diff --git a/klippy/extras/mpu9250.py b/klippy/extras/mpu9250.py
index 813a9397..6fc0dcf0 100644
--- a/klippy/extras/mpu9250.py
+++ b/klippy/extras/mpu9250.py
@@ -117,54 +117,6 @@ class MPU9250CommandHelper:
         val = gcmd.get("VAL", minval=0, maxval=255, parser=lambda x: int(x, 0))
         self.chip.set_reg(reg, val)
 
-# Helper class for chip clock synchronization via linear regression
-class ClockSyncRegression:
-    def __init__(self, mcu, chip_clock_smooth, decay = 1. / 20.):
-        self.mcu = mcu
-        self.chip_clock_smooth = chip_clock_smooth
-        self.decay = decay
-        self.last_chip_clock = self.last_exp_mcu_clock = 0.
-        self.mcu_clock_avg = self.mcu_clock_variance = 0.
-        self.chip_clock_avg = self.chip_clock_covariance = 0.
-    def reset(self, mcu_clock, chip_clock):
-        self.mcu_clock_avg = self.last_mcu_clock = mcu_clock
-        self.chip_clock_avg = chip_clock
-        self.mcu_clock_variance = self.chip_clock_covariance = 0.
-        self.last_chip_clock = self.last_exp_mcu_clock = 0.
-    def update(self, mcu_clock, chip_clock):
-        # Update linear regression
-        decay = self.decay
-        diff_mcu_clock = mcu_clock - self.mcu_clock_avg
-        self.mcu_clock_avg += decay * diff_mcu_clock
-        self.mcu_clock_variance = (1. - decay) * (
-            self.mcu_clock_variance + diff_mcu_clock**2 * decay)
-        diff_chip_clock = chip_clock - self.chip_clock_avg
-        self.chip_clock_avg += decay * diff_chip_clock
-        self.chip_clock_covariance = (1. - decay) * (
-            self.chip_clock_covariance + diff_mcu_clock*diff_chip_clock*decay)
-    def set_last_chip_clock(self, chip_clock):
-        base_mcu, base_chip, inv_cfreq = self.get_clock_translation()
-        self.last_chip_clock = chip_clock
-        self.last_exp_mcu_clock = base_mcu + (chip_clock-base_chip) * inv_cfreq
-    def get_clock_translation(self):
-        inv_chip_freq = self.mcu_clock_variance / self.chip_clock_covariance
-        if not self.last_chip_clock:
-            return self.mcu_clock_avg, self.chip_clock_avg, inv_chip_freq
-        # Find mcu clock associated with future chip_clock
-        s_chip_clock = self.last_chip_clock + self.chip_clock_smooth
-        scdiff = s_chip_clock - self.chip_clock_avg
-        s_mcu_clock = self.mcu_clock_avg + scdiff * inv_chip_freq
-        # Calculate frequency to converge at future point
-        mdiff = s_mcu_clock - self.last_exp_mcu_clock
-        s_inv_chip_freq = mdiff / self.chip_clock_smooth
-        return self.last_exp_mcu_clock, self.last_chip_clock, s_inv_chip_freq
-    def get_time_translation(self):
-        base_mcu, base_chip, inv_cfreq = self.get_clock_translation()
-        clock_to_print_time = self.mcu.clock_to_print_time
-        base_time = clock_to_print_time(base_mcu)
-        inv_freq = clock_to_print_time(base_mcu + inv_cfreq) - base_time
-        return base_time, base_chip, inv_freq
-
 MIN_MSG_TIME = 0.100
 
 BYTES_PER_SAMPLE = 6
@@ -201,7 +153,7 @@ class MPU9250:
         # Clock tracking
         self.last_sequence = self.max_query_duration = 0
         self.last_limit_count = self.last_error_count = 0
-        self.clock_sync = ClockSyncRegression(self.mcu, 640)
+        self.clock_sync = adxl345.ClockSyncRegression(self.mcu, 640)
         # API server endpoints
         self.api_dump = motion_report.APIDumpHelper(
             self.printer, self._api_update, self._api_startstop, 0.100)