Welcome to Holmes Hobbies!


Brushed Motors

Basic Troubleshooting Steps

If your motor or speed controller is acting strangely, smoking, getting hot, doing something it shouldn't, smoking cigarettes and telling bad jokes--STOP RUNNING IT!

It's a lot like driving your car with the check-engine light on. Maybe it's nothing. Maybe it's the difference between a relatively inexpensive oil change and an whole new motor. If something seems wrong, something probably is. Shut down, figure out what is going on, and then do what needs to be done. This hobby is already expensive, don't make it more so unnecessarily.

That being said, if something doesn't seem wrong, something still might be. Holmes Hobbies deals exclusively in performance aftermarket parts. We recommend certain motors and setups for various general situations, but nothing is absolute. When you install a performance part, you MUST test thoroughly to ensure it will operate within its operative ratings according to your specific rig, driving style, and driving conditions. We love this stuff, and we're not trying to be jerks, but these aren't replacement parts, they are performance upgrades, and you must do the work to tune and test your rig. Read through the articles here on the Holmes Blog, and if you have further questions, contact us and we'll do our best to advise you and help you get set up.

We stand by our products. We'll say it twice: we stand by our products. We are a very small company that absolutely depends on the quality of our products and the satisfaction of our customers. If you have trouble, please look through our troubleshooting FAQs, or contact us if you cant find the information you need. We know, maybe better than most, how frustrating it can be to get a brand new part that is going to change your RC life, and suddenly have it all go wrong. This happens, and it isn't fun. Sometimes it's a learning experience, sometimes it's a bad part. Talk to us. Yes, this is our business, how we make our money, but we really do want everyone out there crawling and bashing their way around the world. It's really effing fun. We want you to have fun.

My Brushed Motor Doesn't Run Like it Used to

Yep. It will happen with every one of them.

Brushed motors wear by design. If you have an immediate issue, something else might being going on, and you can contact us and let us know, but the same basic checks will apply, so take a look. There are three basic failure points for a brushed motor in otherwise good condition (meaning not smashed by a hammer or run for ten hours at 120v).


This is the first check every time. There is no such thing as "normal" wear times on brushes. It all depends on how you run the motor, how you drive, and how you take care of it. Racers are used to changing their brushes every five or ten minutes. Super slow crawling guys might run a set for hours on end. Brushes are perishable parts. Keep a few sets around.

Standard Holmes Hobbies motors run our Soft Copper Standup (or Laydown, in some cases) brushes. They are a lovely mix of efficiency and durability.

Nominally, their length is 10mm when new, and should be replaced at half that length, or 5mm. Yes, there is more material there,  but take a look at the channel in which they run, after that point, they start to "fall in," a condition where the brush is no longer held perpendicular to the commutator. In this situation, the brushes no longer make full contact with the comm, and, as the same pressure is applied to the brushes but over a smaller area, wear on the comm increases greatly. This can be very costly, and is the most common issue with brushed motor performance--also potentially expensive. A set of brushes from us runs $7, generic brushes run $3-10. A new armature (which you will need when you destroy your comm) is at minimum $20. Keep an eye on your brushes, and keep spare sets on hand.

Also, check the brush leashes. They can get caught on the brush hood or other parts of your rig and prohibit the brushes from progressing into the brush channel, and thereby limiting or stopping the brush contact with the commutator. This will totally stop a motor in extreme situations, or cause intermittent motor stoppages in more common situations.

Brushes are depleted constantly, and are therefore always "clean.". Don't clean them. Don't try to resurface them unless you know what you are doing. They do this work automatically by the nature of the brushed motors. If they are very discolored, blackened, scalded, or rough and broken, something else is wrong with the motor, or you got some crazy debris in there that tore things up. Keep looking.


The commutator is that segmented copper thing that rotates between your brushes. Those segments are critical. There are two things you want to check for, the condition of the copper segment surfaces, and debris buildup in the grooves between segments.

For the surfaces, you will see some darkening in normal use. The overall surface should look flat from top to bottom, even with the darkening or tarnishing from normal use. As the comm wears, you will see occlusions (looks like gouging) on one or both edges of each segment. This is also normal, as material is removed from the arcing that occurs as brushes make and break contact between segments. Once this gouging is noticeable, it is time for a comm cut (lathe).

Buildup between the segments (in the grooves between the copper pieces) can cause various motor troubles. It is pretty common, especially in fast motors that eat up brushes quickly, or in motors with rapid or non-existent break-ins. If you like to dunk your rig, you might see this as well, as the moisture will hold that nasty junk in the groove. Pull the arm out, and run the back-end of a straight-edge through the grooves between segments to clear the debris, being careful not to slip and slice a groove in the comm surface.

If you have let the gouging get so far as to reach the substrate behind the actual copper, the arm needs to be replaced if you want full performance again. You can make such arms run... but they will never run "right."

Another thing to look at is the winding termination. For each segment, there is a tang which is wrap over (usually) a pair of copper wires. Small rocks or debris can make their way into the motor and break these little segments of wire, effectively shutting down the entire lobe.


