Leigh Dovetails and Dewalt 618 Router

Anyone have experience with this combo. I have a D4R Leigh dovetail jig and a Dewalt 618 router. Using good PC brass bushings I can not get a workable halfblind joint in 3/4 sides and 1/2 fronts and backs.

After 8 attempts following every instruction I gave up. The joint never really changed in fit. It started out tight. Per instructions I raised the bit "Slightly" about 1/128 and cut new. Same result. I eventually moved the bit up 1/16, no change.

I reset the fingers. They started out all set tight against each other. I eventually put a 1/32 between each. Still no change in fit, it was tight. Tight means the joint will not slide together. Tight means trying to pound the joint together with a mallet results in the wood splitting out. (OK that was frustration on # 6)

Finally I started looking at the router. The thing is so loose when you release the adjustment lock I can adjust height by pulling or pushing the base and get a 1/64 of an inch slop. Also and more importent is the side to side concentricty of the bushing to the bit. It can vary so much that the bit shaft contacts the bush. That can't be good.

To allow for this I double routed the last two tests, as in hold router one way, rout... turn router around 180 and rout again. This method did produce the closest thing to a workable joint but still too tight.

Anyone else experience anything like this? OH 7/16 bush and a 128-8 bit starting depth of cut 3/8

Thanks Larry

Reply to
Bubba Wood
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What degree dovetail bit are you using?

Reply to
Swingman

Ok, you mention Joint, singular. If you are trying to correct an ill fitting joint, forget it. You cannot recut a joint. With each adjustment that you make you have to start with new wood. Why? Because the depth adjustments have the opposite effect on mating pieces of wood. One piece may get wider tails which requires narrower pins or visa versa depending on whether you make a deeper or shallower cut. Either way you cannot make previously made tail or pin cuts, narrower.

Because of this blind dovetails are unforgiving on any jig of this style regardless of what router you are using. Every DT bit has its "sweet spot" as to which depth it is going to cut correctly at. You should have scrap pieces of the same type of that you are going to use. Thickness is not really a factor assuming your finger template is resting flat on top of the wood although same thickness is easier to test with. Correct bit depth will be the same for any thickness wood. Make practice cuts until you get the right fit and then record that depth setting for that bit for future DT's. Simply cut the pins and tail off if the fit is not right. DO NOT attempt to "fix" a cut. Start over after making depth adjustments. As you mentioned, if the fit is too tight make a shallower cut. Too loose make a deeper cut.

A few other things to consider. Do not rotate the router when cutting the DT's in case the guide bushings are not perfectly centered to your bit. Be certain that you clean out all the area between the jig fingers when routing. If you unintentionally leave a little extra in there the fit will be too tight.

Reply to
Leon

Just as aside in the event the OP missed it.

As you point out, the depth of cut in half-blind router jig cutting determines the fit, and with the Leigh jig you really need to be using an 18 degree dovetail bit for half-blind joints when using 1/2" material for the _fronts and/or backs_ of drawers.

... otherwise the fit will give you fits.

Reply to
Swingman

Reply to
pat

I'll keep that in mind. I have never used any other bit size other than the one that I have always used for blind DT's. Because you do not want a blind DT to become a through TD, :~) it makes sense to use a greater angle shallower cutting bit for the blind DT's.

Reply to
Leon

Reply to
Bubba Wood

Thanks Pat, I thought of that today. It is a more stable base. I'm sure the problem is the base>bushing>bit centering and the fact that the locking in position on the fixed base is hinky at best.

Larry

Reply to
Bubba Wood

The bushing does not absolutely have to be centered to achieve a proper fit within the tails and pins however if the bushing is not properly centered the mating pieces tend to not align properly on the tops and bottoms of the pieces. Again do not turn or clock the router while cutting. Keep it in one position.

Additionally, you mentioned that you adjusted 1/16", that still may not be enough.

Reply to
Leon

Thanks everyone I figured it out. Not the router or the jig or the bushings. The pin board was cupped. Two light passes through the jointer and new dovetails, everything is fine.

Larry

Reply to
Bubba Wood

Check to see if the pin board is cupped. That's often the problem.

-Zz

Reply to
Zz Yzx

Still running a day late and a dollar short? :~)

Reply to
Leon

Yup. And ugly.

-Zz

Reply to
Zz Yzx

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