UDI RC repair

Since my previous post https://pmetro.wordpress.com/2017/02/05/the-flying-computer what direction would be next? Since there are a overabundance of drones on the market,  many do not get that great of reviews, or over simplify the ease of flying and have a short flight time due to the size of the battery especially at the lower end price points. Some reviewers simply state that there is a lot of junk out there. If you are not experienced and want to join the ranks of drone operators, note recommendations and reviews of current high end drone operators with experience as to what drone they flew as a starter either as a racer or photographer, in other words what is cost effective for multiple  crashes.

Technology has progressed the drone into basically two types, at the higher end of the consumer market, racing or photography. As with other types of electronics smaller lighter and faster can be the general rule to racing drones and photography, (could also be branched out to heavy lifting) stability, reliability and stunning high definition cameras on remote control gimbals  have captured the market. The new announcements releases from leading drone manufacturers to drone operators is the same furor as  the latest smartphone presentation. Prices are reasonable as with every advance there is more technology for the price. This is a growth area with the application of different technology ever expanding.

Drones have given the radio controlled hobby market a kick in the pants. Certainly a few manufacturers have taken the lead and it reminds me of other breakout tech companies when a market first explodes, such as personal computers and cell phones. Some will be shaken out and others will consolidate. The amount of technology applications involved run from remote telemetry, autonomous control, GPS, vision and remote recognition as just a few before even getting into the array of sensors utilized to give the drones stable flight. Racers have not been left out , first person view, cameras and FPV vision goggles make these people look like Borg wanna be’s. Lipo battery technology give racers crazy amounts of power and brushless motor technology constantly boost the top speeds of these racing demons.

So instead of another complete kit, as of yet, after perusing the many hobby sites and quad copter forums, a new drone was out of the question, and trying to keep the cost low would limit me to an unreliable toy for learning flight. Now many of the online hobby shops  carry repair parts with some low cost consumer drone hobby models having practically all of the parts available to build one from the ground up, this is true with racing drones as they can be built in stages but would add up to a high cost , there would be an alternative to  gaining flight practice and  knowledge.     I decided a repair/modification of a drone would be the best route to become familiar with the types of technology being utilized. So off to the junkyard so to speak in search of a decent learner drone needing to be rescued. (Many first time drone buyers simply trying out the hobby crash and burn so to speak, so postings from Ebay on drones for parts etc. gave some promising results)

 

Note: If you want to repair drones look up replacement parts beforehand,  many models are supported either through the original manufacturer or third party sources, ALi Express, Banggood, Ebay, drone forums Etc. Much information can be obtained from hobby sites , you tube videos, online user manuals.

Lets get to it so we can fly….

 

From the drone bone yard, a UDI RC salvage from E-bay. Model 818A.

Basically bought from E-bay used, listed as one rotor not turning. After arrival and check,  one of the propellers is binding . After further checking the motor is the cause.

Ordered replacement motor and also a remote transmitter control  along with spare propellers as the control transmitter  was not included in the purchase this is another factor since many low priced drones have of their own proprietary remote transmitter. (more on this later)

Previously I had removed the canopy cover and propeller guard, a one piece snap off unit and unplugged the connections to the flight controller. Take pictures of the connections or draw up in a note pad a schematic before disassembly or research pin outs for the motor connections and LEDs of the flight controller board. (google etc.)

To disassemble the faulty propulsion unit , remove screw and disconnect strut from the main chassis. On the strut, carefully pry back the motor cover, slide it back and expose the motor. Remove necessary screws and draw enough wire from the strut to access the soldered connection to the motor. The other pair of wires is for the LED on that pod.

Compare the replacement component with the original, the gear is slightly different from the original. Note: The motors ( these are brushed motors) are highly magnetic keep them a distance from any magnetic sensitive material, keep work area clean from metal particles that would stick to the motor. (especially if you work on brushless out runner motors in the future) Also if you work with circuit boards, most all videos and instructions disregard the use of anti static precautions such as wrist grounding ground straps. Electronic Static Discharge can happen and disrupt sensitive electronics and cause a myriad of undetectable problems from total failure to loss or scrambling of data. If you have problems with circuit boards arriving DOA don’t discard that ESD may be the cause of failure. If you work with large amount of electronics or expensive components ESD precautions is cheap insurance. Once you open up the cover (like a cell phone) you have penetrated any shielding to sensitive devices and components.

