Floor 3th, Baoyi factory, Wulian district, Long gang, Shenzhen, China


+86 181 2653 8052

Send Your Mail


How to deal with the problems in CNC machining?

Overcutting of workpiece


  1. Flick knife, the strength of the tool is not enough. It is too long or too small, resulting in flick knife.

  2. Improper operation by the operator.

  3. Uneven cutting allowance. (e.g. : 0.5 on the side and 0.15 on the bottom of the surface)

  4. Improper cutting parameters (such as: tolerance is too large, SF setting too fast, etc.).


    1)with the knife principle: can be large, can be short not long.

    2) add the clear Angle procedure, the margin as far as possible to leave uniform, (the side and the bottom of the margin remain the same).

    3) reasonable adjustment of cutting parameters, large margin corner trimming.

    4)using the SF function of the machine tool, the operator fine-tunes the speed of the machine tool to achieve the best cutting effect.

Split middle problem


    1. the operator manual operation is not accurate.

    2. There are burrs around the mold.

    3.the dividing rod has magnetic.

    4.The four sides of the mold are not vertical.


    1)Manual operation should be carefully checked repeatedly, and the points should be at the same point and height as far as possible.

Use a whetstone or file to remove burrs around the mold. Wipe it clean with a rag, and finally confirm with your hand.

Demagnetize the center bar before dividing the mold (ceramic center bar or others can be used.

Check whether the four sides of the mold are vertical (if the verticality error is large, review the plan with the fitter).

Opposite knife problem


    1. the operator manual operation is not accurate.

    2.the tool clamping error.

    3.The blade on the throwing knife is wrong (the throwing knife itself has a certain error).

    4.There is an error between R knife and flat bottom knife and throwing knife.


    1)Manual operation should be carefully checked repeatedly, and the knife should be at the same point as far as possible.

    2)When clamping the tool, blow it clean with the air gun or wipe it with the rag.

    3)the blade of the throwing knife to test the tool rod, light bottom surface can be used a blade.

    4)a separate tool program can avoid the error between R knife, flat knife and flying knife.

Crash machine – Programming problem


     1. the safety height is not enough or not set (the knife or chuck hit the workpiece when the fast feed G00).

  1. The cutting tool on the program list is wrong with the actual cutting tool.

  2. The tool length (blade length) and the actual machining depth on the program list are wrong.

  3. The number of depth Z-axis and the actual Z-axis are incorrectly written on the program sheet.

  4. The coordinates are set incorrectly during programming.


     1)Accurate measurement of the height of the workpiece also ensures that the safety height is above the workpiece.

The cutting tool on the program list should be consistent with the actual cutting tool

Measure the depth of the actual processing on the workpiece, write the length of the tool and the length of the blade clearly on the program list (generally, the tool clip length is 2-3MM higher than the workpiece, and the blade length avoidance is 0.5-1.0MM).

     4)the actual Z axis on the workpiece, write clearly on the program sheet. (This operation is generally manual operation to be written to check repeatedly).

Crash machine. – Operator


  1. Depth Z-axis tool alignment error .

     2.the number of touch and operation error (such as: unilateral number without feed radius, etc.).

     3.use the wrong knife (such as: D4 knife with D10 knife to process).

     4.the program went wrong (such as: A7.NC went A9.NC).

The hand wheel shakes in the wrong direction during manual operation.

Press the wrong direction (for example: -X +X) during manual fast feed.

     1)We must pay attention to the position of the depth Z-axis tool. (bottom surface, top surface, analysis surface, etc.

The number of touch and operation should be checked repeatedly after completion.

     3) the clamping tool should be repeatedly and procedure list and procedure check after loading.

     4) the program to go one by one in order.

     5) in the manual operation, the operator should strengthen the operation proficiency of the machine tool.

     6) in the manual fast movement, can first raise the Z axis to the workpiece above the movement.

Precision of surface


  1. The cutting parameters are unreasonable and the workpiece surface is rough.

  2. The cutting edge of the tool is not sharp.

     3. the tool clamping is too long, the blade avoidance is too long.

     4.Chip removal, blowing and oil flushing are not good.

     5. programming knife way, (can try to consider smooth milling).

     6. the workpiece has burr.


1) cutting parameters, tolerance, allowance, speed feed Settings should be reasonable.The tool operator is required to check and replace the tool irregularly.

When clamping the tool, the operator is required to clip as short as possible, and the blade should not be too long.

For the downward cutting of flat cutter, R cutter and round nose cutter, the speed feed setting should be reasonable.

4)the workpiece has burr: the root of our machine tool, the tool, the way of cutting has a direct relationship. So we want to understand the performance of the machine tool, the burr edge of the knife.

Tags :
Share This :


您的电子邮箱地址不会被公开。 必填项已用 * 标注

Recent Posts


Have Any Question?

With seasoned experience in the CNC machining field, QH Industrial clarifies its value by empowering every customer.