Lesson Plan Industry Sector

Spline-Miter Joint

Lesson Plan Overview / Details

At the end of the lesson the students will make a spline-miter joint to go with their dado joint for the dog project.

Lesson Time

One and a half class period
3 Hours

Activities in this Lesson

• Music box - Hooks / Set

The teacher will open a music box (jewelry box) playing a tune. He will have the students gather around; look at the box and identify the joints at the corners. The box must have spline miter joints. He will then take out a two picture frame. One is with the spline and the other is without the spline. He will have the students guess which will be the strongest of the two. He will explain that today we will make a spline miter joint.

Alternate hook.

Use the same jig that was made for the dado joint and compare the break points of a spline-miter and a dado joint. (refer to dado lesson)

• Teacher passes out the demo worksheets and shows each tool for making the spline miter:  Back saw, paring chisel, combo square, project drawings and pencil. Students will write down the tool names on their worksheet as the teacher points them out.

Teacher will ask students what they think the joint could be used for. Teacher will explain why the grain structure and surface area is important for a miter joint. He will ask student what other things that a miter joint is used for. Students write down their answers on worksheet.

• The steps to make it - Demo / Modeling

Teacher demonstrates how to make the joint. At each stage students will write down the step on their worksheets. Each time the teacher picks up a tool, he asks what is its name . Teacher will be using a 10” piece of wood.

Teacher says:

“Look at your drawing. Point to the spline miter joint. What is the length of the leg wood? What is the length of the body”?

Step 1:  “From the end of the wood measure over 3 ¾”. Using the 45 degree part of the combination square Mark a 45 º angle and then a 90 º vertical line down the edge of the wood. Mark all the way around”.

Teacher should review how to use a combo square properly while marking.

Step 2:  “Now you will clamp down the wood on a backing board and with your backsaw cut the 45 º all the way through.”

Teacher should talk about splitting the pencil line while cutting to keep the joint accuracy in thousands of an inch. This concept is not part of the assessment but an ongoing theme throughout all projects to encourage accuracy. The teacher should also talk about keeping the saw vertical so that the two 45 º when turned to 90 º they are true 90 º. Encourage the students to work in pairs and watch each others cuts to ensure 90 º

“ Watch when I turn the two pieces of wood my 45 º turns into a 90 º. This is more efficient than trying to cut two 45 º on two different ends of wood”

Step 3:  “Now look at the drawing. How thick is the spline?”.  Now set your combo square to 1/4” and mark both spline's shoulders all the way around. Now on the edge of the wood. Measure down 3/8” for the depth of the spline.

Teacher demo how to clamp wood in a wood vise to free up both hands and use combo square to mark shoulders

Step 4.  “Using your back saw, cut the shoulders on each of your splines. Make sure you split the line. It is better to have your joint a little tight in the beginning that loose so that you can fine tune it's snugness. Remember that too tight of a joint will crack the wood when glue is applied so snug is best. Not too loose or too tight.” Do the same to the other side”

Teacher should demo to the students how to put the spline joint into the wood vise so that the joint is parallel to the ground. This way they saw parallel and flat. Many students want to have the wood sticking up in the vise and use their saw to cut uphill (See picture)

Step 5:  “ With a ¼” chisel. Clean out the wood between the shoulders and chisel it flat down to the proper depth.” Do the same to the other piece of wood”

Teacher demo this process.

Step 6:  “ Fit the joint together and check to make sure the pieces come to together and are flush”

• Review - Check Understanding

Teacher reviews by asking the students to retell the basic steps to make the joint. Have the students look at the rubric for what is expected of them.

• Time to build - Independent Practice

Each student will be making their own joint while the teacher walks around checking. At this stage the teacher can be assessing their understanding and helping when needed.  Remind the students that they can make the joint over and over again if they want to make it better.

• Show samples - Closure

The teacher can end the lesson by showing samples of various miter joints both good quality and poor quality. Have the students choose which one they think are the best.

Assessment

Assessment Types:
Rubrics,

Formal assessment is with the rubric that has been covered with the students.