Utilizing the insulation tubing from original, cut the conductors and solder in the replacement motor, of course following the original wired colored connections. Slip the insulation tubing over one of the soldered connections.

 

Carefully route the wires by gently pulling the through the strut from the opposite end, toward the flight controller. Double check the connection of the fragile wiring before securing motor cover.

secure cover of assembled unit. (bearing below propeller should be flush to top of strut, in this case the propeller shaft is a press fit to lower gear, align as necessary)

 

Make the PROPER  motor and LED and camera if equipped, connection the the main board of previously disconnected. Improper motor connection order will result in a flipping over or uncontrollable drone taking flight. (How do I know this?) Also if the flight controller board was removed from the chassis insure that the proper orientation of the board is followed, most aftermarket boards are marked with an arrow to indicate front (facing) of drone. Not this one. Accelerometers and gyroscopes have to know which way the are headed ! (in relation to the propulsion units). Troubleshooting skills here learned  for flight problems!

One note here: be extremely careful when pulling delicate connections from sockets, some manufacturers use a sealing or locktite type glue. Small connectors such as 2 conductors plugs, grasp the connector , not the wires to disengage. Some sockets  are surface mount soldered and could be pulled directly from the circuit board necessitating a re soldering of socket to the main board.  If plug does not disconnect readily, be aware and proceed cautiously.

At this point (with propellers removed) you could attach battery, pair up the transmitter  and test the motors.

 REMOVE PROPELLERS BEFORE TESTING

 REMOVE PROPELLERS BEFORE TESTING

Rotors should be removed when you power up drone after modification, some unexpected reactions at times will cause the flight controller to start all propellers when battery is connected, due to an improper wiring or damaged flight controller. Assume that motors may start at any time. Again remove propellers.

Checking connection and LEDS, so far the drone is looking good, battery connection resulted in proper lighting and (not shown) blinking led on flight controller)

Secure cowling by snapping on cover/propeller guard. Mount LED headlight (white single LED). Power down and follow manufacturers direction for pairing transmitter, calibration and flight.

Most all drones have a user manual that can be found online. Some might have different conventions on flight controller and transmitter synchronizing  (pairing).

Progressing up the ladder on Radio Control it’s advantageous to get a transmitter that will support multiple Quadcopters, but this comes at a cost and matching transmitter and receivers  to flight controllers is a later lesson. Most of the low cost hobby drones require each their own radio control transmitter  system. When buying drones less a transmitter (control) research if you can buy a reasonable required replacement transmitter as they more than not will  not work with any other type for drone. Or you could swap out the flight controller with one that you already have a properly matched receiver (and/or flight controller) and transmitter using the frame and motors of the drone you are repairing.

**********************************************************

Will it fly ?  Yes ,I was lucky as the motor was the only problem with the drone.

The firmware of the flight controller was undamaged, there is no USB or software available to re-flash the flight controller as in the case of the MultiWii.

The UDI RC with the propeller shroud can take many crashes and collisions without damage. It’s a good learner drone. I have yet to test the camera out.

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The UDI drone has flown many times and is a learning challenge to pilot just around the house. The propellers are protected by the cover/shroud so they only get slightly chipped in my flights. It’s not ultra stable per say, but after some trimming of the controller pitch, roll, and yaw, easy to get to flight with the limited room indoors available to fly. Probably replacement of all 4 motors and prop balancing would improve stability. A good flyer none the less and time to move on to other repairs and construction. Several high capacity 1s batteries were purchased for increased flight time.

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

So could I have bought a complete  used drone instead of a damaged one? Probably so, but missing a education experience and satisfaction of repair, disassembly, motor wiring and how the drone is constructed. Modifiable? Snap off the cover and ditch the camera for weight savings, disconnect the LEDS for power savings, go with slightly larger or smaller props  and  beef up the battery with a higher capacity replacement. Add an FPV camera ? Maybe a trick out paint job or more LEDS?

Drone :  $9.99 Ebay

Controller : $16.65 Ali Express

Motor: $5.31 Ali Express

optional replacement propellers: $2.88 Ali Express

shipping for the drone was about $10.00

shipping for the propellers $2.04

other items shipped free

NEXT : Can a Propel Spyder XL (chromed) be returned to flight status ?

the flying computer

Working with open source programming on the hobby level presents it’s own set of problems for the first time user. Setup of hardware and software on some projects assumes not only that the user has basic skills in hardware setup but also programming.

