MGL Enigma compatiblilty with Trutrak

Happy New Year to everyone,

I am planning my panel. I have an MGL Enigma that I plan on using with my -7. The half built kit I bought came with two Trutrak servos. A roll servo in the right wing and a pitch servo behind the baggage compartment.

Some of my research has me thinking that the Enigma can't run the Trutrak servos. MGL support Trio servos, not Trutrak. Best I can figure.

I emailed SteinAir to see if they make a wiring harness to interface the Enigma and the servos, but I haven't heard back yet. It's the weekend so I likely won't hear till next week.

So...... anybody out there using an Enigma or other MGL product with Trutrak servos ?

Thanks,

Darren

You won't be able to use the servos directly. However, you may be able to interface the MGL EFIS to a TruTrak AP and use the servos.

I'm sure that either Ranier or Lucas will give their two cents worth after the holidays.

So Bob if I want to use the Enigma then I HAVE to get a Trutrak Controller and either use it as a stand alone unit or try and interface it with the EFIS. Correct ? Kind of how I can adjust the radio frequencies either through the Enigma or on the radio itself.

If there ain't no other way then I guess I better start scouting for a Trutrak Controller.

Thanks for the help,

Darren

Or find some Trio servos... Might be cheaper.

Bob Kelly

Wait a second here. Someone just told me that if I get the Trio Servos then I still need a Controller !

I thought the Trio Servos would just plug right into the Enigma and no Controller was needed as the commands for the servos come from the Enigma EFIS.

OR does the Enigma control the Trio Controller which in turn controls the servos ? If you are confused, so am I

Darren

thanks for the help so far.

I've got the Trio servo's and no control head. They are wired into the CommExtender module from MGL. That plugs into the EFIS via USB cable. The comm-extender is inexpensive...around $200, if I recall correctly.

Rainier is doing a great job integrating the autopilot functionality into their EFIS systems. I tested mine for the first time last weekend, and they work pretty well. I've got some minor configuration changes to make, and it should work fine. Just my 2 cents.

Also, the TT servo's are not compatible. You would need to drive them with the TT controller. I think that the TT controller can receive the GPS data from the EFIS, though.

Just my 2cents, and this has been discussed before, but i would keep the autopilot seperate to the efis for some redundancy. You still have a data link but keep the trutrak intact. Also Trutrak is highly renowned and will always be around so that is no issue.
Reniers stuff is great as well, but then all the eggs in one basket.

Hey EJ,

That's a good point you bring up. If the autopilot is hooked to the EFIS and it goes down, then the autopilot is lost too. I didn't think of that. Here's why I ask questions before I leap. There are always good ideas out there.

I'm thinking that the cost of selling my Trutrak servos, and then the cost of getting Trio servos, mounts, MGL com extender, maybe close to the cost of just getting a Trutrak Controller, keep it separate from the EFIS like you said and just go have fun.

Thanks again for the suggestion.

Darren

Ok, I changed my mind again. Now it looks like it is better to sell the TT servos, get some Trio servos and the MGL Comm unit and use the MGL Enigma to control the whole setup.

I do have a Garmin 296 handheld that I was going to mount as a backup Navigation system.

Does anyone know if I can use that MGL Com unit to not only allow the Enigma to talk to the Trio servos, but can I somehow get the 296 interfaced too so that should the primary EFIS (Enigma) fail I could use the 296 as not only a back up Nav but a backup Autopilot ?

Anybody every heard of this being done ?

Thanks,

Darren

I can't imagine a way in which the 296 could drive autopilot servos without a controller Darren. It could send a Nav signal to an autopilot controller, but the servos are just "dumb" motors - they need to be told how to drive by something that is designed as a closed loop control system.

If you are planning a VFR machine, then going with an EFIS/Autopilot all-in-one is perfectly fine, but if you are going to try for IFR, I'd seriously consider what your backup plan for aircraft control and Nav is going to be should the EFIS fail.

Paul

Sorry,
I have not been following Vans for a while so here is my belated answer (yes, I'm back from the holiday !).

Unfortunately we can only support Trio servos and our own (which are now in final prototype and should be flying within a week).
We did ask Trutrak but our request was turned down. We were offered a similar package to AFS (i.e. branded version of the complete Trutrak AP) but decided not to go that way as it would be at a cost that is not compatible with what we like to see.
This then effectively caused the go-ahead to design our own servo.
This does not mean that we will stop supporting the Trio servo in any way but rather that our own servo will complement the Trio servo. In effect you can then choose either a DC motor, clutch based servo (trio) or a stepper motor based solution (MGL) as you like. That means more choice and that is the way I like it.

Rainier
CEO MGL Avionics

Darren S said:

Happy New Year to everyone,

I am planning my panel. I have an MGL Enigma that I plan on using with my -7. The half built kit I bought came with two Trutrak servos. A roll servo in the right wing and a pitch servo behind the baggage compartment.

Some of my research has me thinking that the Enigma can't run the Trutrak servos. MGL support Trio servos, not Trutrak. Best I can figure.

I emailed SteinAir to see if they make a wiring harness to interface the Enigma and the servos, but I haven't heard back yet. It's the weekend so I likely won't hear till next week.

So...... anybody out there using an Enigma or other MGL product with Trutrak servos ?

Thanks,

Darren

Click to expand...

