Login  |  Register
Items 0  |   View order

Spiral Cutters

Spiral Cutters
  The benefits of using spiral cutters. Written by Jim Phillips - Founder of Trend Machinery.

Straight fluted Tungsten Carbide tipped cutters are certainly the most popular type of cutter used by router users. Improvements in design, materials and manufacturing technology over the years has enabled these cutters to cut a multitude of abrasive manmade materials.
With certain applications, the impacting action of straight fluted cutters as the tool rotates can cause fibres to pick up and this results in feathering on veneers and softwoods. Also when feeding fast they can cause the chips to choke up in the cut grooves, limiting cutting efficiency and this reflects in the finish.

Spiral Cutters
  But, with the arrival of the spiral or helical shaped fluting which is machined from solid carbide rods or high speed steel, a number of advantages appeared, especially for the large operators with CNC equipment. But even those using hand routers are now choosing to benefit from the slicing type action of helical fluting. This slicing action imparts an even load on the router and reduces vibration, as there is always a cutting edge in contact with the material.
Spiral Cutters
  The design of spiral tooling enables faster feed rates, up to 10 metres a minute depending on the cutting depth. The helical geometry of spirals vary to suit different applications of the industry. There are three basic types:

Up-cut spirals with right hand helix
This type of fluting lifts the chips in an upward direction away from the cutting area, thus preventing clogging. Although this is an advantage, some form of dust extraction is necessary.

Burning when plunge cutting is all but eliminated and drilling with the router set at a lower speed, becomes an attractive proposition.

On laminated boards there may be some surface feathering which a down-cut tool would prevent. The upwards action of the up-cut may cause the workpiece to rise and good clamping is recommended.

Spiral Cutters
  Down-cut spirals with left hand helix
With down-cuts, feed speed is a little restricted but feathering is virtually eliminated and the finish of cut is first rate. For this reason, such tooling is often chosen when machining boards faced with veneers, laminates or foils.

Spiral Cutters
  Combination up and down-cut spirals
When boards are faced on both sides, the combination spiral comes into its own. If the router is grooving or trimming veneer edgings, the finish is guaranteed to have a clean cut edge on both faces. In operation, the upper down-cut part of the spiral severs the grain on the top surface of the board and the lower up-cut severs the grain on the underside.

When deciding on the choice of cutter, the extra cost of using spiral cutters should be considered. First check to see whether your standard TC cutters have been regularly honed to bring them back near to the original edge.

A tendency to feather edge can also be avoided by scoring a pre-cut line prior to routing the groove.

< Back to Index [^]
  Aspin Interactive e-commerce