Tuesday, July 12, 2011
Here are some basic rules I use when selecting or setting up CNC projects. Let me know your rules, or any tweaks you see to mine. Thanks!
1. Don't make anything that you can buy easily, unless you have some specific reason that over-rides the extra cost, effort, and likely unforeseen problems.
2. Remove as little material as possible. Look carefully at item placement in your material stock, different ways of cutting the piece, possible design changes, etc. to reduce the amount of cutting and the amount of material to be removed.
3. Plan your cuts so that the ones that most depend on the accuracy of the bit's size are done with a fresh bit. Bits wear while cutting, if you're planning on cutting, say, a 1/4" dado with a 1/4" bit, you should do it while the bit still has a 1/4" diameter to minimize post-machining to make things accurate.
4. Test your ideas in scrap material first, unless it's a minor variation on something you've already done. Chances are you'll either find a problem you didn't anticipate, or figure out a way to do it better on the next go.
5. Be fanatical about your means of mounting the work. The accuracy and success of the machining relies on it, so think about this as much as you think about the rest of the project.
6. Once you find something that works, build on it. Once you've developed a routine for mounting, cutting, registering, or whatever that regularly produces the results you want, keep doing it. It helps to take notes and pictures for reminders in case there's a break in operations that leaves you a bit rusty on how you did it before.
7. If something isn't working quite, don't keep tolerating it. Fix it, replace it, find another way. It'll be worth the time saved later.
8. Learn from others. Watch videos online, visit other folks' websites, visit with other CNC machinists, see how it's done with different machines or in different areas than your individual interests.
9. Do "science" projects. Plan and develop projects just for the sake of trying out something new or exercising a different procedure. Just like doing a first work in scrap, they'll save you time in the end.
10. Make one complete finished item before you cut out a whole set of parts production-line style. While it costs a fair bit of time in setup to go through once for the prototype, then go back and start over for production, it's better than finding out you've got a stack of parts that won't work when you get to final assembly.
My CNC Website