Rainier , when will you have specs on your servos? Sound promising. Will you also offer stand alone autopilots?
And while I have your attention, any news of producing a transponder ?

MGL Servo & Autopilot Update

Hi guys,

rv72004 said:

Rainier, when will you have specs on your servos? Sound promising.

Click to expand...

We have preliminary specs on the two servo models (a larger and a smaller one). I am a little hesitant to announce it publicly just yet... What I can say: the smaller one should be perfect for most RV's, and the larger one for L-29/39's!! The servos are currently being test flown.

Realistically they should be going into production towards the end of February 2010.

If you need more information, you are welcome to contact us via PM/email.

rv72004 said:

Will you also offer stand alone autopilots?

Click to expand...

We are looking into it... More along the lines of a REALLY small, low cost EFIS with autopilot.

rv72004 said:

And while I have your attention, any news of producing a transponder ?

Click to expand...

Sorry: due to the volume and cost of the red tape required, no change in status on this one! Indefinitely on hold.

Watch this space!

Hello Bob
I'am building a QB9A and I was wondering if you have Fuel Inj and if so how many fuel filters do you have and where did you locate them. AT THAT POINT! Thanks Ron in OREGON

Just the way I look at it if I lose my EFIS I sure don't want an AP doing anything so why worry about a backup and to do what? EFIS go out I'm hand jobbing her to the hardpac as soon as reasonable safe. Just my .02$, Bill with a MGL Odyssey and TRIO APs in a RV-8a (wiring)

Bill Phillips said:

Just the way I look at it if I lose my EFIS I sure don't want an AP doing anything so why worry about a backup and to do what? EFIS go out I'm hand jobbing her to the hardpac as soon as reasonable safe. Just my .02$, Bill with a MGL Odyssey and TRIO APs in a RV-8a (wiring)

Click to expand...

I think there are a few folks that may disagree. If I'm flying single pilot IFR and the EFIS dies, I want an independent AP to keep the wings level and keep on flying to buy me some thinking time. It will tremedously ease the workload if your EFIS dies.

Hopefully I can fill in some blanks here for Darren.

You really need to consider what you want an autopilot for. If it's to fly vfr (cruise control) then you have three options:

1. Purchase a Trutrak head to drive the servos and install a switch that selects the nav input from the EFIS and the 296.
2. Sell the trutrak servos and buy trio servos and hook them up to the EFIS.
3. Wait for the MGL servos.

Out of those options the first one is the most expensive, but it will give you a very well proven AP with two sources of NAV that doesn't depend on your EFIS. The second two options will work, and at a reduced cost, but you now depend on your EFIS to make your AP work, so if it fails you must be able to see.

If you are installing an autopilot to fly IFR (pilot workload reduction) then you have two options:

1. Purchase a trutrak head and drive it from an arinc 429 interface that has gps steering. This can be an IFR gps or the efis or both with a switch. The MGL documentation states that it can output to a ARINC429 autopilot, but I'm not sure what features are supported. To be complete you would want it to provide GPS steering signals that it gets from a ILS or Glideslope, and perhaps a heading bug.

2. Sell the TruTrak servos and purchase the trio servos, hook them up to the EFIS, then purchase a second EFIS for fault tolerance.

The reason why your choices are more limited is because in an IFR situation the AP reliability becomes much more critical.

If it where me I would buy a digiflight II and be happy.

schu

rv72004 said:

Rainier , when will you have specs on your servos? Sound promising. Will you also offer stand alone autopilots?
And while I have your attention, any news of producing a transponder ?

Click to expand...

We have a mode-s transponder design ready to roll but it has been but on ice for now due to the frightening certification issues (we need to do both EASA and FAA). We want to first get the V6 and V15 radios out plus the V20 nav radio (certification is easier with those) - once that has been done we can concentrate on fighting the red-tape for the xponder (is it not funny that the actual design is much easier than the red tape that follows ??).

Stand-alone AP:
No. We will not do that as we do not want to compete with Trio. Trio has been helpful and very supportive of us and we will repay in kind. Trio will have access to our servos as well so they will be able to offer the same flexibility in future.

We have not released specs or even pictures yet but it looks like we will offer two servos that are different only in torque specs (both maximum as well as residual torque).
The strongest servo does about 15Nm (electronically adjustable down to about 2Nm). This is a lot of force and much more than most aircraft need so we have now added a 8Nm maximum torque version as well.
The servos are capable of measuring force so they can be used for true trim (as opposed to computed trim commands from over/undershoot integration times).
Very unique is a completely contactless and wear-free, high resolution position feedback system (to less than 0.2 degrees repeatable output shaft resolution). The servo is also very fast which is a bonus for autopilots that are able to fly an aircraft in bad turbulence.
Mounting is compatible with certain other servos out there but with some additional hacks to avoid the need for brackets in some applications.
Weights and overall dimensions are also quite similar to other servos while power consumption is down when compared to other stepper motor based solutions.
The servo, as extra bonus, operates on both 12V and 24V systems and can operate down to unusualy low voltages.
For interfacing it supports both RS232 as well as CAN.
The protocols required to drive this servo will be published, as promised, so anybody, including our competitiors can use these servos to add direct autopilot functionality to their products without having to go through the pain of developing a servo.

More soon...

Rainier
CEO MGL Avionics