The Sunfounder quadrocopter kit , consist of a microcomputer and hardware not unlike other microcomputer projects with sensors and software. The supplied documentation in book form with the kit  also assumes that the user has the skills and the proper hardware to connect the processor to a computer.  Even before starting programming or modifying the parameters, the correct drivers must be installed for the USB to serial  connections to the microprocessor. The reason for connecting this device to a computer is for calibration and verification that the proper firmware is running on the controller.

Software and documentation for open sourced programming can be fragmented, that is, different developments or versions for the software components can be found on different sources, posted on web pages, FTPs or forums. Since open source programming can be dynamic in the fact it could be either revised to a newer version from what was originally  issued on one website, or loaded on the hardware, it could also be a stalled project, that receives no additional support. Therefore more than one version may be available and as with all revisions, it’s hoped that the latest revision may still be compatible with the current hardware project but remember that it’s  an collaborative project and while some sites ask for a donation, it’s a passion of programmers to share, comment and revise their efforts available for a global audience usually for free.

Having some experience with programming over the years being mostly with the higher level languages, usually it was with one platform and hardware, now utilizing either a windows or mac environment is not foolproof as each may  have it’s own version of software, hardware  and procedures . Even command line processing and writing assumes that files are placed to follow in the correct directory paths in both execution and installation. Error messages may be cryptic at times. But such is the state of collaborative programming today as one might be inclined to write an app for sale , and BASIC still exists in many forms, open source is the current program exchange and with the online internet connections the process is much faster than the shareware years ago where programming was distributed physically on floppy disks. . One of the most popular types of programming microprocessors is the Arduino   https://en.wikipedia.org/wiki/Arduino, but don’t stop there, many, many,  other microprocessors and systems are available.   There is also  a ton of programming courses and kits online  so education can be done anywhere, for free.

The main reason for the flying computer (quadrocopter) was for education and to familiarize myself with one the current micro processing platforms  to gain experience with hardware interface and programming. A drone would be a good example of  programming with tangible results, in this case flight of a miniature aircraft. The popularity of drones both by hobbyist and commercial uses abounds. It’s  a quest to understand how they actually fly. The prices run the gamut of range and the Sunfounder is the lower entry range of projects for an open source environment that includes all items needed to program, assemble, and fly. Some of the components could also be used if the person would be interested in building other flying devices.

Having an   Arduino editor installed on your computer and  having the knowledge to open, edit and compile and save  the code, it gets  uploaded  to the flight controller. ( a fancy name for a microprocessor decked out with the supporting chips to run several motors).  Basically your are changing the supplied code by commenting out code you don’t need for your flight controller. The code file is written for many different types of flight controllers and hardware configurations. The Arduino editor is a simple version of a text editor, and I’m going to have to learn the language sooner or later  and more reading to familiarize myself with the syntax. For the first time user it’s build able without programming experience, but that’s not the end result I was looking for, as you know once the system is up and running the user can modify the code and actively see the results. There certainly is a wide variety of subjects to learn. Microcomputers, sensors, GPS, flight dynamics, radio controls, motor controls, electronics speed controllers, propeller pitch Etc. Years ago anyone wanting to break into the field of radio control planes was hampered by cost.

the flight controller

flight controller

Notes:

At first my computer didn’t connect and recognize  the USB serial cable to the flight controller board, it didn’t load the USB drivers correctly right away. Finally after restart it showed in the device manager that the driver was installed. This may utilize port settings as necessary. Sometimes Windows will try to look up and install a driver when first connected. Use the USB driver supplied in the download. Again the proper USB to serial driver must be on your base computer connected to flight controller. (DUH)

USB to microcomputer (flight controller) serial interface board

The GUI multiwiiconf.exe didn’t work correctly first try, it seems that JAVA had some files misplaced. It was necessary to copy files to correct directory. Researched on the web for correct procedure. involved both the program/java/ and java/program/ directories. (this is common with open sourced projects, so gain experience with forum setups, Q and A’s  and searches to find answers to your particular problems.) Also the GUI Multiwii, different from the text editor version , isn’t well documented as I tied to change some of the values, by typing , it was a matter of using the cursor and sliding small boxes under the values to modify them if necessary.

also some compatibility issues with the type of platform, 64 vs 32 bit for the miltiwiiconfig.exe. Didn’t run consistently on all occasions.

The GUI runs but at this time didn’t properly show the flight controller parameters yet most likely I have a port setting incorrect.

The 32 bit windows version now works fairly well , some times after starting  the GUI several times the program may hang, and going to the Task manager and stopping multiple occurrences of Java running.

