Tech Support & FAQ

When using single phase 115 volts AC input power, the grinder’s VFD controller will limit the actual output of the 2hp motor to 1.5 horsepower. This is ample for most people and is the most common configuration. Supplying single phase 230 volts AC power to the grinder’s VFD controller will allow the 2 hp motor to realize its full 2hp output. Running the 2 hp belt grinder on 230 volts requires less electrical current (fewer amps) than running on 115 volts.

To change the belt grinder from 115 volts to 230 volts input, first disconnect all electrical power. Inside the KBAC-27D VFD controller clam shell case, move the jumper J1 from 115 volts to 230 volts. Remove the 115-volt power cord. Install a 230-volt power cord with the proper plug end for the 230 volt electrical outlet. Beaumont offers a heavy duty 230-volt power cord with a NEMA 6-20 three prong plug.

• Heavy Duty Power Cord for 115-volt Usage
• Heavy Duty Power Cord for 230-volt Usage

The power of a grinder’s electric motor is determined by the voltage multiplied by the current drawn, so powering with twice the voltage means using half the current.

115 volts – this is the most common and popular voltage because it is easiest to access. Typical household and workshop power outlets are designed for 115 volts in North America. One downside to using 115 volts is that any given power output requires twice the current level (amps) which would be used at 230 volts. This generates more heat and strains the workshop wiring and motor compared to 230 volts, and can lead to more nuisance tripping of circuit breakers. Another downside to 115 volts is that in variable speed models, a 2 hp motor is limited or governed by the VFD controller to produce a maximum of 1.5 horsepower. This is because the VFD controller limits the amount of current available to the electric grinder motor.

230 volts – At this higher input voltage, the grinder’s electric motor will pull half the current in amps for any given power level compared to 115 volts. Lower current levels means less heat and less strain on the workshop and motor wiring, with fewer, if any, nuisance trips of circuit breakers. One downside of is that outlets and breaker boxes may not be configured for 230 volts usage, and professional electrician may be required to provide the wiring.

120 volts is the standard AC voltage delivered on a single hot wire in a home with respect to neutral (or ground) in the United States and Canada. With normal resistance of internal household and shop wiring, the 120 volts may drop to 115 volts at the outlet powering your 2×72 belt grinder or other shop equipment. At the end of long wiring runs the available voltage may even drop to 110 volts. Many tools, appliances and devices will be rated to operate at 110 volts or 115 volts, indicating they are designed to operate at these lower voltages. Single speed NEMA-rated motors supplied with KMG 2×72 belt grinders with nameplate voltage of 115 volts can accept voltages which are + / – 10% of 115 volts, which means allowable input voltages can be anywhere from 104 volts to 126 volts AC. Variable speed KMG disc grinders and 2×72 belt grinders which are set for 115-volt input power can receive + / – 15% of the 115 volts input to the VFD controller, which means allowable input voltages can be anywhere from 98 volts to 132 volts AC.

In the US and Canada, 240 volts is the standard AC voltage supplied to homes, and this is split into its two halves to provide 120 volts to typical household electrical outlets. Electrical resistance in wiring reduces voltage, with greater distances or wire creating greater voltage drops. Voltage levels drop from the electric utility transformer to a house’s main electrical panel, and drop again from the panel to electrical outlets. The 240 volts from the electrical utility may become 230 volts after the panel and may even go as low as 220 volts in equipment which is a long run from the panel.

Variable speed KMG 2×72 belt grinders with 2hp or 3hp motors, when properly set for 230-volt operation, accept power to the VFD controller which is 230 volts plus or minus 15%. This means the 230-volt belt grinder’s single phase input power has an allowable range from 195 volts to 264 volts.

Voltage mismatch may be the culprit and can be easily checked and remedied as follows. Variable speed grinders have a three-phase motors with speed controlled by a variable frequency drive (VFD). The 3-phase motors usually are dual voltage motors, which means they can be run at either 230 volts (low voltage) or 460 volts (high voltage). The VFD delivers 230 volt power to the motor. If the motor is wired for 460 volts when it is receiving only 230 volts, it will appear to run properly but it will have only a fraction of its power. It will be easy to bog down a grinder operating with this type of miswired motor, because the motor is receiving a voltage much lower than its configuration requires.
Check the motor plate for wiring instructions at low voltage (230 volt), and make certain the motor’s wires in its wiring box correspond to this setting. For example, NEMA 2hp and 3hp motors made by Leeson and others, the proper 230 volt motor wiring will have (a) T4, T5, T6 joined together, (b) phase power line 1 joined with T1 and T7, (c) phase power line 2 joined with T2 and T8, and (d) phase power line 3 joined with T3 and T9.

