I upgraded to the Carvetight Z truck. I thought it was a problem however the problem turned out to be the encoder in the motor. This is a used Z truck set up for quick change. It works well. It has 180 hours on it. The belt is in good shape. I have two 1/16 carving bits and one 1/16 cutting bits, one extra 1/16 carving and two extra collets. One bit is missing the side nuts. If you will pay for shipping or stop to pick them up I will pass them on. Send me a message. Vicki