Saturday, September 20, 2008

Why You Need to Learn CNC Now

When is the last time you had something quoted by one of your local CNC job shops?

Here in the Albuquerque, NM area, shop rates have risen to $60 - $100/per hour and I think that is being very conservative.

When I got my first job in manufacturing and design, shops rates and engineering rates were $40/hour in 1995.

I think we are only at the beginning of this phase. You must also remember that the baby boomers have started to retire and will continue to retire very quickly as we approach the next few years. I have worked with a lot of very talented boomer machinists. They are the ones that have taught me the most about precision set-up, speeds & feeds, and just all around common sense in the shop.

I am a generation X'er. I look around at my peers and they are not technical people. They went to school to be doctors, lawyers, teachers, accountants and high end engineers. Most of these guys/girls probably have never tapped a hole in their lives. This is what I have noticed and it is probably the norm from state to state.

Here is another factor to consider. The manufacturing industry in the USA has taken a beating, lots of jobs lost and moved out to China/Mexico. This means alot of people have lost their jobs and gone on to other careers or retirement.

Considering all of the information above I believe soon we will see the "Machine Shop Perfect Storm". This is when shop rates will rise even higher and lead times will become even longer. Good machinists will be in high demand which will drive up shops rates even higher. Now is the time to start learning CNC!!!

The best way to learn CNC machining is to stop your career/life and enroll in a 1 - 2 years long college or tech school program. Then follow that up by another 1 - 3 years as an apprentice at a shop.

Most of us are already in careers and have full time jobs. There are also alot of people that don't live close enough to a school to make this an option. What are you to do!

My suggestion is to buy or build your own cheap CNC router for learning. That will be the fastest way for someone to learn CNC programming, set-up and operation. This is not some long wind sales pitch, this has been my thinking about the industry for the past few years. The nice thing about learning this way is that you can do this on a shoestring budget and when you are done learning and are capable on not crashing on every your machine, you unbolt the motors from your starter machine and bolt them (along with the other electronics) onto your next size up or better material machine. Some peoples websites have said "Don't start with a starter or beginner machine, buy or build the right one the first time". That is a great statement but who wants to crash their really nice big machine the first time they hit the cycle start button. I would much rather plow my spindle into the top of my MDF top plate than into a large aluminum/steel plate. Learn your lessons with an affordable machine to repair and replace.

  • Modular CNC MDF X-axis top plate, $25 replacement cost (you really just need to cut a piece from you own stash of MDF and match drill the holes and you just fixed your machine)
  • Modular CNC Aluminum X-axis top plate, $95 replacement costs

Once you have your starter CNC router, software, electronics box, PC, and motors, I would spend about 4 - 8 hours just playing with your machine and software. Jog it around, manually cut something, click on all of the buttons int he software. Ask your boss if you can go out to the shop and do that with one of his machines. I am sure he'll say no and want that spindle cutting instead of sitting still (standard job shops).

Next up is programming. Go out to the web and download a copy of the standard G & M codes. HaasCNC.com has a nice free download of standard G & M codes. You must live them and love them, be one with the code. I tell people that you need to be like the people from the movie "The Matrix". When they look at the computer code they see "people, places, and things". That is how you need to be, instead of seeing G & M code, x..this y...that, you need to see the machine movement and know what your machine will be doing next. This is very helpful during initial progrma set-up and tryout. Once your program and set-up is proven you can just let your machine run.

Another programming tip is to make sure you get a cool CNC software like Mach3 that includes a CAM program like Lazy CAM. This program lets you upload DXF files to it which it then converts to G & M code automatically. Here is the really slick idea, go to eBay.com and do a search for DXF files. You can buy pre-made DXF files in bundles that have common themes like western, flowers, fishing, etc, etc. You take these files, upload one, covert to code, do a quick part zeroing and cut something. Here is how I have learned alot in CNC programming. Go back to that same program without removing your cut part and run in step block mode. This means that it will run one line of code at a time when you press the start button. This lets you see what each line does. I think this is very important because it lets you become very comfortable with the code, your software , and your machine.

This isn't going to be an overnight learning process. You still need to know about quick, fast, and accurate set-ups and most importantly Feeds & Speeds. A few quick tips: start slow with your feedrates, rough spindle speeds: wood 12,000 - 20,000 rpm, plastic 4,000 - 8,000 rpm, aluminum 2,000 - 7,000 rpm, steel 200 - 2,000 rpm. Those rpms vary depending on your cutter size and # of flutes. Remember when cutting, heat is our enemy, aluminum and plastic like to melt. Nothing melts them faster than too heavy of a cut at 10,000 rpm. If you have seen my aluminum cutting videos you will notice that when I cut aluminum, my rpms were very high due to the cheap spindle I was using but it cut because I was taking a light cut. In the MDF cutting video I take a very large cut of 7/16 deep and plow right through it like butter. That is because the wood likes the higher rpms.

This is all for now. I ahve to go to sleep.

Andy

Monday, September 1, 2008

Your Custom CNC Router

Modular CNC offers a nice and affordable standard line of products but don't be afraid to ask about a custom application that will fit your needs better. We have over 12 years of experience in designing and building custom machinery for people. Email us with anything you may need.

The "Other" Modular CNC

There is another small business with the name of Modular CNC on eBay. So far that is his only selling venue.

My eBay user ID is modular-cnc

We are not related in any way. I believe I got the domain name first and before I thought about it he got the eBay user ID of modularcnc.

He sells circuit boards and other related products and is located in Canada.

www.modularcnc.com is located in New Mexico USA and sells mechanical components for CNC routers and mills.