top of page

How To's and Diagrams

Unable to find any original printed information regarding mixer repair, we developed the following diagrams, instructions, and photos.  They were created for the use of our individual customers and are not to be reprinted or reproduced for distribution, without the written permission of the developer. 

It is our hope that you will find the following instructions helpful.  

We would appreciate hearing from you if they solve your problems.  

We would also like to learn your tricks or cures.

Diagrams, Schematics, and Instructional Pages for Models 40DM and 940


Included in this section:

Simple Wiring Diagram 

Instructions for Disassembling a 3 Head Mixer

Instructions for Changing Bearings  

Instructions for Replacing a Cup Switch with a Micro-Switch Kit

How to Diagnose a Brush Problem

Changing Brushes in a Three-Head

Removing a Condenser on Model 40


Diagrams,Schematics and Instructional Pages for Models 30, 930, 33, and 933


Included in this section:

Simple Wiring Diagram Models 30 and 33

Changing and/or Lubricating Bearings 

How to Fix a Sticky Two-speed Switch, Including Model 18

How to Diagnose a Brush Problem

Changing Brushes

Removing a Condenser On Model 30



Diagrams, Schematics and Instructional Pages for Model 18


Included in this section:

How to Separate a Model 18 Motor

Installing a New Enclosed Bearing

Disassembling a Three-head Hamilton Beach Malt Machine


These instructions will assume that you're starting from scratch and have never installed a micro-switch, bearings, brushes, etc.  These basic instructions will be good to assist you as you disassemble your mixer, as well as put it back together, by following the directions backwards. While you're inside you will have access to your bearings, brushes, and switches, so that you can also give your mixer a general cleaning.  If you run into problems, you can contact us and we will walk you through the job.

If this is all very new to you, we suggest taking pictures as you take the mixer apart, which you can refer to, when reassembling it. 


1. Remove the three black 3-speed knobs on top of the mixer.

2. In order to remove the top half of the head, unscrew the two long bolts on the underside of the head.  (The top half of the cover on your machine lifts off the chrome ring.  Sometimes it’s stuck with years of malt, grease, and dirt.  You may have to use your hand to tap the cover above the chrome ring).  Once it’s loose, lift off the top half of the head cover.  

3. Disconnect the three wires going to the manifold terminals, which are connected to the chrome ring.  Remove three hex nuts holding the 3-speed switches to the chrome ring, and push switches down and out of ring.    

4. Disconnect the line wire from the bottom of the manifold on the chrome ring.  Lift off ring and set aside.

5. Disconnect the odd wire that goes to the back of the 3-speed switch.  This odd wire comes up from the cup-activated switch at the bottom of the mixer.  Do this on all 3 motors.   The odd wire is opposite of the three wires that are on one side of the switch. 

NOTE:  Do not remove these three wires unless you are changing out a 3-speed switch.

6. Remove the 4 long screw bolts that hold each motor, then lift out each motor.  

NOTE:  When reassembling your mixer, you might want to change the position of the motors, as the center motor is usually the one that has been used the most.  The left motor generally has not been used as much, so you can shift it over to the far right or center position. 


NOTE: You can remove the lower part of the head by taking out the four allen screws. However, this is not necessary.   

BUT it’s almost impossible to get the switches out (see step 9) without removing the lower part of the head from the base. If you are doing restoration and other work on your mixer, you will need to remove the four allen screws.

7. Remove back mixer cover by removing  the six screws. This will give you access to your lower switches.

8. Disconnect the two main electrical leads.  A) The one that feeds the three lower cup switches, and B) The one that goes directly up to the bottom of the chrome ring manifold. 

9. Lower switches can now be removed by taking the screws out of the front cup holders. This will release the cup-activated switch inside the machine.


Malt Mixer Man - - 2023


Now that your mixer is apart, you can clean and lubricate the motors, check the wiring, replace the old cord with a good appliance replacement cord, and check and service all switches,  


You can refer to the documents posted on this page, "Changing out Bearings on Hamilton Beach Malt Machines" and "Replacing a Cup Switch With a Micro-Switch Kit" describing how to change bearings and replace switches with micro-switch kits.

