Joyce,

You may not be allowing enough "Z" depth.

Z depth, is the amount of depth you assign the Z axis (cutter up/down) through your software, which works independently form the pressure you apply through the spindle's spring adjustment.

Try adding more Z depth and lightening the spring pressure.

It is possible that the pressure is too light to overcome the pressure needed to start the spindle downward in its motion. The assembly could be faintly stiff and need a good cleaning and re-lubrication, or the pressure is just too little. I had that on an old New Hermes machine also. (It takes more pressure to overcome the static friction than the moving friction.)

The usual answer to this problem is a featherweight, the spindle uses more pressure but the attachment is the flea weight pressure. With the featherweight the contact starts the movement of the assemble, rather than the pressure starting the movement.

Philadelphia, PA (Really Bensalem)

When you finally understand it completely... it changes.