Tolerance

This setting specifies the permissible variation of certain measurements. For example the diagram shows a tolerance of +/- .005" indicating that the length of the rectangle can be between 1.995" and 2.005". See Tolerances for details. For lowest cost select the largest acceptable value.

Recommendations: For 2D parts, popular settings are typically .01" to .05". For 3D .005" to .03" is often used.

Minimum Cutter Diameter

Many manufacturing processes use a round cutter (e.g. an endmill or a laser beam.) The Minimum Cutter Diameter specifies how small a cutter you want to make your part, a small value allowing for greater detail, a large value minimizing cost. (Not applicable to Revolve lines.) Increasing this value can substantially lower the cost of your parts in some cases. Try to use and design towards the largest Minimum Cutter Diameter value consistent with the function of your part.

Based on the selected Minimum Cutter Diameter, the Analyzer will point out red colored areas of uncut excess material. You can lower part cost by allowing such excess material if it will not interfere with the function of your part. If you need the red areas cut, you might need to:

• reduce the Minimum Cutter Diameter;
• reduce the adjacent Z value; 
• increase the radius of inside corners; 
• increase the size of recessed or thru-cut areas; or 
• enable Job | Settings | Process | Secondary process for intricate shapes. 

Alternatively, to minimize cost, consider reshaping sharp inside corners. (Note that the red uncut areas may change if you change your price/time selection.)

Recommendations: For 2D parts, popular settings are typically .02" to .1". For 3D .125" to .5" is often used.

Material thickness tolerance

This setting specifies the permissible variation in thickness of 2D parts. For example, a tolerance of 20% applied to a 1/8" thick sheet would mean that the sheet thickness used for your job could range from 0.1 to .15. For 3D parts select N/A if you want the general linear tolerance (see above) to apply. If you select a percent value, the position of any holes or other features created on the edge of the sheet will be measured from the bottom side of the sheet in accordance with the general linear tolerance. It is usually more economical to use one of the percent values when parts are cut from sheets 0.75 in thick or less.

Recommendations: 20% is usually sufficient for parts cut from sheets. 

Edge Draft

Due to limitations of manufacturing processes, edges (exterior and interior) that should be at 90 degrees to their adjacent surface cannot be exactly 90 degrees. This setting specifies the maximum deviation from 90 degrees that you will permit for edges perpendicular to the Top view. For lowest cost, select the largest acceptable value. Larger values reduce cost especially for 2D parts cut from sheets. For example, for a 1/16" thick sheet and a 10 deg edge draft, the bottom side could have only up to .016" more material at edges than the top side. (Tolerances will be applied to measurements on the bottom side.) If you select zero for this setting, the job Tolerance setting will control.

Recommendations: For 2D parts, 10 deg is usually sufficient.

Flatness

This setting specifies how flat the largest outer flat surfaces will be. In particular, all points on those surfaces will be between two parallel planes the specified distance apart. For lowest cost select the largest acceptable value. For example, a potato chip might have a flatness of ~0.5" and a business card ~0.1".

Recommendations: For 2D parts, popular settings are typically .02" to .1". For 3D .005" to .02" is often used.

Roughness

These settings specify the smoothness of the surface (Top & Bottom views) and edge (Front, Back, Right, Left view), measured as a function of the height of the small ridges resulting from the cutting process. The setting you specify may be met by direct machining, polishing, sanding, grinding or any other method unless a specific method is specified. For lowest cost select the largest acceptable value. For example polished surfaces are often ~1 microinch. Machined parts are often ~63 to ~125 microinch. A phonograph record is ~250 microinch.

Recommendations: For 2D parts 500 for edges. For 3D parts 125.