CNC plasma cutter: Difference between revisions

From RevSpace
Jump to navigation Jump to search
No edit summary
No edit summary
 
(25 intermediate revisions by 5 users not shown)
Line 2: Line 2:
  |Name= CNC plasma cutter
  |Name= CNC plasma cutter
  |Status=Initializing
  |Status=Initializing
  |Contact= Walter
  |Contact= Walter, [[User:Smeding|Smeding]], [[User:Gori|Gori]], [[User:Yotson|Yotson]], [[User:Semafoor|Semafoor]]
  }}
  }}


Line 9: Line 9:
This goal is still a while away for now, but as always, we are full of Ideas and this is a convenient place to put them.
This goal is still a while away for now, but as always, we are full of Ideas and this is a convenient place to put them.


== Specs ==
== System overview ==
* 3x3 m working area
The diagram below shows the proposed system setup.
* movement speed of 1000mm/s
* Calibrated accuracy and precision of +/- 0.1mm


== Axis motors ==
[[File:plasmacnc.svg]]
[[User:Smeding|smeding]] is going to design and build a proof of concept linear (synchronous) motor for use in the X- and Y-axes. This test rig will be used to determine whether a DIY LSM is at all useful for our application and to finalize the design if we choose to go with the concept. Specifically, this involves figuring out:
* How the attainable accuracy compares to the wanted specifications
* How the attainable movement speed compares to the wanted specifications
* A final design for the drive electronics
* Coil and armature geometries
* Rail geometries (magnet size, spacing and orientation pattern and any backing)
* Optimal control schemes


After this, we'll be ready to construct the three rails (2x X and 1x Y) that make up the bulk of the CNC machine.
From left to right:
* design software (like inkscape) is used to design the shape to be cut and to export it as svg.
* job setup software (unknown, but something like visicut) is used to position the shape and convert it to g-code.
* linuxcnc (or possibly grbl) is used to "execute" the g-code through the control hardware.
* the control hardware powers the motors of the cutting table and controls the plasma torch


== Some rough ideas by Yotson ==
We're basing this project on an old X-Z traversing unit originally made for measuring air velocity distributions in wind tunnels at a metrology institute. The current motor controllers, however, seem to be made for a fixed speed and it's probably easiest to replace the electronics altogether.


*1.5 x 3.0 Meter max. material size. Spec of plasma cutter mentions 12mm as max thickness.  
<gallery>
    Table should manage to hold the weight of a 1.5m x 3.0m x 20?mm sheet of steel.
File:X-Z_traverseerunit_front.jpg|X-Z traversing unit before any modifications
File:X-Z_traverseerunit_stuurelektronika.jpg|Current control electronics with DC-motor controllers and Mitsubishi PLC
</gallery>


*weight of plasma nozzle + hoses/wires?
A Z-axis seems required to control the torch height. It won't need to move very far, quickly or precisely, though.


*length of nozzle + hoses/wires?
== To-do list ==
# Decide how to control the machine. There seem to be two basic options: GRBL and LinuxCNC
#* [[User:Smeding|Smeding]] knows a little bit about LinuxCNC and is willing to do some of the work
# Design and build interface/driver hardware for motors and encoders
#* [[User:Smeding|Smeding]] is willing to help with this
#* [[Benadski]] has motor controller hardware that takes PWM as input.
# Set up a PC that can withstand the general environment of the SparkShack (EMI, humidity, temperature)
# Get basic motion control working so that the machine moves
# Design and build interface hardware for the plasma torch, so it can be turned on and off. Will probably want voltage sensing for torch height control.
#* [[User:Smeding|Smeding]] is willing to help with this, too
# Add a third axis to the machine for torch height control
# Put everything together -- implement the software side of things for torch height control and reading e.g. SVG files


*speed of nozzle over material > 10 cm per second. (non cutting)


*nozzle placement accuracy: < 1mm
connection diagram:
<br>
[[File:XY-tafel connection diagram bewerkt.JPG|1024px]]
<br>


*transportable. Able to fit through 'standard' door (on its side, obviously)


*Maybe:
blokdiagram sturing plasmasnijder<br>
'upgradeable' by placing rotary cutting tool, pencil, knife, spray can, .... ???
<br>
 
[[File:Blockdiagram sturing rev 2.1.PNG|1280px]]
---------------------------------------------------
<br>
 
Transport axes:
x, y:  
angle iron and skate wheels + bearings?
 
 
linear motors?
threaded rod, DC motors, encoders?
 
z  :
? + threaded bolt, manual adjustment between height of 0mm and 50mm.
 
 
---------------------------------------------------   
 
== Threaded rod info ==
ISO standard. From HTTP://en.wikipedia.org/wiki/ISO_metric_screw_thread
{| class="wikitable"
|-
!scope="col" | Diameter in mm.
!scope="col" | Pitch (fine)
!scope="col" | Pitch (coarse)
!scope="col" | Rotational speed 10 cm/s lin. motion (coarse)
!scope="col" | Rotational speed 10 cm/s lin. motion (fine)
|-
|20 or 22||2.5||1.5 or||40rps, 2400rpm||50rps, 3000rpm
|-
||      ||  ||2    ||              ||66.7rps, 4000rpm
|-
|30 or 33||3.5||2||28.6rps, 1714rpm||66.7rps, 4000rpm
|}

Latest revision as of 01:43, 21 October 2015

Project CNC plasma cutter
Status Initializing
Contact [[Project Contact::Walter, Smeding, Gori, Yotson, Semafoor]]
Last Update 2015-10-21

After acquiring a plasma cutter at the space, it seemed only logical to try and fabricate a CNC version eventually.

This goal is still a while away for now, but as always, we are full of Ideas and this is a convenient place to put them.

System overview

The diagram below shows the proposed system setup.

Plasmacnc.svg

From left to right:

  • design software (like inkscape) is used to design the shape to be cut and to export it as svg.
  • job setup software (unknown, but something like visicut) is used to position the shape and convert it to g-code.
  • linuxcnc (or possibly grbl) is used to "execute" the g-code through the control hardware.
  • the control hardware powers the motors of the cutting table and controls the plasma torch

We're basing this project on an old X-Z traversing unit originally made for measuring air velocity distributions in wind tunnels at a metrology institute. The current motor controllers, however, seem to be made for a fixed speed and it's probably easiest to replace the electronics altogether.

A Z-axis seems required to control the torch height. It won't need to move very far, quickly or precisely, though.

To-do list

  1. Decide how to control the machine. There seem to be two basic options: GRBL and LinuxCNC
    • Smeding knows a little bit about LinuxCNC and is willing to do some of the work
  2. Design and build interface/driver hardware for motors and encoders
    • Smeding is willing to help with this
    • Benadski has motor controller hardware that takes PWM as input.
  3. Set up a PC that can withstand the general environment of the SparkShack (EMI, humidity, temperature)
  4. Get basic motion control working so that the machine moves
  5. Design and build interface hardware for the plasma torch, so it can be turned on and off. Will probably want voltage sensing for torch height control.
    • Smeding is willing to help with this, too
  6. Add a third axis to the machine for torch height control
  7. Put everything together -- implement the software side of things for torch height control and reading e.g. SVG files


connection diagram:
XY-tafel connection diagram bewerkt.JPG


blokdiagram sturing plasmasnijder

Blockdiagram sturing rev 2.1.PNG