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Recent content by sacem1

  1. sacem1

    Max speed for a gantry crane before it toples

    Right now as usual in these installations there is a solid steel vertical stop welded and grounded to a solid deep foundatio in concrete. SACEM
  2. sacem1

    Max speed for a gantry crane before it toples

    Sorry Greg forgot to comment on the speed limits: My number are a ñittle more conservatives and I have agreed with the crane user to raise the speed from 0.25 m/sec to 0.75 m/sec and addind the safety devices already said. Regards SACEM
  3. sacem1

    Max speed for a gantry crane before it toples

    Thanks again for your responses. I agree with Gregg that if only one wheel locks most probably it would derail instead of tipping over, also I seems logical that if one wheel is locked from turning most likely what will happen is that the wheel blocked will start sliding and not tip over the...
  4. sacem1

    Max speed for a gantry crane before it toples

    I want to thank all your replys in such short time, well my customer does want to double the speed but has agreed in accepting the increase in costs that any requiered device that increases the safety of the gantry crane. The crane IS now in operation at 15 m/sec and it does have the sweeps in...
  5. sacem1

    Max speed for a gantry crane before it toples

    I am posting in this thread as I can not see other more suited, We have this problem: A gantry crane 10 m high, 40 m wide and with a load carry capacity of 30 MT sits on railway trucks wich have 4 wheels resting on a railway ( 2 at each end + 2 midway)the distance between end wheels is 6.5 m...
  6. sacem1

    Clutch Up to 7000 rpm

    Why don't you try a standard high performance auto clutch they will be able to cope with 7,000 + rpm's easily. Regards SACEM1
  7. sacem1

    Steam Turbo-generators

    May I ask why do you need to reduce pressure in your steam line in such amount that cogenerating electrical energy is possible, why don't you start by reducing your steam temp and avoid using energy to create steam in an enviroment that, I assume, is not designed to generate electrical power as...
  8. sacem1

    Polygon Vs Involute spline question

    CoryPad that is a much helpful data sheet for future reference, thanks. The diference between a spline conection and an internal gear one is that the presure angle of the spline does not induce a radial force on the hub as all power is transmited only as if a keyway was used (in this case...
  9. sacem1

    Winch Motor Stalls or Wire Rope Breaks?

    Seems that you have a 2 speed motor with 2 HP ratings: 0.08 HP @ 2 RPM AND 0.33 HP @ 8 RPM with a 40:1 reducer and a 300 mm winch drum, assuming that the wir rope hangs as a single line we will have the load being raised at the following speeds: 300 mm x 3.1416 = 942.5 mm perimeter of the...
  10. sacem1

    What type of bearing is best suited for extreme rpms

    I have not seen any menion to the mecanical integrity of the parts invoñved, the centrifugal force at 2.5 Million rpm's of any turbine should be the critical element of design. At those speeds the friction of the balls/rollers/needles against their running ways would destroy any type of rolling...
  11. sacem1

    Winch Motor Stalls or Wire Rope Breaks?

    The formula that desertfox gives will be correct for the motor ONLY if the motor is directly coupled to the winding drum, if it has any gearing involved you will have to include the reduction in speed (increase in torque) that the drum will be able to deliver as tension to the cable. As a rough...
  12. sacem1

    Looking for large worm and wheel with quad thread

    Look for any supplier that offers you a 7.5:1 ratio and has a 5" or more distance between input shaft and output shaft those sure are larger than 4 DP (which should be around 3 to 3.5" between shafts). Regards SACEM1
  13. sacem1

    In-line spur gear train - How to increase efficiency

    Forget about trying to increase efficiency if you are not having your gear train over correctly positioned and working spindles (bearings/lubrication/fixed distances), its like trying to get more milage from your car and running it with 20 cement bags in the trunk and low tyre pressure and...
  14. sacem1

    Winch Motor Stalls or Wire Rope Breaks?

    With out a power data on the winch motor and the speed that the cargo is conveyed it is impossible to give you an answer. As a general rule from a winch builder point of view you will always stall the motor first and the rope should not fail under any load that the winch can pull. The reason...
  15. sacem1

    Material for use in investment casting

    The investment cast process uses mostly wax mixtures specifically natural bee wax and petroleum based parafin waxes in different combination according to the more detail (more bee wax) or more resistance (more parafin wax), afterwards they can be built into more complicated shapes using...

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