Simple Wiring Diagram Model 40DM and 940


Changing out Bearings on Hamilton Beach Models 40DM and 940 Malt Machines


Follow the detailed "Disassembling a Three Head Mixer" instructions  on this page) and remove the motors from the mixer base.  

1.  After removing a motor from the base, unscrew the bolts on the clips on each side of the motor that hold the brushes.   

    The brush holders are black and stick out like ears from the motor.  Remove the brushes and springs from the holders.  

    Scratch numbers on the motors, (1, 2, and 3) which helps during reassembly and rotation of the motors.

2.  Remove the wire retainer ring from the top of the upper bearing, then take out the spring and washer. (Be careful that the spring doesn't get away from you!)

3.  Remove the 4 bolts from the top of the motor that separate the top and bottom halves of the mixer motor. (No need to disconnect the three speed switch from the coil.)

4.  Lift off the top half of the motor.

5.  Lift the coil and attached 3-speed switch up and off the armature.

6. Unscrew the mixing agitator from the end of the shaft. (Right hand threads, and this is much easier to accomplish with two pair of pliers than trying to use a screwdriver.)

7. Tap downward lightly on the slinger ring (The flat disc that sits about 1 inch above the mixing blade), as it is just pressed on.  Set it aside, as it will be reused on reassembly.


Here is where having a small hydraulic press is very helpful:

At this point the only thing that is keeping the armature from separating from the housing is the pressed on splash ring that sits just below the motor housing. (The ring will also be used during reassembly)


8.  Place the edges of the bottom half of the motor housing upside down on a couple of wooden blocks.  Be sure the shaft and shaft fan are centered and  not directly over one of the blocks.   Press down on the mixing blade end of the shaft.  This will free the bearings and shaft from the bottom housing and allow access for bearing removal.


NOTE:  The bearings on the older machines will be an open bearing and the newer machines have an enclosed bearing. Our replacement bearings are all enclosed.  It is very important before removing the old bearings to measure and mark their exact placement on the shaft to be able to place the new bearings in the same location. Too high or two low on the shaft will result in the brushes not running properly on the armature.


9. The bearings can either be pressed off with the press or be removed with a bearing puller at  this time.

10. Replace bearing and reassemble the motor in reverse order.



Replacing a Cup Switch With a Micro-Switch Kit  

The cup switches in these mixers were probably the weakest link in these heavy-duty mixers. Rather than trying to repair the internal mechanisms of malfunctioning cup switches, Hamilton Beach developed the micro-switch kit with which to replace the cup switches. Approximately 25 percent of the triple head mixers you see today will most likely have one or more of these micro-switch kits already installed. Our micro-switch kits, which are duplicates of the originals, come complete with pigtails and attaching screws for easy installation.


Fig 1

Before starting, refer to the detailed "Disassembling a Three-Head Mixer instructions" on this page.

It is impossible to install a micro switch without removing the old cup switch from the base.

To remove the inner working parts of the old switch: 

Locate the four rivets holding the mechanism. 

Using an oversize drill bit, remove only the outer heads of the rivets. CAUTION: Do NOT enlarge the holes holding the rivets, you will be using the frame later to hold the micro-switch kit.

Using a screwdriver, you can easily pop the headless rivets and the rest of the switch mechanism out of the frame.  


fig 2

My name is Alexa Young

Figure 2 shows the stripped switch frame after the internal mechanism has been removed.

