Keyway Machining – Insights to Making Grooves during Fabrication
Keyways are important featuring in any machining process.
But, how do you make key ways?
That’s exactly what this article is all about. From definition, machining operations, tooling systems to the actual process, you are going to learn all fundamentals of keyway machining process.
But first, let’s start with:
What is Keyway Machining
Keyway machining is a distinct process that imparts unique grooves into machine components like shafts where you can input a key to lock two or more other elements.
You can make these slots using varying methods and your choice should be informed by the component’s purpose as well as the precision you intend to achieve.
How Does Keyway Machining Work
Whether you are looking to engrave a slot that will allow you to lock a gear or coupling to a shaft, you will need to undertake keyway machining. This process will leave your machine or system working like a well-oiled machine and all you need is to follow the underlying steps.
· Workpiece and Tool Preparation
Begin your machining journey by determining the type of keyway you intend to cut, its location on your component, and essential keyway dimensions. Subsequently, determine the best machining method that will help you achieve your desired keyway.
Bear in mind, your component’s material, as well as the length and width of groove you want. Wrap up your journey by loading your component onto your keyway cutting machine and securing it on the vice. This will have you ready for keyway machining.
· Keyway Cutting/Milling
After you have mounted your workpiece, position it correctly to ensure that the cutter imparts the keyway at your desired location. Then proceed to set essential settings of your milling machine or a cutting machine. First, set the feed rate, then set the spindle speed and cutting depth. These settings will determine the quality of the keyway you will achieve.
Consequently, start making the keyway cut and begin with a shallow cut. Proceed gradually until you achieve your desired width and length. When cutting, make certain you constantly apply a coolant to overcome the resulting heating. This will protect your keyway cutter or endmill. If your cut has rough edges, use a deburring tool to smoothen your keyway’s surface.
· Broaching
If you opt for the broaching method, start by picking the ideal broaching tool then mount it on your broaching bushing. This tool will consist of increasingly bigger teeth, which will cut your keyway deeper with each pass. Then, in a single and steady motion, push or pull your broaching tool towards or from your component. This will leave you with a clean keyway. If you are dissatisfied with the cut, you can initiate shimming, which will deepen the length of your keyway.
· Finishing
Once you have a desirable keyway, clean it thoroughly to dislodge the generated metal shavings. This will ensure that your key fits perfectly. If you notice your grooving has rough or sharp edges, use a file to smoothen these edges. Conclude by locking in the key you intend to fit into the keyway. This will tell you if you achieved the perfect slot.
How to Clamp Your Workpiece for Keyway Machining
To mill a keyway with utmost precision, you must securely and tightly mount your workpiece. This will ensure stability, which will consequently lead to precise keyway milling. You can exploit either of the following clamping methods.
· Index Head Method
This clamping method relies on an indexing device, which makes certain that your workpiece is steadily positioned. You will need a three-jaw self-centering chuck to clamp your workpiece. The index head method reigns supreme when machining keyways in multi-slot workpieces.
· Parallel-Jaw Vice Method
This clamping method works best when milling keyways in single-piece production. However, with the right tooling, you can exploit parallel-jaw vice to mill keyways at an industrial level. This method also reigns supreme when it comes to small-medium workpieces.
· T-Slot Method
This method simply requires you to position your workpiece on a T-slot and clamp it using a plate. It works best with relatively lengthier workpieces, especially those with a diameter of 20-60 mm.
· V-shaped Frame Method
When milling a keyway into a comparatively lengthy or thick workpiece, a V-shaped frame will come in handy. This clamping method guarantees steadiness, which consequently makes your keyway machining easier and more convenient. All you need to do is position your shaft’s center along the V-shaped frame’s bisector.
Keyway Machining Operations
Ever wondered how the intricate grooves that lock in keys in machines are formed? Well, there are numerous ways to go about it including;
· Keyway Milling
This keyway machining operation relies on a milling tool specially designed with a profile that resembles a keyway. It is considered relatively slower, but it reigns supreme in cutting varying designs of keyways. You can either exploit;
- Slot Milling: This milling technique thrives in inserting keyways that are relatively large and wide. It relies on a slot mill to machine grooves or slots from your shaft’s sides. This mill comprises cutting edges, which impart the keyway into your workpiece.
