"Comments to Machinist" (CTM) are lines or text added to your drawing to indicate
special instructions to the machinist. Use CTM when your job has a simple
requirement outside the scope of the software. Draw an arrow when a CTM applies to a specific area of the drawing.
To learn how pricing is done for Comments To Machinist see in the CAD Line | Machine | Comments to Machinist.
Example uses of Comments To Machinist:
3D shapes that cannot be modeled in the CAD software such as:
Rounding, chamfering, grooving a portion of an edge
High quantity of repetitions of a hole or shape in order to avoid long computations.
For injection molding, to show the desired location of the parting line, gate and ejector pins.
Special finishes including special colors.
etc.
Avoid references to stock components such as "Make .005 larger than diam of McMaster bolt # 123456." Instead, review the drawing of the bolt and design your part with appropriate clearance and tolerance.
To add Comments To Machinist:
Draw the comment lines and/or text using the line and text tools on the left toolbar. Most comment lines will need at least some associated comment text. When possible follow put each comment line in the proper view and use text to specify the Z value and any settings that would normally go in the Line | Machine dialog. If you need to clarify a comment by showing a projection line in another put a letter next to the primary view and the same letter at the projection view. To show holes at angles other than the six normal views, model the hole using normal CAD lines and add comment text to clarify where you want the hole to actually occur.
Choose Line | Machine.
Select Comments to Machinist.
Select a Line Type.
Click OK.
Be clear and concise:
Clear & Concise
Ambiguous
Not concise
Don't bend 10 parts.
Leave some parts not bent.
As mentioned in my email don't bend 10 parts
With arrow pointing to a circle: 1.002" +/- .001
Part must fit a 1.000" slot.
Make sure length is 1.002" +/- .001"
In some cases Comments To Machinist can actual reduce price - for example for customer-supplied parts, instructions to omit certain machining, etc.
"The parts are awesome! Definitely worth the wait. We also have many other parts we need machined and will be using eMachineShop for those also. You guys ROCK! Sincere Thanks."
