Short courses on CNC operation?

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03-27-2009, 07:04 PM
Ubarch

Short courses on CNC operation?

Hello,

So there's a recent post by me that should be close to this one that explains that I'm looking to learn to use a benchtop CNC to mill some PCBs. Since I wrote that, I've stumbled upon some good fortune. My company may be willing to sponsor me for a short (i.e. not an entire academic semester; most likely on the order of a week or so) course to learn to use our CNC. Does anyone know of anything that might apply?

I'm self-taught when it comes to machining, and almost all of my time has been on Sherline devices, but I have done a few hours of work on full sized machines. I read through the Sherline publications and use some other texts as reference. I have a lot of programming experience, and a lot of electronics experience.

Thanks!
03-27-2009, 08:46 PM
escott76

Quote:

Originally Posted by Ubarch

Hello,

So there's a recent post by me that should be close to this one that explains that I'm looking to learn to use a benchtop CNC to mill some PCBs. Since I wrote that, I've stumbled upon some good fortune. My company may be willing to sponsor me for a short (i.e. not an entire academic semester; most likely on the order of a week or so) course to learn to use our CNC. Does anyone know of anything that might apply?

I'm self-taught when it comes to machining, and almost all of my time has been on Sherline devices, but I have done a few hours of work on full sized machines. I read through the Sherline publications and use some other texts as reference. I have a lot of programming experience, and a lot of electronics experience.

Thanks!

I started my machining adventures with a Sherline, teaching myself. I now work professionally as a machinist and toolmaker. The best thing to know for CNC is a good grounding in machining fundamentals on a manual machine. The skills and unique features of CNC are easy to adapt to given that you understand how to remove material with the machine tool you are using. The Sherline tools are limited in their capability, but this is a good thing. You're forced to understand the forces involved, and the limits of the machine in order to get good results. Knowing this, changing your methods so they work with CNC is not hard.
Are you going to be using CAM with this setup? If you are, training in that would be a good idea. Knowing the capabilities of your software, and how to get it to do what you want is vital at getting good results. I'm still plowing my way through Gibbs cam, work will pay for classes, but I want to get to a little higher level so I better know what questions to ask.
If you aren't using CAM, I can't really help with class suggestions, but you're going to need to know the specific ins and outs of the machine itself. Lot's of different flavors of G-code. Perhaps the manufacturer of the machine offers training? Many do.
03-28-2009, 01:39 PM
Ubarch

I probably won't be using CAM, because nobody is going to shell out $10K for a license. Mach3 is probably the most advanced program I'll be using. Once the mill is up and running for a while, i might be able to request that my company buy such a license with a significant probability of success after a year or so. Until then, Mach3 and GCode only.

I see that Tormach offers a 3-day class. What's up with Tormach?

I also see a lot of online training courses, but my feeling is that these probably aren't worth bothering with.
03-28-2009, 01:53 PM
cjdavis618

Quote:

Originally Posted by Ubarch

I probably won't be using CAM, because nobody is going to shell out $10K for a license. Mach3 is probably the most advanced program I'll be using.

Unfortunately, it doesn't work that way.

There are many things you can do with Mach3 and even the $50 newfangled wizard. But you will need Cad/Cam to be able to do any kind of prototype or detailed work. That is unless you are fluent on Gcode.

There are affordable cad cam solutions out there. I am a "hobby" user and Alibre has let me buy there product over a 12 month period with no interest. It was a total of 5k for the Design expert and Cam expert package. If you wanted to do just 3 axis work, you could knock that down to a little under 2k for professional software.

There are some free programs for CAM like CamBam, and there is Lazy cam from Mach, but they are nothing compared to Alibre cam and Visual mill in my opinion. You can always download the Alibre Express version as well for CAD, and it is a pretty full featured software to be free. There is even an Alibre Cam express that you can use that has limited functions.

If you are serious about learning cnc, then don't wait on the company if they are hesitant to train you in it. Take a leap of faith and do it. The benefits far outweigh the cost.
03-28-2009, 04:17 PM
escott76

Quote:

Originally Posted by Ubarch

I probably won't be using CAM, because nobody is going to shell out $10K for a license. Mach3 is probably the most advanced program I'll be using. Once the mill is up and running for a while, i might be able to request that my company buy such a license with a significant probability of success after a year or so. Until then, Mach3 and GCode only.

I see that Tormach offers a 3-day class. What's up with Tormach?

I also see a lot of online training courses, but my feeling is that these probably aren't worth bothering with.

The last company I worked for bought a HAAS VMC, no CAM, but they did get Solidworks. The attached picture represents something I did with CAD but all hand coded G code (the HAAS did have a semi decent pocket routine which made it easier). I also did the design, prototyping and production for said company with no CAM. It can be done, but it's slow and frustrating.
If your company expects the machine to be productive for them, they are going to have to look into some form of CAM. It doesn't have to cost 10k, there are certainly packages that start out less, and allow you to add modules as you go. Start with a 2.5D and work your way up.
G code is very simple. You are just telling the tool how to move from point to point. It has some commonly used functions built into handy simple codes like those for peck drilling or other canned cycles. What makes it difficult are complex parts that require a large number of simple moves to make it. The computer is much better at figuring out what these moves will be, and not making stupid mistakes while transposing them like putting G01 X10. instead of G01 X1.0 . Learning the basics of G code enough to make chips on the mill shouldn't require a class. But you can't expect to be doing much more than telling the machine to cut simple parts without spending a lot of time to do it.