Additionally, you should check the jumper J2 setting inside the VFD. KBAC drives have four settings for jumper J2, and the proper one is the one which matches the horsepower rating of the motor. For example, if you have a 2hp motor and a KBAC-27D drive, the proper jumper J2 setting is the top setting “A”. If the jumper J2 is incorrectly in “B”, the VFD treats the motor as if it is smaller than it is and limits the power available to it for operation.

Statement of Warranty – Beaumont Metal Works

If you have a variable speed grinder controlled by a VFD there are two wiring problems that can be considered. First, one or more of the wires can be loose in the motor connection box. Second, a variable speed motor can be wired incorrectly. For a 2hp or 3hp variable speed motor with VFD controller, the NEMA 56 frame motor should be wired for LOW VOLTAGE as shown on the motor plate. This is true whether the VFD is powered by single phase 115 volts or single phase 230 volts power. For it to be properly wired, the connections are as follows: This means that the red wire is connected to T1, T7; the white wire is connected to T2,T8; the black wire is connected to T3, T9; the yellow wires T4, T5, T6 are connected together; and the green ground wire is connected to the ground screw in the base of the motor connection box. Other combinations can produce a motor which seems to operate properly but actually generates limited power.

A variable speed belt grinder controlled by a VFD may have internal configuration issues which can be addressed to improve power and responsiveness. Check that jumper J2 is set to match the horsepower rating of your motor. If the jumper J2 is set to an incorrect position, the motor will not perform properly and will deliver much less power than required. For the KBAC-27D VFD jumper J2 position “A”, the top position, corresponds to 2 hp motors, while position “B” is for 1.5hp motors. For the KBAC-29 jumper J2 position “A”, the top position, corresponds to 3 hp motors, while position “B” is for 2 horsepower motors. Here is a table with motor selection settings for the internal KBAC VFD jumper J2:

If your motor has been operated in a very hot environment, it can lose significant performance or stop working completely. Standard NEMA frame 56 / 56C / 56H motors which are used in belt grinders have a maximum ambient temperature ceiling of 40 degrees Celsius / 104 degrees Fahrenheit. This means is these motors are used in locations which are hotter than this ceiling for any length of time the motor will begin to break down. Motors operated in hot environments, without ventilation or with significant amounts of grit and debris can experience overheating, significant power degradation and ultimately failure.

If you have a pulley-driven belt grinder such as the classic KMG, inspect the drive belt for looseness or excessive wear. Using a classic KMG belt grinder, grind hard at the flat platen until it bogs down and stalls. While the grinder is stalling, check to see if the motor is still turning, which indicates a loose drive belt. These motors have a built-in circuit breaker that will trip if you overload the motor long enough. If you are not tripping circuit breakers, then you are not working the motor to full power…another indication that the drive belt might be slipping. If the belt is not slipping tighten the pulley on the motor. You can also adjust the distance between the motor and the chassis by moving the motor on the subplate. The motor feet have slots for the mounting screws, which can be installed in three (3) different sets of tapped holes in the aluminum subplate for change of position and drive belt tensioning.

Beaumont’s classic KMG belt grinder is powerful difficult to bog down, slow down or stop. If you don’t have enough grinding power, here are 5 common areas to investigate.

How “proud” is the steel platen plate on the flat platen attachment?

Extending the flat platen beyond the tangent line of its two 2×2 idler wheels is often recommended by experts so that workpiece contact with the abrasive belt is immediately and continuously supported by the steel platen plate. However, significant extensions of the steel platen plate can present an extra amount of heavy load to the grinder. We would recommend any extension of the platen plate to be about 1/16th of an inch and no more than approximately 1/8 inch beyond the tangent line of the 2×2 idler wheels. Significant protrusion beyond this amount of “proud” will not normally be the sole cause of any ability to slow down, bog down, or otherwise stop the ability of the grinder to move the abrasive belt. Excessive extension of the steel platen plate can present an additional load which combines with other factors to cause the problems we are trying to ameliorate.

If you remove the abrasive belt, can you turn the KMG grinder wheels smoothly and freely by hand?

We expect the idler wheels and the tracking/tension wheels to move very freely and smoothly when turned by hand. The drive wheel at the back of the grinder should also move smoothly and easily when turned by hand, and it will have a heavier feel to its rotation because it is connected to the motor via the drive belt. Rotating the wheels by hand is a quick method to discover if there is any unusual sticking, crunching or binding which presents an unusual load for the motor to overcome.

