Quote:
Originally Posted by GrayHawk
Most of the reports I've seen (previous thread) have been with the TRIO servos. I haven't seen reports yet with the newly developed MGL servos.
It would be nice to see how those are doing.
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We still have not released any although the first batch has been manufactured. We are still adding things to the software, mainly a new communications protocol for those that want to use the RS232 interface - that is now done and you can control up to 4 servos with just a single RS232 port !!! We use the CAN interface for our own EFIS systems but may use the RS232 for the Enigma (as it does not have a CAN bus and this way, if you don't use the available port for something else, you don't need a COM extender module). Both protocols will be documented and put in the public domain for those that want to roll their own autopilot systems.
The only thing left (Nicol is busy with that now) is to put a boot loader in there so it becomes possible to update the software in the field should that ever be required. Hopefully that should be done by the end of the week so we can start shipping.
The first main production batch has now been initiated but this will probably only really come online end of the year. To keep costs down things like the heavy stepper motors are shipped from our suppliers using sea freight so that takes a bit of time.
From my own experience using these servos on my own aircraft I can say that they have pros and cons when compared with the Trio servos.
First the cons:
They are heavier (about the same as Trutrak or Dynon due to use of a heavy stepper motor).
They need more power (about 0.9A for 4.5NM of torque), not too bad though.
Now the advantages:
Easier fitting as the servos have threaded holes not just on the face but also on the sides. That tends to mean in many cases that no brackets are needed as you can simply bolt them to a bulkhead sideways.
The servos measure force on the arm and feed that back to the EFIS. This means we can display real out of trim forces and drive trim motors.
The servo can engage at any angle and use any range (it could even do multiple turns, nice for a capstan solution).
There is no wear of the position measuring sensor as it's completely contact-less.
The servo is very accurate and has zero position uncertainty so it does not jitter and gets to the exact same position every time if commanded to go there (that helps the AP).
Lastly, the servo is faster and that means, if you crank up the servo gain in the EFIS AP setup, you can have the AP stabilize the aircraft much in the same fashion a cruise ship is stabilized in rough seas. Yes, it can't fix up the up/down motion in turbulence but it can fix up bank and pitch upsets before they become an issue - of course that means a lot of control activity in turbulence. Not sure if this is an academic point or of real value but I quite enjoyed playing with this.
The servos have turned out pretty well but have ended up more expensive than I originally was hoping for and I'm worried about the shipping costs as these things are pretty hefty. Costs will likely come down once we can make larger batches and reduce machining costs using casting, only way to reduce shipping costs is to look at sea freight and to make that worth while needs quantity (the famous chicken and egg thing). But we will get there...
Rainier
CEO MGL Avionics
Anybody flying with an MGL autopilot?
Linear Mode
