Common Errors in CNC Router Operation
There is both art and science involved in CNC machining. Skill and experience are earned over time, often through trial and error. But if you're paying for machining services, your bank account, your success — and your sanity — can only weather so much trial and error. Heed the advice that follows to avoid some of these common machining mistakes.
Misuse of Holding Devices
Holding tabs help to steady a part while it’s being routed. However, it’s important to strike a balance between using too few (and risk breaking them) or using too many (and spend more time than you should breaking them off later)—a proficiency that comes with experience. Talk to a professional if you’re not sure how to go about setting up your tabs for the first time. Holding screws are a good alternative to tabs since they can hold more weight, and a good vice can be invaluable in a machine shop.
Improper Feed Rate
Run your machine too slowly and you may burn up too much material too quickly. You may also cause unnecessary damage to your bit as well as your entire setup. Go too fast and you may be unduly taxing your machine or ruining an otherwise nice, smooth edge. Make sure to feed at a rate that is ideal for the material you’re working with, as well as the bit you are using to cut it. If you’re not sure what the proper speed is for different types of materials, consult a professional.
Wastefulness and Poor Planning
All the old adages about wastefulness and planning ahead are true. Poor planning leads to wasted materials, and wasted materials equals lost money. Take care to map out your plans in a way that minimizes waste. Place components as close to each other as possible so that you only have to make one cut along shared edges. This will minimize the amount of cuts you have to make as well as the amount of material you have to use.
Improper Care and Maintenance
As with any piece of equipment or machinery, a CNC router needs to be kept in good repair through proper maintenance and care. Check often to ensure that your machine is properly calibrated and backup your data regularly. Perform a full inspection before each job and clean it after every use. A few minutes spent keeping your router in good condition can save lots of time and money in the long run. Always follow any specific care instructions in the owner’s manual.
Using The Wrong Bit
In precision machining, the end mill — or router bit — is crucial. Use the wrong one for the job at hand and risk damaging the bit, placing undue wear-and-tear on your router, and having your finished product come out looking less-than-perfect. Always use an end mill made specifically for the material you are working with. Do your research and get with a qualified professional to talk about how to select the right bits for your unique projects. The other most important thing about bits? Quality. All parts and accessories are not created equal. Spend a little extra to make sure you’re getting a decent cutter that will hold up to heavy use and produce quality results.
If you’re fairly new to CNC machining, talk to an experienced professional or qualified salesperson to make sure you’re not only getting the right router, but that you are aware of the accessories and parts you’ll need to keep it in good repair. Also, know when to turn complex or delicate projects over to a custom machine shop.