The wheel is the world’s greatest invention, make it work overtime for you
To extract the most from your tool grinder, it’s vital that you are using the right wheels, that they are perfectly balanced and that you keep them in top condition throughout a complete batch.
There are four basic criteria for selecting the perfect wheels for your application:
• Wheel size and shape
• Grit size
• Grit material
• Grit bonding method
Choosing a grit size is relatively straight forward. Use coarser grit size for heavier applications such as fluting; a medium grit size for more general grinding. Select a finer grit wheel for finish grinding, profiling and smaller tools.
There are three grit materials commonly used in tool grinding. The hardest of these (Diamond) is the only grit type typically recommended for carbide grinding. The other common grit materials used in production grinding are Cubic Boron Nitride (CBN); which is often recommended for precision grinding of steels and Aluminium Oxide.
To read more about Grit bonding, dressing, balancing and white sticking your wheel, download the full ‘7 Hot Tips’ e-book.
Get your coolant clean and mean
Your coolant has two primary jobs; lubrication and heat dissipation. The goal in coolant delivery is to inject the coolant as far as possible into the cut zone so that each wheel grit is lubricated throughout its entire contact run. You need to ensure your coolant system has sufficient pressure to obtain the required velocity needed for the particular operation at hand.
Laminar nozzles can improve the effectiveness of both the pressure and flow that the coolant pump is supplying. Delivery of coolant into the cut zone as a laminar flow reduces the amount of turbulent air that is introduced into the coolant stream. Air in the cut zone will decrease the cooling and lubricating efficiency of your coolant so it pays to get your flow as laminar as possible.
To read more about positioning of your coolant nozzles and the importance of clean coolant, download the full ‘7 Hot Tips’ e-book.
Give your tools the support they need
The main reason to support your tool is to reduce deflection of the tool during grinding. Reduced deflection will improve your tolerances, run-out and surface finish. This means a higher quality, longer lasting tool that you should be able to charge a higher price for. It also allows you to increase your feed rates and therefore your profits. And in the last few tools prior to an automated wheel dress, a steady rest can help maintain your tolerances and avoid breakages, even as the wheel starts to dull off.
Even though you might expect to wear out your grinding wheels faster using a tool support system due to your faster feed rates, supporting your tool can actually extend the life of your wheels. This is due to a reduction in vibration and subsequent chipping and wear along the edge of the wheel.
To read more about the benefits of tool support systems, download the full ‘7 Hot Tips’ e-book.
Invest minutes in optimisation to save hours in production
Optimisation begins with good set-up. A huge time waster can be configuring the software of your CNC tool grinder to grind exactly what you want to produce. Therefore, it is important to ensure that your software fully supports your tool types.
One very effective way to quickly prove out a new tool design that could save you non-production
down-time on your machine is “Dry Run” mode. When you have entered all the data give the cycle a quick run through to check that all the machine motion looks reasonable. Better yet, perform your dry run using your CNC’s MPG feed feature if it has one.
If you have a PC loaded with an identical copy of your CNC’s software, and preferably 3D simulation software for the grinding process, you can then set-up your next tool while the machine is producing the current batch.
Deploy your anchor to avoid drift
If you’ve optimised your process properly, machine and tool accuracy should be very stable throughout an entire production batch. However, due to wheel wear and temperature shifts, you might experience slight inaccuracies creeping into your process during the grinding of a batch, which, if unmonitored, might result in part of your batch being ground out of spec.
Coolant Temperature Variation (CTV) Compensation can help when tight tolerances mean even slight temperature changes can adversely affect tool quality. At periodic intervals during a large batch of tools, the machine can use the touch probe to reference a known surface, re-calibrating the machine axes on the fly.
To read more about maintaining stability throughout batches, including the use of Statistical Process Control (SPC), download the full ‘7 Hot Tips’ e-book.
Turn off the lights to save the planet
If you grind a tool with an extremely long cycle time, or if you’ve got a suitable automatic tool loader on your machine, switch off the lights in your factory and let the machine do the work for you, with your process under constant surveillance and control.
Many tool grinders now include automated wheel pack changers. If your tools require some heavy cutting or ultra-fine tolerances, it’s a good idea to include multiple sets of identical wheel packs so you can schedule wheel pack swaps mid batch to keep your production process accurate and efficient.
To read more about automation, download the full ‘7 Hot Tips’ e-book.
Rinse and repeat
A modern tool grinder gives you incredible flexibility to quickly design, set-up and grind a wide range of complex cutting tools, but never forget that a repeat order for a batch you’ve already optimised will be profit straight in your pocket. For your regular runs, try to keep a set of wheel packs just for that job and make sure you have a good filing system for your wheel and tool definition files. This will cut your set-up and qualification time down dramatically.
A 3D simulator is not only good for setting up your next job offline, but it’s also an invaluable package for new tool design, optimisation, diagnostics, costing and training. You can also use it for marketing; just email 3D models of completed tools to your potential customers to show them quickly what you are capable of producing.
To read more about how your 3D simulator can profit your business, download the full ‘7 Hot Tips’ e-book.
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