The Inner Workings of Stock Step Units


The students will demonstrate their knowledge on the various pieces and parts of a stock step unit and the steps in building one by creating a model of one.



Materials Needed

12 pieces of 1/8” plywood cut at 16”x10” (carriage)
6 pieces of 1/8” plywood cut at 14” x 9” (Tread)
6 pieces of 1/8” plywood cut at 10” x 9” (Risers)
Carpenter’s Squares
4 Stair Gauges
Staple Gun with Staples
Table Saw
Miter Saw
Band Saw
Model of Step Unit



Related Documents

• Lesson Five Document   Lesson Five Document with lesson details



Lesson Directions


Anticipatory Set/Hook
Show the students the ending clip from Labyrinth where Sarah, the baby, and the Goblin King are climbing over, around, and across various sets of stairs or the clip from Harry Potter: The Sorcerer’s Stone where Ron, Harry, and Hermione are climbing up a set of stair, it starts moving, and the lines are said, “What’s happening?” “Don’t you remember, the staircases move.”




Step 1: Ask the students why they think step units in theater are important (if you use platforms you need steps to allow the actors to get to those platforms).


Step 2: Take the students to the shop and have them separate into groups of 4.


Step 3: Ask the students what ¼” scale means (1” = 4’).
-tell them that they will be making a step unit at ¼” scale.
-ask them if we want a tread of 12” and a rise of 8” how big are the tread and rise going to be on the model (divide the real measurements by 4 to get scale measurements-tread 3” and rise of 2”)


Step 4: Show the students the carriages on the step unit model.
-Have each pair of students get two pieces of 1/8” plywood to make a carriage.
-Draw on the board a picture of a step unit Carriage


Step 5: Have a student label the scale dimensions on the rise and tread of the carriage.
-get out the carpenter’s squares and have the students place a stair gauge on the 2” and 3” marks
-now have them but the paperclips against their piece of 1/8” plywood. Do this 5 times to make the rise and tread of the carriage.


Step 6: For the bottom rise have the students deduct the width of a tread (for model 1/8”
-for the top tread have them deduct the thickness of a rise (for model 1/8” plywood).


Step 7: Now have the students extent the line from the second to last rise on the bottom
and the second to last tread on the top.
-connect a line where these lines cross the bottom and back of the step unit


Step 8: Now have the students place their two pieces of 1/8” plywood together and staple
twice in the middle of the carriage.
-using the band saw have the students cut out the carriage.


Step 9: Next ask the students if they want steps 3’ wide in ¼” scale how wide should they
Be? (3×12=36” so 36” wide steps ……..36” divided by 4” is 9” wide so scale steps are 9” wide)


Step 10: Create a cut list on the board
Using 1/8” plywood
-3 Treads @ 3”x 9”
-1 Tread @ 2 7/8” x 9”
-3 Risers @ 2” x 9”
-1 Riser @ 1 7/8” x 9”


Step 11: Using the table saw (if available) and the miter saw have the students cut out the
Treads and Risers


Step 12: Starting with the bottom riser and moving to the top glue and staple 4 riser
-explain that when building a real step unit screws will be used instead of staples


Step 13: Starting with the bottom tread piece and moving up glue and staple the 4 tread
-explain that when building a real step unit screws will be used instead of staples


Step 14:Show the students the back of the model step unit
Ask the students to measure the gap at the top of the step unit between the two
pieces of carriage and the top step (8 6/8” x 2”)
-have them cut out a piece of 1/8” plywood according to these dimensions
-glue and staple in this piece


Step 16: Point out the legs on the model of the step unit. Explain to the students that they
will not put these on their models but will on the full scale step units.







Author’s Notes

See the attached document for the drawings.