PC Keyboards: Possible Problem

PC Keyboards: Possible Problem

Manual movement of the lathe's two axes is controlled from the PC keyboard: the four cursor keys control X and Z movements. A single press of any of these keys moves the relevant axis by the smallest movement the machine allows, 1/72mm (0.01389mm).

When a numeric keypad key is held down along with one of these keys, the relevant axis has continuous movement. The speed of movement ranges from 10mm/min, with the 1 key, to 90mm/min, with the 9 key.

For movement at the rapid traverse rate, the numeric keypad 0 (Ins) and the . (Del) key must both be held down along with a cursor key. To set the rapid traverse speed go to File - Settings. The maximum value is 500mm/min but may need to be lower depending on the ability of the PC to output data. If, during a rapid traverse, the movement seems to have hesitations or "stutters", it means that the PC cannot output data fast enough. Reduce the rapid traverse speed to a level where hesitation or "stuttering" ceases - or use a faster PC.

It is for safety reasons that the numeric keypad 0 (Ins) and the . (Del) key must both be held down along with a movement key: without this it would be all too easy to make an unfortunate rapid movement when doing some fine positional adjustment of a tool to a piece of work.

Unfortunately, keyboards are not all the same. There are PC keyboards which cannot handle the combination of the numeric keypad 0 (Ins) and the . (Del) keys plus just one, sometimes more, of the movement keys. When this combination is pressed, nothing happens. By contrast, almost all keyboards can handle numeric keypad 0 (Ins) plus the . (Del) plus simultaneous X and Z movement in any direction, often two.

There seems to be no way of identifying these keyboards in advance. There are two solutions to the problem:

1) Use another keyboard which is happy with the required key combinations. This is by far the best solution as it maintains the rapid traverse safety combination of the numeric keypad 0 (Ins) and the . (Del) key plus a direction key.

2) Disable this safety feature. Go to the File menu item and select Settings. In the dialogue box "Keys for Rapid Traverse" change from the default of Zero + Dot + Direction to Zero + Direction and also read the explanation in the dialogue box.

If you, the user, disable the safety rapid traverse feature, you must accept full responsibility for your action. If there are users of the machine for whom you have a duty of care, you must make a risk assessment and provide appropriate information, training and supervision if it is deemed right to proceed. The preferred solution is to use another keyboard.

Alternative Keyboard
Keyboard Protection