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I love it, what a great idea JF, very cool! Going to put some tape on mine.

I love cheap & easy tips like this!

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"Act your age, not your shoe size" - Prince

If you ever have a weak moment and throw this one into the pond, an alternative method is to close the calipers, tighten the locking screw, and then turning it off. This keeps it from turning itself on when jostled. I got this tip from someone, in a post from years past, and it has saved me from throwing a boat load of calipers into the pond. Before that tip, I was always amazed at some of the new profanity I could think up when that stupid battery was dead.

The usual rule with calipers and micrometers is NOT to keep the measuring faces touching because moisture could corrode the surfaces. Therefore, I suggest using a strip of camphor paper between the surfaces. Camphor fumes resist moisture and prevent corrosion of tools. Many old machinists keep strips of the waxy paper in their toolboxes. Some tool making companies use to include a little brown or green strip of camphor paper in the box as protection during long periods of storage on the shelf or in a toolbox.

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"Act your age, not your shoe size" - Prince

What Chris said.
Side note:
I've never trusted digital calipers or micrometers, too easy to be re-zeroed at the wrong place. Seen it happen too many times.
My verniers have never failed me. Do need magnifiers to read them now days

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Say what you do, Do what you say.

In a machine shop, the rule is that you check even regular mics with a standard before you start using them. Every day. Everyone has a different feel, and you never.know if someone.dropped.them! Zero out calipers every time. If it's habit, you won't.forget.

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Why be normal?

Here’s one. When tapering back braces with a block plane a strip of flexible thin plastic stock with strips of 1/4” ply thinned appropriately to bridge the centerline support strip works great to guide the plane and protect what’s underneath.

95785538-943E-458B-B633-341D55F4C5EE by Terence Kennedy, on Flickr

B00654C0-C140-4033-AC0E-BD1DCEF5D133 by Terence Kennedy, on Flickr

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It's not what you don't know that hurts you, it's what you do know that's wrong.

In that case, I will start locking mine without closing them.

I've not had any problems with my calipers. They turn off after a few minutes whether open or closed. And I really enjoy the benefits of digital calipers. I retired my vernier calipers as soon as the digitals became readily available.

I love that one Terrence! I would always just tape thin junk veneer to protect the center strip and that back. It will be nice to have a dedicated tool for the job.

Small, low braces like this are tough to shape after being glued on.



So I have a piece of 1 x 4 with a rabbet cut into it to hold the brace while I shape it. There's a little dowel at the end, visible on the right, to keep the brace in place. Got this from a talk given by the late Eugene Clark.

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now known around here as Pat Foster
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http://www.patfosterguitars.com

An additional way to protect your valuable tools especially the measuring stuff from rust and corrosion is to keep your shop religiously at 45%. We do and I do with my home shop too and we've never had any tools corroding or rusting.

Do you add a back center seam reinforcement? Wouldn't it be difficult to fit if they weren't exactly square to the brace?

I started doing this on my UTB and really like it.

Pat

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Pat

I use a reinforcement, but I don't understand your question about difficulty.

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now known around here as Pat Foster
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http://www.patfosterguitars.com

The plastic is from sheets with calibrated lines from the C-Thru ruler company. It’s great stuff for making various templates and jigs. You can score it on a line with a ruler and Xacto blade and it will break right on the line when bent. They also make a graduated ruler that is very handy for layout stuff.

Here are a couple of pictures including a little jig I made with the stuff for cutting the brace channels in the back strip.

F92B9084-6466-499F-962B-95427D824DF7 by Terence Kennedy, on Flickr

9C5F41F9-4545-49DE-8272-83B8E837B42A by Terence Kennedy, on Flickr

2EED3F19-149E-46FA-A9E6-6D908D01624E by Terence Kennedy, on Flickr

EACC3626-D1BC-46D9-B442-5007D036A176 by Terence Kennedy, on Flickr

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I was thinking that trimming the back reinforcement strips to length after the braces are glued down if the braces are slightly out of square (due to fitting them as described) would be a little more difficult.

I find them difficult enough to trim them so they are a tight fit when they are square to the brace, seems like it might add difficulty doing it this way. Or maybe the off angle is negligible?

I have struggled with getting those nice and tight. I used to glue that strip on first and then cut them out with a saw and chisel, but more recently I've been gluing them in after the braces are glued which seems a little easier but still hard to trim them in the first to go without taking too much off. I register the side of the strip to make my square cut at the end.

Pat

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Pat

I glue the strip on after I have the index blocks in place on the back and cut the reliefs for the braces before gluing the braces on.

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now known around here as Pat Foster
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http://www.patfosterguitars.com

What I do for a tight fit is make the first cut with my jig (which insures it is 90 degrees to the center strip) by scoring and completing with a #11 blade and the jig. Position the brace flush with the cut and mark the width for the second cut.

Then I cut just inside that mark so the slot is just a little bit too narrow. Remove the cut section with chisels and clean up to bare wood.

Then with a hard sanding block with 150G stuck to it flat sand the brace in the center portion where it fits into the slot. You can fine tune the fit so it squeaks right in. There is a learning curve and I have definitely had loose slots to deal with but I have gotten pretty good at it and usually I only have to sand off a very small amount.

It's good idea to save the sections you removed to cut matching slivers from to shim up a loose slot. If they match well they are usually pretty invisible.

The same technique works for getting a tight fit on the X brace notch.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I’ve messed with a few different ways to do this. Widening the slot to fit the brace always risked things looking out of square for me.

Currently I prep brace blanks very slightly thicker than nominal size - a 1/4”/6.35mm brace blank is prepped at around 7mm. One setup on the table saw and rip a years worth of blanks all the same size. Small square referencing on edge of centre reinforcement at the appropriate location to knife two lines the nominal-ish width of the brace. Excavate waste with chisel. Test brace in slot - it will be slightly too thick to fit. Don’t press it down or you’ll crush the edges of the slot you’ve just chiseled. Set plane for fine shaving. Take full length shaving from brace, test fit. Repeat until you get a nice tight fit. Usually takes one to three shavings. Assuming you start with a straight, dressed brace blank, and the centre reinforcement is straight and square, and you plane evenly the result is all braces square to centre with tight fit and within 0.3mm/.012” of the nominal width. Close enough for me. Reasonably fast for a non-jigged, mainly hand tool method.


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I can’t figure out why this isn’t commercially available. After I smashed my knuckle the last time when the drill chuck slipped, I made one of these. This one, with the ferrule, is the second iteration. I bought a box of 10 of these ferrules on Amazon for 73 cents—the page claimed I was buying one, I got a box of 10. I haven’t bruised a knuckle yet since I started using this.

Cool idea Bob. You know what they say smashed knuckles are the Mothers of Invention and Frank Zappa

here is a helpful tool to get way back for fat handed people

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Right you are, John. One of the reasons I liked having skinny apprentices is their arms could fit inside the soundhole.

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"Act your age, not your shoe size" - Prince

For many years we had the benefit of Ava Dave's daughter as she was growing up. She's all grown up now and doesn't hang around the shop these days so we lost our skinny arm.

I pre-taper the sides before bending, so the shape of the sides on the back is close to the 15’ radius. Time spent Driving the Bus is minimized. I should actually make the template more accurate, it’s still a little high on the upper bout.

Got a vid from my series if you have time.
https://youtu.be/KJISaNigQpM

Got a vid on Driving the Bus, but I only go straight, so not sure if you could call it driving.
This also shows my Beau Hannum style spreaders, which may be worth a look.
https://youtu.be/5yC_JI27nTU