Sunday 17 January 2016

Why does a treadmill motor break down? How to prevent treadmill engine failures

The engine failure are the most expensive repairs on a treadmill. You may be surprised to learn that the main causes of the engine failure are rarely the engine itself. The problem depends usually on an excessive or improper use of the equipment, or, very often, on lack of maintenance. Both of these factors can be affected directly by the user.
Excessive use of the treadmill
What can the user do?
1) Clean and lubricate regularly the running deck = reduces the friction factor
2) Always start with feet on the side rails (FIRST start the treadmill at 1.5 to 2 km / h, THEN step on it) = avoids current peaks and the effect "locked rotor starting"
3) try to maintain walking speed OVER 5km / h. = Reduces power consumption and overheating
4) after training check if the motor overheats. It should be possible to hold on one hand without burning. The outer surface of the motor must never exceed 50 ° C. If the engine gets very hot, try to:
a) better ventilate the treadmill, the engine itself and the room
b) increase the average speed, take breaks (eg. stretching) and reduce the continuous training time
c) check lubrication
d) check that running belt and drive belt are not be TOO TIGHTEN (too much tighten = premature wear).
Sometimes the running belts loose their ability to lubricate and cause high friction. In this case, the walking belt must be replaced to avoid problems for the motor and the board.
Let's see in more detail why these recommendations
When you use a treadmill, heat builds up inside the motor. Imagine two treadmills, both identical except for the fact that one has a small motor and the other has a large motor. If we use both at the same way, both will necessarily have to generate the same power, but to do this the smaller engine has to work more (and less efficiently) than the big engine. This means that more heat develops and consumption is higher. When the engine warms up, the winding insulation or windings can fail, causing problems inside the motor detectable only through special load bench test. The windings can fail and go shorted.
To prevent the engine to warm up, we must keep under control the "duty cycle" i.e. the time of utilization, especially continuous. The Duty Cycle is the recommended amount of "time on" and "off" to the engine. This is one of the factors that a manufacturer of treadmill will consider when selecting a motor for the treadmill. For example, a duty cycle of 30 minutes 50% means to perform a job for a 30 minutes, followed by 30 more minutes of cooling to allow to dissipate heat in the motor. The engines of treadmills most commonly used normally fall into a duty cycle of 50% between 20 minutes and an hour. The not domestic treadmills (for gyms) of the best brands, are rated for continuous use and sometimes include an additional internal cooling to ensure that the engine does not overheat. So the amount of continuous use for a treadmill is really important in determining its overall life. The outer surface of the motor can be cooled with external cooling fans. However, remove the heat from the center of the engine is not so easy to get. Similar problems can occur if the user's weight exceeds the weight design of the treadmill. Often manufacturers indicate over 100 kg maximum weight, but the actual is around 70/80 kg.
Lack of maintenance
The lack of maintenance can lead to the same type of fault. If you do not regularly lubricate the walking belt, it will increase the friction between the belt and the platform during training. The motor of the treadmill must work harder to overcome the increased friction and if it works more, will become warmer. Looking at the motor brushes, if there are burn marks, often this was the cause of the fault. These are signs that the engine has run too much. This problem can easily be avoided through regular maintenance of the belt and replace it when it becomes too worn. It’s not always easy to tell the belt is worn out by looking at its surface. Sometimes, the belt may look OK, but it is the problem. So, each time the engine warms up, belt replacement should be taken into consideration after a first stage of cleaning and maintenance. We suggest you to replace the belt with a new one with a low friction factor. You can buy them on the website www.partsfortreadmill.com
Consider that a tape with double friction factor (a tape of 4/5 years old often gives this) doubles engine work. It's like saying that a user of only 60 kg causes the motor effort of a 120 kg person!
Other failure modes
Of course, there are also other failure modes for engines that it is not possible to influence so easily. The control system (controller) adjusts the motor voltage through sudden PWM pulses (see more details on our blog). This adjustment is adopted on all DC current motors, virtually all of those used on domestic use treadmills. Albeit economical and reliable, this adjustment tends to greatly straining the engine, especially when the controller must adjust significantly speed (that is, when the user, and then the engine go SLOW). Other fault types relate to the phenomenon of demagnetization. Voltage spikes from the card and overheat can permanently destroy the magnetic field of the (permanent) magnet engine. In fact, the most efficient way to magnetize a metal object is to go through a strong electric field in order to align the micro structure of the metallic, and the same way you can de-magnetize objects by changing the electric field so as to destroy the micro structure. When the magnetism of the motor is reduced too far, the system of the treadmill must compensate for this by increasing the amount of electric current (A) flowing through the windings in order to obtain the same effective. In this way, however, it accumulates more heat in the motor, that can lead to the problems described above. While some engine manufacturers (Turdan, Te Wei, Lemmar) have magnets very resistant to this type of phenomenon, other (Megamotor, Icon), encounter this phenomenon of demagnetization more frequently.
Finally, test the engine with a battery is not enough. It will not say anything about the amount of torque that the motor is able to generate for given amount of current (the magnetism and the current directly influence the torque). The only reliable way to test the torque is with special equipment in a laboratory, with special tester for DC motors.
My engine is failure. So what should I do?
If the engine is actually failure and you replace it, do not neglect other factors of maintenance and avoid overheat. No manufacturer does guarantee engine for overheating because it is obvious that the overheating of the motor depends on some conditions of improper use. Instead, you are careful you can restore the correct operation of the treadmill and guarantee yourself many years of pleasant workouts.

4 comments:

  1. My roommate dances on the treadmill at slow speeds, and she ends up varying the treadmill's speed - it sounds like grrrr uh grrrr uh grrrr uh. The treadmill doesn't smell bad or smoke up. I don't want to kill her joy, but this equipment is expensive! Am I worrying about nothing?

    ReplyDelete
  2. My roommate dances on the treadmill at slow speeds, and she ends up varying the treadmill's speed - it sounds like grrrr uh grrrr uh grrrr uh. The treadmill doesn't smell bad or smoke up. I don't want to kill her joy, but this equipment is expensive! Am I worrying about nothing?

    ReplyDelete
  3. My roommate dances on the treadmill at slow speeds, and she ends up varying the treadmill's speed - it sounds like grrrr uh grrrr uh grrrr uh. The treadmill doesn't smell bad or smoke up. I don't want to kill her joy, but this equipment is expensive! Am I worrying about nothing?

    ReplyDelete
    Replies
    1. Hi dear, if your roommmate is thin and the treadmill is good quality, then it's not a big problem for the treadmill.
      I'd suggest you to remember to lubricate the belt (follow instructions on the blog or on the user manual), and check regularly that the belt doesn't drift to one side.
      If you have another friend who can help you, you may also want to check sometimes if the motor temperature goes up, to do so, you need to open the plastic cover who covers the motor compartment. Be careful because there are mechanical parts moving inside, so only check that after turning off the treadmill and removing the electric plug from the outlet, so you are safe. Touch only motor body and it shouldn't bee too hot.

      Delete