# spiral bit



## woodendigits (Apr 30, 2006)

Hey all. It's been a while since my last posting but it's been a trying month for the wife and myself. Between a bad back acting up again and us quitting smoking, I haven't been in the mood for much other than eating black licorrice sticks and sleeping. But I have been using my Bosch RA 1170 table whenever I feel kinda pain-free for some projects. Here's a question for you:

If I have a spiral bit installed and am wanting to make dados and also just barely "kiss" the edges of the boards to square them up, how do you go about aiming the spiral bit for this? A regular 1/2 straight bit is no problem to position (or your work positioned in relation to the blade) but I can't seem to find a way to aim this spiral thing without taking too much. Any tricks?

Oh, about squaring boardsd with a table, I took a hint from one of PAtrick Spielman's books about a fixture that rides in the miter slot. I'll splain later on the "table Mounted" forum.

Thanks in advance.


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## bobj3 (Jan 17, 2006)

Flush Trim Bits work best for a planer job on the router table but if you don't have one or you want to just kiss the edge of the stock with a carb.spiral bit try this, move the bit up in the router table until you see the 1/2" shank of the bit then lock the router and use a brass setup bar or flat stock and zero the bit (just the shank part of the bit) to the fence now move the fence Back just a bit then lock it down now unlock the router and drop the router down in the table util the cutting part of the bit shows then lock the router and run a test to see if it takes off what you want. 

Just a NOTE*** you may want to stick some doubl.stick carpet tape of the left side of the fence, but leave the white part of the tape on,this will give you about .010 offset to help with the snipe at the end of the cut.
Then just pull the tape off when your done.

Bj


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## Dave K (Sep 4, 2006)

Excellent advice Bob gave there. When using spiral router bits, there are two types available. Up spiral and down spiral. Up spiral bits are for hand held routers and router tables. They will pull the wood to the base of the router and eject the chips upwards. Down spiral bits are intended for overarm routers. They will push the work piece down and away from router motor. The chips will also eject downwards.

These bits should not be used opposite of what I've described here. An up spiral bit used on an overarm router can have disasterous effects on the workpiece, the router, the bit and the operator. 

Hope this was of some help.


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