The cup switch can be installed in the same manner in either the 40DM or the 940.


fig 3

My name is Alexa Young

Figure 3 shows an improvement to the switch installation that was made by one of our customers.  He suggested that a 5/16th inch hole be drilled in the top of the switch frame so that the wire going to the three-speed switch would not rub on the mechanism when the cup was inserted.


fig 4

My name is Alexa Young

Figure 4 shows the actual micro switch complete with pigtails, as it is packaged.  The white pigtail will be connected to the 3-speed switch at the top of the machine.  The black lead attaches to the power cord.  The kit also comes with two screws that go through the old rivet holes in the stripped frame 


fig 5

My name is Alexa Young

Figure 5 shows the micro-switch after installing it in the old frame. Remove the two loosely attached screws from the new holder. Place the micro-switch kit in the old frame and install the two screws through the rivet holes in the frame. Tighten screws down to the metal micro-switch holder. 

NOTE:  I would suggest that you adjust your switch at this time, rather than waiting until it is in the mixer.  

The adjusting bolt sits in a slot in the new holder. It must be situated so that the switch will activate when sliding the mixing cup up. Use the adjusting bolt on the micro-switch to secure it in the proper position. If one is available, use a continuity tester to achieve the proper placement of the switch. If not, slowly slide the movable part of the old frame up about 1/8th of an inch until you hear the micro-switch make a small click. If you don't hear the click, move the activator lever on the micro-switch either closer or farther away from the frame.  

Tighten down the two bolts on the micro-switch to keep the activator lever in the proper position.

How to Diagnose a Brush Problem  
As the general principles apply to all mixers, see "How to Diagnose a Brush Problem" under the Models 30, 33, 930, and 933 section below.


Changing Brushes in a Three-Head Mixer

1.  In order to locate and access the brushes, follow steps 1 and 2 of "Disassembling the Three-head Malt Machine" on this page.  2.  Locate the two black brush holders on the sides of each motor, as shown on the "Simple Wiring Diagram for a  Three-Head Mixer" on this page.

3.  Unscrew and remove the metal retaining clip to check condition of brushes and springs.  

4.  Replace brushes and proper springs if necessary.


 NOTE:  Most of the time the brushes are in fairly good shape in the left motor, as it frequently seems to have had less use.  The first motor to go is the center one, followed by the one on the right. Continued use without installing new brushes will often times result in damage to the armature by electricity arcing from springs to armature. Hand "jump-starting" a mixing shaft by giving it a spin after turning the motor on can cause serious damage to the armature. 

Removing a Condenser on a Three-head Model 40DM



My name is Alexa Young

Condensers were put on appliances in the 1940's and 50's to stop interference with radios and televisions while the appliances were operating.  The purpose of the condenser was to cut out the static created by the AC current, as it cycled back and forth. Left in the mixer, they will normally go bad after time and give you a small but scary shock when using the mixer.

Hamilton Beach stopped putting them on their machines in the late 1950's, as all appliances had filters to take care of the problem.

There are several different designs of condensers.  The picture to the left shows two which have been taken out of mixers. The round one to the left is normally the one you will find in the 40DM.

Remove the six screws holding the back cover on. If there is a condenser in the machine, you will see it immediately. It is attached to the metal tin triangle with a screw and nut. Clip the two wires where they join the on to the electrical cord. Throw away the condenser and replace the back.  

Simple Wiring Diagram and Exploded View Single Head Models 30 and 33 ​   ​

Changing or Lubricating Bearings in Single Head Models 30, 930, 33, and 933


If you have the motor separated, you have access to the top bearing.  Normally this bearing does not need to be changed, as it has very little side pressure. Check to see if it is dry, and if so, lubricate it with a light grease. If you run it and it still makes noise, you should change it out. You can remove it using a bearing puller.

You can access the bottom bearing to check and lubricate it by doing the following:


1.  Unscrew and remove the mixing blade from the end of the shaft.  This is easily accomplished by using two pairs of pliers, rather than using a screwdriver.

2.  Tap down on the slinger ring, the flat disk that sits about one inch above the mixing blade, as it is just pressed on.

3.  Unscrew the 3 screws from the inside of the bottom motor housing and remover the top housing ring. 

4. Unscrew the other 3 screws from the cover of the dust shield inside the bottom housing. This dust shield will come out with the shaft when the shaft is removed.