The windings are the copper wires wrapped around the armature that rotates inside the motor. You can get a look at them through the vents in the motor face and can, and to a degree from the gaps in the endbell. If there is a snapped wire, the arm is dead. If the windings are blackened, the arm has overheated and burned up the wire coatings, and the arm is dead (though, it may still run, an even run well sometimes, but it is just a matter of time till failure). Take a look at our article about gearing if the arm has burned up.

Is it REALLY the Motor?

Any motor will only run as well as its controller, and its controller will only run as well as its power and signal sources. All of these will only run as good as their connections. If your motor is new or in generally good condition, and you are experiencing performance issues, first double check your connections (soldering points, connectors, wires).

Next, verify your controller. Yank the motor and put a multimeter set to 20v or 50v across the ESC outputs. At neutral, you should see nothing. At full forward throttle, you should see something very close to you battery voltage (or a percentage of that if you have set your ESC to a lower full-throttle output). Reverse might damage some multimeters, so to test reverse, only if neautral registers zero volts, reverse your multimeter contacts and push reverse.

If your ESC test shows no power output, double check you have your RX connectors installed in the correct direction, and you have a good calibration on your ESC. If you have an issue with the ESC calibration, take a look at our calibration video or instructions. If you aren't sure on the wiring, take a look at our general wiring article.

My Motor Puffed Smoke/Caught Fire

Number One: STOP RUNNING THE MOTOR. Figure out what's wrong before you keep beating it up.

No fun. First, make sure it was your motor and not your ESC or another component in your rig. We expect smoke from the motor, but it isn't always obvious where the smoke actually came from.

Carefully look over everything. If you motor smoked, usually the windings will be blackened and/or the comm will be a mess. We carefully check our motors before shipping to our customers, so if this happened right away, take a look at your gearing, and check for binding in the drive train.

My Motor Needs a Push to Start

This is a very common condition of worn motors, but check for the following:

  • Burned windings.
  • "Hanging Brushes" -- either the brush leases hanging on something, or damage to the brushes channels is preventing smooth brush advance toward the comm.
  • Too short or broken brushes.
  • Buildup between comm segments -- channels between comm segments must be clean, use a straight edge to clear any debris.
  • Broken winding at comm termination -- wire from the arm loops over the tangs at the comm segments, and these can get snapped if something nasty pops into the endbell structure. Once snapped, it's all over for the armature. Push on the looped wire softly with a finger nail to check for breaks. Luckily, this is uncommon.
  • Broken internal winding - also a killer for the arm. Test resistance between each of the comm segments, there should be almost zero resistance between any two. If resistance is infinite, there is a break.

My Brushes Disappeared Super Fast

Fact of life for some, totally unexpected for others. Racers might blow through a set of brushes in five minutes. Snail-pace crawlers might run a set for months.

Brush life is dependent on many factors, the biggest being motor speed, motor condition, and average operating temperature. Fast motors (13t 3-slots) run through brushes left and right. Motor wear is cumulative, so the more you let your comm wear, the faster your brushes will wear. If you motor is hitting high temps all the time, everything will wear faster than normal. All things to consider.

My Motor is Sparking A Lot

Some arcing (sparking) is normal as the brushes break contact with the commutator segment during motor operation. Large sparks may be visible when you brake hard or reverse direction rapidly. If you suspect your motor is sparking more than it should be, take a look at the condition of your commutator, looking for grooving or pitting or a segment that has gotten hot and lifted up. Also check your brushes. Short brushes will cause greater arcing, so will brushes that aren't making good contact on the comm due to the brush leash getting caught on something, bad, broken or missing springs, or the brush channel getting bent up--anything preventing the brush from moving smoothly in and out of the hood.

My Brand New Motor Doesn't Respond At All

On a new motor, this will usually be an issue somewhere else in the setup. On a motor that was previously running fine, it still is most likely a problem somewhere else in the setup. First step is to make sure your motor is actually getting power when it should be. Disconnect your motor and put a multimeter set to 10-20VDC (be sure to put the positive meter probe on the lead that will have positive voltage from the ESC--some multimeters may get damaged testing voltage in reverse). At neutral, you should see next to no voltage. At full throttle you should see voltage very close to the voltage of your battery.

If the voltage is good, do the basic motor inspection outlined above, checking your brushes, commutator and general motor condition. Usually the issue will be pretty obvious, as even poorly setup motors will still try to run if they have the necessary parts in place.

My Motor Runs Backwards

Brushed DC motors are direct current affairs. If you install you motor and it runs backwards, you have several options. If your motor timing is at 0°, you can simply reverse the motor leads to get reverse operation. You can also rotate the endbell 180° to do the same, and this way, the color coding remains the same for convenience. If you are using timing advance, things are a little bit trickier (but not too much!). Checkout the article on Motor Timing.

My Motor Is Getting Crazy Hot

STOP RUNNING IT! Figure out what is going on, before you do more damage.

