D100 + AP74 withOUT servos.

[Robski]

This is going to sound like a dumb question, but here goes.

Can you make use of an AP74 auto pilot interface unit with a D-100 EFIS WITHOUT any servos being fitted? Would it be 'a bad thing' for the AP74 / EFIS to be set up in this manner?

Reading the blurb for the AP74 indicates that it can be used to set values etc in the EFIS (e.g. QFE/QNH), which sounds usefully quick and easy.
Just wondering if all the non-AP functionality works without any servos connected.

In case anybody is bothered, I've ordered the D-100 to partner an EMS D-120 which I bought used from a friend.
I'm intending to fully AP my RV-6 over time, when funds allow.
When I build the new panel for the EFIS over the next few weeks I'm trying to decide whether to
a) buy the AP74 now and fit it so the panel and most of the wiring is finished
b) just make the cutout in the panel for the AP74 and put a plate behind it for now.

Making yet another panel (this will be the airplane's third one) or having to hack around an already finished one later is something I'd rather avoid.

 

[Dynon]

Because of the way the software works, the AP software features just won't activate until you have servos in the airplane. I think the knob should still work, but this isn't a supported configuration.

 

[Robski]

Thanks for the prompt reply.

Sounds like what I thought - the knob will work for EFIS things, but quite understandably the AP stuff won't work.

I fully accept it is an unsupported configuration.
Sounds like the worst that can happen is I will have to unplug the AP74 until I get the servos.

It will be good incentive to keep saving hard for the servos.

BTW - my D-100 arrives today! Woo-hooo! ;D

 

[ploucandco]

Better use a HS34, you get many knobs and that is fully supported without servos

 

[Robski]

Re: D100 + AP74 withOUT servos: HS34 vs AP74

Jacques.
I was just considering whether the HS34 might be a better option.
Seeing as you've brought the subject up...

Does the HS34 work with older NAV radios? I have a Narco Mk12D that I would be wanting to interface. I've read conflicting reports on whether this is a supported radio or not.

How upmarket/modern does a GPS have to be to work with the HS34? I have a tiny and ancient Garmin GPS III Pilot that feeds the currently installed EMS D120 with NMEA data quite successfully. Would that be usable by the HS34, until I get a more modern Garmin GPS.
I currently use an Android Tablet (very successfully) for main GPS navigation, if you were wondering about the wisdom of buying an EFIS while having such a low end GPS!

Does the HS34 do all the AP functions the AP74 does? As I indicated before I will definitely be fitting the RV-6 with the AP servos in the next couple of years when finances permit!

 

[Dynon]

The HS34 does not work with older analog interface NAV radios (it was originally designed to, but it turns out they are harder to interface with than we thought at the time, and so that functionality isn't actually supported). The HS34 can receive serial NMEA just like the D120, so that would work until you get a more modern unit.

The HS34 doesn't have any AP mode activation like the AP74 does (note how the buttons are different on each unit). In terms of adjusting values, though, they can both adjust values like heading, altitude, and baro, in the same way (the HS34 has an additional knob for course and also breaks out heading).

 

[Robski]

Hmmm! Food for thought.

AP74 :-/ HS34

Thanks for the reply.

 

[Robski]

Because of the way the software works, the AP software features just won't activate until you have servos in the airplane. I think the knob should still work, but this isn't a supported configuration.

Fitted the D100 and went with the AP74 option.

Knob works and the system talks to me. Still working out whether the dimmer works or not  :-?

Just need to buy the servos now, but I think the CAA will want me to spend my money on a new radio and ADSB transponder first. 

Thanks for the advice.