The only thing holding the armature from separating from the bottom housing now is the splash ring that sits directly against the lower housing on the outside.  The splash ring is pressed on, and the easy way to remove it is to press it off. (Using a bearing puller will usually do more harm than good.)  A small press is best, but if one is not available, a drill press will work most of the time.   


1.  Turn the bottom motor housing upside down and place the edges on a couple of wood blocks. Note: The armature is much wider than the shaft, so be sure to have the blocks far enough away from the shaft to allow the armature to come down without damaging it. 

2.  Press down on the end of the shaft and the ring will usually come off quite easily, freeing the armature from the housing.


It is very important before removing the two old bearings to measure and mark their exact placement on the shaft to be able to place the new bearings in the same location. Too high or too low on the shaft, and the brushes will not run in the right place on the armature.

How to Fix a Sticky Two-Speed Switch


The switch is usually not the culprit when the mixer does not work, but it usually gets the blame.  The only thing the switch controls is the two mixing speeds.  

Occasionally the two-speed switch will not change from hi to lo.  This is a common occurrence from using the same speed for too long a time, or from not using the mixer over long periods of time. You have to remember that some of these machines are more than eighty years old.

Models 18, 30, 930, 33, and 933 have two-speed switches.  Older models ran on only one speed.

Because of the location, these switches may have collected malt, dirt, and gunk in the internal mechanism, causing it to be stuck in one speed.   

The following will not always solve the problem, but in approximately 75 percent of the cases, this will take care of it.   In order to repair the switch:


After locating the switch on the top back of the mixer head, place a few drops of denatured alcohol or WD-40 around the toggle on the switch, so that it runs down inside the switch.

Vigorously work the toggle back and forth from high to low several times.  If it is still sticky, repeat with the alcohol or WD-40.  This will usually take care of the problem.  If not, you may have to replace the switch. 

Diagnosing a Brush Problem 

If the mixing shaft turns freely by hand and the mixer won't run or has no power, the first thing to look at is the brushes.

There can be other things wrong, such as the cord or switch, but 75% of the time the brushes are the problem.  They are very simple to check and change and the best insurance you can provide for your mixer.

NOTE:  If the mixing shaft does not turn easily, that usually indicates a dry or "frozen" bearing.  If that is the case, see "Changing and/or Lubricating Bearings" above.


There are three main problems that can occur with the brushes:


The first and most common problem is worn down brushes.  Normally, if a brush has only 1/8" remaining, it is time to replace them.  If they get much shorter than that, they can start arcing from the brush springs to the armature and cause serious problems. Changing brushes is not something that you have to do every year.  A new set of brushes is usually once-in -a- lifetime task for the homeowner and about 15 to 20 years for a shop.  It is not unusual to see mixers made in the 40's that still have the original brushes in them.


The second problem that you have to consider is weak springs.  It is important for the springs to maintain a constant pressure on the brush to keep it tight against the armature.  Some of these springs have been under pressure for more than 80 years and have lost a lot of their compression strength.  When changing brushes make sure to also replace the springs with the new proper springs.


The third problem that can occur, and usually the hardest to diagnose, is carbon build-up on the inside of the brass brush canal (brush holder).  This is the small brass rectangle liner inside the head that the brush and spring slide into.  Sometimes, if the brushes have been neglected and have almost worn down completely, or if the springs are weak, arcing can cause carbon build up inside of the canal near the armature.  If there is carbon build up, the brush will not slide in easily and will not put enough pressure on the armature.  This can usually be heard as a crackling noise, as the brushes cannot get past the carbon build-up and are arcing across the small gap.  The crackling noise is not to be confused with the small cracking noise that new brushes will usually make as they "run in".  This sound will go away after they conform to the diameter of the armature, which may have worn down over years of use.


These are problems that you will run into in about any make of malt mixer. In some of the different brands, one or more of the three problems will occur more often. For some unknown reason the Myers mixers tend to have the third problem much more than the first two. Hamilton Beach mixers seem to have problems one and two but rarely number three. 

