Print PDF
Favorite
Email
Step 7Trigonometry and Pocketing
To achieve the neck pocket angle, we will need to mill the pocket with the wood propped up on an angle. To do this, we need a triangular wedge of wood, like a door stopper, to place at the right height.
Please see attached image to understand what I mean. You will need to punch the numbers into a scientific calculator to find the height of X. Use this formula:
X = Length of Plywood * Sin2°
X is the height on the wedge you will need to rest the plywood on. Simply measure from the bottom of the wedge to the sloped side and draw a line where the thickness is the same as the value for X.
Clamp it in place once everything is aligned like the Actual diagram below. Be sure to align the body so that it the center line on the wood is straight with the Y axis of the mill.
Now, you're probably wondering how deep to make this pocket. Measure the thickness of your neck at the mounting point. Subtract 1/4" and this is how deep the pocket should be.
Bring the cutter over to the edge where the pocket will be. Move the axes until the cutter is touching the wood. Set your Z axis to zero for this location. Move the cutter away from the wood and lower it to your calculated pocket depth, and lock the Z axis.
Turn on the mill and mill the pocket as close as you can get to the marked pocket contour. Move the cutter back out of the pocket and shut off the mill. Move the bed as far toward you as possible, and test-fit the neck. If it fits, great! If not, continue to mill it bit by bit until it does fit. It might take you half a dozen tries to get it to fit the way you want it. Once its in place, check that it lines up with the center line acceptably while you hold it in place.
If your neck has no holes, great. Use a soft-jaw clamp to hold it in place in the pocket, properly aligned. Get a drill bit that is a smaller diameter than the neck mounting screws you have. Drill through the back of the body and into the neck. Don't drill all the way through the neck! Once through, remove the clamp and neck and redrill the holes in the body with a drill bit of larger diameter than the screws. If your neck does have holes, you'll have to find a way to transfer their locations onto the pocket so you can drill the holes through the body. I did this with some paper and a pencil, poking holes where the neck holes already were. Then I traced the neck perimeter, and cut it out with scissors. Then I placed it inside the pocket and marked where to drill in the wood. Perfect!
Screw the neck in place and see how it looks! If the alignment is off, you will need to use a round file to file out a few holes in the body, and wedge some slivers of wood into them to push the alignment back straight. That, or re-draw your center line.
Please see attached image to understand what I mean. You will need to punch the numbers into a scientific calculator to find the height of X. Use this formula:
X = Length of Plywood * Sin2°
X is the height on the wedge you will need to rest the plywood on. Simply measure from the bottom of the wedge to the sloped side and draw a line where the thickness is the same as the value for X.
Clamp it in place once everything is aligned like the Actual diagram below. Be sure to align the body so that it the center line on the wood is straight with the Y axis of the mill.
Now, you're probably wondering how deep to make this pocket. Measure the thickness of your neck at the mounting point. Subtract 1/4" and this is how deep the pocket should be.
Bring the cutter over to the edge where the pocket will be. Move the axes until the cutter is touching the wood. Set your Z axis to zero for this location. Move the cutter away from the wood and lower it to your calculated pocket depth, and lock the Z axis.
Turn on the mill and mill the pocket as close as you can get to the marked pocket contour. Move the cutter back out of the pocket and shut off the mill. Move the bed as far toward you as possible, and test-fit the neck. If it fits, great! If not, continue to mill it bit by bit until it does fit. It might take you half a dozen tries to get it to fit the way you want it. Once its in place, check that it lines up with the center line acceptably while you hold it in place.
If your neck has no holes, great. Use a soft-jaw clamp to hold it in place in the pocket, properly aligned. Get a drill bit that is a smaller diameter than the neck mounting screws you have. Drill through the back of the body and into the neck. Don't drill all the way through the neck! Once through, remove the clamp and neck and redrill the holes in the body with a drill bit of larger diameter than the screws. If your neck does have holes, you'll have to find a way to transfer their locations onto the pocket so you can drill the holes through the body. I did this with some paper and a pencil, poking holes where the neck holes already were. Then I traced the neck perimeter, and cut it out with scissors. Then I placed it inside the pocket and marked where to drill in the wood. Perfect!
Screw the neck in place and see how it looks! If the alignment is off, you will need to use a round file to file out a few holes in the body, and wedge some slivers of wood into them to push the alignment back straight. That, or re-draw your center line.
| « Previous Step | Download PDFView All Steps | Next Step » |
 |
Add Comment
|