When the abrasive belt bogs down or slows down from active grinding pressure, is the motor shaft moving at a different speed? Is there significant slippage in the drive belt?

We need to know if the bogging down and slowing down is experienced only on the abrasive belt / KMG drive wheel, or also at the motor shaft. If the motor shaft is still moving properly, it may simply be drive belt slippage.

If the drive belt which connects the motor shaft to the KMG belt grinder drive shaft is worn or loose, there could be significant slippage. Old belts which have become worn or deformed can exhibit sufficient slipping, and thus fail to transmit power from the motor to the KMG belt grinder drive shaft and abrasive belt. Replacing worn or deformed drive belts may address this problem.

Newer drive belts and machines which have been recently assembled may have too much slack in the drive belt. Move the motor slightly away from the drive shaft to increase the tension in the drive belt and improve. The motor position can be adjusted on its subplate. A tighter drive belt between the pulleys has greater ability to transmit power from the motor to the KMG drive shaft. Drive belt tension is measured by deflection, which is how far the drive belt moves when pushing down on the belt at the center point between the motor shaft and the KMG drive shaft.

Optimal deflection is approximately 1/8 to 1/4 of an inch when pressing with 3 pounds of pressure. Of course, the belt also needs to be just loose enough to enable manual movement of the drive belt across all three of the 3-speed positions. If there is no slippage when grinding and when bogging down, too much slack in the drive belt is not a significant contributor to the problem.

Is the wiring inside the wiring box of the motor properly connected?

When the motor runs but does not deliver as much torque and power as expected, it is possible that it is miswired. One example of this is when a dual-voltage motor is wired for high voltage but is provided with low voltage. Other types of mis-wiring can also result in a motor which appears to run properly, but actually produces only a fraction of the power and torque which is expected.

Attached is a switch connection diagram which shows the proper wiring for a single phase 2HP motor receiving 230 volts single phase power. Disconnect the motor from electric power sources, and confirm that the motor is 2HP and is wired as expected.

Is the motor receiving the proper voltage?

When a motor receives a lower voltage than recommended, it may run but it will not perform as strongly as expected. If you have voltmeter and the knowledge to safely measure voltages, check voltage levels both at the outlet where the machine is plugged and at the motor wiring box itself. If the single phase motor is properly wired for 230 volts input power, the measurements should read between 210 volts and 250 volts. If the single phase motor is properly wired for 115 volts input power, the measurements should read between 108 volts and 126 volts. Voltage drops at the motor can result in significantly decreased motor performance and/or significantly increased motor heating.

The Beaumont Horizontal Disc Grinder has a 9-inch disc and a 1 hp motor. It comes mounted on a ½ inch thick plate which is 15 inches x 10 inches. We call this the Horizontal Disc Grinder because the motor shaft and axis of rotation is horizontal and parallel to the floor. When the optional work rest is attached the operating envelope of the Horizontal Disc Grinder is larger than the 15×10 base as shown in the image below.

See the image below of the Beaumont vertical disc grinder with 9 inch disc. The aluminum disc is 9 inches in diameter and the entire unit is approximately 10 inches in width including the edge of the motor wiring box. Mounted on the edge of a workbench, the motor extends 14 inches below the work bench, while the top of the VFD controller extends 14 inches above the work bench. The plate which forms the core of the vertical disc grinder is approximately 15- ½ inches ling and 8 inches wide. The vertical disc grinder is contained in an envelope which is 28 inches tall, 10 inches wide, and 18 inches deep.

A glass platen is a flat platen that has a layer of ceramic glass installed on its steel platen plate. There are two main reasons why many bladesmiths choose glass platens. First, glass platens will resist wear such as grooving, gouging and pocketing better than a steel platen plate alone. Second, ceramic glass platens enable grinding operations to stay cooler for longer compared to steel platen plates alone.

Glass-ceramic has good hardness together with a microstructure grain composition that makes it much more wear-resistant than steel and hardened steel. This makes the glass last longer than steel in grinding work, while generating far less friction. Less friction means less heat. Additionally, glass ceramics have lower thermal conductivity than steel, so they are absorbing and radiating less heat than steel.

Static electricity build up is a problem when using glass platens on a belt grinder. Most importantly, extreme caution should be used when working with a glass platen because if the glass comes loose during grinding or experiences a significant shock it will explode into many, many sharp dangerous shards.