How to Change Brushes 

If your mixer has no power, doesn't have much power, or seems to be losing power, it may be that it needs new brushes. Brushes are probably the most important part of a functioning malt mixer and one of the easiest to maintain.  To determine if the brushes need to be replaced, follow the steps below:


1. With the mixer unplugged, turn the mixer shaft by hand.  If it doesn't turn easily, that usually indicates that the bearings need lubrication.  Bad or dry bearings are usually not the case with a mixer that is being used all the time, as a mixer normally just makes more noise as the bearings become dry.  For help with lubricating or changing bearings, see "Changing or Lubricating Bearings" in another document on this page.

2. Brushes can be checked by unscrewing one of the black plastic button-like knobs (Brush Caps) located on the sides near the top of the mixer head.  CAREFULLY unscrew the brush cap, as the spring is under a little pressure and can fly out.  Attached to the end of the spring is a dark gray carbon "brush" that rides on the armature and makes the mixer run. When these carbon brushes get worn down and become too short, they do not put enough pressure on the armature to give good electrical contact, which results in the motor slowing down, or in some cases not running at all.  

3. If the black carbon brush at the end of the spring has less than 1/8 of an inch remaining, it is time to replace it, as well as the spring.  Replacing brushes is normally done once in the lifetime as they will last 30 to 40 years.

4. Attach the new brush to the end of a new spring, insert brush-end first into the mixer head and replace the brush cap.Care must be taken when replacing the brush cap, as it can break if you screw it in too tightly. Hand tightening is recommended and usually all that is necessary.   


Removing a Condenser From a Model 30

Condensers were put on appliances in the 1940's and 50's to stop interference with radios and televisions while the appliances were operating.  The condenser cut out the static created by the AC current, as it cycled back and forth. Left in the mixer, they will normally go bad after time and give you a small shock when using the mixer.

Thousands of these mixers have been thrown away because of the fear of them having major electrical problems.  

Hamilton Beach stopped putting them on their machines in the late 1950's.

There are two different designs of condensers. The picture to the left shows those which have been taken out of mixers. The round one at the bottom of the picture is normally the one you will find in the older Models 30.  After the mid-40's, the rectangular condenser is what you will find. The condensers measure about 2+ inches long and are easy to spot. Removing the condenser on a Model 30 is a little more complicated than on a Model 40DM.


My name is Alexa Young

Illustration 2 on the right shows a variation of the electrical connection 

in older models 30 and 33

diagram 3.jpeg

Removing a Condenser From a Model 30 - continued from above

The first step is to remove the motor from the base by removing the two bracket bolts.  

Disconnect the wiring between the motor and porcelain base.  There will be one of 2 different types of wiring, one will have two brass screws in the base.  The other will have the two wires connected with wire nuts. Refer to "Illustration 2" above.

Next, remove the brushes and springs from the motor.

Remove the two bolts on the bottom of the motor and separate the two motor halves.  Set the bottom half with the mixing shaft to the side.

Look in the top half of the motor to see if there is a condenser in it.  If it is present, there are three steps to remove it.

1.  Unscrew and remove the ring that holds the two-speed switch at the top of the motor.

2.  Reach into the center of the top half of the motor and push off the two spring-loaded C-clamps that are on the two brush holders.  

3.  Remove the two long hex bolts that hold the coil to the motor housing.  

This will allow the coil and two-speed switch to come part way out of the motor, while still being held in place by grounding screw(s) to the motor housing.  

Remove the screw(s) holding the grounding wire and the entire mechanism will come out of the housing. Clip or remove the two condenser wires where they make the connection to the two cord wires. 

The newer mixers will have wire nuts that connect the motor to the base, and the wires leading to the condenser will be at those connections.  Older mixers will have two brass strips on the motor.  Clip the condenser wires where they join the brass strips.  

Throw away the old condenser with wires and reassemble using the steps above in reverse order.  


