Bench Grinder Variable Speed Control | Detail Guide

At present, owning a bench grinder variable speed control is a trend of the power tool enthusiasts’ community. It is the creation of the most up-to-date technology. But what is the use of owning this tool if people don’t know how to utilize it correctly?

I speak from experience. A few years ago, I bought a grinder to sharpen my chisels. It was not a variable speed bench grinder though.

Unfortunately, I continuously overheated the chisels and blamed the machine for it. Understanding what a grinder is will help in your decision to get the right kind of it. For example, I needed one with a friable wheel since it prevents heat buildup.

Definition and Information

A bench grinder is an instrument whose main feature is its two abrasive wheels. It is what keeps tools sharp and useful until they are too dull to function. It is usually corded and runs on electricity. Different types of wheels are used to sharpen different materials (metals, granite, wood, concrete, etc).

It has grits that chips away at the metal and breaks it into dust. The rotation of the wheel against items is how grinders work. We shouldn’t misuse it trying to shorten stuff in it.

It offers precise control and it is cheap. It can be effortlessly replaced. The maintenance is also straightforward.

Use of Grinders

It is a power contraption everyone (including me) swears is a must in a workshop or for daily household tasks. To an uninformed person, it might seem like an exaggeration even though it is decidedly not. The numerous applications are given below:

·         Removing heavy metal, rust in iron, and other things

·         Restoring severely damaged edges

·         Reshaping edges to form new tools

·         Sharpening drill bits and metals

·         Polishing and shaping wood

·         Grinding steel

·         Buffing objects

·         Cleaning surfaces of objects

·         Gives a new shine to metal stuff

·         Smoothing

·         Repairing home tools

We can only grind hard metals or wood. Soft metals are not appropriate.

Ready-made Grinders

In this era of globalization, we can find any variety of our preferred things. We can buy any bench grinder variable speed control online. Or it can be bought in any local hardware shop.

Notable among them is the one that Delta Machinery sells. The motor is induction. But there are five levels of speed which makes it pretty unique.

The speed range is 2000 to 3400 rpm. It has a 36 grit wheel and a 60 grit wheel. It is versatile for most types of work.

Most of the modern grinders are near to these specifications. They may vary from one another in terms of wheel type, motor type, grit, horsepower, speed, etc. It is also worth your money if you buy a fixed one and change its speed through various means.

The most popular among them is dewalt bench grinder. Its wheels too are 36 and 60 grit. It has a horsepower of ¾ and runs at 3600 rpm.

It is pretty fast so we have to be careful not to overheat our tools. Another permanent speed one is harbor freight bench grinder. It has common solid characteristics.  

External speed controls

There are ways to turn a fixed speed grinder into a variable one. New models have changeable speed built-in because of their universal motors. Still, there are ways to slow down old versions of the equipment. 

Wheel Size

One way is reducing the wheel size. The thicker the wheel is, the slower it will be. To do that, we will require a wheel dresser.

A diamond wheel dresser will suffice. Turn the grinder on and let it reach its full speed. Then, cautiously dress it by holding it against the wheel.

Slowly apply pressure but not too much. It will expose new grit. However, the speed won’t reduce by a lot.

Moreover, the grits need to match the speed rotation. Failure to do so may fracture the stone wheel. Pieces of stone may fall apart.

If this continues, the grinder may explode and harm us. That’s why the quality of the stone needs to be checked after resizing it. 

Pulley System

Here we have to exchange the wheel for a belt pulley. Attach a larger pulley to a shaft. Connect both the large and small pulley through the shaft.

There is a high chance it will not reduce the speed.

Router Control

It is possible to control the speed using a router. This can only happen if there is no built-in router. Universal motor grinders usually have one built.

Induction motors can have one too. What matters is that the horsepower of the engine is below one. 3450 rpm can be decreased to 1750 rpm!

Sometimes, it can cause the machine to fluctuate and lose its rhythm.

Variable Frequency Drive

This is the most reliable way to change speed. It will change the frequency of the motor. The voltage and amperage will remain unchanged.

The drawback is that the motor loses torque. There is a possibility of the grinder easily stopping in the midst of using it.

Some Frequently Asked Questions (FAQs)

1. Can you make a bench grinder of variable speed?

You can easily increase the speed with a variable frequency drive. This helps the motor of the bench grinder to run at variable speed without any voltage change.


Regardless of a bench grinder variable speed control is still a spinning grindstone. It can fray away with carelessness. It requires cleaning and watchfulness.

We should take some precautions before purchasing a grinder. Check if the two wheels snugly bolted. Loose wheels will destroy the gizmo.

 Wearing eye protection is a must when using it. New versions have a safety guard to protect from sparks (but the harbor freight grinder doesn’t have one). Nevertheless, we should be vigilant.

Turn it on and let it warm up to its full speed before using it. This will prevent uneven sharpening. Do not press hard.

The harder you press, the more heat will generate and melt your item. This may sound scary. But, if we take all these safety measures, we can work in an organized and protective environment. 

David A. Thomas is a passionate researcher in the mechanical tools technology sector from Texas in America. He loves to play hockey and often loves to travel to traditional places. However, he is eagerly interested in passing his time in research work.

Write A Comment