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  1. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    please ignore EDIT: OLD DATA
  2. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    this is very clever! as I understand it there will be two main forces involved, the force required to accelerate to the final velocity and then the force that will only be overcoming the weight and the acceleration due to gravity (2.5713N) that keeps it as that same velocity how do I use that...
  3. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    also how fast does the cam need to be going at and how do I relate it to Fh to the speed? I think there's a bit more maths involved! thanks do I still need to accelerate to the final velocity of the block in the first 10% of time?
  4. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    hmm so n is 10 because of the 10 stages of scissor, Fv is the vertical force the cam needs to provide, and that will be n * fv with a little f to differentiate from the capitalized Fv which denotes the vertical force at the cam, and n * fv is needed to accelerate the load at the top of the...
  5. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    so I know that you explained that F = ma , and that I need to add in gravity but as I understand it that has to be the force at the top of the scissor. what do you think the force needs to be at the cam ? also I think that the larger the cam the shallower the slope (ie profile of the cam), the...
  6. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    thank you so do you get what is going on in the thing I'm building, can you visulize what it looks like yellow is an idler gear just to switch direction! and the units for the density are kg/m^3
  7. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    thanks am using openoffice calc, how do I set to 3sdp please ok found round function is there any way to round all to 3sdp's at once or do I go through one by one? went through one by one
  8. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    ok so I've enerted the digits I'll try and use formulas next time round so that if I alter somthing then the precceding values will change automatically
  9. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    this is where i'm learning!!
  10. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    ok i'll learn about spreadsheets! thanks any ideas of what to put in the rows and columns, very new to spreadsheets? thanks so the only things I might be changing now is the rotaion speed of the cam and the speed of the flywheel, I will be experimenting with different numbers for the best...
  11. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    I'm specifically having problems with the force required to lift the weight at the point where the cam touches the scissor mechanism
  12. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    is there anybody else that might have some input to my querie??
  13. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    if you do happen to have a change of heart and get a minute to share your expertise on the problem I would be seriously overjoyed: okay so the initial force needs to be calculated that accelerates the weight (in the first 10% of the 2 second cycle) to the velocity that it stays at (for the...
  14. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    thanks
  15. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    slope = Rmax - Rmin / pi * Ravg (0.45 - 0.318) / (pi * 0.384) = 0.1094190234 v = (0.9 * 1.32) / (0.9 * 2) = 0.66m/s I'm planning on using lightweight plastic for the scissor mechanism with a guide so that it doesn't bend or cripple (its only got to lift 262grams) and for the friction I was...
  16. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    okay so the initial force needs to be calculated that accelerates the weight (in the first 10% of the 2 second cycle) to the velocity that it stays at (for the remaining 90% of the 2 second cycle) - the force to keep it at that velocity till it reaches the top of the 1.32m, then along with the...
  17. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    I get it - I've got to go to college where they are paid to help and that you can only expect so much of people who are just helping where they can! thanks anyhow
  18. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    ok it's only a minor change to the cam (0.318m lowest part of cam, largest 0.45m) rotates at 2pi in 4sec and so lifts the weight through the scissor every 2 seconds, and weight 0.2622kg and distance it moves 1.32m I really do appreciate your time if you could have a go one last time before...
  19. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    don't mean to confuse but I changes somethings to make the theoretical machine makeable ( the first design was not plausible because the gear on the shaft of the flywheels radius was 1/5 of a millimeter - now the radius is 35mm) the height the block moves is now 1.32m and the weight is now...
  20. Maglatron

    I want to know all of the maths concerning this scissor mechanism!

    does that sound right? because energy over distance equal force?
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