate.

    Can anyone provide any tips as to how I can determine what may be the issue and more importantly - how i can possibly fix it? I hope that I may not have ruined this saw as I will not be able to afford another one any time soon. BTW, it's a jet contractor's saw.

    Thanks in advance for any help y'all can provide!!

    Delano

  2. #2
    Mike Schwing Guest
    Delano, glad to see you're taking the time to tune your tools. Far too many people neglect that and wonder why things aren't as they'd have hoped.

    One of the common items under suspicion for your problem is the mitre gauge itself. You may be able to measure it 90 degrees to itself using a square, but unless it runs perfectly true in the slot, with absolutely no side/side slop - you may risk a cut that is out of square. See if you can wiggle the gauge at all side to side in the slot. If you can - that may be the problem. When I build runners for sleds I embed them with brass screws that can be adjusted to clear up any slop.

    I'm no fan of mitre gauges - they're notoriously bad for accuracy. Getting better but still. You can do yourself some seriously accurate crosscutting with a crosscut sled. Get building!

    How square is your engineer's square?

  3. #3
    Join Date
    Mar 2003
    Location
    Southport, NC
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    3,147
    First, never trust a "factory edge" to be straight or square.

    There is a sequence to tuning up a table saw.

    First, adjust the blade parallel to the miter slot. Next step is to adjust the fence parallel to the miter slot. Then adjust the blade 90 degrees to the tabletop and finally, adjust the miter gauge so it cuts 90 degree cross cuts.

    Here is the low tech, low cost way to align a tablesaw that I learned maybe forty years ago and teach to my students now.

    Make 3/4 x 3/4 x 12" hardwood stick. Drill a hole somewhat centered in one end and insert a brass #8 x 1" round head wood screw about half way. UNPLUG THE SAW. Raise the blade completely up. Clamp this board in your miter gauge (if you determine that there is some slop in your slot to miter gauge, use a playing card to take up the slop) so the screw head just about touches the blade at the front. Now rotate the blade by hand and determine which tooth is the closest. Adjust the screw in or out until it just touches this tooth. Mark this tooth. Rotate the blade so the tooth is now at the back of the table and move the miter gauge/stick assembly to the back and see if it touches the marked tooth to the same extent. If it doesn't, adjust the trunnion (if a contractor saw) or the tabletop (if a cabinet saw) until it does.

    For a contractor saw, first use a small c-clamp on the rear trunnion and cradle to keep the assembly from moving. Then loosen the two rear trunnion bolts and use a stick to tap the trunnion until the blade and screw lightly touch. The blade does not move directly around the center so you will need to repeatedly go back to the front of the blade, readjust the screw, and then again measure the back. Be sure to check after tightening the trunnion as the trunnion frequently moves when being tightened.

    The same adjustment gauge can be used to set the fence parallel to the miter slot. Slide the miter gauge to the front of the table and move the fence over to the screw head and insert a playing card between the screw head and the fence just so you can move the card as it touches both the fence and the screw head. Now move the miter gauge to the back of the table and see if you have the same feel when you insert the card. I like my fence absolutely parallel--if you want to have a slight opening to the fence, you can easily estimate the opening by adding a thickness of paper to the card.

    I always show my students with a dial gauge that their adjustments are within .001 - .002.

    You can also use the same gauge to measure blade runout by using a $5.00 feeler gauge.

    Finally, after you are satisfied with the above adjustments, check the position of the splitter to make sure it is exactly in line with the blade.

    Bottom line, there is no need to spend more than the $0.05 for the brass screw.

    Now, take a piece of 5/4 x 3" stock and run it through your planer. Then joint one edge and rip the other being sure the board stays tightly against your fence. Now you have a board that can be used as you intended.

    Put an "X" on one side and using your miter gauge, cross cut the board. Now you make two checks.

    First, lay one of the parts on your tabletop "X" side up and the other "X" side down. Butt them and look at whether the seam is completely closed up and down. This is the test to determine if your blade tilt is 90 degrees. If the seam is not closed, adjust the tilt mechanism and stop pin until it is.

