bxdobs
Posts: 16
Joined: Sat Feb 23, 2019 1:07 am

What are Realistic CNC X Y Z maximums for a PI CNC

Fri Feb 14, 2020 7:58 pm

Curious ... a PI CNC controller sounds like a cool project but wondering if anyone can provide some realistic specs on the X, Y and Z maximum sizes? Maybe I am looking/reading the wrong details ... all I have found so far are projects scaled in inches (11" max) ... perhaps larger scale projects (in feet or yards) require larger stepper motors and controllers ... as scale increases, expecting mechanics would require motors and controllers able to handle more torque and heat tolerance?

IanS
Posts: 246
Joined: Wed Jun 20, 2012 2:51 pm
Location: Southampton, England

Re: What are Realistic CNC X Y Z maximums for a PI CNC

Tue Feb 18, 2020 11:19 am

The size of a CNC machine is purely a mechanical problem. On the Pi side the position is just a number, and despite being a little computer, it can still cope with big numbers.
Larger CNC machines still need to be rigid, which leads to heavier gantry/platform weight, which leads to more powerful motors, thicker travel rails, and longer and more expensive drive screws, although a lower precision one, such as for wood, can get away with toothed belts instead of ballscrews which do not get ridiculously more expensive with size. A larger stepper motor needs a more capable stepper motor driver, but the control signals sent to it will still be the same.

User avatar
Joel_Mckay
Posts: 294
Joined: Mon Nov 12, 2012 10:22 pm
Contact: Website

Re: What are Realistic CNC X Y Z maximums for a PI CNC

Thu Feb 20, 2020 3:49 am

Yes, there are ways to run linuxCNC... slowly...
http://www.micrometer.xyz/cdn/node/18

The grbl firmware for low precision belt-drive machines can be very fast for engravers.

FreeCAD now has the Path toolbox which generates 3-axis g-code.

Cheers,
J

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