# Do Open Loop Steppers Need A Warmup?

**URL:** <https://forum.onefinitycnc.com/t/do-open-loop-steppers-need-a-warmup/17951>\
**Category:** Controller (MASSO) Discussion\
**Created:** [January 8, 2023, 7:51pm UTC](https://forum.onefinitycnc.com/t/do-open-loop-steppers-need-a-warmup/17951 "2023-01-08T19:51:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![jnordyke](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.onefinitycnc.com/jnordyke/32/1881_2.png) [@jnordyke](https://forum.onefinitycnc.com/u/jnordyke)\
**Post date:** [January 8, 2023, 7:51pm UTC](https://forum.onefinitycnc.com/t/do-open-loop-steppers-need-a-warmup/17951/1 "2023-01-08T19:51:57Z")

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Today is my day for asking silly questions. I was re-writing my spindle warm-up routine and this thought occured to me…I had assumed that because there is a holding current to the (original open loop) stepper motors that generates at least some heat they don’t need to be exercised while my spindle routine is running. Is that a safe assumption, or should I be moving the steppers around to warm up while warming up the spindle?

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**Author:** ![makerjace](https://avatars.discourse-cdn.com/v4/letter/m/e47c2d/32.png) [@makerjace](https://forum.onefinitycnc.com/u/makerjace)\
**Post date:** [January 9, 2023, 4:28am UTC](https://forum.onefinitycnc.com/t/do-open-loop-steppers-need-a-warmup/17951/2 "2023-01-09T04:28:54Z")

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Interesting! I could see that from a technical standpoint. I wonder about the approach from a safety perspective. Are you using an enclosure? Would you exercise the Z stepper as well?

There are some built-in “stepper warm-up” moves just from jogging the machine around, homing it, loading stock, and probing. I can’t say I’ve ever heard of someone warming up the motors that move the gantry, but it could be a thing.

Spindle warm-ups are certainly an industry standard for industrial machines. Curious - what did you modify in your spindle warm-up program? And what spindle are you running?

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**Author:** ![TMToronto](https://avatars.discourse-cdn.com/v4/letter/t/7ea924/32.png) [@TMToronto](https://forum.onefinitycnc.com/u/TMToronto)\
**Post date:** [January 9, 2023, 5:06am UTC](https://forum.onefinitycnc.com/t/do-open-loop-steppers-need-a-warmup/17951/3 "2023-01-09T05:06:08Z")

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I have written a spindle warm-up routine as well, and also one that moves my axes their full range at increasing velocities. I am doing both of these more to get the bearings and rails lubricated and the oil evenly distributed, but I imagine it warms the steppers as well. From my research this is more important with expensive, highly accurate CNCs where they want to avoid temperature becoming a factor and impacting parts milled to micron tolerances.

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**Author:** ![pwpacp](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.onefinitycnc.com/pwpacp/32/1718_2.png) [@pwpacp](https://forum.onefinitycnc.com/u/pwpacp)\
**Post date:** [January 9, 2023, 1:03pm UTC](https://forum.onefinitycnc.com/t/do-open-loop-steppers-need-a-warmup/17951/4 "2023-01-09T13:03:26Z")

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In my experience in industry the concern is mainly centered on mechanical functions, i.e. run functions to ambient temperatures to eliminate dimensional drift. The majority of work from a hobby CNC does not require precise dimensional control so I believe axis warm up would actually provide little benefit.  
On the other hand, I move each axis vigorously before each session too.