A couple of years ago, I purchased a Delta 40-690 scroll saw which worked fine for about one year. Then it developed a really loud knocking and banging and vibration. It was repaired, under warranty by Delta but very soon after developed the same problems. Again it was repaired under warranty but developed the same problems again. Then eventually the motor stopped working. At this point Delta replaced the machine, under warranty with a newer model, Model 40-695. This lasted a couple of months then developed the same problem as the 690. Again it was repaired by Delta under warranty but this time it lasted about 1 week now it is knocking, banging and vibrating again. Now Delta are not returning my calls. I was wondering if anyone else has experienced similar problems with Delta machines and if so, how were the problems resolved. Thanks for any help or advice. Don R