CNC Router: Difference between revisions

From CoMakingSpace Wiki

m (→‎WorkBee: InfoBox line break)
(→‎Materials: moving detailed content to "milling experiences"; replaced with general information)
(3 intermediate revisions by 2 users not shown)
Line 21: Line 21:
|location=[[CNC Room|CNC room]]
|location=[[CNC Room|CNC room]]
|access=upon [[CNC Router Introduction|introduction]]
|access=upon [[CNC Router Introduction|introduction]]
|status=needs a last checkup after Z axis modifications<br>(e.g. tighten screws, level spoilboard)
|status=operational (please observe for any <br> problems due to the modifications)
|firmware=[[grbl]]
|firmware=[[grbl]]
|software=[[LaserWeb]], [[Fusion360]], see [[G-Code Sender]]
|software=[[LaserWeb]], [[Fusion360]], see [[G-Code Sender]]
Line 61: Line 61:
* https://www.thingiverse.com/thing:2802301
* https://www.thingiverse.com/thing:2802301


=== G-Code Sender ===
=== Workflow ===
'''This is just an overview and does NOT replace the [[CNC Router Introduction|personal introduction]]!'''
 
# create the tool paths in a suitable CAM software (e.g. [[Fusion 360]])
# [[CNC Router Workholding|secure your workpiece]] on the machine's bed
# insert the appropriate collet & bit as defined in your tool paths
# turn the positioning motors on, home the machine and define the workpiece origin
# put on [[PPE|personal protection]] and turn the spindle on
# send the tool paths to the router in real time via the serial interface (USB)
## options can be found under "[[G-Code Senders]]"


After creating the tool paths in a suitable CAM software (e.g. [[Fusion 360]]) they need to be sent to the router in real time via the serial interface (USB). <br />
Our experiences can be found on: [[G-Code Sender]]


<br clear=all>
<br clear=all>
Line 80: Line 87:
(''For more details, see "[[Milling Experiences]]")''
(''For more details, see "[[Milling Experiences]]")''


=== Plastics ===
CNC routing is most appropriate for non-metal panels/boards. The exact material might dictate your choice of [[endmill]] or [[Router Bit|router bit]]!
[[Material:PC|Polycarbonate]] works better than [[PMMA|acrylic glass]].
 
=== POM/Acetal/Delrin ===
 
==== Bits ====
tested with 2 and 3 sided HSS Bits 4mm-6mm but no indication against any other diameters
 
==== RPM, Speeds, etc. ====
Spindle on level 1 (=16 000rpm)
* Schnittvorschub: 500mm/min +
* Einfahrvorschub: 500mm/min +
* Ausfahrvorschub: 500mm/min +
* Helixvorschub:  200mm/min +
* Eintauchvorschub: 30mm/min
* Depths: 2-3mm
Strongly advise a horizontal Rohteilaufmaß and a final finishing cut to remove any "layer" marks.  
 
==== Cooling ====
Not neccessary with the current settings but might increase the cutting speeds drastically
 
=== Plywood ===
Most kinds of [[plywood]] should work, but of course you only get out what you put in - Micha has had bad experiences with pine plywood as it is much too soft and likes to warp.
 
=== [[Aluminum]] ===
Possible with a lot of patience and the correct bits, but check if it's millable aluminum
* different alloys of aluminum containing Cu, Si, Pb
 
==== Bits ====
maximum two cutting sides
carbide is more rigid than HSS and advised by some online guides
Tested 4mm 2-sided pointy-end bit with acceptable success
 
==== RPM, Speeds, etc. ====
Values are only the tested ones, faster CAN be possible as well
* slow RPM: 16 000 is our minimum but e.g. for a 4mm bit, 6000 RPM would be better 
** different mill or PID-ing?
* Feed Rate/Schnittvorschub: ~200 mm/min
* Einfahrvorschub: 15-20 mm/min
* Ausfahrvorschub: 200 mm/min
* Helixvorschub: 15-25 mm/min
* Eintauchvorschub: 15 mm/min
* Depths: 0.25mm per pass
 
Milling directions (to be tested): Conventional/Up-Cut (Gleichlauf) milling milling for the basic different passes with a finish using Climb-milling/Down-Cut milling (= Gegenlauf)


===== Cooling =====
Cutting certain metals, e.g. millable aluminum, may still be possible with a lot of extra work, but a rigid and liquid-cooled [[CNC Mill|CNC mill]] would be the proper way to go.
Not yet tested
* any sort of lubricant or coolant will increase the efficiency of aluminum milling
** there are suggestions ranging from cutting fluid over WD-40 to candle wax for lubing
** As coolant, a water or alcohol mist seems unsuitable with our pressboard
*** instead, using the air compressor might be a possiblity


== Helpful Links ==
== Helpful Links ==

Revision as of 15:54, 25 November 2018

CNC router.gif

A CNC router is a computerized woodworking machine - basically a router mounted on a positioning system. While it may also be able to handle other materials than wood depending on the bits you use, a proper CNC mill is more precise for machining parts out of metals and other non-wood materials.

