how to change the setting to tension for tennis racket?

[Wiraputra86]

HI kuo, after 2 months I ordered my new pcb and 19v power supply. now my tension head is finish. but I cant get to tension above 15,9kg. how to change the setting to tension a tennis racket?

this is my first run of it.

0728.1.mp4

its pretty accurate but my weight scale is lock the number before it finish pull the string. so far after calibration for 20lbs it pull 19,9lbs

[206cc]

First of all, I want to say great job — it’s really impressive that you even built your own sliding table. The craftsmanship looks excellent! I noticed a few possible reasons why your machine is currently limited to only 15.9 kg of tension. Here are some suggestions:

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1. Sliding Table Resistance

I noticed you might not be using a standard linear rail, which can result in higher friction and resistance.
To reduce this, I suggest:

• Switching to MGN15C or MGN15H linear rails
  (These offer smoother motion and lower resistance)
• Or better yet, using a GX80 + 1605 ballscrew 200mm sliding table module, which will save a lot of setup time and improve consistency.

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2. TB6600 Driver Settings

Make sure your TB6600 driver is configured to output maximum current:

• Set SW4, SW5, and SW6 to OFF
  (This enables the highest current output depending on your model)

If current is too low, the stepper motor may lose steps under heavy load, which limits maximum tension.

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3. Power Supply Capacity

Ensure your 19V power supply is:

• At least 19V 5A, and
• High quality, capable of continuously delivering 5A or more

If the power supply cannot deliver enough current, it will cause the motor to lose torque, which reduces pulling capacity.

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4. Sliding Table Height Alignment

I also recommend slightly raising the height of the sliding table, so that the string is pulled in a perfectly horizontal line. This reduces friction and offset force, helping you reach your target tension more accurately.

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You’re really close to a fully working tennis tension head — just a few tweaks left!

[206cc]

Sorry, I may have misunderstood your question at first.
It sounds like you meant the maximum settable tension is limited to 15.9 kg,
not that the actual pulling force is capped at 15.9 kg.

If that's the case, you can enter Engineering Mode to configure a higher maximum tension limit.

Please refer to the link below, and make sure to complete the following two settings in Engineering Mode:

• 9-1 Load Cell Selection
  (If this setting is changed, please perform calibration again.)

• 9-2 Maximum Tension Setting

Full instructions:
https://github.com/206cc/PicoBETH/blob/main/docs/2.Hardware_Setup.md#ep10-final-settings