If a motor in otherwise good condition is overheating, it's time to look at your rig setup. Start with checking for binding in the drive train or parts rubbing somewhere if this issue just cropped up and hadn't been a problem before. Next, look at your gearing. If you aren't sure about what gearing is about, take a look at the article on gearing. While you investigate, think about your driving style, as well. If you are on the throttle up-hill on 4s all day, your needs are different than someone who is running 2s along gentle trails with a soft throttle finger. You need to adapt your rig to your driving style, or, perhaps, change your motor selection to something more suitable for the kind of driving you are doing.

If it's a motor you have been running a while, you might be in need of a rebuild or other parts replacement/refresh. Go through the basic trouble shooting above and see how you're doing.

Speed Controllers

Basic Troubleshooting Steps

If you are having an issue getting your ESC to do what you want or think it should do, start here to rule out basic setup troubles.

  • Double check installation, following the installation guide for your ESC.
  • Double check connectors
    • Ensure all connectors are clean and making good contact
    • Ensure all connectors are oriented in the correct direction (e.g. RX leads can often fit in two directions)
  • Check the condition of all wires
    • Look for obvious snapped wires or frayed insulation.
    • When in doubt, pull out a multimeter and check continuity
  • Verify the battery condition
    • A good quality battery tester is great, but at minimum, make sure the battery output voltage is where is should be.
  • Verify the motor condition
    • Worn, damaged, or failed motors may make you think the ESC has died or stopped working.
  • Re-flash your firmware via Castle Link
    • Flash an older version of the firmware, and then re-flash the most current version. This will ensure the programming is as it should be and all defaults are set. Default settings should be sufficient to run just about anything.

My ESC flashes all lights and does nothing

An ESC flashing all lights (and beeping, if a motor is connected), indicates no RX signal. Double check that your RX leads are installed in the correct direction, RX is properly powered, and RX/TX binding.

My ESC drives my motor backwards

Either your motor is backwards, or your leads are swapped, or something along those lines.

Our Brushed ESC motor output leads are black and white. At default settings with forward throttle signal, the ESC will apply a positive voltage to the white wire.

Sensored brushless ESCs have three phase wires labeled A, B, and C. These MUST be connected to A, B, and C on your sensored brushless motor.

Sensorless brushless motors can have their rotation reversed by switching around the phase wires.

Brushless ESCs configured to run a brushed motor are a little different, so check the installation instructions for the ESC.

I can't calibrate my ESC

To get into calibration mode the easy way (though you might need three hands) apply full throttle BEFORE plugging in the ESC to the battery. You will hear a musical chime (you will only hear the chimes if a motor is connected) to indicate you have entered calibration mode. Keep holding full throttle until the ESC chimes again and begins flashing a red light with a beep. This indicates the ESC has stored forward throttle and is awaiting full reverse. Give full reverse throttle. The ESC will chime again to indicate it has stored reverse throttle, and will start beeping again, this time with no lights, indicating it is awaiting neutral. Give the ESC neutral throttle. The ESC will chime when it has stored neutral, and then several seconds later, it will chime again indicating it is armed and ready for use. Drive away!

If you are still having trouble:

  • Can't store forward throttle:
    • Some TX/RX setups use reversed throttle channels by default, so consult the documentation for your setup. If the ESC doesn't get what it thinks is a valid signal, it will not let you proceed with calibration.
    • If your End Point Adjustments are outside the range acceptable to the ESC, it may just read these as bad signal inputs and continue waiting. Try holding something slightly less than full throttle; if it takes it, this is probably the issue.
  • Can't store reverse throttle:
    • Same checks as above, but for reverse
  • Can't store neutral throttle:
    • Just about every TX should have a neutral trim (though what it is called by the manufacturer might be surprising). If the current neutral trim setting is out of range, the ESC will still see either forward or reverse throttle, and continue to wait.

ESC goes out when I turn, or cuts out randomly when I'm driving

This is most commonly an RX brown out, and not an ESC issue technically. Brown outs occur when the system draw creates a voltage drop at the RX, which temporaily looses connection or shuts off. Once voltages get back to normal, things will start working again like they did.

First, double check connections everywhere. Rigs bounce and vibrate a lot, something may have gotten loose.

If you have a servo of any decent strength, and it is not powered by an external BEC, you'll most likely need to install an external BEC to clear this up. If you do have an external BEC, you might want to check it's condition (they do go out over time).

If you have lots of auxiliary equipment on your rig, you may want to use additional BECs or separate batteries to keep voltage levels where they need to be across different devices.

Intermittent operation can also occur if the battery condition is poor, or if the LiPo Cutoff settings are aggressive. Make sure your battery is good. Usually the Auto setting for LiPo cutoff is fine, but you can tweak it for the purposes of trouble shooting.

My brand new ESC just went up in smoke/caught fire

10:1 the battery leads were installed backwards. Bad units happen, too, but infantile failures for ESCs are usually less dramatic.

If the ESC smoked during normal driving, and had been performing normally up to that point, you might be pushing the limits of the ESC. Holmes ESCs are rated for high continuous amp draw and voltage, but high voltage, plus fast motors, plus aggressive driving can equal extremely high current draw, which can cause damage.