For dry machining, we often encounter 30 difficult solutions!

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When the feed rate doubles, the cutting force increases by approximately 70%;

That is to say, if G99 is used, the cutting speed will increase and the cutting force will not change too much.
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04
When the actual value X measured is greater than 0.8 compared to the drawing diameter Y, the concave arc of the car may rub against the R produced by the turning tool with a secondary deviation angle of 52 degrees (which is the commonly used turning tool with a main deviation angle of 35 degrees and 93 degrees) at the starting position.
05
The temperature represented by the color of iron filings: white less than 200 degrees Celsius
Yellow 220-240 degrees
Dark blue 290 degrees
Blue 320-350 degrees
Purple black is greater than 500 degrees Celsius
Red color greater than 800 degrees
06

G69: Not very clear
G21: Metric Size Input
G25: Spindle speed fluctuation detection disconnected
G80: Fixed loop cancellation
G54: Default coordinate system
G18: ZX plane selection
G96 (G97): Constant linear speed control
G99: Feed per revolution
G40: Knife tip compensation cancellation (G41 G42)
G22: Store Travel Detection On
G67: Macro program modal call cancellation
G64: Not very clear
G13.1: Cancellation of Polar Interpolation Method
07
The external thread is generally 1.3P, and the internal thread is 1.08P.
08
Thread speed S1200/pitch * safety factor (usually 0.8).
09
Manual tool tip R compensation formula: Chamfer from bottom to top: Z=R * (1-tan (a/2)) X=R (1-tan (a/2)) * tan (a) Chamfer from top to bottom by changing from subtract to add

For every 0.05 increase in feed, the rotational speed decreases by 50-80 rpm. This is because reducing the rotational speed means a decrease in tool wear, and the increase in cutting force is relatively slow, thus compensating for the impact caused by an increase in feed that increases cutting force and temperature.




1) For the current economic CNC lathes in our country, ordinary three-phase asynchronous motors are generally used to achieve stepless speed change through frequency converters. If there is no mechanical reduction, the output torque of the spindle is often insufficient at low speeds. If the cutting load is too large, it is easy to get stuck. However, some machine tools are equipped with gear gears to solve this problem very well.
2) Try to ensure that the tool can complete the machining work of a part or a work shift as much as possible, and pay special attention to avoiding changing the tool midway during the precision machining of large parts to ensure that the tool can be processed in one go.
3) When using CNC lathe to turn threads, it is advisable to use a higher speed as much as possible to achieve high-quality and efficient production.
4) Use G96 as much as possible.
5) The basic concept of high-speed machining is to make the feed exceed the heat conduction speed, so as to discharge the cutting heat along with the iron chips and isolate the cutting heat from the workpiece, ensuring that the workpiece does not heat up or heats up less. Therefore, high-speed machining is to select a high cutting speed that matches the high feed while selecting a small back cutting amount.
6) Pay attention to the compensation of the tool tip R.

Classification Table for Machinability of Workpiece Materials (Small P79)
Table of Common Thread Cutting Times and Back Cut Quantity (Big P587)
Common geometric calculation formulas (large P42)
Inch to millimeter conversion table (large P27)




(1) The extended length of the tool is too long, which leads to a decrease in rigidity.
(2) The feed rate is too slow, which leads to an increase in the unit cutting force and causes significant vibration. The formula is: P=F/back cutting amount * f P is the unit cutting force F is the cutting force. In addition, if the rotation speed is too fast, the tool will also vibrate.
(3) The rigidity of the machine tool is insufficient, which means that the cutting tool can bear cutting force, but the machine tool cannot bear it. In other words, the machine tool cannot move. Generally, new beds do not have such problems. Beds with such problems are either old or often encounter machine tool killers.



When using G71, the values of P and Q cannot exceed the sequence number of the entire program, otherwise an alarm will appear: the format of the G71-G73 instruction is incorrect, at least in FUANC.


1) P000 0000 The first three digits refer to the number of cycles, and the last four digits are the program number
2) The first four digits of P0000L000 are the program number, and the last three digits of L are the number of cycles

If the starting point of the arc remains unchanged and the endpoint is offset by a mm in the Z direction, then the position of the bottom diameter of the arc is offset by a/2.


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If a drill bit is directly used to drill holes on a drilling machine, there may be deviation in the diameter of the hole. However, if the size of the hole is enlarged on the drilling machine, it generally does not run. For example, if a 10mm drill bit is used to enlarge the hole on the drilling machine, the expanded diameter is generally within a tolerance of about 3 threads.
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The larger the cross-sectional area of the tool holder in the hole, the less likely it is to vibrate the tool. Additionally, a strong rubber band can be attached to the tool holder as it can absorb vibration to a certain extent.

When turning the copper hole, the tool tip R of the tool can be appropriately large (R{{0}}.4-R0.8). Especially when the taper is under the turning, the iron parts may be OK, and the copper parts may be too laggy.