CNC Router
Description
We currently have a under construction C BEAM based CNC Mill. The mill took its first cut on 20/02/2016.
The CNC Mill is based on the C BEAM profile from open builds, it is currently a X/Y table type "C BEAM MACHINE" thats 400x400x120mm but we have all the parts to make it a 1000x750mm gantry style ASAP.
To use the machine you have to be inducted; it is also a numerically controlled power tool with a variable Z and so considerable care should be taken in preparation and operation.
Please see the CNC_Mill/Feeds_and_Speeds page for information on the kind of cut settings you can use on the mill when setting up your CAM.
Specifications
- 800W water cooled spindle 220V 6.5A with ER11 collet
- 1.5kw VFD capable of 3000-23000 rpm
- 3.2Mn NEMA 23 steppers
- 20V 4 A power supply
- 2.5A Stepper drivers
- Control via GRBL running on a arduino screw terminal sheild
- Raspberry PI serial to JSON server making the CNC shield available on chillipeppr.com when at the space.
- 325x250x100mm workspace
- No load max feed of 5000mm/min
- 6 x Capacitance 6-36V end stops
Configuration
Here is the basic configuration of the machine to judge it against others you may see.
GRBL
The CNC uses G code parsed by GRBL. Send the command $$ to GRBL to read the current configuration. This should not be changed unless something significant changes with the machine.
- X steps/mm = 200 (1/8 microsteps)
- Y steps/mm =
- Z steps/mm =
- Accel X =
- Accel Y =
- Accel Z =
- Max Rate X =
- Max Rate Y =
- Max Rate Z =
VFD
The spindle is controlled by a VFD. The current configuration settings can be found on the VFD page.
Drivers / Motors
Drivers are TB6600's 'capable' of 50V 5A
- 1/4 microstep mode
- Full power
- Supplied with 36V
Motors are 3.1Nm Nema 23
- Wired in series mode
- [Datasheet]
Build notes
The end stops are wired as follows:
1 - Positive 2 - Gnd 3 - Signal 4 - Signal
Experimentation is required to determine which detector
Pledges
A pledge tracker can be found on this google sheet [1]
Design
The first machine is a 'out of the box' C Beam Machine kit [2]. This is a X/Y table machine based on the C Beam aluminum profile which offers better stability and accuracy than OX type v slot or shapeoko.
This kit will be used to make the plates for its own upgrades into our specific 1000mm x 750mm gantry style machine with dual X drive based on this design. [3]
Parts Status
We have purchased the majority of parts from Colin at robocutters.co.uk[4], he offered a wealth of advice, a great discount and is genuinely interested in supporting Hackspaces.
- A C Beam machine kit
- 3 NEMA 23 Motors
- 1 1000mm linear actuator kit
- 1 750mm linear actuator kit
- 4 750mm 60 aluminium profiles
- 16 wheel kits
From China we ordered as a kit:
- 800W 60mm mount water cooled spindle
- 1.5kW VFD
- 12 VPump
- Various collets
From other sources:
- 6 C.P type limit switches (swwils)
- Radiator (swwils)
- 4 Core spindle cable (swwils)
- RUMBA Board + Drivers (Martyn)
- E-stop (Aidan)
- Arduino CNC sheild (swwils)
- Arduino UNO (swwils)
- 36v 10A PSU (Aidan)
Parts needed
- Cable chains (larger machine)
- Regular stop / go button
Build log
- First cut occurred
- Limit switches installed.
- Hard limits set
- Soft limits set (but broken!)
- Dir inversion issues (0,0 should be lower left?)
- Dir inversion worked out (its actually correct to set machine into negative space)
- TB6600 Stepper Drivers Installed
- Wasteboard installed
- Some hold downs installed
- Machine tightened and thread locked (blue)
Upcoming
- Writing documentation
- PWM spindle control / enable
Software Proposals
GRBL vs TINYG [5]
CAM [6]