6-axis CNC Blade Grinder

Taking blades to Finish Size and Surface Finish

Generic 6-Axis CNC Grinder Layout for a 6-

axis grinder (Artist’s concept).

X, Y, Z and A in Table.

B and C in “spindle”.

Barrel Tool

Tool Record Continuation

Orientation to Part Barrel is twisted

around axis of Spindle – C-axis

Barrel is held so that contact point is normal to surface

Axis of Barrel is rotated along Stations.

Grind/Polish Process

A possible method of grinding/polishing is described.

The process consists of taking a blade semi-finished with +.005” scallop and up up +.015” stock per side to finish.

Process Continued Initial track is

roughed at tip of blade.

Blade is rough ground to remove scallops and close to finish dimension.

Depending on blade, belt and material multiple roughing passes might be required.

Initial finish pass is made.

Part is probed at one point to determine compensation due to belt.

Tool “length” is adjusted and finish pass is made.

CNC capability Continuous 6-axis

operation with 5-axis tool length compensation is required.

Sustained 6-axis block execution time of approximately 2 milliseconds with 5-axis tool length compensation.

Probing of part is desireable.

Ability to utilize subprograms.

Ability to adjust tool length with-in part program.

Part Program Structure Grinding/polishing

operation is controlled by a master program.

The master program invokes the following programs:

Tip end slot grinding Blade roughing/semi-

finish. Program is invoked with varying tool length offsets based on number of passes needed.

Blade finish program. Point probe. Probing

of point is used to make adjustment of tool length based on barrel dernier, belt grit, and other process related conditions.

Blade finish program re-run with tool length adjustment.

Open Track at Tip

FILENAME 132D3733R.NF2 CREATED 4-MAR-93 19:53:54 PART NO: 132D3733R.NF3. 4.5 120 5248 1 3 2 1; OPERATIONAL INPUT PART NO. 132D3733 ROUGH TIP-R;******************************************; BEGIN OPERATIONAL INPUT1.5 1. 150. 150. 150. 121 98 200 1. GRIND SURFACE USING A 20.000" BARREL; 122 RECORD-13.3301 107.267 122 90 315.0 -5.0 126 3 1 2 .0006 .0006 123; LINE CUT FOR TIP1. .01 3. 95 302 -303 -304 170 2

Rough Grind Blade

FILENAME 132D3733M.NF2 CREATED 4-MAR-93 19:53:54 PART NO: 132D3733M.NF3. 4.5 120 5248 1 3 2 1; OPERATION INPUT PART NO 132D3733;******************************************; BEGIN OPERATIONAL INPUT1.5 1. 150. 150. 150. 121 98 200 .75 20. GRIND SURFACE USING A 20.000" BARREL ROUGH GRINDING PASSES-13.3301 107.267 122 90 315.0 -5.0 126 3 1 2.2 .0006 .0006 123 .01 3. 96 -301 404 11. .6 -302 304 303.75 .005 .005 123 170 2

Inspection Program

FILENAME 132D3733I.NF2 CREATED 4-MAR-93 19:53:54 PART NO: 132D3733I.NF3. 4.5 120 5248 1 3 2 1.125 10. 10. 10. 121 75 .25 20. -.05 .05 PROBE SURFACE-13.3301 107.267 1225.0 -5.0 126 3 1 2 1. 0. 0. 90 1 2 11. 2.5 104 302 15 15 170 2

Finish/Polish Blade

FILENAME 132D3733A.NF2 CREATED 4-MAR-93 19:53:54 PART NO: 132D3733A.NF3. 4.5 120 5248 1 3 2 1; OPERATIONAL INPUT PART NO. 132D3733 FINISH-A;******************************************; BEGIN OPERATIONAL INPUT1.5 1. 150. 150. 150. 121 98 200 .75 20. GRIND SURFACE USING A 20.000" BARREL; REMAINING FINISH PASSES-13.3301 107.267 122 90 315.0 -5.0 126 3 1 2; AREA SWEEP FOR FINISH PASS IS 0.125.2 .0006 .0006 123 .01 3. 96 -301 404 11. .125 -302 304 303 170 2

Level-II Capabilities D-curves may be calculated using the

Barrel Tool. The D-curve is calculated in the same manner as any non-Ball End Mill.

The reference offset for the D-curve is ½ the diameter of the barrel.

Interactive Level-II plots this tool showing the barrel and some of the belt leading in and out of the barrel.

Program point of tool is center of barrel at outside edge.

Roughing Program

Notes Surface finish is directly

related to: Grit of belt Proper coolant flow Machine and CNC

performance Hardeness (dernier) of

barrel

Method of compensating machine for belt condition is CNC dependent.

Barrel Radius must be less then minimum concave radius along stations.

Diameter must be less than minimum concave diameter along templates.

“I” analysis provides information on minimum radii of selected surface.

Stator CNC Ground

CNC Ground Rotor

CNC Ground Rotor