E-Sharp News
June 2019
The regrinding industry is experiencing change. Regrinding or resharpening of high-performance cutting tools and drills is a cost effective and environmentally friendly solution for extending the life of tools. Resharpening is offered by tool service providers across a wide range of manufacturing industries, i.e. Automotive, Aerospace, Medical, Power Generation or Woodworking applications to name a few.
Tool and Cutter Grinders are traditionally sold to cutting tool manufacturers and regrinding services and these companies make up the largest market. However in-house CNC tool grinding has become increasingly attractive to manufacturers who use a sizable volume of tooling.
Resharpening is driven by environmental responsibility and the need to reduce overall tooling cost. The cost to recondition is generally lower than replacement cost and it is commonly understood that the resharpening process is typically less than half the cost of producing a new tool. When you consider that an endmill can at least be reground three times, the numbers become even more compelling.
Tool service providers generally offer a high-quality, high precision resharpened tool and aim to provide performance near to original manufacturers specifications. However, the question becomes, when is it more attractive to in-source the resharpening of tool, not only from a cost perspective.
A large tool consumer can potentially save cost by bringing reconditioning in-house. An added bonus is the additional flexibility with turnaround time often being reduced. Therefore, it is not just the cost of the tools, but the loss of production if the right tool isn’t available when required that should be considered. Machine shops can run into overly long regrinding times, especially when they use unusual geometries. In addition, the machine shop doesn’t need to carry excess inventory providing back up.
Today’s CNC tool grinders are easier to use than ever, but conversely tools are more complex. While ANCA has introduced technology to easily automate mixed batch regrinding to ensure the process is easy and effective -any company new to tool grinding still must build up in-house expertise.
In any case it’s a big step, not only because the investment into a tool and cutter grinder can easily be $300,000. Plus, there’s the cost of grinding wheels, workholding, coolant, utilities, floor space, and of course, the operator. A suitable CNC tool measuring machine will add to the set-up expense.
How to evaluate the economics of taking reconditioning in-house
While an in-house tool and cutter grinding machine provides freedom to produce quickly and improve effectiveness in new ways, a machine shop that considers adding in-house tool grinding typically faces a difficult investment decision. As a result, cost of outsourcing and the investment of bringing tool resharpening in-house needs to be compared on a case by case basis.
Tips how to approach the business case
The cost of regrinding in-house will depend on the utilisation of a tool and cutter grinder – to approach the question in an objective way firstly determine the hourly rate of the investment. This includes the cost of depreciation, interest, floor space, energy, maintenance and consumables cost. The cost of the operator will come into the equation based on 1,2 or 3 shift operation and if the machine has the capabilities to run unmanned.
Based on the hourly rate and the estimation of cycle time per tool reground a manufacturer will be able to compare the base cost of in-house resharpening opposed to outsourced services.
Once you have a cost comparison it will be important to evaluate also the “soft factors” like:
- Cost of spares to maintain production while tools are reground;
- Outsourced resharpening cost/tool x number of spindles needed in the machine shop;
- Consider turnaround times/waiting times and possible cost of lost production in the event of a delay in regrinding service;
- Tool quality;
- Other processes required like edge preparation or coating;
- Plus, service and shipping costs.
ANCA – Resharpening Made Easy
ANCA drives the future of regrinding by providing solutions to customers problems and is traditionally working with leading industry partners like Zoller to develop integrated solutions.
Zoller and ANCA have developed a reliable and error free data transfer to automatically pre-set the regrinding process. This includes the wear of the tool measured. The regrinding parameters can then be allocated to a corresponding pallet location when a tool loader is used. Once the tool is picked up by the loader and presented to the workholding – ANCA ATM Auto Tool Measurement) digitises the tool. The Automatic Tool Measurement cycle has been developed to make regrinding a fast and simple operation. This cycle measures the most commonly required parameters for almost all tool types. A mixed batch of tools can automatically be loaded and reground.
ANCA Loadermate software can group the tools by tool type, required regrinding operations and infeeds based on the wear factor. The Loadermate allocation sets up a mixed batch of tools for unmanned operation.
ANCA offers a variety of automated regrinding solutions for mixed batches – such as collet loading (Tool and collet are getting changed together), or collet changing and RFID. With RFID the required information is recorded at programming station and the tool is coupled with the RFID tag. The machine picks up the tool together with the RFID tag, scans the RFID and automatically calls up the grinding program. The RFID is parked while the tool gets loaded and reground.
With the ANCA RFID solution customers can chaotically load tools into a loader pallet by creating an individual program for each tool. The tool position inside the pallet can be swapped with another tool anytime if a tool needs to be resharpened in a hurry.
The tool and cutter grinders can run the regrinding operation individually and unmanned, the duration of unmanned machine usage depends on the type of loader and the capacity of pallets.
26 June 2019