Cutting aluminum

[rocks101]

Hi guys, I just bought and finished assembling the hobbycnc kit with the 3 200oz/in stepper motors, are these powerful enough to cut aluminum, and if so what mode should i run them in. Any help would be greatly appreciated thank you.

[WP1]

The short answer is "certainly" with the qualification of the right machine design, the right cutting tools, feeds, speeds, etc.

There are a great many variables that will determine the prcaticality such as the size of the machine (mass of the moving parts), type of drive (inefficient threaded rod vs. efficient ballscrews), Type of aluminum to be cut (many different grades and tempers), etc.

The machine that I've been building is currently using threaded rod until I am satisfied with it and convert it to ACME screws. I'm using 80 oz steppers with the HobbyCNC chopper board. The approximate work area is 2' x 2' x 12" and I have a RotoZip RZ1 as a spindle.

I haven't tried aluminum yet since I'm still finishing construction, but I have done test cuts in MDF that leave me with little doubt that with a good 1/4" end mill and a speed control to slow the spindle down to a suitable speed this machine could reasonably cut aluminum with moderate depth passes.

The 200 oz steppers should give you plenty of strength as long as the rest of your machine design is appropriate.

Pete C.

[rocks101]

Thanks for the info wp1, im thinking of having a work area of also 2'x2' and the machine will be built entirely out of aluminum, because i have acess to a machine shop. I'd like to know what mode should the steppers be run in 1/2,1/4,1/8 or 1/16 to give the most torrque.

[MrBean]

I don't think the microstepping settings will change your motors torque. It certainly won't improve it. The main reason for microstepping is to reduce motor vibrations. It also increases your resolution and the amount of step pulses required to move the motor any given distance.

Regards Terry.....

[ger21]

Originally Posted by MrBean I don't think the microstepping settings will change your motors torque. It certainly won't improve it. The main reason for microstepping is to reduce motor vibrations. It also increases your resolution and the amount of step pulses required to move the motor any given distance. Regards Terry.....

Microstepping really doesn't increase the resolution. This explains it beter than I can. http://www.machinedesign.com/ASP/vie...strSite=MDSite

[MrBean]

Yeah. I've read that kind of thing before. Although that is correct and accurate. On my machine I changed from full step drives to microstepping, due to resonance problems. When I cut a circle out of some material with the old drives (full step), you could see small ridges where the axis were interpolated to cut the circle. With the new drives (1/8 mircostep). Those marks are not visable, even under an eye glass. So for me resolution was increased (the smallest movement achievable). Accuracy is within .003" and I'm happy with that. It's more accurate than I expected it to be. I'm still fiddling with the setup, so it may get better yet.

That's my experience so far, but I'm hardly a seasoned CNC'er.

Regards Terry.....