• See Glass Platen

Here are some troubleshooting and re-application tips for the glass ceramic platen which might help:

1. The ceramic glass needs to be completely supported by the epoxy on its entire bottom surface. Even a small area without consistent support of the epoxy is a potential break. This includes even small air bubbles or voids. During application it helps to be able to press down gently but firmly and squeeze out any air pockets, perhaps even move the glass in a tiny circular or angular motion parallel to the steel plate. Work out any and all voids and air bubbles while the epoxy is in its very early thick liquid state.

2. The ceramic glass needs to be no longer than the underlying steel platen plate. For the KMG 2×72 belt grinders, we sell the 2″ x 8″ long glass and our Beaumont KMG steel platen plates are typically 2″ x 8.05″ – 8.125″ . If you find the glass is overhanging the steel platen there is an increased chance of breakage from the abrasive belt pulling that overhang down like a lever with the edge of the steel platen acting like a fulcrum. That is a recipe for a break in the glass ceramic near that end.

3. The ceramic glass needs to be aligned in the center of the steel plate. It needs to lined up so that none of it hangs over the steel plate. Similar to item 2 above, this is important to avoid any overhang edges which are potential sites for breakage. This is most important on the 2 inch wide ends, and less important on the 8″ long sides, but it all matters.

4. Apply light clamping or no clamping of the ceramic glass after proper positioning, during epoxy curing on the steel for the 2×72 belt grinder. Some people are convinced that very gentle clamping is important, but only minimally enough to control for inadvertent movement, nothing more. Other people are convinced that clamping should NOT be done at all, because some of us tend to clamp a little tightly, and a strong clamp will flex the glass slightly while the epoxy cures. If there is flex in the glass from a clamp during epoxy setting and curing, when first using the glass platen the induced flex will act like an invisible void, and it will break immediately. If you are clamping, keep it gentle and consistent across the surface.

5. After installation and before use, adjust the ceramic glass platen surface so it is exactly even with or slightly proud to the tangents of the 2×2 idler wheels on the platen attachment. A glass platen which is too proud, and sticks out much more than 1/16th of an inch (some would say 1/8th inch is okay) increase the strain on the glass end as the abrasive belt goes over it. The abrasive belt is “pulling” down the edge of the glass and will increase stresses which ultimately find any weak spots from air pockets / voids or weak spots from induced flex of a strong clamp. Generally speaking, the platen plate with glass attached needs to be recessed into the platen attachment enough to compensate for the 0.19 inch thickness of the glass plus the thickness of the epoxy. On the Beaumont platen attachment, this means using the 3/8-16 nuts to tighten / loosen the depth adjustment for proper repositioning.

6. To remove the ceramic glass from its steel plate base, carefully heat the back of steel base with a gas torch. The JB Weld epoxy can withstand temperatures of up to around 550 degrees Fahrenheit. Heat the steel backing plate which holds the epoxy evenly and gently, making sure that you do not warp it, and you should not heat it much beyond 500 – 600 degrees Fahrenheit. As the steel heats and transfers its heat to the JB Weld epoxy, the epoxy begins to soften and break down, and you will be able to carefully slide the glass off the epoxy. As with the installation and use, be extremely careful because the glass can break with dangerous shards. A putty knife can be used to scrape off every bit of the failed epoxy in chunks from the steel plate. After the epoxy has been removed, allow the steel to cool down. Then it can be cleaned with an emory cloth as in our video, or it can be cleaned with an abrasive on a suitable hard, flat surface or even a flat grinder. Final cleaning steps would include either acetone as in our video, or rubbing alcohol, before starting the re-application of a new piece of ceramic glass.

• See Glass Platen

Under normal operation the Power light on the VFD controller will be a solid green when the grinder is powered, and its on/off switch is both working and in the “On” position. Before the motor is engaged by pushing the three position Start/Run/Stop switch UP into the Start position, the Status LED light will be a solid green. Once the Start/Run/Stop switch is pushed up to Start and springs back into the center Run position, the Status LED light will slowly blink green while the motor is moving under normal operation.

Here is a table of the status lights from the VFD controller.

The flat disc is the most popular option on the Beaumont 9 inch disc grinder, both as a vertical disc grinder and as a horizontal disc grinder. Disc grinders are great ways to achieve precision flats 90 degree grinds on smaller pieces such a handle components, locks, spacers and blades, so flat discs are the natural default. Flat discs also provide a flat plane for easy of application of adhesive abrasives with minimal unwanted air bubble or wrinkles. Flat discs are expected as a default on disc grinders. Beaumont’s beveled discs have a slight bevel which drops about 1 degree off center, which means that the beveled disc’s outer edge is approximately 1/8th of an inch beneath or behind the disc center. Thus beveled discs held you avoid the accidental upward grind when your workpiece reaches across the center of the disc . The disc bevel is also flat enough to enable proper application of adhesive abrasives onto the aluminum disc.

