SimuCUBE final hardware has just born

Today we received the first samples of final SimuCUBE board designs. Testing of it shows no flaws so we’re giving the green light for the first 250 pcs batch assembly! All parts are already in stock, so assembly should not take too many days.

SimuCUBE with the needle bed SimuCUBE production tester device

SimuCUBE with the needle bed SimuCUBE production tester device

The photo above shows also the work-in-progress test bed for SimuCUBE that will be used to test & verify the operation of every shipped SimuCUBE. The device under test will be placed on the top of the bed and the spring loaded pins will contact certain pads on the bottom of the SimuCUBE board to allow tester to contact all necessary signals at once.

Force feedback wheel first test drive

The decision to build a racing simulator with servo motor based force feedback has yielded first tangible results. The picture below shows the current setup of a force feedback wheel with a 36 Nm (peak) motor equipped with a sin/cos encoder. The system is being driven by IONI Pro HC and a STM32 Discovery based interface.

Simulator direct drive wheel is operational but lacks buttons

Simulator direct drive FFB wheel is operational but currently it lacks other controls. Mechanical parts design and tooling was implemented by Aki.

The first test drive on iRacing put a wide smile on our faces immediately and gave more motivation to make faster progress on it :)

The plan is to experiment with wheel effect calculations, such as friction, inertia, damping and spring, inside the drive firmware to take full advantage of high resolution feedback devices. Also it’s a good platform to test how far IONI can be pushed in output current ratings in this kind of system.

IONI power handling statistics

We run number of tests to each manufactured drive, one of them being a load endurance test. The test is done by driving constant 9 Amp sinusoidal current from all four power lanes and clocking the time of how long it takes drive to heat up by 25 Celsius. This test is used to verify proper characteristics of the power stage. Each tested drive must score above a certain level of endurance to be passed.

Load endurance test with IONI Pro and IONI Pro HC

Load endurance test with IONI Pro and IONI Pro HC

The statistics above shows endurance results from about 200 tested drives. From here we can see that Pro HC model has average endurance times of 47.7 seconds while Pro has average of 27.5 seconds. This means that on average HC model takes 1.73 times longer to get equally warm during the test. On the other hand, it could be understood that on average HC model dissipates 42% less heat.

The test also reveals that the variance is higher on HC model. There are few extraordinary good units probably due to varying characteristics of the MOSFETs even though both model MOSFETs are made by same manufacturer. Pro HC model uses the newest and lowest loss type that is available today in this size while Pro uses couple of steps lower rated devices. I hope some day the MOSFET manufacturer manages to avoid the variance and start offering transistors that perform like the best ones seen here.

Despite of the variance, the best thing is that there is clear bottom level on both types, so any unit will not have troubles meeting the specs.

Experimenting with high current IONI

We have started tweaking the IONI drive in order to push it beyond it’s present output current limits. This includes testing of lower loss power MOSFETs and current sensing resistors to achieve reduced heat dissipation. So far we have achieved 35-40% reduction of heat dissipation at high currents.

MOSFET replacement under way. The new ones are installed on right side. These particular transistors have exposed top side thermal pad for heat sinking.

MOSFET replacement work in progress. The new ones are already installed on right side. These particular transistors have exposed top side thermal pad for external heat sinking.

CNC router test with IONI Pro

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!

IONIZER – an external power stage board

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 early proof-of-concept board

IONIZER proof-of-concept board

IONIZER bottom side showing the discrete power MOSFETs

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:

  • Can be made to virtually any power
  • Not highly expensive

And cons:

  • If built with assembly errors, can be hazardous
  • Some safety & protection features add complexity on circuity (STO, over temperature & short circuit protections)
  • Industrial manufacturing may not be cost effective (more complex solution than Argon)

Tell me in the comments how useful do you see IONIZER and which voltage & current range would be your preference :)

Green light (almost)

The prototype IONICUBE 1X has been now assembled and tested. Functionally everything is Ok, which is the most important thing, but few adjustments in layout and component selection will be made. No big deal – no delay!

IONICUBE 1X prototype (with temporary type pin header etc)

IONICUBE 1X prototype (with temporary type pin header etc)

In the other news, we’re over $30k in the Indiegogo campaign! Pure awesomeness! This means that the very next IONI firmware release will buff current rating to 18 Amps onĀ  devices that are sent for the campaign contributors :)

IONICUBE 1X motherboard prototype

The prototype boards of IONICUBE 1X has arrived! On-board features include:

  • Carry single IONI drive
  • On-board regenerative braking resistor drive (need just an external resistor)
  • Support mechanical end-of-travel switches and homing switch
  • Motor holding brake output with driver
  • 20 pin ribbon cable connector for I/O and setpoint signals
  • Support 3.3V, 5V and 24V1 I/O signal levels
  • Charge-pump enable input for safety
  • E-stop switch input (safe torque off)
  • ARGON Servo Drive compatible encoder connector pin-out
  • RJ45 connectors for SimpleMotion V2 usage and configuration
  • On-board 0.5A 5V regulator to power drive logic and feedback devices
  • DIN rail mounting option
IONICUBE 1X prototype (not yet assembled)

IONICUBE 1X prototype (not yet assembled)