Tear out on maple end grain

Discussion in 'Guitar Building' started by SimonB15, Jun 24, 2015.

  1. SimonB15

    SimonB15 Active Member

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    I've just routed my 4th tele style headstock, and maintained my perfect record of the bit catching on the end grain at the top. This one gave me the shits because I was being especially careful not to do exactly that, and it was the worst it's happened yet (big chunk tore off). I'm after some advice on how to stop this happening.

    My method is to draw the outline from the template, band saw out the rough shape, disc sand right down to the line, use the table router with 2" (straight) bit with the template on to finish it off. In this case, the cleanup required was the width of the pencil line.

    I don't have the coin for a spiral cutter just now, but in my mind that would go a long way to solving the problem. Otherwise what else can I do? I'm considering giving up trying to route that bit and just sand it instead. Advice appreciated!
     
  2. Knarbens

    Knarbens Well-Known Member

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    Hey Simon! The headstocks of the first two guitars I built together with my buddy had tear-out at the tip. I was doing mine and the bit kinda jumped!? Later when my buddy was doing the same task the bit grabbed the neck and threw it away ... The router was mounted to a table (Not sure how you did?) but I gotta say that we've been unexperienced.

    I'm always kinda scared to work holding the workpiece instead of the router? To me it feels saver and better to hold the router and move it over the workpiece.

    I think it's about how tight you hold the workpiece? When the bit catches grain and the piece moves ... it tears out?
     
  3. SimonB15

    SimonB15 Active Member

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    Cheers Knarbens. I was using my table router too. I use my table router more often than my handheld, and am generally pretty confident with it.

    I've never had the piece pulled out of my hands and thrown, usually it grabs the end grain, jumps, and usually split or take a small chunk out of the wood. Yesterday's, though, took a piece almost an inch square. I've glued it back in and finished the end with sandpaper, but there will likely be a small glue scar on the end grain.

    When I hold my work piece on the router table, I grip it firmly enough to maintain control, but if it does grab and want to throw, I'm ready to let go, because the last thing I want is my fingers being pulled in to a spinning router bit...
     
  4. Musclesturtle

    Musclesturtle New Member

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    I've had the same experience with my Stratocaster headstocks. The first two I did the same thing that you are doing, which is sanding to the line then routing. You might be able to try thicknessing the headstock first, and then routing it so that there is less material for the bit to grab. Also, how old and/or dull is the bit that you're using? This will matter a lot when it comes to whether or not the bit will grab. I too am saving up the small fortune required to purchase a double bearing upcut spiral bit, but I might just take the shortcut and sell my first born...
     
  5. DRF

    DRF Member

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    For me using a router table is right up there in scariness as using a jointer. As others pointed out any problems come down to stability, a sharp bit and feed rate. It's kinda the same thing as if you put an end mill into a drill press to mill steel...or even a router bit for that matter to do wood, there is chatter, flexing and it grabs the work piece and scares the shite out of you. So tearing a chunk out is doing the same thing but a part of the work piece gives rather than grabbing.

    In short, if you have a hefty table, a hefty good router mounted tight, a good sharp spiral bit -1/2 inch variety and not 1/4 inch, not feeding too much almost trimming it would minimize problems. Also not just end grain but "climbing" the piece is what scares me when I've done it.
     
  6. SimonB15

    SimonB15 Active Member

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    Climb cutting is challenging, and the alternative is downhill routing going in the "wrong" direction, but that's also something I've found very hit and miss, but admittedly most of the time I've had trouble has been with the same bit I've had these tear out issues with. Some wood, I'm thinking specifically in this case of the Australian wood Tasmanian Oak (also called Victorian Ash) which has incredibly stringy grain, when attempting to downhill route it grabbed even more than when climbing.
     
  7. SimonB15

    SimonB15 Active Member

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    The bit is probably 3 years old now. When I did my first headstock and it grabbed it was basically new, but I knew less then and was likely trying to do too much. This bit has seen a lot of action, though, and I wouldn't be surprised if it is a bit blunt. I've considered flipping it over so the template is on the underside and using a newer bit with the bearing on the shaft.. But yes, the good quality spiral cut bits cost a bomb. This is the bit I'm looking at: Solid Carbide Two Flute Double Bearing Spiral Bit : CARBA-TEC $202 Australian plus shipping...
     
  8. Musclesturtle

    Musclesturtle New Member

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    You might be better off sanding for $202. I like sanding and filing my headstocks now because once you get good at it it only takes a few minutes, plus, you can add bit of personality to your guitars that way lol.
     
  9. Duplex Dave

    Duplex Dave Active Member

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    Can you pre-cut, sand, and file your piece so that you're only trimming .020" or 2-3mm of material off? You can also down cut safely with that little of material removal.
     
  10. SimonB15

    SimonB15 Active Member

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    On my latest piece I was definitely trying to route less than 2-3mm of material. It was scarcely more than a hair. I expect the router bit is a little on the blunt side, at least for that activity.

    Out of curiosity, what do others do when their bits get dull? Sharpen or replace?
     
  11. Duplex Dave

    Duplex Dave Active Member

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    I think some of them can be sharpened by a professional.
    You either send it out or replace it, I would imagine the company that sells the $200 bit offers a re-sharpening service on those quality bits. If it's only a $10-$20 bit then it would not be cost effective to re-sharpen.

    I bought a bench top jointer from a guy. He didn't like it. He had tried to sharpen the blades himself and thought the machine was junk. I purchased new blades for around $18 and it runs like a champ. Just an example of what not to try and sharpen.
     
  12. otterhound

    otterhound New Member

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    I replace .
     

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