Hobby CNC, the rotor way

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Hobby CNC, the rotor way

Tres Burritos: Sep 3, 2009

helno posted:

I have been running a very light duty foam cutting machine for a few years now. Occasionally I cut tougher stuff like G10 but it is not really meant for that.

Turn down your volume. https://www.youtube.com/watch?v=6edHmzVR_mg

I work mostly in google sketchup and the designer of the CNC machine I own developed a free CAM plugin to work with it.

http://sketchucam.jimdo.com/ it generates standard gcode that should work with just about any contoller.

http://www.planet-cnc.com/ Controller I am using. Works really well easy to calibrate and setup.

Is that using like ... rollers as one of the axises? I've never seen something like that before.

# ¿ Jul 20, 2013 18:33

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# ¿ May 2, 2024 13:44

Tres Burritos: Sep 3, 2009

Speaking of assholes with super nice shops, I really enjoyed reading this guys:

http://lcamtuf.coredump.cx/gcnc/

stuff.

# ¿ Jul 26, 2013 06:28

Tres Burritos: Sep 3, 2009

I've always thought that this might be an acceptable way to get yerself some aluminum in bar form.

# ¿ Jul 29, 2013 06:35

Tres Burritos: Sep 3, 2009

So I've been wondering, where in the chain from cad -> making cuts does G-Code get changed into revolutions of a stepper motor or servo? Is that what Mach3 or Linux CNC does?

# ¿ Oct 2, 2017 05:54

Tres Burritos: Sep 3, 2009

Sagebrush posted:

Depends on the design of your machine, but yes, sometimes that can happen in LinuxCNC or Mach3.

1) 3D model geometry is analyzed to generate
2) toolpaths, which are then post-processed into
3) g-code, which is interpreted by
4) the machine host or driver (LinuxCNC, etc), which generates a
5) timed sequence of motor steps, which are sent to the
6) motor driver ICs, which convert the step pulses into
7) alternating pulses of the proper voltage on the motor coils, which
8) rotate the motor shafts by the specified amount.

In a more fully integrated machine, like an industrial CNC or a 3D printer, the g-code is interpreted onboard by the machine's firmware and the motor drivers are run from the processor's GPIOs.

So given parts 4 and 5, how do machines running on Mach3 do closed loop? It seems to me like there's no place for feedback in that loop. So if you want a closed loop system are you limited to a more integrated machine? And then don't you lose some of the software functionality?

# ¿ Oct 2, 2017 06:21

Tres Burritos: Sep 3, 2009

As another baby step on my road to a DIY cnc machine I decided to bite the bullet and buy a linear rail and carriage from mcmaster carr. Turns out that they're ground THK rails & carriages :catstare:

.

Explains the price.

# ¿ Oct 7, 2017 21:32

Tres Burritos: Sep 3, 2009

That's totally a piece from a movie prop but I can't remember which. Some sci-fi thing I think.

# ¿ Jan 9, 2019 18:36

Tres Burritos: Sep 3, 2009

I'm trying to wrap my head around how you would measure that two linear rails are:

1) parallel
2) level

For leveling would you use a straight edge and a machinists level?

For parallelism, I haven't the faintest clue. Would you have an indicator on one rail measuring the other? Or would you have like a reference straight edge in between the two and then measure the distance between that to either rail?

# ¿ Mar 5, 2019 19:06

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# ¿ May 2, 2024 13:44

Tres Burritos: Sep 3, 2009

That's a really small work envelope. What's your budget?

# ¿ Jul 29, 2019 23:08

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