Regrind Endmills?

Should you regrind/resharpen your carbide endmills? Here's a section from the Dormer Regrinding Guide with our comments in red italics:

RESULTS OF REGRINDING

Reduction in Diameter 

A loss in diameter occurs when grinding the periphery of the primary land. This 

progressively impacts the end mill’s deflection capacity when under load. Compare 

Figs. 1 and 2.

The change in diameter changes the tool point frequency much like different diameter tubes of a wind chime produces different tones.

Reduction In Radial Rake Angle
An end mill must possess a rake angle that is suitable for the material being machined.
After each regrind there is not only a reduction in diameter, but also a subsequent
reduction in the radial rake angle. This, together with the corresponding, if slight change,
in helix angle significantly affects the efficiency of the end mill. Compare Figs. 1 and 2.
Face rake angles can be re-established by regrinding the flute face of the end mill.
Reducing the rake angle increases the cutting forces and the amplitude of the deflection of the tool point, changing its frequency.

Increase In Secondary Land Width
The secondary land width increases substantially as a result of regrinding, which in turn
increases regrinding time and cost. Compare Figs. 1 and 2.

Reduction In Flute Depth
As a consequence of reducing diameter, there is a corresponding reduction in the flute
depth. Because of the subsequent impact on chip evacuation capabilities it can force
the utilisation of feed rates that would be considered far less efficient. Compare Figs. 1
and 2.

Cutting Tool Cost Comparison Utility

When the Boeing Research and Technology group of St. Louis works with Boeing suppliers to refine their machining processes, the researchers advise these shops to consider more than just the purchase price of the tool. A cheap tool can be expensive, if it limits the productivity of the machine...read more
For your convenience, you can download Boeing's Powerpoint slide and Excel file here.

Counting Tray for Small Fasteners and Helicoils

When I had a distributorship we sold a lot of small fasteners. Socket head cap screws, set screws, nuts, washers and helicoils. As a service to our customers we would break boxes and sell them only what they needed. No need to buy 100 when you only needed 12 for the job. Counting them out was a chore. We set up a workstation just for the small sizes with a counting scale. But the scale didn't work with tiny fasteners, like 4-40 helicoils. If we only had one of these, the job would be much easier. For years I tried to talk my pharmacist out of one, but never could. Now you can buy one:
http://www.amazon.com/TPS-3722-Counting-Tray-Spatula/dp/B003K7RMDS

Mazak Cutting Demo with BlueSwarf Dashboards

Consistent Tool Stickouts for Consistent Dynamic Performance.

Tool length plays an important role in establishing the tool's vibration frequency. Using our new mini-barcode labels with a scanner and the Tooling Cloud's existing search box you can quickly look-up a tool assembly's endmill stick-out length for fast and consistent changeovers. You don't need barcodes, just enter the tool assembly's Dashboard number.

JoePa at IMTS

Almost ten years ago we had just moved to Penn State's Innovation Park and we manned their booth at the school section of IMTS. They gave us a stand-up Joe to bring with us so we got him a badge.

Thanks, Coach