The Surface Grinder Attachment uses powerful neodymium permanent magnets. Neodymium magnets are sensitive to working temperature and will begin to lose their magnetic strength at working temperatures of 75 degrees Celsius (167 degrees Fahrenheit) and higher. Demagnetization will happen rapidly at higher temperatures and at longer exposures to high temperatures. We recommend replacing the magnets if they have experienced temperatures above 75° Celsius or 167° Fahrenheit.

• Magnets for surface Grinder Attachment

Asking about appropriate bench top height is a great question. So much of the bench height depends on the operator and the intended usage. In our shop, we use a KMG-TX belt grinder on a heavy wheeled table that has a base which is 27″ off the ground, which puts the center of the flat platen roughly 41″ off the ground using top tool bay in vertical mode and about 45″ in horizontal mode. We find this a good place for grinding in the shop above the waist, close to a “belly level” when standing for most of us. It is comfortable and easy to use for our purposes, which involves some quick finishing, chamfering, deburring and rounding of steel parts.

We sometimes operate the grinder on our assembly tables which have a base height of about 33 inches off the ground. This is probably closer to a “typical” bench height which is usually 33-34 inches. On our 33″ tables, the KMG-TX has a top tool bay which would center a flat platen or wheel around 47″ and the lower tool arm bay would be about 45″. For reference, if you have a classic KMG, the tool bay on the KMG classic would produce a flat platen / contact wheel center which is about 40″ high on the 33″ base table. If you have built habits and skills around using a classic KMG belt grinder on a particular bench, they will be most easily transferred to the KMG-TX operating vertically on a bench which is approximately 6 -7 inches shorter.

While we believe that most of our customers stand while working with one of our grinders, we also know many who set them up for sitting exclusively while grinding. So much of this depends on how you choose to work.

TX envelope: TX vertical orientation, the center of the platen is at 14″ to the base plate. In horizontal orientation, TX is 18″ to the base plate.

In vertical operating mode with a flat platen, excluding the VFD and any work rest, the KMG-TX fits within a cube measuring 14” wide, 27” tall, and 29” deep. With a 10” wheel attached this KMG-TX configuration is 14” wide, 27” tall and 30” deep.

In horizontal operating mode with a flat platen, excluding the VFD and any work rest, the KMG-TX fits within a cube measuring 20” wide, 20” tall, and 29” deep. With a 10” wheel attached this KMG-TX configuration is 20” wide, 20” tall, and 30” deep.

The VFD controller installed on Beaumont’s KB bracket is 8” wide, 13” tall and 8” deep.

KMG-TX base is 8 wide x and 13

Classic Direct Drive Envelope :
KMG variable speed 2HP with 6” direct drive wheel and flat platen installed on 18” tool arm:
Height top to base 16”
Width left to right 15”
Length front to back 29”

The classic pulley driven configurations, both 3-speed and variable speed , sit on top of a 19″ x 19″ sub plate.

The KMG-TX base plate itself is 12.6 x 8 inches, 3/8 inch thick, and has a hole in each of its corners for secure mounting to the workbench. Each of these base plate holes is 0.385 inches in diameter. As seen in the unboxing and setup video on our website for the KMG-TX, we secure the KMG-TX to a base sheet of thick plywood using these holes and 3/8-16 bolts. The base plate holes are 7.25 inches apart on center from side to side, and 11.866 inches apart from front to back.
Here is a picture of the mounting holes on the base of the KMG-TX.

The motor control mechanism is a variable frequency drive (VFD) controller. We make a steel bracket we call a KB Bracket which holds the drive vertically on (or below) the workbench. This KB bracket has two (2) holes in its base, each of which are 0.323 inches in diameter and are 3.0 inches apart on center. These are suitable for mounting using 5/16-18 bolts or screws. The KB bracket is 1/4 inch thick steel. The weight of the KMG-TX with its motor attached is approximately 125 pounds.

The black locking levers are also known as adjustable handles or clamping handles. To tighten or loosen the clamping handle it must be all the way down in its control position at the base of its center axis. It will either have an audible click, or a tactile click, or it will be visibly closest to its threaded post when it is in the proper position for tightening and loosening.
To rotate the black locking lever into a better angle for clearance or handling, pull the handle at the base of its center axis away from the threaded post. When it is away from its threaded post it will rotate about the post / center axis without engagement.

