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Thread: CNC For Dummies
12-23-2010, 08:30 PM #1
CNC For Dummies
Hello, I'm looking into CNC machining for my gunsmithing business. Where do I start in the big world of CNC machines?
Any help is appreciated.
12-23-2010, 08:34 PM #2
Figure out what your needs are first.
Are you looking for a machine first then try your best to program it?
12-23-2010, 09:04 PM #3
Just like any machine purchase, there are things you must identify first. The answers to these questions lead you to the machine that best suits the application.
1. What parts are you making?
2. What materials are they?
3. What processes do you want to run on the machine?
4. What standard tooling is available to do the processes?
5. What workpiece size do you need to machine?
6. What is the required throughput?
7. What is the required accuracy and repeatability of the parts? (A & R are _not_ the same thing!)
8. What is the budget?
9. What is the ROI time required?
10. What is the daily operational time of the machine expected to be?
11. How much room do you have to place the machine?
12. What are your power options?
Answer these questions and then we can help a considerable amount.
12-24-2010, 06:56 AM #46. What is the required throughput?
12-24-2010, 07:21 AM #5
CNC For Dummies
Most of your work will be in milling, drilling, and all the parts are pretty small.
There are a lot of used milling machines available, look for a used on, but make sure you see it in operation. I suggest you get a machine with the Fanuc control.
To start learning about CNC programming, look at the mill-drill examples I have on my website, you will see that its not too complicated.
Over the years I have trained a few guys in a position like yours, just getting started, they learned it and so can you.
Good luck, write to me with any questions you might have, the email is on the website.
12-24-2010, 07:27 AM #6
12-24-2010, 07:35 AM #7
Thank you Tony, agreed! I've simply never heard that terminology. "Throughput". I would agree that it is pro'ly the factor. In my case it would be as much as humanly possible plus some. Getting into 30 hour days and metaphysics and stuff.
Maybe the terminology is a Southern thing
12-24-2010, 07:49 AM #8
I am in the same boat as you I want to learn cnc but have no experience so I just went out and got an old inexpensive mill and I am going to mess with it and learn how to run it. I set my expectations pretty low I want it to do simple tool paths back and forth across fixtures that I have and use on manual machines. It will be up and making money in a few days even with my lack of understanding. I learn best just teaching myself so I got a bunch of books and a machine and will hit the ground running after christmas.
12-24-2010, 08:25 AM #9
1. Detachable magazine systems for rifles. Commonly called Bottom Metal and Clip.
2. Aluminum, 316 SS & 4140
3. I want to be able to complete all the machining on the mill. (Wasn't sure how to answer this one)
4. I don't foresee any exotic tooling needs. End mills, fly cutters etc.
5. Workpiece blank will be 6" x 1 1/4" x 4" (LxWxD)
6. Minimum orders are 50 pieces.
7. +- .001, repeatability must be very high.
9. 3 years.
10. 3-4 hours.
11. Garage workshop scenario.
12. 220 single phase.
Thanks to you all for your replies.
12-24-2010, 09:04 AM #10
I agree the best way to learn something is to get into it a make a mess. No learning like fixing your own mistakes.
My local community college has a good selection of CNC courses I have discovered. Fairly inexpensive at $400.00 per course for 36 hours of instruction.
CNC - Introduction to Programming
- This course introduces the learners to CNC terminology and codes. Learners will apply mathematics and machine code to create CNC programs.
CNC Intermediate - Milling
- Focus on the operation of the CNC machining center and the CNC milling center. Focusing on a hands-on approach, students will expand on skills acquired in the introductory course. Students will produce a first-off workpiece by using programming and editing fundamentals to set-up, edit programs, and produce a first-off work piece.
- Utilizing MasterCam software, this course addresses advanced word address (G-Code) programming for both machining and turning centers, canned cycles and macros. The principles covered are applicable to a variety of CAM software packages and CNC programs.
CNC - Intro to Controllers
- In this course learners operate controls for the CNC machining centre and the CNC turning centre. They program and set the control to simulate a part program in operation. This course provides the theoretical foundation for the hands-on CNC intermediate lathe and mill course.
