How CAV Does It: Getting The Upper Hand With Limitations Of CNC Design

Computer numeric control is a term with a lot to flex. This is a field with zero tolerance for engineered tolerances so that everything fabricated fits like a glove. Imagine the CNC as the fiery crucible where Hephaestus forged precise implements of war for the gods, except that we have considerably less ambitious (and neutral) designs with the CNC rig at our place, but you get the idea!

So, as is with everything that is coded and mechanized, there are CNC limitations that only human wit can overcome. At CAV Tool, we fabricate close tolerance products like jigs, fixtures, bearings, and parts fabrication. And despite all the computerized control, being human is what gets us through to obtaining the perfect finish by improvisation and following safety guidelines with our CNC & SPC setups to deliver on quality.

Let’s hit a refresher on the CNCs we know and then how we bend them to our wills.

Applications of CNC

1. Milling – A form of subtractive manufacture where precise surfaces and fits are fabricated in parts like fillets, gears, bearings, etc. Of course, we utilize jigs and fixtures to keep the piece in place, some made of our designs.
2. Cutting – Unlike the manual control of a lathe machine, the CNC cutting setup can include laser or water jets for precision cutting.
3. Routing – Sensors guide cutting tools to lathe elaborate surfaces on metal, resin materials, or wood.
4. Multi-axis – Imagine a sculpting machine that deals with the five-axis (x, y, z, & a, b). This CNC-guided rig is for complex designs involving subtractive manufacturing.
5. 3-D Printing – A form of additive manufacture that can utilize various materials to create sculptures, parts, tools, and even minimalist homes.

Limitations

1. High installation costs and power expenses.
2. Repair costs, replacement parts, specialized materials are all costly.
3. Requires CAD & CAM software knowledge. Even the simple process of troubleshooting a program error requires experienced professionals.

How We Overcome Limitations

Usually, with milling and lathe work on standard parts, the issue is with tool access and tool geometry. Imagine trying to carve a block of cheese only from one direction, with a teaspoon; you won’t get far with the required dimensions in complex parts. Drills and cut tools used in CNC tend to impart their geometry onto workpieces which can cause sharp internal edges or corners that will need to be smoothed out.

Milling and lathe also approach the workpiece from one direction, whereas more mobility may be required, plus the considerations for tool geometry. The best way to work around this is to mill the piece to minimal requirement, allowing a precise 5-axis CNC to smooth out the rough edges. Of course, all of this has to be first rendered on CAD regarding tool geometry, access, material hardness, and tool axis.

For larger workpieces, the CNC weight limits have to be considered, and the part is split into subassemblies if the original CAD blueprint and structural analysis allow it. Custom workpieces are easier to tool if the tooling can be observed with the naked eye, as accuracy and precision are of utmost importance to our clients and us.

Apart from these workarounds to deal with CNC limitations, we ensure all CNC machines are calibrated before working on a piece. All the metal shavings from the milling, cutting and lathe machines are brushed off, cleaned, and surfaces oiled. We ensure our CNC operators receive revision sessions and updates on developments in CNC design and operation.

If you are looking for fabricators of precision tools like retainers, cut-off dies, punches & buttons, jigs & fixtures, or need legacy parts fabricated, then CAV Tool are at your service! We are fortuitously active and operating in Grand Rapids, MI, so if you require our cutting-edge services, you are entitled to an estimate, on the house!

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