So- several years ago I was made aware that my spindle (4HP HSD) was "noisy" and I would need to replace it eventually. I did nothing about this at first. I knew the advice was solid, but it didn't sound all that noisy to me. ( I had come from using a router and it was not as noisy as a router).
I got into several large projects after that, and one had a very tight delivery time line- and I did not want to have an issue if the spindle failed in mid-project. SO, I ordered a new spindle from ShopBot. BUT- I didn't install it. I figured the machine would tell me when I needed to replace it. I THINK that was about 4 years ago, and I have kept the new spindle, sitting upright and it gets a gentle spin every now and then- but no other interaction.
So- I was planning on replacing the pinions ( also about 4 years old now)- and decided it was time to put that spindle on. I mean the thing HAS gotten noisier. Not awful, I guess. But noisy.
The new spindle so quiet that you have a tough time knowing if it is spinning during a 9K initial warm up- even if you are as close as 5-10 feet away! Oh My Gosh! I should have replaced this thing a couple years ago! What a blessing! Yes. I still get bit noise from the cutting process, but it is SO QUIET! It is going to make my future cuts a much better experience!
Keep your machines up and maintained!
Monty