router bits and chipping

[peter havriluk]

On my fourth project using my binding cutter I ran into some chipping at the edge of the channel (curly cherry). I have no idea as to whether I'm going past the useful life of the router bit or whether the cherry itself is inherently fragile with a tendency to chip. The router bit was installed shiny new for the first project and used for nothing else since.

Any suggestions as to how I can determine whether the router bit itself is contributing to my problem?

Thanks!

[Carl Dickinson]

Not sure about curly cherry but have cut quilted maple, narra and some fancy bocote which have been chippy in other operations. I've been doing a quick dress of the cutter before each guitar with small diamond wands you can get from most sources. Also I've been doing a climb cut all the way around before a final pass the other way. Seems to make a clean edge.

[peter havriluk]

Thanks for answering. I admit confusion: is a 'climb cut' one in which the router bit rotation follows the direction of cut or travels against the direction of the cut?

[Carl Dickinson]

I guess that "the router bit rotation follows the direction of cut" would be a way of describing it. I use a tower type binding jig with the body in a cradle, moving it around under the router. The body is rotated counterclockwise in a climb cut (hold on to it tight) then clockwise for the final cleanup. The diagram on the SM site shows a climb cut in certain quarters to prevent chip out. I find it easier for me to do it all the way around.

[Herman]

FWIW: I always follow the SM recipe to make the first cut in "quaters" (in fact in 8ths) and a final cut couter clockwise. Never had chipping out.
Herman

[Tim Benware]

FWIW: I always follow the SM recipe to make the first cut in "quaters" (in fact in 8ths) and a final cut couter clockwise. Never had chipping out.
Herman

I do the same and that's the way i teach it in my guitar building classes. Very rarely get chip out but some wood just does. Torrified and Sinker tops can catch a grain line and fling a chuck flying if you aren't careful about the cut direction.

[Dave Bagwill]

Ok you guys.
The diagram attached is one we are familiar with.
My router is attached to the bottom of a router table, so my bit is spinning counter-closckwise.
If I'm not wrong, the diagram (which I've inverted because my bit is not spinning clockwise with the router above the guitar) shows the correct feed angle.

I'm only asking because I cannot cut a perfect channel no matter how much I try, how many virgins I sacrifice, or promises to feed the hungry I make.
I use the SM router bit and bearings.
I will chip, I will dip, and other words that rhyme with those, but no perfect channels. Not semi-perfect.
My friends, Dave is at the end of his rope.
I do not have $400 bucks for the LMII router fixture and a Bosch Colt (plus shipping, another $400 or so. I exaggerate, but shipping some binding material from southern California costs more than the binding material) but I'm pretty much thinking that I need to save some coin to get one. This granadillo and this torrefied wrc top are kicking my buttocks when it comes to channels.

So - sorry to drag you in, though I feel better now - I just want to make certain that the 'feed theory' above and in the diagram is correct. What say you?

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