Recommended pulley's for Delta printer



  • Any recommendations for the pulley size for a delta printer (16 or 20 teeth)?

    Bed size: D500mm

    Motors are Nema17, 42BYGHM810.
    Step Size: 0.9°
    Rated Current: 2.4A
    Rated Holding torque: 4200gcm
    Resistance: 0.8Ω
    Inductance: 1.8mH
    Detent torque: 220gcm

    Thanks
    Fredrik



  • it depends on the sliders you are using.
    the belt path should match the diameter of the pulleys



  • @Veti the printer is under design so the width of the belt path can be chosen but it looks like it will be 18mm



  • you will have to make the decision as to what you want.

    16 tooth. lower top speed, higher accuracy compared to 20 tooth.

    on my corexy i use 16 tooth pulley, on my delta i use 20 ( because of the sliders otherwise i would use 16)


  • administrators

    There are several consideratoins:

    • As @Veti says, you should make sure that the rest of your mechanics is compatible with whatever pulley size you choose.

    • Assuming GT2 belts, at x16 microstepping the steps/mm will be 160 using 20 tooth pulleys, or 200 using 16-tooth pulleys. So slightly better resolution per microstep using 16-tooth pulleys (5um) vs 20 tooth pulleys (6.25um). Also, 5um is easier to work with than 6.25um when measuring Z probe trigger heights.

    • The full step resolution will be 100um using 20 tooth pulleys, or 80um for 16-tooth pulleys. Some users prefer to use a layer height that is a whole number of full steps; in which case 100um is easier to work with than 80um.

    • 20-tooth will allow a slightly higher speed than 16-tooth before you run out of either VIN voltage to counter the motor back emf, or step generation rate

    If using 1.8deg motors then I think it's worth using 16-tooth pulleys to get better resolution. With 0.9deg motors, I don't think it makes much difference. I started off using 20-tooth pulleys and 1.8deg motors, then changed to 16 tooth pulleys for better resolution. But then I changed to 0.9deg motors. I still use 0.2mm layer height even though it is not a whole number of full steps.


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