When the center hole drilling machine with a flat end face is drilling, and deviation occurs, the following methods can be used for processing.

If the drilling position is found to be offset or skewed, this can be resolved by sharpening the cross-cutting blade, replacing the drill bit, or reducing the feed rate.

1. Adjust the drill bit and workpiece positioning: Ensure the cutting edges of the drill bit are symmetrical, and the workpiece end face is perpendicular to the drill bit centerline. If the drilling position is offset or skewed, this can be resolved by resharpening the cross-cutting edge, replacing the drill bit, or reducing the feed rate.

2. Use a guide device: In deep hole machining, use a longer guide bush or guide block to improve guiding accuracy and reduce skewing caused by poor guidance.

3. Change the motion form: In deep hole machining, using a dual rotation method where the workpiece rotates and the tool rotates and feeds in the opposite direction, or a method where the workpiece rotates and the tool feeds unidirectionally, can effectively control the workpiece skew.

4. Regular measurement and correction: During drilling, the hole skew should be measured regularly. If it exceeds the standard, measures should be taken immediately to correct the skew. For example, adjust the upper carriage rotation, mast cylinder, etc., to correct the skew.

5. Use a stabilizer and spiral drill rod: Using a stabilizer and spiral drill rod during drilling can increase the length of the large-diameter drill bit, overcome the bending formed by the gap between the bottom drill rod and the hole wall, and thus reduce the drilling skew.

6. Appropriately increase the cutting speed: Use the centrifugal force of the chips to promote chip removal. If the skew is not significant, the workpiece or drill press drill axis can be moved slightly to correct it; if the skew is significant, a slightly larger recess can be punched with a sample punch, or a chisel can be used to chisel several grooves in the area where more needs to be drilled, to reduce the cutting resistance in this area and allow the drill bit to move to the correct position before drilling.

Through the above methods, the skew problem when drilling center holes on a flat end face drilling machine can be effectively solved.