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Recent content by hyboxis79

  1. hyboxis79

    Brushless DC motor life expectancy

    Can anyone recommend me a way to calculate Mean Time Between Repair (MTBF) of BLDC motor. Is there a way of estimating it without the help of the manufacturer? The engine specs are: 2 poles 21 winding inrunner 1:4.4 transmission 76.1 mm length 27.6 mm diameter 15 Ampere 15 volt max rpm 60k...
  2. hyboxis79

    Brushless DC engine starting torque

    There are people in this forum who helped me with motors before so I don't see anything wrong with it.
  3. hyboxis79

    Brushless DC engine starting torque

    Can I rely on saying that the starting torque of a BLDC engine is the multiple I_max*Kt . I find it problematic because I am not sure BLDC controllers are entirely predictable I would be glad for some help..
  4. hyboxis79

    Stall torque - BLDC

    thanks clyde38 this helps with the theory But the bottom line as you said is that I can't be sure of the stall torque because it depends on current that the controller of the bldc motor allows me draw and on the manufacturer.
  5. hyboxis79

    Starting Torque of a Brushless DC engine

    I've noticed somebody calculating the starting torque by the equation T_stall= K_torque*(V_nominal/R_armature) Does that mean the motor has to overcome the large amount of current it has at the beginnig can anyone elaborate? thanks
  6. hyboxis79

    Starting Torque of a Brushless DC engine

    Is there anyway of predicting what will be the starting torque of a BLDC motor (BRUSHLESS DC MOTOR) without asking the manufacturer? Can I know the starting torque by consulting the manufacturer of the BLDC motor controller?
  7. hyboxis79

    Stall torque - BLDC

    Clyde 38 I have another question for you. The stall torque in the spreadsheet you gave me is calculated by finding the current running at nominal voltage when no emf is induced. From what I understand you refer to the current as the starting load. Can you explain why? what about the friction...
  8. hyboxis79

    Stall torque - BLDC

    thanks Clyde38 this excel sheet is really useful.I havn't understood all of the equations but I am on the way. The excel sheet that motorman sent is a bit above my current level of understanding but thanks anyways
  9. hyboxis79

    Stall torque - BLDC

    Here is the catalog: http://files.engineering.com/getfile.aspx?folder=6862f175-95ee-4fbd-bc02-ad8308e5fa8e&file=Hacker-2008-WEB_28+29-1.pdf
  10. hyboxis79

    Stall torque - BLDC

    Motorexpert, I am looking at a R/C motor company called Hacker motors Catalog. They don't have a lot of specs in their brochures. Regrading the maximum power the differences. Although I would achieve similar power outputs I would notice the differences in power inputs. Since there's a...
  11. hyboxis79

    Stall torque - BLDC

    Looking on a BLDC motor catalog for motors with the same iron there are different motor windings but similar maximum power ratings. Other than that I know the operating current, no load current, armature resistance, terminal voltage 1. Just to be sure since it has a permanent magnet the no load...
  12. hyboxis79

    BLDC motor constants

    thanks Clyde38. I've downloaded the book and still havn't looked at it.
  13. hyboxis79

    BLDC motor constants

    I have catalog specs for a brushless DC motor saying [I_0] no load current @ 8.4V = 3.84[amp] [R_a] = 0.0063 Continuous Current = 45 Amp No. Winding = 6 Voltage= 14.8 - 18.5 max power = 700Watt (15 Sec) Kv=5000RPM/Volt 1. Is it possible to find the motor torque constant with the help of...
  14. hyboxis79

    BLDC: Coil Windings and their effect on maximum RPM

    On the matter of added current conduction.... Looking on a BLDC motor catalog for motors with the same iron I've noticed different motor windings but similar power ratings. Since you have a thicker wire more current will be drawn from the power supply. Although the current goes up the voltage...

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