    Next, put one of the parts on edge with the "X" facing you and the other on edge with the "X" away from you. Now again look at the seam. It should be perfectly closed up and down. If it is not closed, then your miter gauge is not exactly set to 90 degrees to the miter slot. Adjust the miter gauge until it is correct.

    Once these two tests prove out, you know your saw blade is perpendicular and your miter gauge is at 90 degrees.
    Howie.........

  4. #4
    thanks for the replies, Mike and Howard. I do appreciate it. I should have mentioned that the tuning I did was with a dial guage. miter slot was within .001 and .002 and the miter gauge is an incra gauge so i took up all the slop with the 6 adjustable points on the runner.

    One thing I did just think about is that after making the cut and turning the machine off the saw it vibrated just a bit as the blade slowed down. It's almost like when your car tires need alignment and as you brake it wiggles a little as you come to a stop.

    I will go back and try Howard's method as it seems a bit easier of a set up. The only thing is I do not currently have a jointer and so I usually purchase my wood surfaced already and then use a router for a straight edge.

    As for the square I guess I just assumed it was on. How does one check if you don't have another reference to measure against?

    thanks again!

    Delano

  5. #5
    Join Date
    Feb 2003
    Location
    Collin County Texas
    Posts
    2,417

    Howard, Please add this write up to the Articles archive

    Your detailed description deserves to be on file for others to reference in the future. Please consider submitting it to the articles section of SMC, I think it would be of value to many many people.
    Best Regards, Ken

  6. #6
    Join Date
    Mar 2003
    Location
    Southport, NC
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    3,147
    To check the vibration, put on a different blade and see if it still happens.

    Frequently (most often) it's only a harmonic vibration caused by the belt. I don't know what type of saw you have, but if it is a Contractor Saw, you can try getting a notched belt or a segmented (link) belt. Another choice is not to worry about it. It's not really a problem.

    In other cases it's the motor slightly vibration as it slows down. Again, no real problem.
    Howie.........

  7. #7
    Join Date
    Feb 2003
    Location
    Murfreesboro, TN
    Posts
    26
    To check for squareness place your square on a board and draw a line. Flip the square and line it up with your mark. If the square lines up with the mark then it is fine. If it doesn't, you need to adjust your square. Of course, this assumes the edge of your board is straight.

    Keith Z.

  8. #8
    Join Date
    Mar 2003
    Location
    Southport, NC
    Posts
    3,147
    No matter how much you spend for a device, you still don't know if it is square. I ran a large tool and die shop and we purchased a number of Brown & Sharp and Starrett devices and some of them where not "square". Now we had "standards" that our quality department periodically had validated by an outside service that we then used to verify the worker's tools.

    One day, one of our designers brought in two plastic drawing triangles he had purchased at a local art supply store. He had them compared to our standards and they were as accurate as the tools could measure. The triangle cost a couple of dollars each. They would certainly serve very well as the "standard" in any woodworking shop to validate and/or adjust other devices.

    An excellent way to validate the accuracy of the plastic squares is to use two squares on a flat surface. Get a $10-12 plastic 30-60-90 drafting square. To prove it's exactly 90°, take two to a glass counter, put the shorter legs on the counter and face the longer legs away from each other and butt them together (like a teepee). If the legs exactly butt, you can assume you have two perfect 90° angles. Using one of the plastic squares, do the same thing using your other tools. Any that mismatch, means that the tool is not square. You can also take the plastic square with you whenever you go to purchase another tool. Keep your "standard" somewhere where it doesn't get banged up.

    Finally, remember that the wood you are using will expand and contract a couple of thousands from one day to the other. Does't pay to get too uptight.

    While we are at it, I also only purchase the cheapest of adjustable squares. I square them with a drafting triangle and an auger file until they are square across 10". And I own a Bridge City square that isn't that accurate. Stainless steel machinist's squares are only square until you drop them. I have had several over the years and each has found a away to drop to the floor.

    The key is to NEVER use your best square on for day to day measuring. Use it only as a reference tool to verify your other day to day tools.
    Howie.........

  9. #9
    Howard,

    I agree with Ken and think you should submit these posts as articles. They are very informative and have been a huge help to me. I'm hoping to go through your regiment later this week to fine tune my saw. Again, Thanks!

    Delano

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