[WRMorrison]

I'm glad I found this post; I have a G4003G due to arrive this week...thanks!

-WRM

[kae]

WRMorrison, I am hopeful that you don't have any problem at all when you have your machine up and running. I am very pleased with the lathe in every other way. I have sent all this information to Grizzly and it has been forwarded to their quality control department. Hopefully they will solve the problem. I will be anxious to know if the harmonic is a problem for you. Please let me know after you get yours up and running.

[WRMorrison]

Just in case though, I've got those dampeners on the way from McMaster.

-WRM

[maxalw]

For those who have followed this thread, I made some progress today.The problem was a "harmonic" pattern on any turned surface. Changing feeds and speeds did not make any difference, the problem was always there. I determined that the problem was in the motor. I did this by a very simple test. I removed the drive belts, left the motor turned off and had a friend drive the gearbox pulley with a hand drill while I took a light cut. The result was a perfect finish. To further test my theory, I then started the motor but still drove the gearbox pulley with the hand drill. The result was a return to the harmonic pattern. Vibrations from the motor were being transferred into the headstock because of the metal to metal mounting. At this point, I knew the problem was in the motor. The next day I stopped by a local motor shop and explained my problem. They told me that they saw this problem quite often in Chinese motors. He told me that he found that if he took the motor and re-dipped and baked the stator, many times the problem went away. They had found that the laminated metal sheets that comprise the stator weren't tightly bound together and they created a resonance. He said he could re-work my motor for $50. I asked if he guaranteed it would work and he said no but he felt 95% sure it would solve the problem. I dropped off the motor, he performed the process and I picked it up yesterday. However, when I picked it up, he said he doubted if this would work because it still had the same buzz in it as before he dipped it. He did offer one piece of advice and that was to try to use a vibration damping motor mount. He said they were available from McMaster-Carr. I paid the $50 bucks, came home and found the item at McMaster and ordered four of them at about $3 each. I was hoping to salvage the $50 already spent. They arrived today and I mounted them with the motor and I am happy to say that about 90% of the "harmonic" pattern is gone. I suspect that the remaining resonance is coming through the drive belts. The only other solution is a new motor. For now, I am satisfied with the quality of finish. It is many times better than before. The McMaster part number is 9217K49. There are a number of choices for compression load, shear load and bolt size. The way my motor mounts, shear is the main concern as was the 8mm bolt size. The reason that rubber pads did not work was that the bolts still transferred the vibration into the headstock. The vibration damping mounts I refer to does not have a bolt that goes through the rubber. The studs are isolated from each other by the rubber mount. If you go to the McMaster web-site, you will see what I mean.

Always have a different problems, when i am using something Chinese. Thanks anyway