The Argon firmware release 2.0 beta version together with Granity 1.8 preview is now available for public testing!
For complete list of changes and downloads, see this page. We’re reading every feedback, so please send some of your thoughts in comments here, or by email :-)
Due to popular demand, we brought BL series servo motors back in stock!
They have little bit different specifications than the earlier BL series motors. Now these motors are rated between 24 and 48 VDC which makes them ideal match with IONI drives. Also BL70 series motors have been upgraded from 4 000 CPR to 10 000 CPR encoders for smoother and stiffer operation.
Servo motor selection
The awaited IONICUBE 1X has been now released and available through the web shop! Also documentation is online in the Wiki.
IONICUBE 1X
On-board features include:
Granity configuration software has been successfully compiled on LinuxCNC distribution and works without any issues (except the default screen resolution being quite low :). The plan is to include pre-compiled Granity for Linux in the future releases.
Granity running on LinuxCNC 2.6 distribution
In other news, Granity 1.8 is coming soon with Argon support. Same time the Argon firmware version 2.0 will be introduced.
The new IONI firmware version has been released! It adds long awaited SinCos encoder support to the drive.
See the video below as comparison of SinCos and incremental encoder. The main advantages of SinCos are: silent (no dither), more stiffness and more precision. The only drawbacks are the availability and price of such encoders.
The other added features include application specific functionality for torque mode. This includes rotation limit (added safety) and torque setpoint scaling by analog input. These may be useful especially for OpenSimWheel project builders.
See a LinMot special linear actuator driven by IONI Pro servo drive. This utilizes the new SinCos encoder support!
Last days we have been working on supporting SinCos encoders. SinCos encoder is exactly like standard incremental encoder, except it has sinusoidal analog outputs instead of digital quadrature waveforms.
SinCos encoder signals vs digital incremental encoder signals
The beauty of this is that the analog waveform can provide infinite position resolution when the phase angle of signals are calculated. The latest prototype firmware of IONI Pro now supports SinCos interpolation which increases the resolution that we would get from digital counting by the factor of 16, 64 or 256 times. I.e. a 1000 pulse (or cycle) per revolution analog encoder with 256X interpolation yields resolution equal to 256 000 quadrature pulses per revolution (PPR) or 1 024 000 counts/per revolution (actual position resolution of motor).
SinCos encoder interpolation: the first graph shows position counter in digital mode, the middle shows interpolated angle from sine and cosine signals and the last image shows the combination of these two to form the high resolution position count.
Very high resolution helps especially to make motion smoother, quieter and stiffer. The initial tests show amazing smooth performance of the motor in velocity and position modes. There was no dithering or groaning noise from the motor and at same time the motor position holding stiffness was jaw dropping. It felt like the motor was physically jammed as the eye, hand or ear can’t notice any movement.
During Easter weekend I was testing IONI on my own DIY CNC router. Steppers ran above 2000 rpm making the machine run faster than it ever has.
IONI has native resolution of 25600 steps/rev (or 128 fold microstepping), which may lead to insufficient step rate from the CNC controller. In my case the LinuxCNC was able to generate only 33 kHz step rate, so step mutliplier in drive has been cranked up to 25x. This normally would reduce microstepping and cause noisy operation, but not with IONI when setpoint smoothing feature is turned on. At 0:32 you will see a comparison between setpoint smoothing off and on.
Special thanks to Aki for video editing!
IONI drive firmware release 1.1.0 brings a new useful feature that automatically measures motor characteristic resistance and inductance and completely takes the guesswork out of torque controller tuning.
It takes single click to auto-set resistance and inductance
The definition of inductance
Using automatic measure is the new recommended approach to set MR and ML parameters accurately even when motor data sheet would provide these values. This is because many data sheets unfortunately provide inaccurate values. Some manufacturers have apparently characterized motor inductance at high frequency range (hundreds of kHz) which typically gives a value more than 50% off from the real inductance.
Having accurate values also opens doors for sophisticated stepping motor control features such as advanced vibration damping which rely on accurate motor characteristics. This is a subject for another update!
We have been quietly experimenting on a special IONI motherboard that has discrete power stage to extend IONI power capability. We already have a proof-of-concept board that is equipped with leftover VSD-E mosfets (61A 200V rated). After couple of weeks of use, we could not tell the difference between integrated and external power stage by observing motor control performance and smoothness.
IONIZER proof-of-concept board
Bottom side showing the discrete power MOSFETs
IONIZER has been considered to be available as DIY board (bare PCB) and a reference design where users could modify it to match virtually any power need. However, it’s not ready and many changes are needed to have our approval (such as galvanic isolation of all I/O, short circuit protection and switch to PCI-E 8x socket for newer IONI). Finishing this might be a subject for another crowd funding project.
Some pros are:
And cons:
Tell me in the comments how useful do you see IONIZER and which voltage & current range would be your preference :)