How to Run a Wendt CNC Machine
A practical walkthrough for operators and process engineers who grind PCD, PCBN, carbide and ceramic cutting edges on a Wendt machine. It covers pre-start checks, wheel dressing, program values, dry run, in-cycle monitoring and shutdown. By the end you should know whether a given part belongs on this machine at all.
In this article
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Key takeaways
Pre-start checks on a Wendt CNC machine
A Wendt machine is a grinding platform, not a milling center. The wheel removes material by abrasion at 20–35 m/s surface speed, so anything loose in the loop shows up as chatter or a burnt edge within seconds. Before you power up, walk the machine: check that the wheel guard is seated, the coolant tank is above the low mark, and no chips sit on the linear guide covers. Air pressure at the inlet should read 0.5–0.6 MPa. Below 0.4 MPa the clamping and axis brake interlocks may not release cleanly.
Power the controller and let it complete its self-test before you touch the pendant. Then home every axis. On most Wendt configurations this is X, Y, Z plus the B rotary and the wheel-head axis. Homing establishes the reference for the coordinate system, and if you skip it the machine will happily grind in the wrong place. After homing, jog to the wheel dressing station and check spindle runout with a dial indicator. Keep it under 0.005 mm at the flange. Above 0.01 mm, dress the wheel before anything else.
Check the workholding next. A collet or fixture that repeats to 0.02 mm is fine for roughing a carbide blank and useless for a PCD insert with a 0.005 mm edge spec. Indicate the part or the fixture datum, not the vise body. Write the reading on the setup sheet. If the part sits on a magnetic chuck, demagnetize after grinding; residual magnetism pulls chips into the next setup.
Finally, confirm the program matches the part in your hand. Program number, wheel type, and the material code in the header. Operators who skip this step tend to discover the mismatch at the first plunge, which is an expensive way to learn.
- 1Air supply0.5–0.6 MPa at the inlet, dry and filtered
- 2Spindle runoutUnder 0.005 mm at the wheel flange
- 3CoolantAbove the low mark, correct concentration for the material
- 4Program headerWheel type and material code match the job
Wheel dressing and program setup
Dressing is where most Wendt runs are won or lost. The wheel has to be open enough to cut and true enough to hold the edge geometry. For a diamond wheel grinding PCD, take 0.01–0.02 mm per dress pass, two passes, at a traverse that lets the wheel spark out. For a softer bond on carbide, 0.02–0.03 mm per pass is normal. Feeding too fast loads the wheel with metal and the next part burns. Feeding too slow glazes the bond and the wheel rubs instead of cutting.
Dress frequency depends on volume, not on the clock. A common rule is to dress every 15–25 parts on PCD and every 8–12 parts on carbide, then shorten the interval if edge quality drifts. Record the wheel diameter after each dress. Once you have removed 3–5 mm of radius, the wheel is near the end of useful life and the bond starts to behave differently.
Programming follows the same logic. Set the grinding wheel surface speed first, then work back to spindle rpm. PCD edges usually run at 18–25 m/s, carbide at 25–35 m/s. Depth of cut per pass stays small: 0.005–0.02 mm for finishing, up to 0.05 mm for roughing where the geometry allows. Feed rate on the rotary axis for a peripheral edge is typically 50–200 mm/min. Faster than that and you trade edge quality for cycle time.
Use a separate offset for the dressing station and the workpiece. Mixing them is the classic cause of a wheel that cuts 0.03 mm deep on the first part and air-grinds on the second.
- 1PCD dressing0.01–0.02 mm per pass, spark out, dress every 15–25 parts
- 2Carbide dressing0.02–0.03 mm per pass, dress every 8–12 parts
- 3Surface speedPCD 18–25 m/s, carbide 25–35 m/s
- 4Finish depth0.005–0.02 mm per pass for the final edge
Running the grinding cycle and reading the signs
Start the cycle with the coolant on and confirm flow before the wheel touches the part. You want the stream hitting the contact zone, not the top of the guard. Flow of 8–12 L/min is typical for edge grinding; pressure matters less than where the coolant lands. If the part comes out warm to the touch after a light pass, the coolant is missing the cut.
Listen to the first 30 seconds. A clean grind sounds steady. Chatter is a higher-pitched rattle that shows up in the finish as evenly spaced marks, and it usually traces back to wheel balance, runout, or a fixture that is not rigid enough. If you hear it, stop the cycle. Finishing the part will only produce a scrapped edge with a nice pattern on it.
Watch the load meter or spindle current. A slow climb over the cycle means the wheel is loading with metal or the bond is dulling. A sudden spike means the depth is too aggressive or the part moved. Both are reasons to pause and inspect. On a Wendt machine, the difference between a good edge and a burnt one is often one pass at the wrong depth.
For long cycles, check the first part fully before releasing the batch. Measure edge radius, check the rake face under magnification, and confirm the surface finish with a profilometer. If the first part is inside ±0.005 mm and Ra 0.2–0.8 μm, the run is stable. If it is drifting, stop and dress rather than compensating in the offset.
- 1Coolant8–12 L/min aimed at the contact zone
- 2ChatterEqual spacing marks mean balance, runout or rigidity
- 3Load climbWheel loading or dull bond — stop and dress
- 4First partFull inspection before the batch is released
Shutdown and maintenance habits
Retract the axes to the park position and let the spindle coast to a stop. Do not hit the emergency stop for a normal shutdown; it dumps the reference and you will home again next morning. Wash the guards and the wheel area with the coolant gun, then run the chip conveyor or the tank separator. Swarf left overnight sets like paste and finds its way into the guideways.
Check the wheel after every shift. Look for glazing, loading, or a chipped edge on the abrasive. A small chip becomes a large gouge on the next part. If the wheel is near end of life, note the diameter on the setup sheet so the next operator does not start a critical job on a worn wheel.