This is a learning experience for a first time user trial and error processor with frequent searches on the web for solutions.

There also may be updates and revisions to the programs to download

Finally the Multiwii GUI runs and read the data from the flight controller , the calibration of the accelerometer can be accomplished.

Next. the receiver is connected to the flight controller and the transmitter is activated, and the receiver is synced to the transmitter, now the data from the movement of the remote controller can be read by the GUI.

assembly of the frame and motors.

After the completion of the assembly, the battery can be connected and the drone is ready for flight. After several attempts, the battery life is very limited, the drone was unable to fly. More diagnostics are needed, the power to each of the 4 motors is not balanced and will not propel the multi copter to level flight.

closeup of the flying computer !

After loading a different version of the Multiwii and some tweaking, the drone was able to liftoff and I found out more aggressive thrust is needed to launch the drone , several flights upwards could be accomplished by holding the drone and launching it midair but flight control is a problem as it’s more difficult at first to control the direction and height of flight. ( also the drone is operated indoors, and is fast, a very large room would be better.) OUTSIDE? No,  there are restrictions on drones and it would be advisable to read and understand the safety rules and regulations for flying one. (airports are  one restriction)

a bare bones build, less the supplied LED board (lights), for flight testing, charging the battery.

More study and tweaking  of the software is needed for more stable flights.

All in all the Sunfounder is a complete entry level kit, all parts you need are contained in the kit including  a 4 channel transmitter (remote control). It provides a challenge for the first time microcomputer programmer and an introduction into radio control flying.

https://www.sunfounder.com/drone/multirotors/6d-box/sunfounder-6d-box-mwc-multiwii-drone-quadcopter-diy-starter-kit-for-arduino-with-2-4ghz-rc-6-axis-gyro.html

Light it up!

Taking a break from recipes, now a little tech, lighting in the kitchen area was due for a makeover.

Energy efficiency is being touted and the current lights consist of a ceiling fan light fixture, not always used, two can lights placed over the counters, one to the left of the sink and one to the left of the stove. ( The hood over the stove already has a LED bulb installed ,an A19 style) and a florescent fixture over the sink.

Over the years I tinkered with the can fixtures, incandescent , then compact fluorescent, and then back to incandescent. The sockets and bulbs were never really aligned with the reflectors and uneven light patterns and glare were the result. As slow as I move on a project, replacement cans (4) were first ordered with an additional 2 for placement over the dining area table to supplement the pendant light fixture over the table. (That pendant hanging fixture already has a LED bulb installed in it.) Months later, the bulbs were ordered.

Usually with can light fixtures, trim kits have to be bought along with the fixtures. The LED replacement modules are all that’s required, no trim kit is necessary. They are expensive compared to incandescent bulbs, but the LED’s consume around 12 watts each for 800 lumens of soft white at 2700k and have a long life.
The new cans are 6 inches diameter compared to the existing 5 inch fixtures in the kitchen , so the cut outs had to be enlarged. No big problem, a hole saw for a drill was out of the question, too expensive for just drilling 4 bores. A reciprocating saw would be used, and I found out the a fine tooth metal blade worked better than one for wood. Also the ceiling is not all that thick. Plaster and sheet rock construction.

The can light replacement and the LED module.

One requirement of the LED modules, is to gut out the fixture of any brackets that hold the socket.

Ceiling cutout to the enlarged from the existing fixture that has been removed. Paper template is supplied with the fixture.

You have to install a romex clamp on the connection box, not supplied. The fixtures also have push on connectors, no wire nuts are necessary.

Thickness of ceiling requiring cut. Oh! I’m supposed to mention that the power is off before you begin working.

The wired fixture ready to be installed in the ceiling.

The installed fixture and LED module.
Documentation:

LEDs sourced from Amazon.com

Can light housings sourced from Home Depot.

The spring clips are a lot harder to engage than pictured, a small mallet may help and also pre-bending them may help, also as noted on the instructions, self tapping sheet metal screws may be used on the clips.

Two fixtures installed in the dining area .