I think I will look into some of these.
12-24-2010, 11:52 AM #11
I highly suggest the classes.
Since the budget is low and it's a small business, I agree with Heinz in that a used machine is probably the only option here. I don't know that you'll hit your budget with a good machine. Probably be a fixer-upper in that price range. Most will require 3-phase, this means an RPC is most likely going to be required. For the parameters you noted, most any decent smaller CNC mill will be capable.
12-24-2010, 12:05 PM #12
Remember also to budget for vises, tool holders, cutting tools, etc. And phase converter if needed.
12-24-2010, 01:03 PM #13
Theoretical machine output - all influencing factors = effective throughput.
It's the "real" value of average # parts off the machine in a given time period on a regular basis. It encompasses change over, tool changes, operator breaks, maintenance issues, scrap and anything else that would have an effect on average good parts output.
12-24-2010, 02:02 PM #14
12-26-2010, 02:16 PM #15
You're going to have a hard time meeting those requirements with a 10K budget. I wouldn't try machining any 300 series S.S. on a cheap hand machine (which is what you'll get for 10K). If you're assembling guns and distributing them, you should really outsource your work.
You can't even buy a decent indexer for a milling machine with 10K.
Look at our company's website. That material is gravy, with the right machine. We've machined loads of parts for DOD and gun manufacturers.
Screw Machine Shop - Screw Machine Parts and CNC Machining - Progressive Turnings -
12-26-2010, 03:58 PM #16
12-26-2010, 04:56 PM #17
My introduction into CNC was a love/hate relationship.....it started with a used cnc lathe from auction (big mistake!!)...
Then after a year with messing around, I ditched the old machine and bought a new machine with all the goodies I wanted, a warranty and factory help..
4 yrs later and I'm hear with big smiles.....after factoring the machine payments that will disappear next year, this has been the single best part of our 32 yrs in business...
Hind sight is 20-20, I do use the conversational programming in the control for one/offs, but learning G Code has been coming along.....
Of course I'm talking lathe work rather than mill work, but my suggestion would be to jump in to the newer controls and the rest will come easier after the initial learning curve.....
Having a budget too low blows this theory away though......
12-26-2010, 05:38 PM #18
10k was a number I picked without any background on the CNC machines. Like any business the outlay of capital is based on the sale of the product. The parts that I am currently targeting all retail between $200-$300. I am trying to break into the market as a supplier, so I can't pin down my sales volume yet. I would have to think long and hard before I parted with much more then 10k. Perhaps I should outsource the parts first, establish a market and them move into manufacturing.
These parts are available in the US but trying to import them into Canada is proving harder and harder. The US government is imposing huge fines on companies that haven't paid the licensing fees. I have to buy a license as well just to receive the products. It's a shame really the folks I have been dealing with are great people but the profit margin is getting smaller and smaller with all these news fees etc.
12-26-2010, 06:28 PM #19
I sold and installed a Bridgeport Boss cnc mill to LeeRoy Wisner about 15 years ago. His first cnc. The BP Boss series with a Centroid retrofit with probing typically brings $6500.00 usd in decent shape, with tooling. If tight, it is capable of the repeatability you mentioned. You will make lots of money and lots of parts. Here is the current page from Brownells , Wisner gunsmiths offer.
Brownells Search - World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools
12-28-2010, 02:13 PM #20
CNC For Dummies
You probably know that there are a lot of small shops here in the US making parts similar to what you are making.
I had a guy here for a couple of days of training, he is from Utah and bought a CNC mill from a local dealer.
We made a mount for a front scope that goes unto a custom rifle.
He sent a print ahead to me and I helped him to quote the part.
If I can help you, I'll do the same for you as a free service, its no big deal for me to figure it out.
The machine he bought is the rotary pallet KIA mill you see on the video on my website.
Its cost was almost double what you are looking for, but it will give you an idea.
He pre-learned from my mill DVDs before coming here. The CNC knowledge on my DVDs is generic and applies pretty much to any of the Fanuc mill controls.
Good luck: Heinz.