Simple Jigs and Techniques #1: Simple Precision Arc Inlay Jig

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Blog entry by shipwright posted 06-20-2012 12:44 AM 3214 reads 18 times favorited 24 comments Add to Favorites Watch
no previous part Part 1 of Simple Jigs and Techniques series Part 2: Precision Router Jig for Straight Lines. »

I had the need this afternoon for a way to cut a curved groove for a veneer inlay. It needed to be absolutely accurate and easy enough that even I couldn’t screw it up. A half hour later I had this little jig. I thought someone else may find it useful.

The first photos are self explanatory and show the simple construction and assembly of the base and pivot arm. The featured performer is one of my personal favourite Harbour Freight tools, the trim router.

In the next photo the base has been cut off at the 6 1/2” radius that I require for this job. This is the only critical measurement here and it can be made with a regular tape measure. The accuracy lies elsewhere.
As you can see, I like to do cutoffs over foam insulation.

This one shows the obvious, that is that the cut in the base is exactly where the cut will be in any piece the base is clamped to.

Here I’m making a trial cut in a piece of plywood to check depth of cut to match my veneer thickness.

Here’s the obvious again. I love it when these things are this obvious. It makes it much harder (although not impossible) to screw up in a moment’s lack of focus. The inner cut radius is exactly where the edge of the base is.

Now the depth of cut has been adjusted and exactly matches the veneer thickness.

And finally, here’s why this has to be so precise. There’s just no room for error here. Even so, I will be making this cut in the morning with a clear head and I’ll be thinking it through very carefully before any routers get turned on.

There are lots of bells and whistles that could be added to this but all I needed was a one time non-adjustable, deadly accurate, deadly obvious jig that I could make, use and chuck. That’s the way I usually think about jigs in general.

Thanks for looking. I hope this helps someone somewhere.


-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fiberglass trees.

24 comments so far

View a1Jim's profile


113725 posts in 2616 days

#1 posted 06-20-2012 01:11 AM

hey Paul
These kind of Jigs are great good job .Thanks for sharing.

-- Custom furniture

View rustynails's profile


558 posts in 1568 days

#2 posted 06-20-2012 01:31 AM

How are you getting the piece of veneer to fit in the grove? As in width wise and arc? I am guessing you are using the jig with a knife to cut the veneer?
Thanks Richard

View shipwright's profile


6186 posts in 1837 days

#3 posted 06-20-2012 01:35 AM

The veneer arc is cut on the chevalet.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fiberglass trees.

View Mathew Nedeljko's profile

Mathew Nedeljko

701 posts in 2869 days

#4 posted 06-20-2012 01:51 AM

love it Paul…one time use and chuck. Seems like the only way to screw it up would be to go past your starting and finish point. Maybe think about adding some stops to limit the rotation to exactly what you need?

-- Aim high. Ride easy. Trust God. Neale Donald Walsch

View gfadvm's profile


13765 posts in 1729 days

#5 posted 06-20-2012 01:52 AM

A great jig but the project in progress is amazing! Can’t wait to see it finished.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View peteg's profile


3407 posts in 1862 days

#6 posted 06-20-2012 02:55 AM

Aaaaahhhh the thinkin man is at it again,
Paul you make it look like these crafty aids just simply fall of the bench no sweat, .... yer right
Bet there are a few copies made of this one :: )))

-- Pete G: If you always do what you always did you'll always get what you always got

View lightweightladylefty's profile


2957 posts in 2751 days

#7 posted 06-20-2012 03:19 AM


We love your solution! It seems I spend more time making jigs than the actual cuts! Our next project is to build a 50,000-square-foot warehouse to store all the jigs. After that we’ll need to hire staff to keep them documented so we can find them when we need them.

Oh, wait, maybe we should just chuck them and not build the warehouse or hire the staff!


-- Jesus is the ONLY reason for ANY season.

View rustynails's profile


558 posts in 1568 days

#8 posted 06-20-2012 03:34 AM

The veneer arc is cut on the chevalet

Thanks Paul

View Douglas Bordner's profile

Douglas Bordner

3992 posts in 3102 days

#9 posted 06-20-2012 12:37 PM

Pucker factor of 12 on that cut. Very ingenious, and I can absolutely see a HF trimmer in my future for dedicated jigging. Thank you for sharing this.

-- "Bordnerizing" perfectly good lumber for over a decade.

View Bluepine38's profile


3191 posts in 2124 days

#10 posted 06-20-2012 01:18 PM

Wonderful jig and easy to make and use, now if I could just manage to make the beautiful project you are
using it on, I would really be happy. Thank you for sharing.

-- As ever, Gus-the 76 yr young apprentice carpenter

View SPalm's profile


5174 posts in 2921 days

#11 posted 06-20-2012 01:28 PM

Nice work Paul.

HF trimmer – I need to check that out.
Routing over foam board – Love it.
What you are really working on – My gosh….


-- -- I'm no rocket surgeon

View eddie's profile


7744 posts in 1653 days

#12 posted 06-20-2012 01:45 PM

shipwright very cleaver jig , could be used for many more things ,thanks for sharing and the project in progress its looks to be a beauty.

-- Jesus Is Alright with me

View helluvawreck's profile


18752 posts in 1905 days

#13 posted 06-20-2012 01:46 PM

You sure do nice work, Paul. That’s a nice jig too.


-- If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away. Henry David Thoreau

View mafe's profile


10515 posts in 2128 days

#14 posted 06-20-2012 02:01 PM

Clever simple jig, with a precut side that gives you exact place to set it.
Keep the head clean.
Best thoughts,

-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

View DocSavage45's profile


6595 posts in 1881 days

#15 posted 06-20-2012 02:23 PM

when you do it it seems so simple. LOL!

-- Cau Haus Designs, Thomas J. Tieffenbacher

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