Student Building a CNC Machine for Metal

[MetalCNCing]

Hi,

I'm building a CNC machine, for fun (yes im only 15, HS student), I have these slides and Steppers (880oz-in) , with a five axis driver and output buffer for higher amperage.

Steppers: http://www.orientalmotor.co.jp/cgi-b...K&frameSize=85

Slides: http://igus.bdol.com/show_hts.asp Model: HTS-30-AWM

I want to machine steel, other metal's, plastic, and wood!!

But I dont know if the steppers can handle the table, and the steel machining, I dont mind if it moves slow, I just want 2 machine metal (steel, brass, an what not!!)

My setup is moving table (like a router X-moving-table, Z mounted on Y), 54" by 54", so I would like some feedback on what I can do, other options, about the steppers and gear-boxes, and what ever else u can think of!! I havent spent a penny on this equipment, all donations! So im not buying anything!!!

[sendkeys]

what is your budget?

can't really help until we know that

With money you can do anything. but im guessing you dont have alot? as i was broke when i was 15 :P just the software might be to much for you for anything but a 2axis router system.

talking 200 for the cheapest 3axis software i know of. then maybe run it with turbocnc but that is 60 now i think. really be nice to run it on mach2/3(150)


do you have access to software in your school? or are you only thinking 2axis ? doing somthing like dxf cad pictures to gcode.

[Bloy2004]

I CAN say for sure that those unsupported bars on the slides will be inadequate for rigidity when working metals.

[MetalCNCing]

I havent built this machine yet, I'm just asking for idea's, but I want 2 know about how many (oz-in) of torque i need 2 machine steel. Is the 880oz-in enough?

I have the software, and hardware interface (5-Axis), I'm trying to build the machine now, software is later, I have a shopbot controller, rebuffered for high amperage output up to 15Amps per Stepper/Axis (48v power-supply).

Thanx

-Allen

[balsaman]

Yes, it's enough. You have access to a machine shop? What are you making this machine out of?

Eric

[sendkeys]

hmmmm ok then.

[JFettig]

Im impressed, at 15 I had just bought my mini mill and learned how to machine, it sounds like your a little ahead?
It also sounds like you have some funding for this? How big are you looking to make this machine?
Have you considered getting a mill/drill and converting that instead. It may make life a little easier, You will also be able to use those stepper motors.

Are you actually thinking about building a 5 axis machine? If so, there are ways you could actually convert a mill/drill into a 5 axis machine. A squair column mill would be needed and access to lots of equiptment Im sure.

you may want to take a look at this site, the design for 5 axis mill that Im thinking of is how he does his mill. rotary table and rotary B axis head.
http://www.rainnea.com/cnc_5axisMill.htm

Jon

[MetalCNCing]

I havent decided yet (dont know which is better), Aluminum (6061 or 7075) or Steel. But on the steppers, should I put a gear-box? For more torque, dont mind for slow machining!! I have another question about the router motor, for machining steel, or (metal in general), how many HP motor do I need? (7.5 or 10HP?) and or High Frequency?

[UKRobotics]

7075 is better than 6061 but considerably more expensive. You will also want one that is quite hard such as T6 as the softer tempers are easily scratcted and damaged. Most of the machines i've seen have the stepper motors connected directly to the ball screw but it all depends on which ball screw you are using, the motors you've got, how fast you want it to go and how much torque etc. 7.5HP motor ?! or 10?!!?! both sound a little high to me. I think you'll find only the big bridgeport VMC type machines will use a spindle motor that big. 1hp = 750watts, 10 x 750 = 7500, 7.5kw = 31.25 amps @ 240v or 65amps @ 115v. If you want to use a motor that size you will really need to think about 3 phase. For reference, my 360mm x 120mm x 200mm mill which weighs about 300kg and will cut most metals quite happily only has a 0.8kw spindle motor.

[PaulH]

Even if you're building a metal mill, you don't need that much HP. The big thing to remember is that metal doesn't require a lot of RPM to cut. Sometimes less speed and more torque is the right answer.

The Sherline and Taig mills are quite capable of working with aluminum. I have a friend who does it all the time. The Sherline mills have a 1/3 HP motor that runs between 70 and 2800 RPM using an electronic speed control.

I havent decided yet (dont know which is better), Aluminum (6061 or 7075) or Steel. But on the steppers, should I put a gear-box? For more torque, dont mind for slow machining!! I have another question about the router motor, for machining steel, or (metal in general), how many HP motor do I need? (7.5 or 10HP?) and or High Frequency?

[MetalCNCing]

Well I dont have 3-phase available, but i have 100-Amps@240V sub-panel in garage (in-house). I want to machine steel at 2-Inches/sec, Can you guy's possibly tell me some company where they have spindles for machining metal (steel), but I'm going to machine other materials as well like plastic and wood! So it has to work for almost everything!!

I have AIM, if you want to chat, My SN is: ProDJAllen007

Thanks everyone!!

[JFettig]

ok, now you just have crazy ideas, you want to machine steel at 120ipm, good luck bud.

Jon