# Cnc Depot Spindle running strange **URL:** \ **Category:** General Chat\ **Created:** [April 13, 2026, 6:56pm UTC](https://forum.avidcnc.com/t/cnc-depot-spindle-running-strange/6018 "2026-04-13T18:56:20Z")\ **Posts on this page:** 1\ **Showing post:** 6
**Author:** ![MichaelR](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@MichaelR](https://forum.avidcnc.com/u/MichaelR)\ **Post date:** [April 14, 2026, 1:37am UTC](https://forum.avidcnc.com/t/cnc-depot-spindle-running-strange/6018/6 "2026-04-14T01:37:08Z")
Avid has mentioned they started adding a capacitor between the pins that provide the voltage to the vfd to address rpm stability. Eric will probably be by to add his 2c but I think if you talk to support they will get you what you need. > [@AV40S speed oscillation](https://forum.avidcnc.com/t/av40s-speed-oscillation/5557): > > I got an AV40S spindle a while back and this week I did a little milling with a 2.5” slab slayer bit. I noticed during the spindle warmup and then during use that around 16k rpm the speed oscillates pretty noticibly. I have never seen this with a bit that doesn’t have a lot of angular momentum like this one. I’m not too concerned, just wondering if others have seen this, or I have something to look into here. I am also using the old VFD that came with my original 3hp spindle, but the 3hp and… --- _[View the full topic](https://forum.avidcnc.com/t/cnc-depot-spindle-running-strange/6018)._