Question: Are there any No No's that I should be careful to stay clear of when running my Electronic Speed Control (ESC)?

Answer: We have sold many many ESC's.  From the questions and service requests we get we can pretty well sum up the No No's and Must Do's as follows:

a) Read Everything First! Every instruction! Every Warning Label! Browse our Knowledge Base while you are at it. About 90% of problems can be avoided by Reading First.

b) Do NOT screw up the electrical connections! Polarity is important. If you are not sure, figure it out first... trial and error testing can get expensive!

c) Do NOT exceed the maximum electrical specifications!  Pay attention to the maximum allowable Voltage, Current and Wattage (Volts x Amps).

d) Do NOT operate without a safety fuse system!

e) Do NOT use your plumbing tools or hammer or anything but the smallest of tools! An ESC is not a farm tractor. Often there is nothing to adjust. On some ESC's there may be an adjustment you can make with a small Phillips (cross) or flat bladed screw driver. Some ESC's use small jumpers or dip switches. Emphasis here on small and gentle and only if absolutely necessary and only if you know what you are doing!

f) Do NOT overheat. Ensure adequate cooling by exposing the heat sink and entire ESC to moving air.

g) Do NOT get dirt, water or metal objects into the ESC! ESC's really hate water. Get 'em wet and you might as well start reaching for your wallet. Nobody will warranty an ESC that has been wet. It leaves tell tale signs that stand out like a pimple on your nose. Stay the heck away from water, rain or moisture of any kind. Also protect the ESC from dirt or anything metal. Generally if you can keep moisture out, that will also prevent dirt or metal from contacting the ESC as well.

Question: Are there any No No's that I should be careful to stay clear of when running my Brushless Motor?

Answer: We have sold many many brushless motors.  From the questions and service requests we get we can pretty well sum up the No No's and Must Do's as follows:

a) Read Everything First! Every instruction! Every Warning Label! Browse our Knowledge Base while you are at it. About 90% of problems can be avoided by Reading First.

b) Do NOT screw up the electrical connections! Polarity is important. If you are not sure, figure it out first... trial and error testing can get expensive!

c) Do NOT exceed the maximum electrical specifications!  Pay attention to the maximum allowable Voltage, Current and Wattage (Volts x Amps).

d) Do NOT use a propeller that is bigger in diameter and/or bigger in pitch than the specifications provided! Use the recommended propeller.

 

e) Do NOT overheat. Ensure adequate cooling by exposing the motor and entire ESC to moving air.

f) Do NOT operate the motor if the prop appears to wobble when you turn it by hand! Look at the back of the hub as you rotate the propeller over by hand. The back of the hub should remain in one plane throughout the rotation, not wobble.

g) Do NOT operate if the motor appears to vibrate! Look at the prop shaft when it first gets going. If it looks blurry to the eyes or sounds strange it is vibrating. Excessive vibration will destroy your motor and possibly hurt your servos as well. Stop and check all bolts for tightness and make sure the prop is turning true (no wobble) and that the prop is balanced.

h) Do NOT operate with loose fasteners! Check bolts, nuts, screws etc for snug tightness. Do not over tighten but keep them snug. Check periodically, particularly after the first few times you use the motor. Use blue thread locker such as Pacer Z42 to help keep fasteners from loosening up. If you find that fasteners are continously loosening up even after the motor has been used many times, you have a vibration issue. Check for sources of vibration. Excessive vibration will destroy your motor.

i) Do NOT operate at High Throttle on the ground or test bench for longer than 10 seconds! High Throttle static operation such as this where the airplane is not moving, induces maximum load on the motor while not providing proper air flow to help cool it. Heat will build up quickly, particularly if the motor is cowled. Heat is bad news. Heat can melt the windings down and quickly destroy the motor.

j) Do NOT operate without a safety fuse system!

k) Do NOT assume an electric motor is the same as a glow or gas engine! An electric motor is very different. Electric motors will attempt to overcome any load they encounter, even to the point of destroying themselves.

l) Do NOT use your plumbing tools or hammer! A brushless motor is not a farm tractor. Small hand tools only. Snugly tight does not mean you tighten things to the point they strip.

m) Do NOT get dirt, water or metal objects into the motor! If you drop a small screw or nut when working on your model, find it first before turning on your motor. Electric motors have strong magnets. Chances are that if you drop something small and metal into your model and can't find it... that it will be inside the motor. Turn the motor over by hand and pay attention to any unusual resistance, grinding or other odd sounds or feel. Find the missing metal item before operating your motor!

 

 

Question: My brushless motor came with a label attached to the prop shaft or firewall that strongly warned me about the maximum propeller size that I should use with the motor and recommended a particular prop. The READ ME FIRST sheet that came with the motor also made reference to this. Why does the prop size matter?

Answer: Electric motors are very different than glow or gas engines. An electric motor will attempt to overcome any load. Rather than just stop, it will work very very hard to overcome any load and can draw massive amounts of current  from the battery, through the speed control and into motor while doing so. In the case of a totally locked motor for example, the current will become very high and we include a fuse in the line that will blow to protect the system.

This characteristic of electric motors is both good and bad. The good part is that an electric motor can produce a great deal of torque (power) from the first revolution whereas an internal combustion engine must get spooled up to a higher RPM level before it really begins to produce power. This is one of the main reasons combustion powered automobiles need a transmission... without a transmission we'd never be able to get our cars rolling in the first place.

