How does one cut a round hole with a router?

Discussion in 'Archived Threads 2001-2004' started by Shade Watson, May 10, 2001.

  1. Shade Watson

    Shade Watson Stunt Coordinator

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    The subject says it all. Do I need some kind of router jig? What is this called? Where do I get one (like is it a common hardware store item, or something that needs to be special ordered)?
    Thanks for your replies.
     
  2. Pete Mazz

    Pete Mazz Supporting Actor

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    You can either buy one or make one.
    If you buy one make sure it can do the sizes you need. You may have to buy two to get a tweeter sized hole and a subwoofer sized one.
    In the spirit of DIY, it's very easy to make. First you need to buy a "collar" for your router. This is a round plate that attaches to the base of your router and accepts collars of different sizes. Get the 3/4" collar. Put a 1/2" bit in your router. The bit will project thru the collar. Now for the jig. Cut a piece of material (whatever) about 5" wide by 12" long. Using a 3/4" drill bit, drill a hole about 3" from one end of the material and centered on it. This hole will accept the collar on the router. Now measure from the center of the hole to your desired radius. Drill an 1/8" hole here. Drill an 1/8" hole in your baffle to center the jig. Simply put the jig on your baffle, tap the 1/8" shank of the drill bit thru both, and place your router on the jig so the collar sits in the 3/4" hole. Start the router and plunge to desired depth. If you want to route a recessed driver, route the outer dimension first, use a new center, and route thru the smaller circle.
    Pete
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  3. Patrick Sun

    Patrick Sun Moderator
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    If you aren't up to making your own circle jig, you can get one from Sears for around $20. Here's what I use (the bottom portion of the photo):
    [​IMG]
    And here is it in action:
    [​IMG]
    The Jasper Jig comes highly recommended if you plan of making speakers as a hobby. They cost aorund $40, and I know you can get them at http://www.partsexpress.com .
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    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  4. Shade Watson

    Shade Watson Stunt Coordinator

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    How would you route out a 4" hole with such a jig? Wouldn't the base of the router be in the way? I need to cut 4" holes in my internal braces.
     
  5. Patrick Sun

    Patrick Sun Moderator
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    You can flip around the lever that the pilot bit is connected and route circles as small as 3" in diameter, and it goes up to 24" without a homemade extender.
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    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  6. Shade Watson

    Shade Watson Stunt Coordinator

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    Patrick,
    Are you refering to the Jasper Jib, or the Sears jig?
    I plan to get to work on Saturday, so I would rather get the Sears and save $20.
     
  7. Patrick Sun

    Patrick Sun Moderator
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  8. Chris Hoppe

    Chris Hoppe Stunt Coordinator

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    Shade's collar idea is cool, but you have the added expense of the router bushing guides.
    For my circle jig, I just made a long rectangular piece out of 1/4" plywood and mount the router base to one end of that! Just remove the plastic base your router already has and you can use it to mark the screw holes to drill.
    The bushing idea is handy though. It allows for a quicker change.
    I've done circles smaller than the router base by drilling the pilot hole through the piece and a pilot hole in the bottom of the jig. Then I just drive a screw through the bottom of the piece so that it sticks out the top a bit. Then you can guide the jig down onto the point of the screw.
     
  9. Brian Bunge

    Brian Bunge Producer

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    Shade,
    As far as I'm concerned, the Jasper Circle Jig is well worth the extra money! Can you say "perfect, repeatable cuts without measuring?" The Jasper Jig cuts 2 1/4" to 18" holes without measuring!
    Brian
     

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