When making some chair legs (in cherry) I bandsawed the rough shape – less than 1/8th from the final line then stuck the rough leg to a 1/4″ plywood template with double sided tape. I then took it to my router table with a 1/2″ diameter piloted straight bit (two flutes) for final shaping. When I did this for most of the legs it went fine. But on a couple of them the bit seemed to “grab” or bite into the wood and severely “gouge” it, ruining the piece. I can see why this would happen on endgrain but I was careful to start the cut away from the end of the leg so am at a loss for why this happened. Any tips for template routing to prevent this?
thanks
Jeff
Replies
Are you sure you were working with the grain rather than against it? When doing things like table legs you can find yourself going against the grain on one or more of the pieces even though you are working in the same with with all of them.
A dull or low quality bit will tend to chip or tear out more than a good bit. to further reduce this I always use bits with shear angle on the cutting edges. That forces more of a slicing cut that helps control the chipping and tearout.
Tom Hintz
Because there is always more to learn!
Crummy cutter, less than great clamping to the templet and too much waste/pass.
What then?: Use a plunger with a new stout bit and divide up the work in stages.
Routs
When you template route a curved shape on a straight grain piece of wood you have a grain transition at the apex of the curve. (See attached picture). Therefore you would be routing against the grain for a portion of the leg. Of course the grain direction of the piece of wood you are routing has an impact on where the grain transition point is and how badly you are routing against the grain. This may explain why some legs were OK and why others were not.
Whenever I template route I climb route very carefully the section where I am against the grain. I apply little pressure against the bearing in order to keep good control and do multiple passes, even if I have as little as 1/8" to remove. DISCLAIMER: Climb routing can potentially be dangerous. If you are not familiar with this technique please read up on it.
Thanks, I suspect your explaination is correct- I was using a new, good, bit (1/2 in shank- Whiteside) so I don't think that was the issue. I think a spiral cutter may have been better and climbcutting in some places would have been appropriate- unfortunately I didn't notice the grain transitions in time. I had to re-make two legs and then I spoke-shaved them to the line.
Jeff
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