The Simple CenterLine Finder


Simple CenterLine in Use

Close-up of top centering arms

Bottom of Centering Arms

The New Bridge Squaring Device

The New Bridge Square Attachment

Bridge Centering and Squaring Attachment

Simple CenterLine Scriber

Simple CenterLine Scriber in Use






The Simple CenterLine Finder and Bridge Squaring Attachment

The newest revolutionary jig from Luthier Suppliers!! This jig was inspired by the Center Line Finder jig created by Charles Fox of American School of Luthierie. We liked the idea so much, we decided to improve on the jig by giving this jig a complete overhaul. It now works with all thin and large necked instruments including acoustic guitars, archtops, electric guitars, bouzouki's, and classical guitars.

We added 2 sliding arms that move in and out in exact line with the centerline. When the plastic dowels contact the side of the neck, it pulls the centerline base in tight and automatically puts the center line over the fretboard and all the way to the end of the instrument. This allows you to see the centerline from the peghead all the way to the tail of the instrument. The center line is scribed on the bottom of the jig to avoid parallax issues. We have 2 black 3 prong knobs that are used to tighten it in place for added security. The plastic dowels that contact the side of the neck are very smooth and sure not to scratch or mar the finish.

NEW! A new Bridge Squaring attachment for the centerline finder...this attachment to the CenterLine Finder allows you to lock the position of the bridge squaring attachment using a brass set screw. This attachment is sold seperately. See below for price. Thanks to Jeff Suits who created this jig and asked us to sell it. A BIG thanks to Jeff!

There are 2 main uses for this jig:

1. When attaching a neck to the body, it is necessary to determine if the neck aligns properly to the center line of the body. This usually involves fiddling with a straight edge clamped to the fretboard while trying to line it up with the centerline of the body. The Simple CenterLine Finder is much quicker than pulling out the straightedge and clamps. This jig takes less than 10 seconds to align everything with the center line!

2. When setting up the bridge before gluing, you must align the bridge with the center line of the body and neck. This also takes a long time for setup, but with The Simple CenterLine Finder and Bridge Squaring Attachment, you can have the bridge centered and squared to the center line in 10 seconds!

Dimensions: The jig is made of 1/4"(6.5mm) thick acrylic that is 2 3/8"(60mm) wide by 34" long. The arms will fit a 2 3/4"(70mm) neck width to a 1"(25.5mm) neck width. The minimum neck length that it will fit is 12"(1ft).

Box contains: The Simple Centerline Finder fully assembled, 1 Simple CenterLine Scriber, 1 Golf Pencil, and one Bridge Squaring and Center Finder.

In addition to this jig, you will receive a Bridge Centering and Squaring attachment. It is placed onto the jig in the bridge location and held in place by small rubber bands to allow you to center and align your bridge exactly in relation to the centerline.

If you would like to upgrade the bridge square device, you can order the CL Finder with the upgraded bridge squaring attachment. Here is a picture comparing the 2 attachments. The one with the brass set screw is the upgraded version:

You will also receive one Simple CenterLine Scriber. Just insert the pencil in the hole and then place on a square piece of material less than 3 1/2" wide. Turn and push down as you slide down the length of a the material, and it will put a center line on the piece of wood. This jig was designed to work with neck blanks that are less than 3 1/2"(88mm) wide. The blank must be at least 6" long(152mm), and must be a squared blank. This jig will not work with a tapered piece of wood.

See Customer Testimonials HERE


Price: $74.00 (plus $11 shipping)

(When added to the cart, the price includes shipping and prices below include shipping, If you are outside the US, please contact me before ordering. Shipping is usually between $30-$60USD))


To purchase the CenterLine Finder with standard bridge square attachment and scriber $85:

To purchase the CenterLine Finder with the NEW bridge square attachment and scriber $104:

To purchase Only the NEW bridge Square attachment $26:


Instructions for Use

This jig comes pre-assembled and looks like this when taken out of the box:

1. Place on instrument neck as shown making sure the dowels are in the complete open position. You can do this by pushing the knob towards the nylon nut until the dowels are in the open position. You may need to loosen the black knob first.

2. Squeeze the two plastic dowels together until they touch the side of the neck. Do not press too hard.

3. While holding the dowels against the neck, lightly tighten the black knob. DO NOT OVER TIGHTEN, as these nylon screws can be stripped. Now repeat these steps for the upper arm.

4. Now you can see the centerline as it extends from the peghead end of the instrument all the way to the tail end of the instrument. You can adjust the neck until the centerline of the neck matches the centerline of the body.

5. To use the Bridge Squaring Attachment, just place it on underneath the centerline base in a predetermined place(you will need to mark your scale length, then adjust for the front of you bridge).(NOTE: This picture shows the bridge attachment without the use of rubber bands. This particular one was fit exactly to the jig so it could be snapped on. This is currently not available, instead you will need to use rubber bands to hold this jig on. Pictures coming soon.) Then you will need to butt the nut end of the centerline finder against a dummy nut, then tighten the plastic dowels against the neck and tighten the knobs. Now all you need to do is to mark the centerline on the bridge and slide it under the centerline finder until it makes contact with the Bridge Squaring Attachment. Line up the bridge centerline with the CenterLine Finder's centerline, and the bridge is now located. Just tape it down, and prepare for gluing.


