Exercise: draw a round flange with 6 holes on a PCD, step by step

This exercise walks through drawing a round flange — one of the most common parts in piping, pumps, motors and laser-cut work. Along the way you use the key commands: typed coordinates, circles, centre lines, polar array, dimensions, leaders and file export. It takes about 15 minutes.

The drawing

Before you start

1. Open DXCAD2D Online and choose File → New.
2. In the Layers section of the side panel add layers CENTER and DIM. Layer 0 is for the part outline.
3. Turn on OSNAP (F3) with the centre and quadrant points ticked.

Step 1: outer circle and bore

1. On layer 0, press C, type 0,0 Enter to put the centre at the origin, then type 60 Enter (the radius of Ø120).
2. Press C again, type 0,0 Enter, then 25 Enter for the Ø50 bore.
3. Press Z to see the whole drawing.

Step 2: centre lines and the pitch circle

1. Choose layer CENTER, set the line type to centre and the weight to 0.25 mm.
2. Press L, type -67,0 Enter, then 134,0 Enter, then Enter again to finish — a horizontal line extending 7 mm past the outer circle on each side.
3. Press L, type 0,-67 Enter, then 0,134 Enter and Enter for the vertical line.
4. Press C, type 0,0 Enter, then 45 Enter for the Ø90 pitch circle.

Step 3: the first hole, then a polar array

1. Go back to layer 0 and set the line type back to continuous.
2. Press C, type 45,0 Enter (where the pitch circle crosses the horizontal axis), then 5.5 Enter for a Ø11 hole.
3. Click the new hole to select it, type PO and press Enter (polar array).
4. Click the centre of the flange (the snap catches the centre) or type 0,0 Enter.
5. In the options box at the top right set the count to 6 and the total angle to 360, then click Create or press Enter — six holes exactly 60° apart.

Step 4: dimensions and notes

1. Choose layer DIM, press D, click the left and right quadrant points of the outer circle and drag the dimension above the part: 120. Do the same for the bore (50).
2. Put a Ø text before the values, or use a leader instead (next step), so the machinist knows they are diameters.
3. Type LE, click the edge of one hole, click where the text goes and type 6× Ø11 THRU on PCD Ø90.
4. Place the text 10 thick and the material under the view.

Step 5: check and export

1. Type ME and click the centres of two neighbouring holes: the distance must be 45.00 (the chord of 60° on a Ø90 circle equals its radius).
2. Press Ctrl+S to keep a .json file for later edits.
3. For a laser shop: hide layers CENTER and DIM, then choose Export → DXF…. You get just the outer circle, bore and holes.
4. For a drawing to read: show all layers, choose Export → PDF…, tick Add drawing frame + title block and fill in the part name, material and general tolerance.

Going further

• Change to 8 holes: delete the extra holes and run the polar array again with a count of 8.
• Put the holes between the axes (offset 30°): before the array, rotate the first hole with RO about 0,0 by 30.
• Make the holes M10 tapped holes — see tapped and drilled hole callouts.

If you get stuck, every command is explained in the user guide.