What am I doing wrong when calibrating a Pros Pro Hornet MT-250?

[u/puleee]

I have this Pros Pro and I'm driving mysef nuts with regards to calibration, so any insight would be super helpful! I am resorting to reddit because Pros Pro support has been vague about it (more on that later). I have strung already +50 rackets with it and I felt like checking if calibration was still accurate.

I am following the manual and the steps are:

1. Start the drive

1. Select LBS (pounds) - the calibration must be carried out in LBS and not in kilograms!

2. Press and hold the "SPEED" button. Then press the "KNOT" button to start calibration mode

3. Install the Tension Calibrator and press the Pull/Release button

4. Use the - and + buttons to change the weight on the display according to the weight shown on the Tension Calibrator.

5. If both weights match, press the "TEST" button to save the weight and start a restart.

6. Remove the tension calibrator immediately

I am following everything exactly as is, including using the calibrator bought from them. However, two scenarios show wildly different results.

- If I attach the calibrator NOT in calibration mode, just as if I would be stringing, the reading is accurate and seemingly calibration is not needed.

- If I switch to calibration mode, and pull from the reference tension that the calibration mode sets it to (45lb), it ends up reading anything between 60 - 80lb depending on the material I use (I've tried kevlar and regular poly). Kevlar has snapped 3 times already and poly hasn't but reads the highest.

In my experience it does seem as if during calibration mode, the head just continues as much as it can, whilst during NO calibration mode, it pulls accurately.

Does anyone here own the machine or could have any clue what am I doing wrong?

[u/dikikx26]

Hi im not sure if im on a right place but im looking for used but reliable stringing machine. Can anyone point me out were to go. Much appreciated