New bores were required in the dining area, small holes were first  drilled along the perimeter of the diameter of the opening needed to prevent the ceiling from cracking when cutting with the reciprocating saw and finished with a course rasp,  checking in the attic space first for proper placement between the joist, also a line (electrical) fished down (time consuming) to the existing dining room light dimmer for power. An additional dimmer is planned to be added for the new fixtures.
Now the kitchen and dining area are very well lit, is is not a harsh type of light as with one of the LED flood light type bulb in the back hall. One other advantage other than the obvious energy savings is that it will be many years till they require changing. More A19 LEDs will be replacing incandescent bulbs in the future. The most used fixtures are being done first.

one note ;if you are considering installing new additional fixtures and deciding on placement, wire one of the can fixtures to a cheater cord with the led installed and onto a extension cord (safely). Plug it in and hold the fixture close to the ceiling in the desired location and have someone check the spread of the light pattern to see if it meets their requirement. Less work than patching holes.

apple- America-and-a-squeezed-middle-class

This is mostly a food blog , but sometimes a tech article I read on-line sparks my attention.

and now the news from the current political elections is un-escapable for the most part

 How U.S. Lost Out on IPhone Work

NY Times, Business Day ,The Economy

By CHARLES DUHIGG and KEITH BRADSHER

Published: January 21, 2012

my comments:

Asia is the leader of large scale manufacturing. This

article focuses on the electronics industry.

notes:

“Companies once felt an obligation to support American

workers, even when it wasn’t the best financial choice,”

said Betsey Stevenson, the chief economist at the Labor

Department until last September. “That’s disappeared.

Profits and efficiency have trumped generosity.”

(a)this was creating jobs for the sake of creating jobs.

 

    "…a current Apple executive said. “We don’t have an

obligation to solve America’s problems. Our only

obligation is making the best product possible.”
(b)this is  focusing on making a product, not influenced by political distractions

…

    "For technology companies, the cost of labor is

minimal compared with the expense of buying parts and

managing supply chains that bring together components

and services from hundreds of companies. For Mr. Cook,

the focus on Asia “came down to two things,” said one

former high-ranking Apple executive. Factories in Asia

“can scale up and down faster” and “Asian supply chains

have surpassed what’s in the U.S.” The result is that

“we can’t compete at this point,” the executive said. "

    "Another critical advantage for Apple was that China

provided engineers at a scale the United States could

not match. Apple’s executives had estimated that about

8,700 industrial engineers were needed to oversee and

guide the 200,000 assembly-line workers eventually

involved in manufacturing iPhones. The company’s

analysts had forecast it would take as long as nine

months to find that many qualified engineers in the

United States. In China, it took 15 days. "
(c)Other countries are set up demographically and geographically to make efficient use of manufacturing

supply chains and labor for mass production in shorter time spans. They have the resources and control

mastered.

 

Other governments support and motivate a national pride towards production and manufacturing versus individual

financial gain (very debatable) and have the qualified work force ready.   Some governments are better at a

growing a service economy.

It seems that Asia is the only place to build fast moving (changing technology) products in great numbers at a price that makes

them affordable.

What does that leave us, the U.S. ? In the technical field; programming? software development?

So here is a follow up question , if you will: Multiple choice, no correct answer(s) at this time

What is the United States better suited at producing?
What ones will grow or shrink or remain the same?
(a) legal professionals
(b) Doctors
(c) political parties/ politicians
(d) health care systems
(e) financial/credit systems
(f) welfare systems
(g) an up to date infrastructure
(h) discourse
(i) non-profit organizations and exemptions(too many to list)
(j) Research and development
(k) Political Action Committees
(l) an affordable education system
(m) a chaotic tax code (AKA red tape)
(n) regulations
(o) benefit packages
(n) small businesses/manufacturing
(p) artistic expression
(q) agriculture
(r) defense/law enforcement

(s) computer programming/servicing/software development

add your own

I’m  poking fun at the USA, this is who we are. A diverse culture. Asia has it’s problems too, and no telling where they will be after 15-20 years.

No doubt though that hobbies should be encouraged as they were in past. They are the first step in education of the trades.

Have they been displaced by dismissing them as nonsense as they have no social redeeming value? Personally speaking, a home with out a work bench is not a home.

Toyota headlamps

Both headlamps were installed and fit the vehicle. The details follows for a 1993 Camry.

Plastic headlamps (and other vehicle lamps) are a problem as they age, they get cloudy, and have moisture problems and UV  exposure make them brittle and prone to cracking and breaking. There are many remedies available that claim to restore the the lenses but they can be expensive and the lens cleaning may not last. If you provide the labor, installing new replacements is the best way to go.

