BELT LOSES POWER
This condition is when the treadmill operates normally without a person on the belt and then slows down when someone steps on the belt or when the treadmill operates normally for a given period of time with someone on the belt then abruptly begins to slow down.
There are four typical causes for this problem (listed in order of our experience:
1) The walking belt and/or deck are worn. (85% of the time)
2) The walking belt and/or motor belt are too tight- if you have adjusted either recently. (8% of the time)
3) The motor has lost torque and needs brushes or has demagnetized or has developed high resistance. (5% of the time)
4) The controller is dropping output. (2% of the time)
Walking Belt is Worn:
The only certain way to test for a worn walking belt is to take a DC amp draw (if you have a DC treadmill) or an AC draw (for AC). Trying to look at the belt or a feel test is highly unreliable. Better tests, if you lack a DC ammeter (they are expensive for a good one), are a coast test or an incline test. To test the deck, go back to the Troubleshooting section and download the belt and deck inspection instructions. The coast test is to get on the treadmill as the lowest incline setting and walk on the treadmill at 3 MPH. Pull the safety key and it should take you 2-3 full steps to stop (this is a general rule…some like a few Tunturi models stop on a dime even with a healthy belt but for most models, this tests works well upon). Fewer steps indicate high friction. The incline test is to put the treadmill at max incline and walk on it at 3 MPH. If the treadmill operates normally at max incline but bogs down at minimum incline, replace the walking belt. Gravity takes over for the drive system eliminating much of the friction problem. On some heavily worn walking belts, this test will not eliminate the problem.
Walking Belt/Motor Belt too Tight:
If you have adjusted the walking belt or motor belt recently, check for this problem. When the belts start slipping, some people just crank down the belts and on treadmills, tighter is not necessarily better. The tighter the belts, the more the drive system has to work to keep everything moving. You should be able to lift the walking belt (with the treadmill unplugged) in the center of the treadmill about 2-3” without straining. Tighter belts should be loosen but make sure you don’t create a dangerous slipping situation by loosening.
The motor belt (with the treadmill unplugged) should be able to be turned by hand to almost a 90 degree angle from its normal operating position. Loosen the belt if too tight. Make sure to test for slipping and if it does with the proper tension, replace the motor belt.
Needs Brushes / Demagnetized Motor / Resistance Problem:
Typically when we find a motor that has lost torque; it needs a new set of motor brushes. Typically we can make brushes for almost any motor if we don’t already stock them. Motor demagnetization is not that common but it does happen and it is normally easy to diagnose. If you have confirmed the belt and/or deck is not worn and the belts aren’t too tight, you can test for a motor torque problem. DO NOT USE YOUR HAND OR ANY OTHER BODY PART TO IMPEDE THE MOTOR…YOU WILL LIKELY LOSE YOUR BODY PART IN THE PROCESS IF THE MOTOR IS GOOD. The step to test for the motor is to use a foreign object preferably on a long shaft. First determine the direction of the motor spin (most have directional movement printed on the motor tag), then apply pressure with an object with downward pressure on the flywheel in the direction the flywheel is turning (do not attempt to put force against the rotating direction of the flywheel as you can easily injure yourself). If you can slow the motor, typically you need brush replacement. To test for demagnetization, the motor must be disassembled. Once you have the motor retaining bolts removed, remove the motor core by sliding it out of the end of the housing. If the magnets pull the core against the housing and it is difficult to remove, the magnets are good. If the magnets do not attract the core, the motor has to be replaced. To test for high resistance on DC motors, you must use a multi-meter for accurate testing. Put a test lead in the positive lead (usually red) and the other in the negative lead (usually black) and then set the meter to the ohms scale. Readings that are normal are between 1 and 2. Some small motors will have higher readings and larger motors have lower readings. Readings above the normal range indicate you have high resistance in the motor and we have seen them incredibly high. Since the copper flexes every time it energizes, the ability of the windings to conduct electricity is reduced over time. Large motors typically are more cost efficient to have rewound. Smaller motors are typically cheaper to replace.
This is the most uncommon of the causes. Typically replacing a controller in this situation will not solve the underlying problem and then you will end up replacing a belt as well as a control. Normally if a control is dropping output, it will do it with a person on the belt or not. Tests of DC output dropping is normal in many controls since they have a current limiter which will automatically drop output to prevent burning up the board. This is best diagnosed by eliminating the other possible problems first. If you are left with the control as the cause, replace the control.
Walking Belt Friction Problems
As the walking belt wears, it creates more friction with the deck which creates more heat in the belt causing it to wear further. Additionally, the increased friction requires the motor to work harder to keep the belt moving at the same speed. With this in mind, it causes the motor to draw more electricity and therefore, more power to move the belt.
The motor has to get rid of this excess energy in some way so the way it normally does it is by releasing it in heat so that's why treadmills with belt problems typically overheat the motor too. All of this to say that if the breaker starts tripping, you know that the belt is causing the motor to pull too many amps and the safety system is working as it should. If the breaker has tripped more than a few times, it will need to be replaced because the breaker weakens every time it trips. Additionally, the walking belt will need to be lubricated at a minimum and if you want to be very aggressive toward the symptoms, replace the walking belt.
WHY USE TREADMILL BELT CLEANER?
If your treadmill is properly maintained, you should not have to clean the backing of the belt, unless it is in a normally dirty area (we recommend that you keep your treadmill out of these areas). What you must do to the backing of the belt is lubricate it. We have formulated a lubricant (World Famous Treadmill Lube) that has an agent that actually repels dirt from the underside of the belt. It also has another agent that has a high heat constant which means it takes more energy to heat it up (that keeps the heat lower). So, if you keep it maintained (cleaning, etc.) and lubricated, you shouldn't have a problem with dirt on the underside of the belt. To understand why to use belt cleaner, you first have to understand the dynamics of a conveyor belt driven system. Most home treadmills have a DC controller attached to a DC motor which is belt driven to a front roller which is a belt driven conveyor system. Walking or running on this conveyor system creates heat (from the friction of the belt backing). If you have too little friction, the treadmill will not operate properly (the most evident problem is on an incline the treadmill will keep speeding up). The energy exchange process creates heat.
The pressure that is exerted against this system from the user, for the average person, equals hundreds of thousands lbs. of pressure every mile. In other words, no matter what the lubricity of the belt is, the potential for heat build up is great. If you combine this with a nice layer of dirt on the top of the belt (acting as an insulator) your heat constant will certainly rise. Removing the dirt layer from the top of the belt helps reduce belt heat and thereby lowers the amp draw requirements of the DC electrical system. This helps the controller and motor run cooler in addition to the heat level of the belt. We have tested treadmills before and after belt cleaning and have seen a 20% reduction in the amp draw of the unit. This could be a major contributor to the longevity of the
1) motor brushes
2) armature of the motor
3) DC motor controller.
1) motor brushes
2) armature of the motor
3) DC motor controller.
Since heat is also an enemy of the walking belt and deck, lower operating temps can also extend their life. You don't have to have our belt cleaner to clean your belt. Another way to clean it is to use water and a nylon bristle brush. Make sure to let the belt completely dry before using it again and don’t get water underneath the walking belt.