• Here is a link to an Instagram post showing the locking lever: https://www.instagram.com/reel/CqvHr2WgXe6/?igshid=YmMyMTA2M2Y=
• Black Locking Lever

The black locking levers are also known as clamping handles or adjustable handles. Beaumont uses these locking levers to tighten and hold tooling arms or other equipment such as the Adjustable Work Rest in the desired position for grinder operation. Lift the handle to rotate freely, then release the handle to engage and tighten or loosen.
If the locking lever is not securing the equipment adequately, visually inspect the base of the handle where it meets its threaded post. That base must contact the clamping surface when tightened in order to hold properly. If it is blocked by the position of the equipment or other material such as paint or debris, it will not hold completely. Reposition the equipment or remove the blocking material to regain full holding power of the locking lever. If there is a gap between the base of the handle and the clamping surface, check the threaded hole to ensure that it is tapped completely through. Short tapping depth will prevent the locking lever from engaging deeply enough for a proper hold.

If it is difficult to properly tighten the adjustable handle there are other possibilities. A steel tool arm with a clamping vise in its end is more difficult to tighten than an aluminum tool arm with a clamping vise in its end. Beaumont Metal Works makes steel and aluminum clamping tool arms. If the base of the locking lever handle is contacting an aluminum clamping surface directly, friction between the handle base and the aluminum sometimes makes further tightening difficult. To address this, simply install a flat washer between the base of the handle and the clamping surface. Equipment such as Beaumont’s Articulating Work Rest comes with aluminum clamping links, black locking levers and grade 8 flat washers.

• Black Locking Lever
• Articulating Work Rest

The Surface Grinder Attachment for the KMG, KMG-TX and other 2×72 belt grinders is a manually powered attachment which holds a workpiece magnetically in place against a moving abrasive belt supported by a contact wheel. The Surface Grinder Attachment is useful for flattening or thinning steel.

Here are optional methods which may help you improve the finish surface:

1. Use an emory bar, flat grinding stone or other hard abrasive tool to sand and flatten the bump of the 2×72 abrasive belt where it is fused together. This seam in the 72 inch abrasive belt is usually much thicker than the rest of the belt. This belt bump or belt seam will be performing nearly all the grinding unless it is sanded down because it is initially the first and only part of the abrasive belt which is grinding on the work piece. By grinding this seam flat, the rest of the belt will be more engaged in the grinding operation, resulting in more consistent, smoother operation and results.
2. Install a uniformly worn, previously used belt on the 2×72 for applicable surface grinding operations. A good used belt which has been uniformly worn has already had the excess thickness or bump at its fused seam abraded down to match more closely the thickness of the entirety of the abrasive belt. Using a belt which is more uniform in thickness over the entirety of its surface area will result on more consistent, smoother, finishes on the work piece.
3. Use progressively higher grit belts. As the abrasive grit has finer grains with higher grit numbers, the backing the 2×72 abrasive belt can also become thinner and finer.
4. Make sure the arm supporting the Surface Grinder Attachment is tightly secured to the grinder so it does not move during operation.
5. In a tilting grinder such as the KMG-TX which operates ither vertically or horizontally, make sure the tilting mechanism is both locked in place and tightened in place to reduce unwanted movement from the adjustable chassis. On the KMG-TX- the tooth of the black index lock should be pointing into the pivot point of the chassis ad fully engaged in its receiver slot. Also, on the KMG-TX, the front black locking lever should be tightened in place on the half-circle pivot place to reduce and unwanted movements.
6. The black adjusting screw split nut for backlash control on the feed control axis of the surface grinder should be appropriately tightened. This black adjusting screw split nut on the threaded rod between the feed control knob and the magnetic chuck, near the inside of the feed control riser, can be tightened with a 5/32’ hex key or allen wrench. Tightening this black adjusting screw split nut will make it more difficult to turn the feed control knob, and simultaneously limit the backlash slippage inherent in a threaded feed system. Backlash is the ability of a screw-driven control system to experience movement between the surfaces of interacting threads. Tightening the black adjusting screw split nut will reduce the amount of backlash movement in the direction of the feed control.
7. Take successively smaller “bites” as you approach the completion of the surface grinding operations. Improved finishes are more likely as thinner and thinner layers of material are fed into the abrasive belt for grinding off.
8. Move the chuck across the active grinding very slowly and steadily to improve the surface finish.

