Special Deal Design Guidelines

Drawing Requirement Instructions

1. No complex 3D surfaces or organic contours;
2. Panelization (arrayed boards), logos, or complex features are not supported. Final approval is subject to system review;
3. For parts ≤ 5 mm thick, internal sharp corners are relieved to a minimum radius of R0.5.

   For parts > 5 mm thick, internal sharp corners are relieved to a minimum radius of R0.75

4. We do not support special‑offer prototyping for parts with overly simple designs (e.g., blank panels or simple plates with only a few drilled holes). JLC reserves the right to cancel such orders.
5. Create the hole in the 3D model using the specified pilot hole diameter. The system will automatically identify it as a threaded hole. Once confirmed, the thread will be machined accordingly.

Special Note on Chamfering

If no chamfer is modeled or non‑standard 45° flat chamfers are present in the model, parts will be deburred with a default C0.2 chamfer.

For flat chamfers in the model, please use standard 45° chamfers. Avoid radii or C‑chamfers other than 45°, otherwise the system may flag them as out‑of‑range.

Examples of Supported Models

Examples of Unsupported Models

Logo processing (UV printing / CNC engraving / Laser Marking)	Curved-surface machining	Panelization (arrayed boards)
Blank plates	Fillets smaller than R0.5	Sharp corners
Spherical recesses	Double-sided stepped features	Double-Sided Fillets
Arc-shaped grooves	Parts with round chamfer on one side and step feature on the opposite side	Internal V-Grooves
Double-sided tapered structures	Cosmetic part

Threads Instructions

1. Do not add chamfers at the entry or bottom of threaded through‑hole bottom holes. Standard chamfers will be machined according to the corresponding thread size. Adding chamfers to the model may cause the system to fail to recognize the thread correctly.
2. Do not model threads as solid geometry. Only model the thread pilot hole.
3. As a general guideline, the pilot hole depth should be approximately 3× the thread major diameter, and the tapped thread depth should be approximately 2.5× the thread major diameter. For example, for an M2 thread:

   Pilot hole depth: 2 mm × 3 = 6 mm

   Tapping depth: 2 mm × 2.5 = 5 mm

4. Thread machining is not supported for parts with thickness greater than 14 mm.
5. For blind‑hole tapping, taps cannot reach the hole bottom. The machined effective thread depth will have a depth tolerance of approximately one thread diameter. Please design the thread engagement length reasonably (engagement length of 1‑2× diameter is recommended).

Design example: For an M3 thread, if the hole depth in the 3D model is 7.5 mm, the actual effective thread depth may be approximately 5–6 mm. Design screw insertion depth at 4‑5 mm.

Thread Detection Rules

Model the holes in your 3D CAD model to the appropriate tap drill diameter. The system will automatically detect the threads, which can then be machined after confirmation.

1. Blind Hole: The minimum thread depth is 1.5 times the tap drill diameter. Threads will not be detected if the depth is below this limit.

   Example: For an M2 blind thread with a tap drill diameter of 1.6 mm, the minimum thread depth is 2.4 mm (1.6 × 1.5).

2. Through Hole: The minimum thread depth is equal to the tap drill diameter (1.0×). Threads will not be detected if the depth is below this limit.

   Example: For an M3 through thread with a tap drill diameter of 2.5 mm, the minimum thread depth is 2.5 mm (2.5 × 1.0).

3. Maximum Depth: The maximum thread depth is 3 times the nominal thread diameter. Threads will not be detected if the depth exceeds this limit.

   Example: For an M2 thread with a nominal diameter of 2 mm, the maximum thread depth is 6 mm (2 × 3).

The special offer covers standard-pitch (metric coarse) threads only. All other threads — please submit a regular quotation request

Simulation Model Instructions

The simulation model represents the expected geometry of the part after machining. By comparing it with the user model, you can identify areas where material has been overcut or remains unmachined.

Important Notes

The current simulation model does not reflect secondary machining, EDM, wire cutting, or other processes. Please disregard any remaining material at the bottom of the part, clamping features, and other details that may not be represented in the simulation model.

Please check whether the features in the simulation model match your expectations, particularly for missing features, residual sharp corners, or other potential issues. If you identify any problems, please contact us at support@jlccnc.com.

Gouge (Red): Material over-removed (e.g., oversized holes/slots, undersized bosses).

Excess Stock (Blue): Material unmachined (e.g., uncut internal corners, missing features).