This section is about our CAD software and how it relates to the machining, fabrication and finishing processes.

Fabrication Machines

Fabrication machines make the basic shape of your custom part – cutting the necessary holes, slots, and other shapes. You must specify a selection for each line in your drawing.

To assign a machine to a line in your drawing:
  1. Select the line.
  2. Choose Line | Machine. A dialog box appears.
    1. Select a machine:
      Auto – use this for most cases – it automatically chooses the optimal machine(s) to make your part. 
      Bend – use to bend sheet metal.
      Thread & Tap – use to tap holes or thread shafts.
      Comments to Self – use to make comment lines and text not seen by the machinist.
      Comments to Machinist – use to make comments lines and text seen by the machinist.
  3. Specify any settings if needed.
  4. Click OK.
If you have an unusual reason to specify that a particular machine (for example, a milling machine) be used, use Comments To Machinist but it is recommended to specify only the shape and specifications for your part, not how to make it.
If you have an unusual reason to specify that a particular machine (for example, a milling machine) be used, use Comments To Machinist but it is recommended to specify only the shape and specifications for your part, not how to make it.

Finishing Machines

Finishing machines treat the surface of your custom part. For example you may want to nickel plate a part to protect it from oxidizing or mechanically brush the surface of the part to create a textured look.

Review specific finishes here.
To specify finishing:
  1. Choose Job | Finishing.
  2. Choose the desired finish and check Selected . A checkmark appears.
  3. Enter any additional settings using the controls that may appear below the grid.
  4. Repeat steps 2-3 as needed.
  5. Click OK.

Decorative Parts

For parts that need a decorative finish: 

  • For fine mechanical finishes, choose a low surface roughness in Job | Settings | Specs.

  • Specify special requirements not covered in the system using Comments to Machinist.

  • See tips on decorative finishing.

The data presented in the Finishing dialog was collected from several sources. Although the sources are believed to be reliable, the accuracy of the data is not guaranteed. The data is intended as a general guide. If one or more parameters are critical to your design you should verify the data independently. Please contact us with corrections.

Tap and Thread

A tap is a tool for creating internal threads in holes. You can tap or thread holes or protrusions in your part. For example, you might tap a hole for a bolt or thread a protrusion to mate with another part.

To tap holes or thread protrusions:

  1. Select a circle.
  2. Choose Line | Machine | Thread.
    • Thread system – Inch/Metric/Taper – select one or click User defined (see below).
    • Thread settings grid – choose the desired thread from the Size column to match the intended screw or nut.
    • Threads are right hand by default. Use Comments to Machinist to specify Left Hand.
    • Set the thread length in the toolbar Z control. The maximum thread length is slightly less than the drill depth. Enter the length of fully formed threads (measured from the “near” edge) or check Maximum
    • To also thread from the opposite view (e.g. both ends of a rod or hole), select the opposite view and apply the thread feature again.

Note: You will see a small floating disk in the 3D view to remind you that the adjacent region is threaded.


Important tips

It is impractical to machine threads fully to the bottom of a hole or to the end of a boss on an external thread. Therefore, depending on the design, for an external thread that ends at a boss (a larger diameter) it may be necessary to create a groove (replacing ~3 threads) so that a mating part seats properly.

The CAD software will automatically create two concentric circles and parts will be machined to the indicated thread size according to the Unified Thread Standard specs.

If you have a male and female component, use the exact same thread spec for each.

Edit thread length using the Z Axis edit control on the numeric bar. To add tapping or threading with the Revolve feature use Comments To Machinist.

User Defined Threads 

To specify values not shown on the grid:

  1. Select User Defined.
  2. In Size enter the major diameter. For example for a 1/4-20 you would enter .25″. For a metric M10 you would enter 10mm. You can enter larger values such as 3″ for such applications as lens mounts.
  3. In TPI enter number of threads per inch. For example for a 1/4-20 you would enter 20. 

To specify more exotic threads and taper pipe threads not on the grid:

  1. Draw a circle of the minor diameter (or slightly smaller if you don’t know the minor diameter) 
  2. Use Comments to Machinist to describe the desired thread.

Standard Finish

For 3D machined parts with no finishing specified, the eMachineShop machinist will use discretion whether to vibratory tumble parts or leave parts as machined. It is generally recommended to leave the decision to the machinist.


tumble_finish machined_finish

Vibratory tumble

This finish does the best job of removing sharp edges and burrs and is more economical as it does not require machining chamfers to avoid sharp edges. (Chamfers were however machined in this example.) 

As machined


This finish has a machined appearance. If you choose this finish it is strongly recommended, for safety, to include in your design chamfers on all edges to break sharp edges (this increases machining time and hence cost). This finish requires special handling which also adds to cost. You can request this finish under Job | Finishing | Machined Finish. 

Please note that the finish for each particular design or run will likely vary slightly from the above examples which are displayed only for general guidance.

Laser Marking

Laser Marking allows you to add text and graphics to your custom parts.

To place text on a part to be laser marked:
  1. Select the text tool from the Left Hand Toolbar (fourth from bottom).
  2. Click on the area you would like the text to appear.
  3. Type in your text.
  4. From the top toolbar | line type drop-down | select Laser Mark.
  5. You may change the Marking Type (outlined or filled) and Font Style from the drop down menus on the top toolbar.
For design tips, click here.

Note: Laser Marking can only be utilized on flat surfaces.