• Finishing 8×3 Contact Wheel
• Surface Grinder Attachment
• Tri-Helix Contact Wheel

When you type in your credit card information for an online purchase, the website payment system communicates with your bank through a card network such as Mastercard or Visa to ask permission to withdraw the purchase amount from your account. Your bank then decides whether to approve the transaction based on your available funds or credit and the likelihood that the transaction is fraudulent. The system responds almost immediately if the transaction is approved or rejected. If approved, your bank puts a hold on the funds until they are sent to us to complete the purchase.

If the purchase was rejected, it could be from a data input error, such as when the name, address or credit numbers were entered incorrectly or otherwise failed to match the bank’s records. Reentering the data properly may fix the problem. Additionally, fraud protection software is designed to reject attempted transaction which have been entered incorrectly multiple times. Sometimes this simply requires waiting a day before completing the purchase by entering the correct data. Finally, the bank which issued the credit may have other holds on the account for security or purchase volume purposes, or there may be insufficient funds available to complete the desired purchase. In this case, it is best to contact your bank which issued you the credit card to ask them to remove a security hold and authorize the purchase. Then you should be able to complete the online purchase information on our website.

If the power light goes off, the electricity provided to the VFD controller is being interrupted. We would suggest starting at the electrical panel of your workshop and working towards the machine, looking for loose connections, damage or failures. Here are some places to consider in your investigation.

Inspect the circuit, looking for things such as a loose or very old circuit breaker in the wall panel.

Inspect the outlet, looking for signs such as a worn out receptacle that has a faulty ability to hold the plug, or some damage or failure which has loosened or blocked the internal wire connections.

Inspect any other connected used between the power cord of the grinder and he wall outlet. We have seen failures in connections such as power strips which inadvertently failure or trip on/off.

Inspect the power cord itself. Bent or loose prongs on the plug, damaged or exposed conductors along its cable length could be locations of interrupted electricity flow or present other dangerous conditions.

Inspect the on/off switch in the VFD controller. It is possible that this switch is the faulty connection. Look for burns, cracks or loose connections at the switch body and wires. It is possible to carefully bypass the on/off switch with the proper jumper setup. If bypassing the switch solves the problem, it is necessary to install a new replacement switch, which is available at Beaumont Metal Works.

Motors draw more current during startup and at varying loads and speeds.
A circuit and circuit breaker should provide at least 125% of the Full Load Amps, rounded up to the nearest multiple of 5 breaker size. For typical 56H NEMA 2 HP single phase motors, full load amperes is about 9 amps, and its circuit and circuit breaker fuse size is 9 * 1.25 = 11.25, rounded up to 15 amps. This 15 amps circuit fuse and capacity is the minimum we would suggest, and if you have the proper wiring for it and want to limit nuisance tripping, it may be prudent using a 20 amp circuit with a 20 amp breaker. For NEMA 56-frame 2hp single phase motors, 15 amps capacity with 15 amp circuit break is the recommended minimum.

For example, the Leeson 2 HP single phase 1725 RPM motor at 230 volts has name plate current listed at 9.2 amps, with a power factor (PF) of 0.86 and efficiency (EFF) of 0.82. The TechTop 2 HP single phase 1740 RPM motor at 230 volts has name plate current listed at 8.65 amps, with a power factor (PF) of 0.92 and efficiency (EFF) of 0.815. Both of these 56 frame NEMA single phase motors at 230 volts input power would be sized with a 15 amp circuit and 15 amp circuit breake fuse.

The most popular motor configuration for the KMG-TX is the 2hp wired for 115 volts. We run our in-shop KMG-TX for production work this way and use it every day.

Standard outlets are configured for 115volts. This lower voltage uses a higher current level, and the VFD will govern the motor to set a ceiling on its actual output at 1.5hp. This is more than ample for most people and most uses, even tool makers and knifemakers. Ordering a 2hp KMG-TX comes pre-wired for 115 volts input power as a standard from us.

However, if you have the ability, we would recommend getting the 2hp motor and running on 230 volt power. At purchase, add the 230v power cord, and send us a note or leave a comment on the website purchase screen to ask us to wire the grinder for 230 volts. We will install the 230 v power cord and set the internal jumper for 230 volt usage before shipping to you. The higher voltage (230v vs 115v) means the grinder requires half the electrical current flow – the system runs cooler and I think a little better with the lower current and the higher voltage.