NOTE: While apart, this is a good time to lubricate the mixer bearings.  There is a small gap where the shaft goes through the dust shield, just above the bottom bearing.  A little bit of spray white lithium grease around the shaft, where it goes through the dust shield, will normally lubricate the lower bearing sufficiently. A SMALL amount of white lithium grease applied to the top bearing will take care of it. The white lithium grease will penetrate like WD-40, but does not dry out, making it a better choice. 

How to Separate the Motor on a Model 18 



1. Remove the motor from the base by taking out the two large bolts on the back of the motor that hold the bracket to the base. Set the base aside.

2. Remove the brushes and springs. The small black brush caps on each side of the motor can be unscrewed with a small slot-headed screwdriver. There are springs behind the brush caps so carefully remove the caps, or the brushes and springs will fly out. 

3. Remove the top chrome cap on the motor. You should be able to twist it off by hand, but if not, use a piece of cloth and some channel locks.  

4.Under the top cap you will see a flat wafer-like cap that has to be unscrewed.  Use a pair of channel locks to unscrew the cap, being careful, as it holds a spring and there will be some pressure on the cap. Remove that spring.

5. After you have removed the spring, you will see 1 or 2 (one may have been lost) washers that are sitting on the bearing. The bottom washer should have an outer lip pointing up which has another washer with a dome top sitting inside the lip. The dome on this washer should be pointing up.  NOTE:  The dome must be pointing up when you put it back in. There are three parts to the bearing:  Inner race, ball race, and large outer race. The inner race is a piece that fits on the very top of the shaft.  It is a small piece about three-eights of in inch long. The ball race sits down onto the inner race. The outer race is a large ring that fits down around the ball race. 

6. Remove the two screws on the bottom of the motor head.

7. With your hands, work the top and bottom halves of the motor up and down.  Looking down into the top of the mixer where you just removed the top chrome cap and all of the washers, you will be able to see the outer race (large ring) of the bearing loosening and separating from the ball race.  It should separate and move up enough to allow you to get a small  screwdriver between the outer race and the ball race.  Move the screwdriver around gently, (it doesn't take any force) so that you can lift the outer race out of the cavity. After the outer race has been removed, the ball race will still be down on the inner race at the top of the shaft.  

8. Grasp the two halves of the motor and give them a sharp snap to pull them apart. The ball race will stay in the top of the bearing cavity as you pull the shaft down out of the top half of the motor.

9. Remove the ball race from the cavity. 


NOTE:  When reassembling the machine, be sure to place the ball race on the inner race in the cavity first, followed by the outer race.  If you put the outer race in first followed by the ball race, you will never be able to get the motor separated again without destroying the bearing. 

ALSO NOTE:  If the large outer race of the bearing was previously put on first under the ball race, it will be impossible to get the motor separated without ruining the ball race  The ball race will have to be pulled out with very small needle nosed pliers and a new bearing installed. As old original open bearings are no longer manufactured, a new enclosed bearing must be installed. Directions for installing a new enclosed bearing follow. 

Installing an Enclosed Bearing in a Model 18

1. Remove the ring holding the two-speed switch

2. Reach down inside and push the alligator clips off the brush holders

3. Remove the two bolts holding the coil in the top of the motor.  Lift out the coil along with the two-speed switch.

4. There will be a small drip/grease shield in the top of the motor. Remove the three small screwws holding the shield in place and discard the shield. It is necessary to remove the shield so that the new bearing can slide up into the bearing cavity.

5. Reverse the three steps above used to remove the coil, before putting the coil back up into the motor.

6. Before pressing the new bearing onto the shaft, you must remove the inner race of the old bearing that is still attached to the end of the shaft. The inner race is the small grooved piece about three-eights of an inch long, which can be removed using an adjustable bearing puller. 

7. Press the new bearing onto the shaft.  The top of the bearing should be flush with the top of the shaft.  

8. To reassemble, place the washer with with the lip; domed washer Domed Side Up; spring; screw-on cap; and the chrome top cap back on the mixer.  

bottom of page