Top up the lubrication points on the schedule, and note any axis that sounds different from yesterday. On a machine that holds ±0.005 mm, a change in sound is data. Log it, and if it repeats, get it checked before the next tight-tolerance job.
Keep the setup sheet current. Wheel type, dress history, offsets, and the inspection result of the first part. That record is what makes the second run faster and safer than the first.
- 1Park, do not E-stopNormal shutdown keeps the reference intact
- 2Clean the swarfChip conveyor and tank separator every shift
- 3Inspect the wheelGlazing, loading, chipped edge, remaining diameter
- 4Update the setup sheetDress history and first-part inspection result
Step by step: how to run a Wendt CNC machine
Eight steps from cold machine to released batch.
- 1Walk the machineCheck guard, coolant level, air at 0.5–0.6 MPa, and that guide covers are free of chips. Fix anything before power up.
- 2Power up and homeLet the controller self-test, then reference X, Y, Z, the B rotary and the wheel-head axis. Do not skip an axis.
- 3Check spindle runoutDial indicator at the wheel flange. Keep it under 0.005 mm. Above 0.01 mm, dress first.
- 4Dress the wheel0.01–0.02 mm per pass on PCD, 0.02–0.03 mm on carbide. Two passes, spark out, then re-check runout.
- 5Load and indicateClamp the part and indicate the datum, not the vise. Record the reading on the setup sheet.
- 6Set offsets and verify the programSeparate offsets for dressing and workpiece. Confirm wheel type and material code in the header.
- 7Dry run at +5 mmRun one full cycle in air with a +5 mm Z offset. Watch the path, the rotary moves and the coolant timing.
- 8Cut, inspect, releaseRun the first part, inspect edge radius and finish, then release the batch only if it is inside spec.
Starting parameters by work material
Typical starting points for edge grinding. Adjust to the wheel bond and the edge geometry in front of you.
| Material | Surface speed | Dress depth per pass | Finish depth per pass |
|---|---|---|---|
| PCD | 18–25 m/s | 0.01–0.02 mm | 0.005–0.010 mm |
| PCBN | 20–28 m/s | 0.01–0.02 mm | 0.005–0.010 mm |
| Cemented carbide | 25–35 m/s | 0.02–0.03 mm | 0.010–0.020 mm |
| Ceramic | 15–22 m/s | 0.005–0.015 mm | 0.005–0.010 mm |
| HSS | 28–35 m/s | 0.02–0.03 mm | 0.010–0.020 mm |
| Cermet | 20–28 m/s | 0.01–0.02 mm | 0.005–0.010 mm |
Symptoms, causes and what to do
Three columns that have to line up: what you see, why it happens, what you change.
| Symptom | Likely cause | Action |
|---|---|---|
| Chatter marks on edge | Wheel out of balance or fixture not rigid | Re-balance wheel, re-indicate fixture |
| Burnt edge, blue tint | Wheel glazed or coolant missing the cut | Dress wheel, redirect coolant to contact zone |
| Size drifts over batch | Thermal growth or wheel wear | Dress more often, check coolant temperature |
| Slow load climb | Wheel loading with metal | Reduce depth per pass, increase coolant flow |
| Sudden load spike | Depth too aggressive or part moved | Stop cycle, inspect clamp and offset |
| Poor finish, Ra high | Feed too fast or wheel too coarse | Lower feed rate, dress with finer passes |
When a Wendt machine is the right call
If the part needs a ground PCD, PCBN or carbide edge held at ±0.005 mm with Ra 0.2–0.8 μm, this is the right platform. If the feature is a 3D contour in aluminium with no abrasive requirement, a 5-axis mill will be faster and cheaper. Send the drawing and we will say which one it is.
Questions operators ask
What parts are worth running on a Wendt CNC machine?
Anything that needs a ground abrasive edge: PCD and PCBN inserts, carbide cutting tools, ceramic wear parts, and tooling where edge radius and rake face finish drive the tool life.
Parts that are purely geometrically complex but have no edge requirement usually belong on a milling center instead. The decision is about the feature, not the material.
How often should the wheel be dressed?
Base it on part count and on what the edge looks like. PCD typically every 15–25 parts, carbide every 8–12 parts, at 0.01–0.03 mm per pass depending on the bond.
If edge quality starts drifting inside that interval, shorten it. Dressing is cheaper than scrapping a batch.
Why does the first part come out undersize?
In most cases the dressing offset and the workpiece offset have been mixed, or the wheel was not spark-out dressed before the cycle started.
Dry-run one cycle at a +5 mm Z offset and confirm the dresser position separately before you cut the first part.
Can GreatLight grind PCD and PCBN edges to ±0.005 mm?
Yes. We hold ±0.005 mm on edge grinding and finish to Ra 0.2–0.8 μm, with 100% inspection before shipment and reports on request.
We work to ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022, and we can sign an NDA before you send drawings.
What is the largest part you can process?
Our maximum processing size is 4,000 mm, with a 4,000 × 400 × 150 mm travel envelope on the largest machines and a Ø400 mm rotary table for round work.
Smaller envelopes at 750 × 1,150 × 550 mm and 500 × 500 × 450 mm cover most edge tooling and insert work.
How do you keep the run repeatable across batches?
The setup sheet carries wheel type, dress history, offsets and the first-part inspection result. Every operator works from the same numbers.
We also monitor in process and do a final inspection on 100% of parts before shipment, so drift shows up before the parts leave the floor.
Send the drawing, get a process answer
Upload your part and we will confirm the grinding route, wheel selection and inspection plan. Quotation and free DFM analysis within 12 hours.
12-hour quote100% inspectionNo MOQNDA on request
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