The Impact of Vibration on Precision Machining and Its Solutions

Environmental vibration is an invisible killer that can't be ignored in precision machining. It may cause the equipment to shift or cause the surface roughness of the workpiece to increase.From vibration source analysis, precision impact measurement, and solutions for vibration control, to sharing vibration control methods, equipment optimization plans, and daily maintenance techniques, the course helps participants to improve the quality of their products.

The actual effect of vibration on precision processing.

When you're busy in the workshop, you've probably run into situations like this many times: The machine's parameters are set just right, but the size of the finished part is always a little off, and there are some strange patterns on the surface.At such times, don't be too quick to blame the machine for being temperamental.

For example, a heavy truck passing nearby, or a punch press on a neighboring workbench suddenly starting up, can cause vibrations that are transmitted to the machine tool. This is like someone tapping the spindle with a small hammer. If the position of the tool or workpiece is shifted, the accuracy of the work will be compromised.

Where do the vibrations come from?

The sources of vibration can be broadly divided into three categories: (1)

- Ground vibrations: from unstable foundations for heavy machinery or the transmission of vibrations from railroads.

The sound of large fans, the sound of traffic on roads outside the factory.

Vibration from the machine itself: Imbalance of the spindle at high speed, resonance of the cooling pump motor.

Three steps to identify the culprit.

Don't spend money buying vibration reduction equipment until you've first found out where the trouble is.

Cell phones can also be used as detectors.

Nowadays many vibration detection apps (for example, VibSensor) are sensitive enough to detect a difference of 0.01 mm in amplitude.They attached their mobile phone to the machine's base and monitored the vibration peaks during the machining process. By comparing this data with the workshop's log book, they were soon able to narrow down the time when the problem occurred.

The clay method.

This is one of their secrets--they stick a small piece of clay in a different place on the machine, and after half an hour of processing, they see which one has deformed the most.Although it looks very primitive, it is very effective for finding the vibration hot spots on equipment.

The company has developed a vibration reduction scheme that can be implemented in the workshop.

The "soft and tough" approach to vibration isolation.

- Hard isolation: The machine is given a concrete foundation, with the depth dug down to at least the depth of the frost layer.

- Soft cushioning: Install rubber-metal composite vibration pads on the base of the equipment. Don't skimp and buy pure rubber, which will deform in three months.

Space management: The company keeps its vibration-sensitive CNC centers as far as possible from the compressor room and factory roads, which are "minefields" of vibration.

A few tips for fine-tuning your equipment.

Spend 10 minutes every Friday afternoon to do a quick maintenance check.

1. Check the radial runout of the spindle with a dial indicator. If it exceeds 0.005 mm, the spindle should be dynamically balanced.

2. When you are applying lubricant to the guide rails, feel the bottom of the rails to see if there are any hot spots.

3. When checking anchor bolts, don't just look for looseness; also check whether the anti-loosening glue has aged.

What should we pay attention to in long-term earthquake protection?

Don't think that once you've installed a shock absorber you're done. We suggest you do the following three things every three months: 1.

--Use a laser interferometer to recheck the precision of the machine tool's positioning.

- Check whether there are any new construction projects being carried out near the factory.

Training operators to recognize abnormal vibration (for example, by listening for a "buzz" from the spindle).

Remember that vibration control is a continual process of improvement.Last year, using these methods, we were able to lower our defect rate by 37 %. Now we even dare to accept rush orders for parts for the space program that require five-axis machining.If you have any experience with this, please share it in the comments section below.