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Ok, so this happened over the weekend cutting a uke tenon:



Not a big deal, it was the first pass and I trim the end of the tenon down by almost a 1/4” after routing so it’s totally save-able. I have another template on its way from Luthiertool.

Now the question - I believe this happened because I was using a big Bosch router and it hung up for just a second and I probably pulled a bit too hard to try to free it up. It flexed the skinny tongue on the template and snapped it off. I was using a 3/8” cutting bit with a 1/2” guide bushing. I’d like to switch to using my Dewalt 611 with the plunge base. This means a 1/4” shank bit is needed. I feel like I’ll be able to see and have better control with this smaller router when doing this small tenon.

When routing using templates like this what matters is the bit to bushing offset correct?

Meaning:

1/2” bushing - 3/8” cutter = 1/8” diameter offset.

So I can use a a 3/8” bushing - 1/4” cutter to get the same 1/8” offset. Right?

Seems pretty basic, just making sure.

Brad


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Your thinking is correct... the same end result.
But, just to nitpick, shouldn't the offset in your scenario above be 1/16", not 1/8"?
Sure, the difference is 1/8"....

Right, it’s 1/16”. Stay in school kids.

Thanks, Ken!!


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Maybe not needed but I use a screw countersunk into the template tongue and screwed into the neck.

For routing a mortise and tenon neck joint, that sounds like a pretty good idea to me. That plastic finger otherwise just sits out there on its own . . .

Also, Brad, since you will be using 1/4" shank bits, I would take lighter passes. There is more opportunity for bit flexing with the smaller shank.

Good suggestions! Screwing it down sounds like a winner to me for sure. I have to take the tenon down quite a bit anyway so a small woodscrew hole would get removed in the process. I like it. Thanks!

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Brad, just looking at your pics. it looks like that tongue on your jig is 1/2". So your M&T must be
5/8". If so, nothin' wrong with that. Mine are 3/4" meaning that tongue on my jig is 5/8", a little
sturdier, I too use a small screw out near the end to ward off any flexing in use. Here I like to use
the biggest router and bit combo possible 'cause more power is better when cutting end grain.
I used to watch Tim Allen a lot a while back.

Thanks, Ken. The M/T is for a uke so it is indeed smaller. Good point about power. I was headed down the compact router path before the idea of screwing down. With that in mind I may as well stick with the bigger router I think.

Thanks for the help!


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Yep screw it down. I have used the StewMac templates for 16 years and they came with a hole for a screw.

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what you missed is the direction of feed. I bet you started on the left side with the spinning bit that walked into what should have been your tenon. Also don't try and take it all in one pass to about 4 cuts . Once you become more comfortable with the set up you will do fine.
Personally I think this template is a poor design. You want at template that rides off the pattern that would be your tenon . The template you have has way too much room for error
https://www.lmii.com/obrien-neck-joint- ... aight.html

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Thanks, John. The template broke after making the cutting pass and I was coming back around. The router hung up and I put too much pressure onto the inside if the template. I do think that screwing it down will solve it for sure. Yes, I do multiple passes.

Can you help me with the template though? I don't know what is different (other than plexi vs MDF) between the LMI one you linked and the one from Luthiertool? Note, the template is the picture is for a uke so it's very small in comparison.

Brad

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