Here is some advice when dealing with an aged vehicle, there are a few things that you should consider: ( I did not have a repair manual available)

Before even staring the job, unpack and check the new replacement  headlamps to make sure they are the correct replacements and see how they  mount. Beforehand, check how the headlamps are attached to the vehicle, what type of hardware is used and what size  and type of wrenches/tools will be needed. The vehicle may have been worked on before and when replacing exterior hardware, such as headlamps, the fit may be difficult or mixed or improper mounting hardware may have been used. On an aged vehicle rust can be a problem, the day beforehand it is recommended that penetrant (WD40 or liquid wrench) be applied to the places where the headlamps are bolted in. Before replacement, insure that the headlamps are properly functioning ,electrical problems should be corrected before replacement. Get an idea of how they are aimed, there are various methods to check alignment. Check the connectors and wiring harness for damage, oxidation, fraying etc. The headlamps that I purchased included the bulbs, so it would be a simple matter of plugging in the electrical connections. Some mounting hardware (bolts, screws) may snap or the heads of screws strip or rust out. Have a drill with small bits available to drill them out. You can re-tap the holes if you have proper taps, either metric or SAE and have the correct replacement hardware, or nut and bolt the drilled out mounting location. Plug in the headlamp electrical connections first and test them, then finish bolting them in place. Alignment varies with the type of headlamp there are usually two axis  of adjustment. Other note, If the gas struts that hold the hood up are worn, prop up the hood, in this case I used the grille that had to be removed for the headlights to be replaced!

Old lamps

New Replacements

Now, my wife is satisfied with the results, she can see much better at night. Next will be replacement of the front side maker lamps (Toyota) and the headlights on the Topaz .

removing HEAT

Refrigerators don’t make things cold ! They remove heat. Heat transfer, energy transfer.
We take for granted the fridge until maybe the light bulb inside burns out or the ice cream doesn’t get as hard as it used to or the milk (or beer) doesn’t get cold enough.
This is a basic two door (side by side) fridge with out the bells and whistles , Ice maker, water dispensers etc.
Refrigeration depends on removing the heat from inside and venting it to the exterior of the fridge.
Most rely on proper air circulation both inside and outside to work effectively and efficiently .
Keeping the condenser coils, those located some where outside the box, clean promotes proper energy transfer.
Older fridges had the condenser coils on the back and simply gave off heat. Now they are usually at the bottom and air circulated over them by a fan.
It is recommended that these coils be cleaned often.

in this case remove the grill as the manufacturer recommends.

with a vacuum and a crevice tool, clean the coils

while your under there, remove and clean the drip pan.

When the fridge goes through the defrost cycle the melting ice has to go somewhere !

If you never clean it, it may cause odors, the water that collects in it normally evaporates, you don’t have to empty it periodically.

You can remove the back cover and clean the compressor, fan and coils of dust buildup that traps in heat if you desire. CAUTION ! some of these components may be hot and of course unplug the fridge before cleaning. Note any copper tubing that is touching another surface or rubs against another tube, over time this could wear due to vibration, cause noise, and or refrigerant loss. Isolate.

A look at the evaporator coils in the freezer, cover removed. It’s not necessary to clean these. This fridge relys on a fan to circulate air over the coils removing heat and ducting it from the freezer to the fridge side for cooling.

With simple periodic cleaning, you fridge will always keep your cool !

Replacing the Motor brushes Kitchen Aid K45

The 20 + year old Kitchen Aid mixer occasional sputtered and then would not start without manually rotating the flat beater usually indicating a bad armature or brushes. fortunately the motor brushes are easily serviced. Unplug the mixer, unscrew the brush caps (one on each side) and carefully withdraw the spring-loaded brushes. Carbon brushes are not expensive and were obtained online from Goodmans. Brushes are $5.98 a set (2), and a replacement for a worn flat beater was $12.99. One important point when replacing the brushes is to note that they are not rectangular but have a diagonal edge on one side. The end of the brush holder, internally, not seen, is slightly crimped on the edge to correspond with the diagonal side of the brush. Simply speaking, note the positioning of the old brushes when they are removed and align the new brushes the same way. The other problem encountered is that the brushes must be able to slide into the holders with little or no effort. The springs will press them into contact with the armature and they must be free to slide into place. One brush on mine stuck and had to be sanded slightly to insure contact with the armature. I also have had the mixer apart to clean the armature contacts, and years ago to grease and replace a stripped gear from most likely overloading attachments, most parts are still available and diagrams downloadable/ printable for assembly/disassembly. So this crucial piece of equipment mixes on.

the old and new motor brushes