Common Influencing Factors Of Deep Hole Drilling

Through modern thinking, offline presets, and enhanced processing of coolant and chips. We can fully tap the potential of the latest cutting-edge interchangeable drills in CNC deep hole processing.

In drilling processing, customers usually want to process and shape at one time. Still, the drill is a relatively rough tool, and the size after processing always exceeds the specified range. Nevertheless, people still have high expectations for the tip interchangeable drill bit. As long as it is appropriately applied, this kind of drill can ensure that the processed holes are straight and smooth, and there is no need to use special finishing tools for secondary processing.

Compared with similar products, the tip interchangeable drill bit shows higher flexibility and cost-effectiveness in large diameter drilling applications. People have high requirements on the accuracy and efficiency of drilling, especially the processing depth, such as holes with a size ratio greater than or equal to 9:1.

A Presupposition Is a Prerequisite.

The deeper the processing hole, the longer the drill bit required, and the longer the drill bit, the more significant the impact of its deflection on the processing result. Even the slightest shaking can cause premature tool wear and affect the straightness and surface finish of the machined hole in some deep hole machining.

bta deep hole drilling machine details new 02
bta deep hole drilling machine

However, we cannot adjust or replace the tools frequently. Specifically, we cannot allow staff to enter the work area to install indicators or other early warning devices in a modern production environment. Are we allowed to put paper or other isolation items between tools to prevent tools from touching each other? But we can use the presenter offline assembly tool to avoid these problems in deep hole processing and save a lot of time.

In addition to saving time, this operation also makes it easy to find and measure the drill edge zone, preventing costly errors.

Coolant Cooling Chips

Except for X-rays, the chip shape is the only way to judge the drill’s performance during cutting. The ideal chip shape curled—the longer and more delicate the chip, the lower the efficiency of removing heat from the cutting area. Color is also essential. If the cutting area’s temperature is too high, the chips will turn gray, black, and blue. Chip discoloration means that the heat needs to be reduced by reducing the spindle speed, while fine flakes indicate the need to increase the feed speed to cause the processed material to crack but not peel.

One of the most overlooked issues during drilling is coolant. The coolant will have a significant effect on the shape of the chips. Adjusting the coolant’s concentration and flow rate can help solve the problem of “bird’s nest”-shaped chips.

The bird’s nest layout can avoid too strong bit feed. Water-soluble coolants are used in various conventional processing due to their excellent heat dissipation effect. In other words, semi-synthetic or pure oil-based formulations can better improve the lubrication effect in individual cases and ensure that the chips are short and not sticky. Compared with water-based lubricants, although the embedded coating will accelerate the tool’s wear and cause the parameters to be conservative, it can improve the heat resistance effect and play a specific compensation role.

The use of coolant during drilling cannot ignore, and the machining tool must transmit sufficient coolant pressure. Small drills have higher requirements for pressure during chip removal to keep the chip removal speed equivalent to the material removal speed. The higher the pressure, the faster the chip removal and the quicker the drilling speed.

Peck drilling means problems.

As more and more specific problems arise, the previous standard drilling strategy may no longer be applicable. One example is pecking.

If there is no time to change new tools or make other adjustments, peck drilling is the only option. However, pecking will cause the drilling speed to drop. Also, withdrawing the device in the middle of processing will partially form but not peeled chips in the hole. Carbides have wear resistance but are relatively fragile, and pecking drills are prone to chipping and breaking the tool, resulting in failure or failure. Even if the device is not affected, the workpiece will be affected. As mentioned earlier, most drilling will have dimensional errors. It may only exceed a few miles (1 mil = 0.001in), but even such a small mistake can cause the inner hole to be rough in some operations.

Tool Self-Finding Center

Another outdated method is to use a smaller diameter 90° point drill for positioning drilling. Drilling, in this way, is more intuitive. Compared with large-diameter exercises, when drilling a small-diameter drill, it is easier to correct the deflection if it occurs. The top angle is an acute angle, which can help the drill bit drill into the part’s specified position faster and easier. However, most CNC machine tools are exact in positioning, and the diameter of the directional hole is the same as that of the central drill. The function of the drill bit is also compelling. It can drill holes at obtuse angles and plug into the pure workpiece material.

Most of the tip interchangeable drill tool can find the center by themselves, and the tip angle is less than 90°. Therefore, the device will affect the aperture in front of the auto-centering point. Using the same tool diameter and tip angle can ensure that a more extended drill bit can correctly complete the work that cannot be done by point drilling.

When drilling deep holes, sudden acceleration to the highest speed and feed rate will cause safety issues and risks and affect the work effect. Therefore, the recommendation for the general-purpose T-A cutter bit is: be cautious when drilling directional holes.

Keeping a cautious attitude when approaching the semi-finished hole can avoid scars or breakages. It ensures that the edge of the drill bit is in contact with the material before speeding up. The semi-finished spot is equivalent to a casing. Keep the drill in the middle position to ensure the parts And personnel safety.

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