- End Milling: This technique works best when you are attempting to impart shallow and comparatively long keyways. All you need is a specialized end mill to mill the slots from your workpiece’s end.
· Keyseating
This keyway machining operation exploits a reciprocating keyway cutter, which cuts your keyway while your workpiece remains stationary. It is revered for its cost-effectiveness and ability to cut deep keyways into relatively humongous shafts or workpieces. It is, however, relatively slower, and questions about its accuracy have been raised.
· Keyway Broaching
Renowned for its high precision and smooth surface finish, broaching ranks high amongst contemporary keyway machining operations. It relies on a broach, which imparts your keyway by wrenching towards or away from your workpiece. Acquiring the required tooling will however cost you relatively more but you will appreciate the speed and quality of this method.
· Electrical Discharge Machining
This machining operation reigns supreme in machining keyways with sophisticated geometries onto hardened workpieces such as dies. It exploits an electrically charged wire, which makes it possible to achieve highly precise keyways. It also eliminates the need for mechanical force.
· Keyway Shaping
Also referred to as slotting, this operation exploits a single-piece cutter to craft keyways into your shaft or workpiece. It thrives in creating internal keyways and many people revere it for its simple setup and ability to drill keyways in blind spots. Its quality of finish is however inferior to that of other methods.
Keyway Machining Tools
As small and insignificant as keyways may seem, they play a significant role and require specialized equipment to create. These tools include;
- End Milling Cutter: End mills thrive in creating varying types of keyways but to achieve your desired quality of groove, you may have to initiate several passes. To impart curved keyways, you will need a ball end miller and to impart regular keyways, you will need a slotting end mill.
- Plain Milling Cutter: Characterized by a tubular body fitted with sharp cutting edges, these keyway cutters are easy to use and can impart deep and shallow keyways.
- Woodruff Keyslot Miller: These cutters have a dimension that equals the dimensions of your respective key. They are specialized to create woodruff key slots of varying depths.
- Straight Shank Keyway Miller: Equipped with a tubular shank, these keyway millers are mainly used to impart grooves on hubs and shafts. Most straight shank keyway cutters feature two to four teeth but you can order a customized cutter with multiple teeth.
- Broaches: Fitted with several teeth, whose length deepens progressively, these keyway cutters thrive in the mass production of components with keyways. They impart keyways in a single pass, making them relatively faster than the other keyway cutters.
Common Issues with Keyway Machining and Their Solutions
Despite having the right keyway cutting machinery, experience, and expertise, you may experience several hurdles when machining keyways. These hurdles include:
- Chattering: Failure to securely clamp your shaft and incorrectly positioning your workpiece will likely lead to chattering. To overcome this, simply lower your machining speed and securely fasten your workpiece.
- Rough Surface: If you notice that your keyway is rough or uneven, the first thing you should do is check the condition of your cutting tool. If it is worn out, replace it or sharpen its edges.
- Misaligned Keyways: A misaligned keyway means that your key will not fit perfectly. This may be a consequence of inappropriate machine setup or machine wear. To overcome this, work on your machine’s setup and ensure your slotting tool is in perfect condition.
Common Keyway Machining Applications
The machinery that keeps your life moving smoothly relies on keyways. This means that keyway machining is one of the most exploited machining operations and its use transcends:
- Industrial Machines: Keyways play a starring role in numerous industrial machineries including pumps, lathes, and conveyors.
- Automotive Industry: The automotive industry relies on keyway machining to produce transmission shafts and crankshafts among other automotive components.
- Construction Machinery: Key construction equipment including loaders and bulldozers feature keyways, which allow efficient movement.
- General Engineering: A myriad of general engineering components including spindles, bearings, and couplings rely on keyway machining.
- Marine Equipment: The marine industry exploits keyway machining to produce transmission shafts, gears, and other shaft connections.
Conclusion
As you can see, keyway machining process involve many operations. With the information in this guide, you can easily conduct your keyway machining operations easily.
At TSINFA, we offer a wide range of equipment for all machining operations. For any inquiries, contact us now.
