Disaster with binding router jig

[TroyWoodyard]

Alright… so that the reader can feel my pain and help me with my ignorance.

First time using a tower style jig.

Error 1. I was too busy paying attention to the jig and rushing to get my channels cut and I routed through my tail graft and back stripe… I was prepped for the picture frame mitered panel look, but alas, it appears I am butt jointing my purfling. Bummer.

Problem 2. I set up the top face down in the carriage which meant the back taper was stronger than my donut slope so the channels in the upper bout were probably 2-3 hundredths shorter than in the lower bout… on purfling probably .03” compared to .06”. Is this standard operating procedure, or is my donut too flat?

Big huge problem 3. I took the binding in one pass on the back and it worked fine. Tried the same on the top and the side started to blow out. The crack only just spread past where the binding ledge will cover so I am stabilizing with CA and trusting that and the binding to hold it all together. It’s a personal guitar and a learning experience so I’m okay chancing this repair method. Perhaps the back ledge was okay due to the Krefeld lining holding it together and the peone on top with the gaps didn’t provide the same support. Should I have climb cut the binding or took it in 2-3 passes? What did I do wrong? I thought I could take .07” I’m one pass but perhaps not when it cuts all the way through.

Problem 4. I turned my trim router on with the bit too close to the side and it kicked into the side. Damage to the side is minimal, but now the router shakes. Seems I either broke the bit or bent the spindle. Grr.

It’s late so I stabilized my crack and will have to investigate a solution this weekend.

Any comments, suggestions, or snide remarks welcome.

[phavriluk]

We all have said blasphemous oaths....it's a memory aid.

We learn to measure twice, cut once. Maybe involuntarily.

[Fathand]

#3
I climb cut around the whole guitar then reverse and conventional cut to remove fuzz that climb cutting sometimes leaves. Not guaranteed to prevent tear out but seems to help a lot.

Some of my bits are stepped to cut the binding and purfling notch together. One does a 3.5mm purfling notch plus the 1.5mm binding. 5mm = .197" at the top of the notch so .07" should be doable.

[Fathand]

# 2 I've had this problem on a 000 and a J 185 at the upoer bout about 2 " from the waist.

Sometimes I clean it up hand holding the router the old way or setting the back more parallel to the bench, which would seem to defeat the purpose of the tower but seems to work. I use the guitar mold as a carriage if that makes a difference.

[TroyWoodyard]

After sleeping on it, I think it’s all going to be okay.

But does anybody have design suggestions for what to do about routing my purfling on the back strip and end graft? Should I just run the side purfling across where the miters were intended and not worry about it, or would there be a way to fix it or disguise it?

[phavriluk]

Rout off the end graft and do that part over?

[TroyWoodyard]

Originally Posted by phavriluk

Rout off the end graft and do that part over?

I can do that relatively easily… but what about the back strip? That one probably bothers me more than the end graft.

Do you think it will look terrible to do the butt joints? I kind of think only luthiers would notice [emoji23]

[phavriluk]

I run my binding around the side/back intersection as if it's one continuous strip. Just like factory guitars.

No help from me, I'm afraid.

A picture would help.

Good luck with it!

[Howard Klepper]

Originally Posted by TroyWoodyard

Alright… so that the reader can feel my pain and help me with my ignorance.

First time using a tower style jig.

Error 1. I was too busy paying attention to the jig and rushing to get my channels cut and I routed through my tail graft and back stripe… I was prepped for the picture frame mitered panel look, but alas, it appears I am butt jointing my purfling. Bummer.

Problem 2. I set up the top face down in the carriage which meant the back taper was stronger than my donut slope so the channels in the upper bout were probably 2-3 hundredths shorter than in the lower bout… on purfling probably .03” compared to .06”. Is this standard operating procedure, or is my donut too flat?

Big huge problem 3. I took the binding in one pass on the back and it worked fine. Tried the same on the top and the side started to blow out. The crack only just spread past where the binding ledge will cover so I am stabilizing with CA and trusting that and the binding to hold it all together. It’s a personal guitar and a learning experience so I’m okay chancing this repair method. Perhaps the back ledge was okay due to the Krefeld lining holding it together and the peone on top with the gaps didn’t provide the same support. Should I have climb cut the binding or took it in 2-3 passes? What did I do wrong? I thought I could take .07” I’m one pass but perhaps not when it cuts all the way through.

Problem 4. I turned my trim router on with the bit too close to the side and it kicked into the side. Damage to the side is minimal, but now the router shakes. Seems I either broke the bit or bent the spindle. Grr.

It’s late so I stabilized my crack and will have to investigate a solution this weekend.

Any comments, suggestions, or snide remarks welcome.

"Tower style jig." I get what that is. But do you mean the router only moves up and down, while you move the guitar cradle around? That has always looked scary to me. I like to have a hand on the router. My fixture has the router on a telescoping arm that pivots on a lazy susan, so the guitar stays put. More work and $ to build, but IMO worth it.

1. Yeah, well. Not exactly sure what you mean, but we've all been there. It hurts to have a mental lapse, but what really hurts is when you have the same lapse a second time!

2. .03" is a big difference, although if it's your purfling cut it should be invisible in the end. Re-adjust the cradle supports betwwen doing top and back so that the router spindle is perpendicular to a line between the neck and tail blocks so you don't have such a steep downhill slope to the upper bout. And make the radius of the bearing surface of the donut smaller (got photo?).

3. I always climb cut half of each bout for purfling, so the router movement each half-bout is downhill--from wider to narrower. But for binding I've found it best to use a standard feed into the cut direction so the router doesn't want to pull itself along. Were your sides thinner than .070"? If your binding cut is deeper than the side thickness it becomes important for the side to be backed up by the lining, as you suspected. How big was the gap between peone/dentils? If it gets big enough, you could be routing a scalloped rabbet.

The other factor here could be the bit. Is it sharp? You can sharpen a carbide router bit with a very fine diamond EZ Lap. Give each blade an equal number of strokes and look closely at what the honing pattern on the carbide looks like. And a rabbeting bit with a slight downcut helps, but should not be necessary.

4. That should not be enough to damage the bit or bend the spindle. Did you have almost the whole bit shank inside the collet? What brand trimmer?

[TroyWoodyard]

https://share.icloud.com/photos/029e...WgVDnoQvSiWl_w

https://share.icloud.com/photos/0c00...N_btkuKCYmZJxw

https://share.icloud.com/photos/06ca...4VepSYRArn1W1Q

[TroyWoodyard]

Let me know if these pictures work.

Maybe this picture will show why I can no longer miter the purfling a so it makes sense.

And yes I was cutting Al the way through the side and I think that combined with the prime was the problem. I’ll try climb cutting the whole thing and report back.

[TroyWoodyard]

I can’t type… I cut all the way thru the side and I think that combined with gaps between peone caused the problem.

[phavriluk]

When I'm routing binding ledges, I do so in multiple passes, .020" or so in each pass.

[TroyWoodyard]

Do you climb cut? Maybe if you already have the ledge established that would hold everything together and prevent the blowout I experienced without climb cutting.

[Bowie]

Just wanted to say, thanks for this thread. I'm one who feels mistakes are the best educators and appreciate the discussion here. I've only been routing for a couple years now and haven't come across too many hurdles but it's good to know what can potentially go wrong.