In a recent trade show, an attendee asked me this unique question…
What would cause my machines to ‘walk’? The floor is level, but a couple of my machines will still move.
Note: For those new to the industry, a ‘walking machine’ physically moves away from the original position where it was installed. This movement may be as little as a couple millimeters or as much as a few inches.
First, always level the machine by placing the level on the tie bars. Always make sure you check all 4 tie bars. Many people make the mistake of levelling the machine by the base of the platens. Some of the best systems use a rotating laser with a group of sensors placed on the tie bars to measure the tie bars relative to each other.
Second, check the parallelism of the platens. This can be easily measured both when the mold is open as well as when the mold is closed. The best way to check this is to have an expert come in and use a computer assisted system which can accurately measure the parallelism, twist, linearity of the platens at rest, under tonnage, as well as during platen movement.
Third, check the lubrication system. Any busted or leaking seals, as well as blocked lubrication lines may cause abrupt movement of the platen. This is often evidenced by a series of rings or streaks on the tie bars. You may also feel a vibration when touching the machine as the mold opens and closes.
Over time, ANY awkward platen movement that is not linear and level may cause the machine to ‘walk’. This can become very costly as it can often cause tie bar strain, platen twist, and uneven clamping. You must implement a routine schedule for checking the levelness, parallelism, and lubricaion of the machine, since any of these can cripple or ruin your molding machines.