I have an Altimill 4x4 and only have had it for a few months and all of a sudden the spindle is making a high pitched sound, like the bearings need lubrication. I don’t want to take the spindle apart to try and grease things since it’s basically new and I would hope it’s a simple defect and I can have it replaced. It’s the spindle that I purchased from Sienci along with the Altmill, I think H100. Any advice on what might be causing the noise and or how to fix it? I don’t want to void any warranty I have so I am being very cautious of hoe to proceed.
Interesting . . . After a little more testing, I have determined that when I run the spindle without cutting anything and at any speed, there is no noise and it’s perfect. However, no matter what material I carve, speed, feed or depth, the sound comes back. I have even used different bits too and the sound is only there when actually cutting. Maybe I am being hypersensitive to the sounds the CNC is making, but better safe than sorry. Thanks for the feedback, I’m open to more.
@grainandgain mine was doing it a bit this morning while I was doing a surfacing operation. Some of the sound is of the cutting but the high pitched noise is coming from the spindle.
Thanks for posting the video, that is pretty much the same sound mine is making. How long have you had that spindle and is it from Sienci? I have included a clip of mine and the sound can be heard even when not carving anything. The clip is an air carve to demonstrate the noise. To me, I think they are the same issue. Thanks again.
Thanks for the responses. Well, I have other issues now as the spindle will just stop in the middle of 3D reliefs almost every time i try to complete a job. I put in a support request already, so waiting to hear back. Might be a good learning experience.
Mine just started doing this today 1/15/26 a very high pitch noise 86db doing an air cut no bit in the spindle. I put in a ticket hoping to hear back from Sience soon.
Kelly at sienci sent me this gcode to run on my spindle and it worked pretty good. He said to run it once in a while to keep the bearings evenly lubricated.
@grainandgain Thanks for that. I submitted my own ticket earlier this week but wasn’t told to run this file again. Am doing it now.
I went through the g-code and understand what it does. I also asked Copilot and it confirmed what I was thinking. What I’m unsure about is how long does it run at each speed. Nothing in the g-code seems to indicate a length of time , except for the 1200ms dwell between each speed. The Altmill instructions state that this file will take 100 minutes to run, so I’m guessing about 20 minutes for each speed.
As I’m typing this, 20 minutes in and I hear the spindle go up to 9000 rpm.
Still would like to know where the 20 minutes is defined.
G4 is a dwell command, P is seconds - 1200 seconds is 20 minutes.
It changes the speed, dwells for 1200 seconds, then proceeds to the next speed change.
@KGN yah, I was just about to edit my reply after I realised that 1200 is in seconds not ms like copilot told me. Had I made the mental conversion of 20 minutes = 1200 s a bit sooner, I would have figured it out without Copilot’s “help”. But I hadn’t read the Altmill guide at that point and didn’t know the file ran for 100 minutes.
Just for fun, I told Copilot that it was GRBL g-code. It said that it’s analysis of 1.2 s was still correct but that some post-processors use seconds instead of milli-seconds.
I then told it that grbl actually uses seconds for dwell and it said:
It takes about an hour and forty minutes. No matter what you see in gsender, don’t interrupt it, at some point the screen will display how much time is left and percentage complete. It though me off at first because at first there was nothing showing how long it would take.
And to be sure . . . ya never know. No bit needed, it’s just gonna spin and spin.
