box (finger) joint jig - smart table saw

This is the instruction manual for a box-shaped joint fixture that is necessary for this special woodworking technique.
I did it at TechShop in Menlo Park (
I need this tool so I can create a box connector (
Sometimes referred to as Knuckles)
Use the dado stack bit on the sawstop table saw.
A fixture is needed to easily cut 1/2 "fingers" at the end of the board and space of the same size.
Using this tool will make these cuts clean and efficient.
The box joint is a replacement for the more popular swallow tail joint.
One interesting point is that the box-shaped joint is stronger than the tail joint and does not require a custom tail clamp.
Instead, you can make this all day with scrap and belt box joints.
The strength test was performed when this structure was created and you need the following sections :-Wood scraps -
Ideally some 1x12 and 2x4 scrap-
The length depends on your table saw, but the 2 feet length should be enough. -Wood screws -1 1/4" (at least 14)-
The following tools are also required (
All of this is available at the tech store! ):-
Table saw with standard blade and dado stack bit set-Mitre saw-Power sander-Power drill-
Wood drill-1/8"
According to the requirements of the wooden screws, Phillips or flat head drill bit-
Carpenter Square-
If you are making a fixture, let's say you are familiar with the tools and parts above.
That said, this is an Instructure, so I will discuss it in detail if necessary.
Please comment on your correction.
The size of your rails may vary depending on your desktop saw.
The grooves on the sawmill table seen at the MPK Tech Shop are slightly narrower than 3/4 ", about 1/4" deep, somewhere between the third and half of the total length of your table.
Measure your groove and tear off two thick enough wooden strips from the end of your 1x12 "plate to flush it with the surface.
If your guide rail is too high, your fixture will rub at the bottom of the groove instead of sitting flat on the table.
I use a bench saw with a standard blade to tear the strips off and tune them to the correct width and height on the Sander.
Ideally, your guide rail should be at least 1/3 to 1/2 as long as you have a table.
Too long, you will have too much resistance and you may hit something on the other side of the table.
It's too short for the tour guide to do their work.
However, the length is not as important as the height and the ability to pass through the channel smoothly.
Before moving on, take a minute to slide the guardrail back and forth and slide side by side.
They should slide easily along the Groove (
Polishing will also help.
Guide rail will be smoother)
Rip cuts a 4 "board from your 1x12 scrap. (
I missed this photo when assembling the structure.
I'm sure you'll understand. you're smart.
For Your Entertainment, here is a photo of a flying horse flying from Pizza Hut floating island to an astronaut.
I didn't do this and I found it here: the box connector will be set exactly to do halfinch cuts.
You can make it a wider or narrower cut, but it will be fixed to any width you build it.
Any table saw using the dado bit will almost certainly support half
Width slot in inches.
If you decide to make the fixture into a different specification, then replace all the measurements here with the required width.
Set the tear fence to 1/2 "and the blade height to hair above 1/2 ".
Take your remaining 1x12, lean it vertically against the torn fence and pass it through the blade.
This will set the width of the gasket.
Next, set the height of the blade to fit the full thickness of the board you are using and keep the tear fence at 1/2 ".
Cut off the rest of your gasket.
Note: This will be hard at the end as your smallest part will be between the blade and the tearing fence.
Use one push stick and the other scrap.
Or even rotate the board to the other side and re-rotateset your blade.
I just found out that keeping the torn fence at 1/2 "for the sake of two cuts, which gave me a perfect square with no idea, but dealing with such a small piece on the table saw
As always be careful!
When you are done, you will have a stick of 1/2 "1/2.
Use a herringbone saw to cut off two lengths of this stick, about 4 inch long. Now that you 've done all the tear cuts, it's time to start connecting the rails.
For this step, you need the track, glue and the widest remaining part in 1x12 (
Should be 6-It's wide now.
I'm lucky to have a new piece so my base is a full 12 "wide but it doesn't have to be that wide).
