No announcement yet.

How to reduce router tear out?

  • Filter
  • Time
  • Show
Clear All
new posts

  • How to reduce router tear out?

    Hey, I've been using routers for years, don't mean I've been using them right though. Looking for advice on how to eliminate router "tear out" thus spend less time sanding out damage, as much as I love my Delta B.O.S.S. (bench oscilating spindle sander).

    I always push slowly, make light passes, short depth cuts, use relatively sharp bits... but still end up with nasty pits. I use double flute flush trim bearing bits. How do the triple flute compare?

    Any difference in cut between 1/4" shank vs 1/2"?

    I just purchased a ridgid bandsaw, my next purchase will be a Milwaukee 3 1/2 horsepower router. I know the monster is heavy at 15 lbs, but it'll be mounted on an overhead XY router frame. I'm currently using a sad little ryobi 1 1/2 hp router. I've been blaming the low horsepower rating for the pits, it this the culprit?

    Any advice would be appreciated... or just tell me to "shut up & get used to sanding".

    Here's a picture of a XYZ router I built this week. Almost done, just gotta make a router mount & tracer mount. Please excuse the duct taping holding the router & tracer, just for the picture, so you can get the idea. Basically this jig moves back/forth, left/right, up/down (actually arcs like a see/saw). It has a router mounted on one arm and a tracer on the other. Plan on using it for copying contours & neck profile. It's currently sporting a under powered DeWalt trimmer, but it should be fine, this won't be the work horse of the shop.

    CNC parts $220 shipped
    3 bearings
    4 clamps
    3 rails 3/4" x 55

    Misc Hardwood & Lumber $70
    3/4" MDF (bought damaged 4' x 8' sheet to save money)
    6 - 2"x4"x8' - bolted to dad's ol' craftsman table saw
    1/4 Nuts & Bolts
    6 - 1 3/8" U-Bolts
    1 3/8" Water Sprinkler Pipe (black H shaped) - Free from work
    DeWalt Trimmer Router - free from friend

    Total under $300

  • #2
    Re: How to reduce router tear out?

    some times I have found reversing the direction of the cut helps, instead of going the normal direction go, where the bit is climbing out of the stock.
    When using your router it's important to feed the router against the bit's rotation. Feeding the router in the opposite direction might result in the bit climbing out of the cut.
    I know this is not the recommended way, but the by doing this the wood it self supports the cut, if you go the "correct direction" you pealing off wood,

    also plan the cuts of the project so any end grains are cut first as they are more likely to tear out and chip, but because you have the with the grain cut many times what tore out will be cut off in the next cut, back up end grain helps as well. with some scrap.

    a nice page on the diffrences,
    Last edited by BHD; 12-22-2009, 09:23 AM.
    Push sticks/blocks Save Fingers
    "The true measure of a man is how he treats someone who can do him absolutely no good."
    attributed to Samuel Johnson
    PUBLIC NOTICE: Due to recent budget cuts, the rising cost of electricity, gas, and the current state of the economy............the light at the end of the tunnel, has been turned off.


    • #3
      Re: How to reduce router tear out?

      I do the same thing... reverse your cut direction. Go slow with light passes, especially once you have the higher HP router. It doesn't take much to for the router to get a mind of it's own. How long have you been into guitar making? It seems like you are just really getting started. I have made a few over the last 10 years and really enjoy the satisfaction of playing a guitar I have made.


      • #4
        Re: How to reduce router tear out?

        Yes - another vote for a very light cut in the reverse direction.

        Also, the bit is important. Up-spiral types in a hand-held router operation are especially prone to tearing up the top edge of the wood.

        But in woodworking, the wood is the biggest variable - nothing can prevent 100% of the problems.


        • #5
          Re: How to reduce router tear out?

          Climb cutting helps (as mentioned above). Be careful, have a good grip on the router if working handheld or on the workpiece at the table. Several small bites are better than one large one.

          Also, if you are working a profile that will need to remove a lot of wood and you can pre-cut a chamfer at the table saw, do that first. Now your bit only needs to remove small portions of wood.

          You can backup the exit side of a cut by clamping, taping, gluing or just a push block (at the router table) to minimize tear out as bits exit.

          Sharp, CLEAN bits do the best work. 1/2" shanks tend to chatter less but not all profiles can be found in 1/2" shank bits.


          • #6
            Re: How to reduce router tear out?

            Don't start on the edge or tip of what your routing. Start a few inches in and work your way around.


            • #7
              Re: How to reduce router tear out?

              Thanks for all the advice.

              How about the double flute vs triple flute bits?

              Does router horsepower also help? I'm using a 1 3/4 horsepower currently. Was wanting to upgrade to 3 1/2 horsepower (mounted on a xy router jig).

              Here's an alder Jazzmaster I made years ago. Only one that I had saved to the comptuer, doesn't show the neck pocket & profiled edges that I later added... but gives you an idea.

              Rough cut & drilled out cavities. Mustangs & Jazzmasters, poplar & northern ash.

              Poplar, Mustang

              Jazzmaster, lacking neck pocket shaping

              Attached Files