1. Do not share user accounts! Any account that is shared by another person will be blocked and closed. This means: we will close not only the account that is shared, but also the main account of the user who uses another person's account. We have the ability to detect account sharing, so please do not try to cheat the system. This action will take place on 04/18/2023. Read all forum rules.
    Dismiss Notice
  2. For downloading SimTools plugins you need a Download Package. Get it with virtual coins that you receive for forum activity or Buy Download Package - We have a zero Spam tolerance so read our forum rules first.

    Buy Now a Download Plan!
  3. Do not try to cheat our system and do not post an unnecessary amount of useless posts only to earn credits here. We have a zero spam tolerance policy and this will cause a ban of your user account. Otherwise we wish you a pleasant stay here! Read the forum rules
  4. We have a few rules which you need to read and accept before posting anything here! Following these rules will keep the forum clean and your stay pleasant. Do not follow these rules can lead to permanent exclusion from this website: Read the forum rules.
    Are you a company? Read our company rules

Calculating the weight lift

Discussion in 'Electronic and hardware generally' started by MagicMike, Jan 28, 2014.

  1. MagicMike

    MagicMike New Member

    Joined:
    Jan 26, 2014
    Messages:
    24
    Balance:
    961Coins
    Ratings:
    +2 / 0 / -0
    My Motion Simulator:
    2DOF, 3DOF, DC motor, Arduino, Motion platform
    Assume that you have 3 motors 12v - 15A. How you can calculate how many kg your sim construction can lift with safety?

    The weight of the human is 80kg
    The weight of construction 7kg
    The weight that the motor wants to lift up 3kg

    ..So the total weight is about 90~ kg
    Last edited: Jan 28, 2014
  2. MagicMike

    MagicMike New Member

    Joined:
    Jan 26, 2014
    Messages:
    24
    Balance:
    961Coins
    Ratings:
    +2 / 0 / -0
    My Motion Simulator:
    2DOF, 3DOF, DC motor, Arduino, Motion platform
  3. bsft

    bsft

    Balance:
    Coins
    Ratings:
    +0 / 0 / -0
    Depends on the frame design, if its a 2DOF pivot, most of the weight is balanced on a point and the motors move it back and forth off centre, so even wipers will move a 110kg person on a seat mover or a light full frame.
    If you are going into full lift of frame and person, thats where it gets a bit tricky.
    Mind you , there is a 6 x wiper 6DOF in testing that lifts 90kg easy in progress.
    What frame did you have in mind?
    • Useful Useful x 1
  4. value1

    value1 Nerd SimAxe Beta Tester SimTools Developer Gold Contributor

    Joined:
    Jan 9, 2011
    Messages:
    2,184
    Location:
    Zug, Switzerland
    Balance:
    14,463Coins
    Ratings:
    +3,318 / 11 / -1
    My Motion Simulator:
    2DOF, DC motor, JRK, Joyrider
    3×12V×15A = 540 W
    Assuming an efficiency of 60% you have around 300W power output.
    With P = m × g × h / t and m = 90 kg, g = 9.81 m/s² you can lift the 90 kg about 35 cm in 1 sec.
    • Informative Informative x 4
    • Useful Useful x 3
    • Like Like x 1
  5. CalSim

    CalSim building things

    Joined:
    Jul 24, 2014
    Messages:
    89
    Occupation:
    bacteriology analist
    Location:
    Spain
    Balance:
    1,309Coins
    Ratings:
    +41 / 0 / -0
    My Motion Simulator:
    DC motor, Arduino, JRK
    @value1 Please repeat that calculation with my numbers, im amazed, hahaha
    6 motors 24A constant 48A peak 12v, 120mm Dia pulleys, how many kg would it be able to lift?

    I dont really understand the h/t on that formula, speed? where does it comes from?

    Edited: got 0.35 with 300kg 1036w/(300*9.8)=h/1

    h=0.35 m/s supossed 35cm/sec the same that him, why?
    Last edited: Oct 28, 2014
  6. Ponch

    Ponch New Member

    Joined:
    May 28, 2014
    Messages:
    12
    Balance:
    289Coins
    Ratings:
    +18 / 0 / -0
    @CalSim , in the @value1's calculation the watt per kilogram ratio is about 3.6 W/kg.

    In your 6DOF, the ratio is about 3.4 W/kg (6.8 W/kg peak), so it is not strange to find similar results.
  7. value1

    value1 Nerd SimAxe Beta Tester SimTools Developer Gold Contributor

    Joined:
    Jan 9, 2011
    Messages:
    2,184
    Location:
    Zug, Switzerland
    Balance:
    14,463Coins
    Ratings:
    +3,318 / 11 / -1
    My Motion Simulator:
    2DOF, DC motor, JRK, Joyrider
    The potential energy that you need for lifting the platform 35 cm is:
    Epot = m×g×h = 90 kg × 9.81 m/s² × 0.35 m = 309 J
    When you lift your platform in 1 second, the power required is P = Epot/time = 309 W
    P = 6× 24A × 12V = 1.728 kW. Assuming that the efficiency of your motors is 60 % you have 1 kW power available.
    With this you can lift your 300 kg in 1 sec for 35 cm indeed ThumbUp.jpg

    Please keep in mind though, that in many cases, not all 6 motors will lift up at the same time!
    • Like Like x 2
    • Informative Informative x 1