Just wanted to share this marvelous work of Tomomitsu (Japan) on arranging the VFD inverter box of his 6DOF platform! Looks great and organized, and even equipped with easy hook up plugs!
I had support for RC servos since long time, but they were treated as real motors using external potentiometer for position feedback. I just finished the coding for direct use of RC servos, and applied it on my 6DOF mini platform.
I re-visited the 6DOF platform case here in San Diego. I had to figure out why we keep observing
stepping in the motors motion. I turned out that the motors where connected as STAR instead of DELTA. That has impact on the amount of current the motor coils can deliver in position between the phases, where the waveform tops are not in max values, resulting in less force.
Cable colors and numbering may differ from motor to motor, so always consult the motor's datasheet for the proper DELTA type connections!
Many ask what kind of motors are these and what are their specifications. I'll provide here some link to these motors models and VFD inverters that were used for the 6DOF platform on the above photo.
Today I visited Richard here in San Diego for a calibration of his 6DOF platform. Some additional calibration is needed in the software side (Ian's BFF 6DOF) but it already beats commercial platforms with its performance! I had to limit the motors max speed to 50% because in some cases it kicks really hard!
Here is one of the numerous videos I took of the calibration testing:
Richard Elliot's first test... X-plane, BFF 6DOF software, AMC644USB controller. First working home 6DOF platform just a few miles from me, (San Diego CA)
I had sourced some good LCD's with backlight from time to time. I was tired from the usual black letters on green backlight, so I was using LCD's with white letters on blue backlight. But I found a supplier with good price for LCDs with yellow letters on black... hmm.. What do you think looks better? Comments please!!!
I decided to post here some videos that demonstrates my controllers working with 6DOF software. It demonstrates Ian's BFF 6DOF software for FSX/x-plane and an unofficial 6DOF math/driver/plugin for x-sim.
This is a photo of a (still incomplete) 6DOF extension board for VFD v2 that I got yesterday in my email (Thanks Shawn):
Its smaller in size than the first prototype and the quality of the board is superb!! The ruler is in Inches. I hope to have them delivered to me in a about a week.
I'm pleased to announce that I have a new AMC motion controller available now called AMC1280USB.
It runs with the same features of the AMC644USB plus some extra features and easier accessible ports. Its built around the ATmega1280 microcontroller that leaves enough extra ports for features like 6 true PWM channels for smaller DC motor 6DOF models and many extra features still to be announced.
As the ATmega1280 is surface mount part I decided to use a arduino mega as base although I don't use the arduino libraries or bootloader at all. Actually I have to remove the DTR signal from the arduino board as its not needed with my bootloader and causes unnecessary resets when you open the com port from any motion software.
Here are some photos of it:
And here is the newer version of 6DOF extension board for VFD inverters that is also in production right now.
More technical details will be announced soon as well the support files library in the "projects" page.
I just got in the mail a nice complete demonstration set from SEW Eurodrive that includes:
Movitrac B inverter (220v)
AC worm Gearmotor
24v Power Supply (for the 6DOF extension 24v direction signals)
Extra accessories for the Movitrac (RS485 face plate and USB to RS485 adapter)
It was a pleasant surprise fromVic Alsace which I would like to personally thank!!!
Here is the contents of the huge box next to the AMC644USB and the 6DOF extension board.
I'll get everything up and running for demonstration videos the next few days.
-Added software change of direction for digital contact-less position encoders with fixed direction.
For example (6127V1A360L.5 or 6127V1A180L.5). Now you can choose between all six sensors being:
a. Positive (CW) for 1-2-3-4-5-6
b. Positive (CW) for 1-3-5 and Negative (CCW) for 2-4-6
c. Negative (CCW) for 1-3-5 and Positive (CW) for 2-4-6
-DIP2 switch defines the Serial speed on startup.
a. DIP2 position ON defines 115200bps serial speed.
b. DIP2 position OFF defines 230400bps serial speed.
The new firmware can be found in the dropbox file library of the AMC644USB project.
Here is a video explanation of the software change of direction for the contact-less position encoders:
Here is a video of AMC644USB connected to x-sim with 6DOF values, I used 3 axis for the acceleration of X,Y,Z and another 3 axis with the relative rotation speed of X,Y,Z.
Turns out to be 9DOF, if take in consideration the data for the Digital Dashboard (Speed,Gear,RPM), all devices working together with 1ms delay in the USO section of X-sim Profiler. The Digital Dashboard code had to be fixed to work with these high refresh speeds with custom serial speed 125kbps. Also added blinking for the dashboard lights for gear shift indicator.
The AMC644USB runs in 230kbps baud serial speed and 16-bit data for positioning.
I decided to shape up the digital dashboard a little bit. I made a base board for the Arduino Nano with socket header same as the TM1638 displays use. Added external power supply jack with 5v regulator, in case the arduino is connected to a USB hub and can't draw lots of current from the USB.
Changed the code to improve the serial communications. Custom baud serial speed of 125kbps. Now its stable enough to run with delays of 1ms along AMC644USB without running out of buffer space or freezing because of the high speed 16-bit data transfers. This change was mandatory to be able to have the x-sim USO running all devices (AMC644USB + Dashboard) with delay of 1ms. Among others added some extra code for flashing the shift indicator lights without delay, just by using a custom timer.
After a long waiting, my 6DOF extension boards arrived from France. I wish there was a "next day" PCB service. No matter what you use, it will take at least a month to make boards (production + shipping time etc).
I made them single layer with a few jumper connections on the top side. I was going to use PCB jumpers for the data connections to the various modules but in the end I just soldered them on the bottom leaving one row for each signal set exposed for special interfacing. Since there was no option for silkscreen I had to resort placing the port labels on the connectors, but I think that it look good.
I started assembling them yesterday and I hope all will be ready by Friday for shipping all around the world. The post office lady will hate me for having to process that many custom declaration forms.
Here are some photos of the tests I performed on them as well some details:
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