[bottleworks]

I have a Supermax 1-1/2 VA mill that I have converted to CNC. At higher scale speeds, this mill's head is LOUD. I didn't remember is being loud when I first bought it. It sat for close to 6 months with the head upside down waiting for me to set it up. The last owner claimed that the head was rebuilt by a professional rebuilder a few years prior. The noise is in High, neutral, and low at 1/2 speed to max. I pulled off the motor and upper cover. The belt looks great. No apparent wear on the upper pulley half bushing, nor the bearings that I could spin by hand.

I only have been using the mill in high....I don't anticipate needing the low range anytime soon. Could I cut the timing belt to eliminate that gearing? From what I can see, in high, that section of the head isn't used. I am concerned that this is as simple as lack of lubrication. I have greased the zerk in the back of the head, run oil down the quill splines and oiled both cups. Is there something that I'm missing?

[bottleworks]

Well, I took it all apart. I didn't realize how simple these things are. I removed the T-belt. Checked the gearing was well lubed (it was). Reassembled. Noise is still there. It's definitely coming from the variable speed pulley setup. After searching, I've come to understand that these designs are loud. I guess that's what I'm hearing. I have a VFD on this mill, so I might change to fixed pulleys eventually.

[bottleworks]

Starting this thing up again, it just keeps sounding louder. I've posted a short video on youtube. Can you folks check it and tell me what you think of the noise? The clip is at:

Mill Noise - YouTube