Testing of this jig was done with the help of Michael Bashkin of Bashkin Guitars ( A guitar neck was ready to be fitted to the body. It was tested against his manual method of locating the centerline and the bridge. Below are pictures and explanations of the testing:

1. We placed the Simple CenterLine Finder on the guitar neck.

2. We made sure it was butted up against a dummy nut.

3. Here you can see that the neck was off by about 1/8". Now he will need to verify that the CenterLine Finder will match his manual method.

4. Here are some shots of checking the neck alignment with the bridge manually. Found out that the Simple CenterLine Finder was 100% correct:

5. Now to correct this. Here are some shots of removing the neck and using the sandpaper method to remove a tiny amount of wood from the cheek.

6. Success at last! This whole process took about 10 minutes.

7. Next we decided to test the bridge squaring and centering attachment. We snapped it on to the centerline base in the exact location of the bridge(after we located the scale length, then adjusted for the material in front of the saddle). We marked the centerline on the bridge and slid it under the base and butted it up against the squaring attachment. Then we aligned the centerline of the bridge with the centerline of Simple CenterLine Finder. NOTE: This picture shows the bridge attachment without the use of rubber bands. This particular one was fit exactly to the jig so it could be snapped on. This is currently not available, instead you will need to use rubber bands to hold this jig on. Pictures coming soon.

Next we went back to step 4 to verify that the jig worked. The answer was 100% correct.

Customer Testimonials

-- I got the gadget today replacing the original. The centerline is right in the middle of the jig as opposed to the original where it was off around .015 on mine. Checking a fretboard it was right on the mark compared to my regular way of measuring. I think you have a winner. I like the bridge positioning accessory. - Terry K

--...this is the second item I buy from you (for now!) and all I have to say is you are the way a business should be!.... - Peter M.

-- I received the CenterLine Finder today!!! Thanks --- it looks great!!! --Kathy M( )

-- Wow.  Nice CenterLine Finder.  Something tells me that you might have fudged a bit, and sent mine a little earlier than it should have been.  If so, thank you.  Both it and the Brace Maker arrived yesterday, and they look great.  This Brace Maker is symmetrical from end to end.     You are contributing some wonderful tools to this craft.  Thank you both. --John C.

-- This one is BEAUTIFUL! The addition of the bridge-squaring attachment was a stroke of genius. It all works perfectly! I tested the centering and the squaring of the attachment, and I could find absolutely no error. Thanks for a great tool! Bill Cory ( and

-- I recieved my center line finder yesterday and I couldn't be happier.  This tool is very well thought out and very soundly constructed.  I'm sure it will get a lot of good use in my shop. Thank you very much, -Joe B.

-- I just tried the new version of the centerline jig. Very Nice!!!! Thanks for the support with the redesign -Andy Z.

-- The centerline finder arrived yesterday and it's great!! Thanks for developing this design. I'm sure that it will see much use in the future. Thanks again, Pete L.

-- Received my jig in good order and finally pulled it out of the box and gave it a try.  It's a great jig.  The Archtop neck/body that's in the works, I thought I had centered dead on -- turned out to be 1/32" off line.  This jig is a must have in my view! - Anthony Z.

-- I received the Jig and it is perfect ! I really like it. It is so precisely built. Just a  Very  nice jig.  - Dave A.

-- I recieved the centerline jig yesterday and I am very pleased with it. Very nice stuff it will make it much easier to find my centerlines. Thanks for coming up with such a cool jig. --Tom Doerr (

-- The Center Line tool is too cool! Ingenious! Crafted with excellence. --Tony Vines (

-- Hi, These jigs are just what I've been looking for in guitar tools. Well designed and user friendly. I couldn't wait to get them out of the packaging. Your neck alignment tool gives me the comfort of knowing the neck is properly aligned and greatly reduces my time in setting the neck. Simply set it once and it is on and off the neck in a flash with each tweak of the neck joint. WOW! The bracing radius jig is a must have for every guitar builder. You have taken a tedious task and have made it a delight! Simple ingenious. Thank you and very much appreciated. --Michael L.

--I got the centerline finder today, and it was perfect timing since I was fitting a neck to a guitar when it arrived. Makes lining things up a piece of cake...VERY nice product! Thanks for the fast service, and the great jig! Russ W.

-- I used the center line finder over the weekend. It is AMAZING. Man, it made my life simple. There are guitarmakers out there who think they don't need one of these (at least one)....they are wrong. Thanx again! Peace, Michael Greenfield (

-- Just wanted to let you know that I used your centerline finder last night to set the neck on my 000 (my first) and was more than happy-- everything came out spot on.  I'm thinking to myself: "it can't be this easy," then realized
how much more trouble it would have been using a straight edge.

Great products.  Keep 'em coming!
Best, John

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