Problems and solutions in using U drill

Compared with ordinary drills, the advantages of U drills are as follows:

▲U drills can drill holes on surfaces with an inclination angle of less than 30 without reducing cutting parameters.

▲After the cutting parameters of U drills are reduced by 30%, intermittent cutting can be achieved, such as processing intersecting holes, intersecting holes, and interpenetrating holes.

▲U drills can drill multi-step holes, and can bore, chamfer, and eccentrically drill holes.

▲When drilling with U drills, the drill chips are mostly short chips, and the internal cooling system can be used for safe chip removal. There is no need to clean the chips on the tool, which is beneficial to the processing continuity of the product, shortening the processing time and improving efficiency.

▲Under standard aspect ratio conditions, there is no need to remove chips when drilling with U drills.

▲U drill is an indexable tool. The blade does not need to be sharpened after wear. It is easy to replace and the cost is low.

▲The surface roughness of the hole processed by U drill is small and the tolerance range is small, which can replace some boring tools.

▲U drill does not need to pre-drill the center hole. The bottom surface of the processed blind hole is relatively straight, eliminating the need for a flat bottom drill.

▲Using U drill technology can not only reduce drilling tools, but also because U drill uses a carbide blade inlaid on the head, its cutting life is more than ten times that of ordinary drills. At the same time, there are four cutting edges on the blade. The blade can be replaced at any time when it is worn. The new cutting saves a lot of grinding and tool replacement time, and can improve work efficiency by an average of 6-7 times.

/ 01 / Common Problems of U Drills

▲?The blade is damaged too quickly and easily broken, which increases the processing cost.

▲?A harsh whistling sound is emitted during processing, and the cutting state is abnormal.

▲?The machine tool vibrates, affecting the processing accuracy of the machine tool.

/ 02 / Notes on using U drill

▲When installing the U drill, pay attention to the positive and negative directions, which blade is facing up, which blade is facing down, which face is facing inward, and which face is facing outward.

▲The center height of the U drill must be calibrated. The control range is required according to its diameter. Generally, it is controlled within 0.1mm. The smaller the diameter of the U drill, the higher the center height requirement. If the center height is not good, the two sides of the U drill will wear, the hole diameter will be too large, the blade life will be shortened, and a small U drill will be easily broken.

▲U drills have high requirements for coolant. It must be ensured that the coolant is ejected from the center of the U drill. The coolant pressure should be as high as possible. The excess water outlet of the turret can be blocked to ensure its pressure.

▲The cutting parameters of the U drill are strictly in accordance with the manufacturer's instructions, but the blades of different brands and the power of the machine tool should also be considered. During processing, the load value of the machine tool can be referred to and appropriate adjustments can be made. Generally, high speed and low feed are used.

▲U drill blades should be checked frequently and replaced in time. Different blades cannot be installed reversely.

▲Adjust the feed amount according to the hardness of the workpiece and the length of the tool overhang. The harder the workpiece, the greater the tool overhang, and the smaller the feed amount should be.

▲Do not use excessively worn blades. The relationship between blade wear and the number of workpieces that can be processed should be recorded in production, and new blades should be replaced in time.

▲Use sufficient internal coolant with correct pressure. The main function of coolant is chip removal and cooling.

▲U drills cannot be used to process softer materials, such as copper, soft aluminum, etc.

/ 03 / Using tips for U drills on CNC machine tools

1. U drills have high requirements on the rigidity of machine tools and the alignment of tools and workpieces when used. Therefore, U drills are suitable for use on high-power, high-rigidity, and high-speed CNC machine tools.

2. When using U drills, the center blade should be a blade with good toughness, and the peripheral blades should be sharper.

3. When processing different materials, blades with different grooves should be selected. Generally, when the feed is small, the tolerance is small, and the U drill aspect ratio is large, a groove blade with smaller cutting force should be selected. On the contrary, when rough processing, tolerance is large, and the U drill aspect ratio is small, a groove blade with larger cutting force should be selected.

4. When using U drills, the machine tool spindle power, U drill clamping stability, and cutting fluid pressure and flow rate must be considered, and the chip removal effect of U drills must be controlled at the same time, otherwise the surface roughness and dimensional accuracy of the hole will be greatly affected.

5. When clamping the U drill, the center of the U drill must coincide with the center of the workpiece and be perpendicular to the workpiece surface.

6. When using U drills, appropriate cutting parameters should be selected according to different part materials.

7. When using a U drill for trial cutting, be sure not to reduce the feed rate or speed arbitrarily out of fear, which may cause the U drill blade to break or the U drill to be damaged.

8. When using a U drill for processing, if the blade is worn or damaged, carefully analyze the cause and replace it with a blade with better toughness or more wear resistance.

9. When using a U drill to process stepped holes, be sure to start with the large hole first and then the small hole.

10. When using a U drill, make sure that the cutting fluid has enough pressure to flush out the chips.

11. The blades used for the center and edge of the U drill are different. Do not use them incorrectly, otherwise the U drill shank will be damaged.

12. When using a U drill to drill holes, you can use the workpiece rotation, tool rotation, and simultaneous rotation of the tool and workpiece. However, when the tool moves in a linear feed mode, the most common method is to use the workpiece rotation mode.

13. When processing on a CNC lathe, consider the performance of the lathe and make appropriate adjustments to the cutting parameters, generally by reducing the speed and feed.