# AutoCAD exercise: a stepped shaft > Draw a stepped shaft in AutoCAD: half its outline as a polyline, chamfered, mirrored about the axis, and its lengths as chain dimensions. Free, step by step. Draw this stepped shaft in side view, in millimetres: 150 long, with diameters of 30, 40 and 30 over lengths of 40, 60 and 50, and both ends chamfered 2 by 2. Draw the half above the axis as one polyline, chamfer it and mirror it; then the edges seen across the shaft, the axis and the lengths. The diameters are the ones given here. - **Exercise:** Intermediate · Mechanical · 2D - **Commands:** [`PLINE`](https://mellowcad.com/docs/commands/pline.md), [`CHAMFER`](https://mellowcad.com/docs/commands/chamfer.md), [`MIRROR`](https://mellowcad.com/docs/commands/mirror.md), [`LINE`](https://mellowcad.com/docs/commands/line.md), [`DIMLINEAR`](https://mellowcad.com/docs/commands/dimlinear.md), [`DIMCONTINUE`](https://mellowcad.com/docs/commands/dimcontinue.md) - **In the editor:** [Open it with its drawing](/draw?drawing=shaft), dimensioned beside where you draw yours ## The drawing A stepped shaft in side view, 150 long, its lengths dimensioned in a chain. ## Step by step The engine draws each step and writes its history as you would type it: the prompts in AutoCAD 2027's order, with the same option letters. After a command's first point, a typed point is measured from the last one, as dynamic input measures it, and the history writes it with @; \# measures from the origin. ### 1. Draw the upper half On the Outline layer, one [`PLINE`](https://mellowcad.com/docs/commands/pline.md) from `0,0`: up `0,15`, along `40,0`, up `0,5`, along `60,0`, down `0,-5`, along `50,0` and down `0,-15`, back to the axis. Enter ends it. 1. Draw the upper half ```text Command: PLINE Specify start point: 0,0 Current line-width is 0.00 Specify next point or [Arc/Halfwidth/Length/Undo/Width]: @0,15 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @40,0 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @0,5 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @60,0 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @0,-5 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @50,0 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: @0,-15 Specify next point or [Arc/Close/Halfwidth/Length/Undo/Width]: ``` ### 2. Chamfer the ends [`CHAMFER`](https://mellowcad.com/docs/commands/chamfer.md), then `Distance`: `2`, and Enter takes `2` for the second distance too. `Multiple` chamfers one corner after another without starting again: pick the two segments at each end's corner. 2. Chamfer the ends ```text Command: CHAMFER (TRIM mode) Current chamfer Dist1 = 0.00, Dist2 = 0.00 Select first line or [Undo/Polyline/Distance/Multiple]: D Specify first chamfer distance <0.00>: 2 Specify second chamfer distance <2.00>: Select first line or [Undo/Polyline/Distance/Multiple]: M Select first line or [Undo/Polyline/Distance/Multiple]: Select second line or shift-select to apply corner or [Distance]: Select first line or [Undo/Polyline/Distance/Multiple]: Select second line or shift-select to apply corner or [Distance]: Select first line or [Undo/Polyline/Distance/Multiple]: ``` ### 3. Mirror it [`MIRROR`](https://mellowcad.com/docs/commands/mirror.md): pick the polyline, press Enter, then the mirror line from `0,0` to `150,0`, the axis, and Enter to keep the original. 3. Mirror it ```text Command: MIRROR Select objects: 1 found Select objects: Specify first point of mirror line: 0,0 Specify second point of mirror line: @150,0 Erase source objects? [Yes/No] : ``` ### 4. Draw the edges With [`LINE`](https://mellowcad.com/docs/commands/line.md), the edges seen across the shaft, each `0,30` up from the bottom: from `2,-15` and `148,-15` at the chamfers, and from `40,-15` and `100,-15` at the shoulders. 4. Draw the edges ```text Command: LINE Specify first point: 2,-15 Specify next point or [Undo]: @0,30 Specify next point or [Undo]: Command: LINE Specify first point: 40,-15 Specify next point or [Undo]: @0,30 Specify next point or [Undo]: Command: LINE Specify first point: 100,-15 Specify next point or [Undo]: @0,30 Specify next point or [Undo]: Command: LINE Specify first point: 148,-15 Specify next point or [Undo]: @0,30 Specify next point or [Undo]: ``` ### 5. Draw the axis On Centre lines, the axis: a line from `-8,0` to `166,0` further on. 5. Draw the axis ```text Command: LINE Specify first point: -8,0 Specify next point or [Undo]: @166,0 Specify next point or [Undo]: ``` ### 6. Dimension it On Dimensions, [`DIMLINEAR`](https://mellowcad.com/docs/commands/dimlinear.md) for the first length, 40, placed below. [`DIMCONTINUE`](https://mellowcad.com/docs/commands/dimcontinue.md) carries on from its second extension line: `#100,-20`, then `#150,-15`, typed from the origin with #, and Enter twice to end it. A last [`DIMLINEAR`](https://mellowcad.com/docs/commands/dimlinear.md) gives the whole length, 150, further below. 6. Dimension it ```text Command: DIMLINEAR Specify first extension line origin or : #100,-20 Dimension text = 60 Specify second extension line origin or [Select/Undo] : Select continued dimension: Command: DIMLINEAR Specify first extension line origin or