Gunsmithing Taking a CNC course

[winniedonkey]

I'm set to take a 18 week course in a few months. I figured this would be the best place on here to ask about what I can do to make myself as successful as possible. I'm already set up for math review/studying, however any focus points would be a huge help. No machining background, just excited to learn. Follow on schooling is being looked into currently. Greatly appreciate any help. Thanks.

 

[Ledzep]

Get familiar with Cartesian coordinates, X, Y, Z.

Work and tool offsets, and basic G and M codes. Feeds and speeds, maybe tooling geometry for different materials.

I'm sure they'll cover it all but it doesn't hurt to have a clue before hand.

 

[flyer]

You need some machining background. At minimum, buy a Chinese mini-lathe, a bench grinder for sharpening the tools, a pair of calipers, a micrometer, some drill bits, several feet of brass, steel and aluminum bar stock and a jug of cutting fluid, then learn to cut, face, drill and bore.

That will give you a bit of feel and using a shitty lathe will let you figure out how to deal with chatter and other machining problems that you might never see with a better lathe.

Machining on a mill isn't going to translate exactly but it should give you enough of a base to work with.

 

[winniedonkey]

Thanks for the replies. Noted and on it. Any recommendations on a lathe that is a good starter?

 

[flyer]

Get something cheap. Learning to work around it's flaws is one of the big lessons.

 

[winniedonkey]

Understood.

 

[eMc9002]

How much was your course? I have no Machining background whatsoever (just trades). Looking into this myself.

 

[TxSteel]

Get familiar with Cartesian coordinates, X, Y, Z.

Work and tool offsets, and basic G and M codes. Feeds and speeds, maybe tooling geometry for different materials.

I'm sure they'll cover it all but it doesn't hurt to have a clue before hand.

Everything Ledzep said, and i would emphasize learning feeds and speeds.

 

[winniedonkey]

I stopped in the other day to drop off paper work, literally everything yall have said was all over the white boards. Must be important stuff, haha.

 

[winniedonkey]

How much was your course? I have no Machining background whatsoever (just trades). Looking into this myself.

7k

 

[J McGriddle]

Learn how to read measuring tools. You can't make a precision part if you don't know how to read micrometer and test indicators.

 

[damoncali]

Buy a copy of the machinery's handbook. You can get lost for hours in there reading about things you never knew existed. You can get a copy of Autodesk Fusion 360 for free (for educational/noncommercial use) and get a feel for 3D CAD. And while not directly applicable, you might benefit from running through one of the free online tutorials on computer programming just to get in the frame of mind of telling computers what to do.

Another take on the mini lathe: If you pick one up, you need to take it easy on the materials. Delrin, aluminum & brass are ok. The only steel that isn't frustrating to cut is 12L14. None of those require cutting fluid on a mini lathe. You'll probably want to sell it when you're done, as they're very limited (the spindle bore is something like 5/8", and they chatter and crash at the drop of a hat - they're just not very rigid or powerful). I'm not sure how helpful it would be, to be honest. They're really poor quality and not at all comparable to whatever it is you'll use in class. With some hands on instruction and a real lathe, you can probably learn in an hour what it would take a week and $1500 to figure out on your own with a mini lathe. I've gone the latter route, and it's a long, somewhat frustrating process.

 

[MGN]

Learn trig. Once you understand Soh Cah Toa you can understand what the prints are missing so you can program correctly. This will help with bolt hole locations angle locations and other features.

 

[Threadcutter308]

Get something cheap. Learning to work around it's flaws is one of the big lessons.

Unfortunate, but very, very true. The above is very good advice.

 

[Vargmat]

Trigonometry is key, you will need it alot.
I studied trig for 2 months straight when I became a certified CNC-machinist.

 

[flyer]

Another take on the mini lathe: If you pick one up, you need to take it easy on the materials. Delrin, aluminum & brass are ok. The only steel that isn't frustrating to cut is 12L14. None of those require cutting fluid on a mini lathe. You'll probably want to sell it when you're done, as they're very limited (the spindle bore is something like 5/8", and they chatter and crash at the drop of a hat - they're just not very rigid or powerful). I'm not sure how helpful it would be, to be honest. They're really poor quality and not at all comparable to whatever it is you'll use in class. With some hands on instruction and a real lathe, you can probably learn in an hour what it would take a week and $1500 to figure out on your own with a mini lathe. I've gone the latter route, and it's a long, somewhat frustrating process.

Depending on the school, if you get a week behind in the class, you might not make it through. I don't know of schools that ever give back tuition so that $1,500 might be well spent although you probably don't have to spend that much to get a cheap mini lathe, bench grinder and the rest I mentioned above.

 

[MGN]

I would also suggest looking up and learning GD&T

 

[Waorani]

Soh Cah Toa

Long time since I've heard that.

 

[MElank]

Throughout engineering I could never remember Soh Cah Toa or was it Sah Coh Toa? I just started calling it SOuthern CAlifornia. Never had a problem!

 

[mcfred]

Fixturing, order of operations, and tooling speeds and feeds for a given material are what you should learn. If you can hold it, know what to cut, when and how to cut it, then you're set. That applies to all machines; manual or CNC, lathe or mill.

MGN's suggestion on GD&T will greatly help you understand what all the line art on a blueprint means. It will not teach you how to be a draftsman or an engineer. Lots of engineers are poor draftsmen, and worse machinists. I can engineer you something that's impossible to machine. Some of the best engineers I know started out sweeping the floors at CNC machine shops as teenagers, who went on to get their Engineering BS.

Trig helped me a lot, but there's lots of software/tool path generators available that will fill that hole if necessary. Learn Trig if you intend to choose a career as a machinist, as a hobbyist there're work-arounds.

*edit* can't spell.

 

[wildbill38]

Buy an old used copy of machinery handbook.
Buy a heavy 10 Southbend. It will stay with you for ever, start to finish.
Just start turning things.
Buy a good heavy duty pedestal grinder. Light stuff will just frustrate you.
Good calibers and micrometers, the rest you will accumulate as you learn. (Never ends)
The math part will come along as use the tools to turn, thread inside and outside and get used to runnig the lathe.
With you own equipment you will learn chip load, (speeds and feeds )and the oh no factor.
It is still cheaper than crashing a CNC machine.
Learn to make drawings and then make the part. Expect to pay dearly for a good cad,cam program.
I realize it may cost you more than you intended but a fundamental foundation will really help you along.
Have a good time learning the trade.
Strictly my own opinion. I am 72 and still at it.
Bill

 

[winniedonkey]

Thank you everyone for the advice. As I learn and have questions I will bombard you all for guidance. The nice thing is they allow you to stay after class and come in on fridays if one wants to. Luckily I am just smart enough to realize the blessing that extra training has to offer.