PC Keyboards: Possible Problem

PC Keyboards: Possible Problem

Manual movement of the mill's three axes is controlled from the PC keyboard. In the X and Y directions, the four cursor keys are used and, in the Z direction, the Page Up and Page Down keys are used. 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 or Page Up or Page Down key. To set the rapid traverse speed go to Options - Settings. The maximum value is 600mm/min but the recommended top value is 500mm/min though this may need to be lower depending on the result of the Rapid Rate Test in Options - Settings.

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. Occasionally there is a PC keyboard 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, most keyboards can handle numeric keypad 0 (Ins) plus the . (Del) plus simultaneous X, Y and Z movement in any direction, often all three.

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 Options menu item and select Settings - Keyboard. In the dialogue box change from the default of Zero + Dot + Direction to Zero + Direction and also please 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
PC Specification for Running WELmill
Rapid Traverse Speed
What moves - the milling head or the table?