At least square one end of the plate on the herringbone saw (
That is, make sure it is perpendicular to the side).
This is important for the next step.
Measure the length of the remaining widest part of 1x12 and the width between the guide rail.
Subtract the rail distance from the length of the plate, divide the number by half, and measure the distance from the end.
For example, suppose I have 24 "of board, the gap between rails is 10 ".
The difference is 14 ", half of which is 7 ".
So I came in 7 "from one end of the board and marked it with Carpenter Square (
Now, just one end).
Stick a track to one side of the line closest to the end of the plate.
Straighten it with your square. (
In the first picture, I obviously did not use the combined square of the Carpenter.
I would recommend always using the combo square as my fixture does deviate a bit from the angle).
If you are too impatient to allow the glue to dry, drill a few holes first and screw it in place.
It doesn't have to be beautiful, so I screwed them very tightly in order to sink them below the surface of the track.
This prevents the screw head from rubbing on the table.
This is the use of 3/4 screws.
Because you know the width between your rails, measure the width from the edge of the fixed rail closest to the center, mark your next line, and set the next rail in the same way.
When the glue is wet, take the time to install the fixture on your table saw to make sure your width is correct.
It is important that the guardrail is aligned to the saw slot on the table, which is more important than aligned to the end.
Once you know that the width is correct, fix the guide rail in place with 3/4 screws, be sure to sink your head again.
To make sure your guide rail is working properly, test the square degree of the guide rail and be clear about the middle position of the plate, go through about half of your base and check it with a square.
Go and find the 4 "rip cut you made in step 3.
Let me wait first. OK Got it? Good.
Draw a line with your square, perpendicular to the end of the board you have in the previous step about 2 inch square meters from behind the base. Double-
Check if the line is cut perpendicular to the middle.
In any case, it's more important that you cut perpendicular to the end of the plate, so there's a good way to make sure you're surrounded by squares.
Fix the back plate with glue and screws.
Put two screws from each side below.
Use 1 1/4 screw this time, but make sure again that they bury themselves below the surface so they don't scratch your saw.
In addition, make sure to leave a gap of several inches from the center cut.
Support the board with 2x4 scrap.
Put it behind the back panel, screw it down from the bottom and pass through the back panel.
Okay, it's time for fun. . .
Install your wall skirt at 1/2 "(
Or the width of your choice
It may not be worth less than 1/2).
Remove the torn fence.
Set the height of the board that suits you for the base.
1/2 "cut by fixture "(or whatever)
Wide pass in your fixture.
Take the two 1/2 square sticks you made in step 4.
Place one of the rods flush down to one side of the groove.
Glue one side of the other stick and dock it with the other stick and back panel.
Remove the first block without moving the adhesiveon piece.
Let this dry.
Don't bother to screw this in place, it's too small.
Your fixture is done!
Small pieces are still necessary, so don't throw them away.
I don't have a companion to record the first use of the fixture with me, but I took a lot of photos here.
Set the dado bit above the fixture base, high enough to cut out the groove as wide as the replacement plate of the corner joint (e. g.
, If your board is 3/4 thick, then set dado bit 3/4 above the bottom of the fixture.
Start with a board and attach it to the gasket in front of the back panel.
The free spacers are used to offset the plates, so the grooves are actually matched with each other, not to meet each other.
The fit of the joint will start without the gasket and your plate will be perfectly aligned.
Pass the dado bit through your material.
Remove the loose gasket and leave it.
Attach the material to a fixed gasket and then perform the next cut.
Now, set the groove you just passed through the gasket and proceed to the next pass.
Repeat it until you cut to the end.
For the partner of this joint, start the first pass without loosening the gasket and repeat the above steps to cut the groove to the end.
Once you cut two plates to fit one joint with each other, you can put them together and the top and bottom should be aligned. Congrats!
You have a jig!
Let's do some great things with it now!
Or, come to the MPK tech store and use my!