The large majority of people go with the 2hp and standard 115v input and are very, very happy with it. If you go this way, you could always have the option to run this system on 230 v power at some point in the future by changing power cord/plug and internal J1 jumper. Same motor, same VFD will run either way.

We would love to get a KMG grinder in your shop!

Installing the steel platen plate a little bit “proud” to the line of the abrasive belt travel will improve the tendency of the abrasive belt to maintain contact with the entire surface of the flat platen plate.

One way to do this is to take a piece of plain paper that is 8-1/2 x 11 inches, and cut it in half along its vertical axis so that you have two pieces of paper, each about 4-1/4 x 11 inches. Each piece should be folded in half, then in half again, then in half a third time. This creates a stack of 8 layers of paper, with a thickness approximately 30-40 thousandths of an inch (0.030 – 0.040 inch). Loosen the four bolts of the platen assembly (two 1/4-20 on the steel plate PPL and two 3/16-18 on the L-brackets). Position the entire assembly upright so the platen plate face sits on a clean flat surface, and insert the folded paper underneath each 2x2wheel of the platen assembly. Make sure the platen plate face is touching and flush against the clean flat surface, while the wheels are flush against the folded paper which is on the same clean flat surface. This serves to raise the 2×2 wheels about .030 – 0.40 inch above the face of the platen. Align and tighten all four bolts. The face of the steel platen plate will be slightly proud and will extend about 0.030” – 0.040” beyond the outer surface of each 2×2 idler wheel. Extending the steel platen plate past the natural strait travel line of the abrasive belt increase the load on the motor a minor and negligible amount when the extension is not too significant. This improves the ability of the abrasive belt to remain in contact with the entirety of the platen plate face during operation.

Any of Beaumont’s KMG belt grinders would be suitable for mitering / joining / coping bicycle tubes. Basically combine one of our belt grinders with a Small Wheel attachment and the one or more small wheels which match the diameters you work with. Everything on our website is 20% off during our Winter Sale right now using coupon code GRINDKMG

Her are couple of options to look at, the premier KMG-TX and the more budget friendly (yet power and widely loved) classic KMG.
1. The KMG-TX with articulating work rest is our premier, professional belt grinder with attachments:

a. KMG-TX with Articulating Work Rest, variable speed 2hp motor, flat platen and 10 inch contact wheel. Go to the following link, select (Articulating Work rest w/arm), (no belt package), and (2hp Motor for 110v or 220v) https://beaumontmetalworks.com/product/kmg-tx/

b. Small Wheel Attachment to hold the small wheels: https://beaumontmetalworks.com/product/small-wheel-attachment-for-kmg/
c. Small Wheels should be selected the sizes which you need. Beaumont offers 10 different small wheel diameters, from 1/2 inch to 2 inches. Here is the link: https://beaumontmetalworks.com/product-category/small-wheels/

2. Our classic KMG is also professional grade and very heavy, and one of the most affordable ways to do this. Use a 3-speed KMG grinder to avoid the cost of the VFD and get the durability of the single phase motor and use the same attachments which work on any of our KMG grinders:

a. KMG belt grinder, 3-speed 1.5 hp motor plug into common household 115 volt single phase, with flat platen and simple work rest. (KMGPL-3SP-1.5) Go to the following link, and in the drop down menus select (3-speed 1.5hp motor), (4 inch drive wheel) and (Just the Platen Attachment): https://beaumontmetalworks.com/product/the-kmg-industrial-belt-grinder/

b. Small Wheel Attachment to hold the small wheels: https://beaumontmetalworks.com/product/small-wheel-attachment-for-kmg/
c. Small Wheels should be selected the sizes which you need. We offer 10 different small wheel diameters, from 1/2 inch to 2 inches. Here is the linke: https://beaumontmetalworks.com/product-category/small-wheels/
d. You would also want to add the Articulating Work rest with Classic KMG Universal Bracket / UM-Link to have the ability to adjust a work rest to the proper position for abrasive coping / joining. Here is the link: https://beaumontmetalworks.com/product/txartwrsys/

We have many customers who use our belt grinders for miter joining / coping / tube notching. One example would be Nash Motorcycles in California who uses a KMG-TX, with an articulating work rest, and a small wheel attachment with a variety of Beaumont small wheel sizes to match the tube diameters. They cope and join steel tubes for some of their custom equipment for Harley Davidson motorcycles using the KMG-TX belt grinder.

We also have a video on tube joining / coping using our KMG classic and our equipment on Beaumont’s YouTube channel at https://youtu.be/jy_guBBaUTU?si=JbWudeD5SMVZ0yXq