On the website of somebody I’m following, one speaks about a small spanish origin CNC machine, the Cyclone PCB factory (link to the website); I found this project quite interesting for several reasons:
- While it has been designed for PCB manufacturing at the begenning, its uses can be extended to other applications: engraving, cutting of soft and thin materials, drawing, and so on,
- Plenty of parts come from 3D printing,
- A lot of parts are common to 3D printers (bearings, threaded rods, smooth rods, endstops, electronic card amoung others), and since I’ve some extras …
- It’s a way to be initiated to such tooling at a low cost, and another way to take advantages of our 3D printers,
- A lot of links exist on the numerical softs to drive this CNC, all “free”.
I spent last few weeks (among other things) in re-drawing this small CNC under FreeCAD, both to be permeated with this technology, but also to be able to make changes following my needs such as:
- A worked bed slightly bigger, i.e. at A4 format (210×297 mm) – the height/depth is not the main criterion here,
- the clamp device that can be use whatever the size of the substrate is,
- the use of the spindle I finally ordered (at the begenning I planned to use my Proxxon tool)- I’ve to adapt the clamping interface,
- The design of a CNC housing to limitate noise and dust.
Highly instructive project, with its inevitable batch of pain .
A) Current Design modelled under FreeCAD
From the STL files of the 2.2 release (measured under FreeCAD), I redrawn all the parts and I made the assembly; finally few changes will have to be done on the 3D printed parts.
Some pictures of the project :
In the attachement the merged CAD assembly (PCB_cyclone_assembly_muxed – compressed file with 7zip) – the validated model will be uploaded after that some small changes are done and bugs in the Assembly2 module fixed.
Please note the CAD model includes dozains of parts (including the screws and the washers for example), and a lot of sub-assemblies: this experiment is quite formative in FreeCAD design point of view.
B) (My) new design
NB: the weight of the spindle exceeds 900 grs that is quite heavy especially for 8 mm smooth rods (remind the second moment of inertia and the deflection consequently directly depends on the diameter in ), changing to 10mm smooth rods is a sustainable solution.
In addition I would like to use a “working bench” of A4 format (297 x 210 mm) instead of the current 160 x1 00 mm.
The CAD models and the part list are currently upgraded (some parts to be ended).
Linear bearing LM08UU
Threaded rod M8
Smooth rod Ø8 mm
screws M3 and M8
|Arduino + shield CNC||14.08€||information gave in a forum (need to be tested)||Aliexpress|
|Crocodile clip cable (batch of 5)||2.34€||One is needed for the auto-levelling||Aliexpress|
|Spindle 400W||95€||Collet ER11 + PWM speed controler||ebay|
|PSU 48V||26.82€||PSU 480W||Aliexpress|
D) 3D parts printing
The last few weeks have been devoted to master the 3D printer and its software (Repetier in that case). The first parts were printed even if the (re)design of the CNC has not been finished (see figure hereafter):
- the parts in orange are identical to the ones of the original design
- the parts in black were redesigned in order to take into account the changes (new smooth bars diameter and the bushing consequently – Igus® bushings instead of the traditional LM10uu linear bearings have been chosen).
|(first printed parts)||
2nd frame printing failed after 5 hours and
at 3/4 hour to the end 😕
For the 3D printing, I used the following diameters:
- (nozzle of 0.4 mm),
- Material : PLA for all the parts except the ones in contact with the spindle that will be in ABS material,
- Hotend température at 210°C (measured with a thermocouple onto the heater block) and the bed at 50°C,
- infill at 40% – pattern = grid,
- Skin/shell thickness of 0.8 mm,
- “Raft” systematically used (easier to unstick the part from the bed, especially the parts having a huge contact surface),
- at least 2 parts are printed at the same time, except for the frame (huge surface and long duration – more than 5 hours).
E) Final Assembly
F) First tests
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.