The down side of this ability of electric motors to automatically attempt to overcome any load by drawing more current from the power source is that the motor will pull more and more current until the load is overcome or something blows. Sometimes the speed control will detect this and shut down, while at other times when the current really goes through the roof, a fuse in the line will pop. However, if the current draw is high but just below the level at which the ESC will shut down the motor will run and attempt to overcome the load. Massive amounts of current flow into the windings of the motor and this produces heat... lots of heat. In time this heat will melt the insulation on the windings and it's all down hill from there. Once the insulation begins to melt some of the windings will short out, more current flows, more heat, smoke appears and the end comes quick! In some cases this can happen in seconds... in other cases it can take 10 minutes or so.

OK... so what the heck does all this have to do with propeller size? Well, as far as the motor is concerned, the prop is the load on the motor. A prop with a big diameter induces more load than a small diameter prop. More pitch causes more of a load than low pitch. Bigger diameter props coupled with more pitch is double trouble if you exceed the propeller specs for the motor.

So, when we release a Power Module and/or Power Pack for one of our models, we have carefully matched the propeller, speed control, motor and battery to give you the best performance and best durability. If you change the prop to a larger prop or a prop with more pitch, you are changing the whole system and the part that suffers is the motor and sometimes the speed control. If you "over prop" a motor it will burn up quick. Sometimes in as little as 10 seconds. The worse scenario is over propping and then doing a run up of a cowled installation on the ground or test bench. This maximizes the load on the motor because the model is not moving and the prop cannot "unload". Static run ups also do not produce as much airflow into and out of the cowl to cool the motor and ESC. Static run ups on the ground or bench can gang up on the motor very quickly... they maximize the load on the motor while restricting the cooling air flow... ugly stuff!

Bottom line... pay strict attention to the maximum prop size specifications and use the prop we recommend. If someone tells you to do otherwise, make sure they buy you a second motor first because you are going to need it within anywhere from 10 seconds to 10 minutes later! You also might pick up a spare ESC while you are at it!

Question: I see the term "Brushless" in some of the information about electric motors. What does this mean?

Answer: A tradional motor utilizes brushes to feed electricity to the armature (coils of wire) of the motor. The brushes physically brush up against the commutator (sometimes called a commutator "ring"). The commutator rotates with the armature and shaft while the brushes do not move. Various designs are used. Some commutators are split into segments and each time the brushes move over a different segment, different coils in the armature are "excited" by the electrical connection. Other designs use two or more continuous (non-segmented) commutator rings and alternate the current polarity and magnitude as the motor revolves through 360 degrees of rotation. Although simple and in spite of some very good material science work going into the composition of brushes over many decades of improvement, inevitably the brushes and commutator wear because they are in physical contact. Dust and contaminants in the air can accelerate this problem. Pitting due to electrical arcing can also occur particularly in high load, high current and/or high voltage situations. When the brushes wear down they must be replaced and eventually the commutator needs servicing as well. Often that is the end of motor because changing the commutator is an expensive process. Bottom line is that motors with brushes are wearing out from the first time they turn. It's just a matter of time. The plus side is that Brushed motors are easy to make, well understood, as common as dirt and hence generally cheap to manufacture.

A brushless motor is exactly what it purports to be... brushless! The magnets of a brushless motor rotate instead of the armature and hence the armature coils can be permanently wired up to the electrical feed. The rotating shaft is suspended in ball bearings and is never in direct contact with anything physical other than the bearings supporting the shaft. Brushless motors therefore last much longer, never need servicing (other than possibly bearings) and generally also produce more power more efficiently than a brushed motor of a similar size and weight. Unfortunately, in order to phase the current and time the excitation of the coils correctly, a brushless motor must rely on a sophisticated electronic controller made specifically for brushless motors. All of this sophistication, power, efficiency and longevity comes at a price... it costs more to make a brushless motor work properly than a brushed motor. You get more for your money but you gotta pay to get it! Bottom line here is that the brushless motor and the Lithium Polymer battery have together transformed electric model flying in a way that has not been possible before. It's not cheap but it works extremely well and for the first time we now have brushless motors, ESC's and LiPo's that when carefully matched up into a system, can give us performance and duration that was formerly only possible with glow or gas powered combustion engines.    

Question: I see the term "Outrunner" in some of the Electric Motor information. What does "Outrunner" mean?

Answer: The following explanation should help you out.

a) A tradionaal "Inrunner" motor is the generally familiar design we have all become used to since electric motors were first invented. The inside of the motor rotates including the drive shaft to which is often attached a gear or pulley of some sort. The outside case of the motor is fixed. The case does not rotate and the case is often incorporates some sort of mounting flange or holes allowing the outside case and the motor itself to be bolted or clamped down to a platform or mounting system. From the outside of this traditional inrunner type of motor, only the shaft appears to rotate.

b) An outrunner motor has the shaft attached to the outside case of the motor and when the shaft rotates the entire outside case of motor rotates along with it. The inside of the motor is fixed and usually attached to a mounting plate of some sort at the back of the motor. This design has been around for many years but in modeling it is relatively new. Outrunner motors are generally brushless high power motors and offer the advantage of usually producing more power and being more efficient (using less energy) than inrunner motors.