To use this machine, you need to familiarize yourself with at least two pieces of software:

There is also an interesting new approach of handheld CNC routing coming out which may remove the size constraints that come with any fixed-frame machine.

Uses

You can make furniture or even build a house. For more ideas, check out the CNC Milling Ideas.

WorkBee

MachineInfoBox

Ooznest WorkBee CNC

Workbee frame.JPG
Synonyms: DE: CNC-Fräse, Portalfräsmaschine
Material: wood
Used with: 6 mm, 8 mm, 1/4" or 1/8" end mills;
some kinds of router bits
Location: CNC room
Access Requirements: CNC Router IntroductionSome use of "" in your query was not closed by a matching "".
Status: operational (please observe for any
problems due to the modifications)
Firmware: grbl
Software: LaserWeb, Fusion360, see G-Code Sender
Manual: product page, click "documentation" tab
Tutors: NitramLegov
Pakue
Johannes
LuzianSome use of "" in your query was not closed by a matching "".
Similar (More or Less): router, CNC mill


We built the 1500mm x 1500mm version of the WorkBee CNC, which is based on the Openbuilds OX. It can currently cut sheet material of up to 50 mm thickness on a work area of approximately 1250 × 1250 mm.

Details on setting it up can be found in issue #8 - maybe you would like to help?

Router

The router mounted to it is a Dewalt D26200 (GB; known outside Europe as DWP611). You need to consider the sizes of its collets (Spannzangen) when buying your router bits.

  • no-load speed: 16000 - 27000 rpm
  • max cutter diameter: 30 mm
  • available collet diameters:
    • 6 mm
    • 8 mm
    • 1/4 inch (6.35 mm)
    • 1/8 inch (3.175 mm)

The collets of the DW613, DW620 and DW621 also fit the router and are easier to get in Germany than the original ones.


Electrics

The spindle and the CNC controller + motors are hooked up to an electrical box on the left wall. You'll find a switch and an outlet for the spindle there. In case of an emergency the whole box can be shut off via one of the two emergency stops (inside the CNC room and on the outside above the access control). Everything except the Raspberry Pi will be turned off in that case.

Dust Extraction

We have added a cyclone dust separator between the shop vac and the CNC router itself. Thereby, the bulk of the shavings and dust should be collected in an easily emptied box rather than the shop vac's bag.

The part that attaches the dust extraction hose to the router is called a "dust shoe". We are currently using this one designed by Patrick. The next version should ideally fit the dust extraction hose without an adapter and include a kind of transparent, flexible "skirt" to optimize the airflow.

Other interesting designs:

Workflow

This is just an overview and does NOT replace the personal introduction!

  1. create the tool paths in a suitable CAM software (e.g. Fusion 360)
  2. secure your workpiece on the machine's bed
  3. insert the appropriate collet & bit as defined in your tool paths
  4. turn the positioning motors on, home the machine and define the workpiece origin
  5. put on personal protection and turn the spindle on
  6. send the tool paths to the router in real time via the serial interface (USB)
    1. options can be found under "G-Code Senders"



Tips & Tricks

  • to avoid tear-out at the edge of a sensitive workpiece, it may be worthwhile to surround it with some sacrificial material (like MDF) before routing [1]

Spoilboard

Ooznest recommends a 6mm spoiler board, our first one is 20mm thick. It is mounted to the frame using 4 drop-in T-slot nuts. Cutting into the boards will make it uneven, from time to time it is neccessary to surface the spoiler board again.

When there is time, we would like to drill workholding holes into the spoilboard.

Materials

(For more details, see "Milling Experiences")

CNC routing is most appropriate for non-metal panels/boards. The exact material might dictate your choice of endmill or router bit!

Cutting certain metals, e.g. millable aluminum, may still be possible with a lot of extra work, but a rigid and liquid-cooled CNC mill would be the proper way to go.

Helpful Links