wirejock

wirejock

Well Known Member
I'm out of town so spare time is being used working on wiring diagrams. I'm drawing the trim diagram and have some questions.
1. Skyview and Vertical Power both have controllers for flap and trim. Which do you prefer of maybe a combination. Why?
I would like both flap and trim position on the Skyview MFD. Runaway protection is also preferred but I think both have the capability.
2. Where did you connect the wires? Trim servo has two whites, orange, blue and green.
I'm pretty sure the whites are switched such as the hat switch on the stick. I think I know where they would go on the VP-X. I'm not clear how the other three connect to the VP-X or Skyview.
Drawings would be appreciated.
 
I'm not that familiar with the Skyview screens. Do they also control the speed of the flaps, or at what speed they can be deployed? That is one of the key advantages for the VPX.

I have AFS 4500s. The VPX controls the flaps and trim. Then passes the position information to the EFIS, wich replays the current state of both on the screen.

Hopefully, the same is true with Skyview.
 
I am controlling mine with VPX and its working good so far (only 9 hrs). The only thing is, when I trim in cruise, I just barely bump my coolie hat and sometimes its to much. I could slow the trim speed down to reduce the sensitivity but when I'm doing touch and goes, I need it to be fast to go from landing config to take off config. Not sure if using Skyview would help this....... I really like controlling the flaps thru the VPX cause I can set it to stop at three degree settings and then return to home with one press of the button.
 
Can't remember how to get to it, I think in the "configuration" software but you can set an airspeed at which the trim sensitivity changes. For example I think I have mine set to 100% below 100mph, above is like 50% or less.

I have found no difference in hooking it to the vox or dynon, I hooked it to the dynon. If I ever upgrade the Efis it's less wires is the only advantage. Either way will display on your trim indicator or vs screen or both if you wire it up that way. With the vpx and dynon you will need a position sensor to get the full function from the flaps that the vpx has available. I bought one but haven't hooked it up yet, it's so easy to look out the window. All I'm missing out on is an in-cockpit indication and the single button push full up feature and the single press stop points that you can set to whatever you want, up to four stops I think.
 
southtarnation said:
Can't remember how to get to it, I think in the "configuration" software but you can set an airspeed at which the trim sensitivity changes. For example I think I have mine set to 100% below 100mph, above is like 50% or less.
Click to expand...

Wow! Gonna have to check that out. It would be very useful!
 
southtarnation said:
Can't remember how to get to it, I think in the "configuration" software but you can set an airspeed at which the trim sensitivity changes. For example I think I have mine set to 100% below 100mph, above is like 50% or less.
Click to expand...

MikeyDale said:
Wow! Gonna have to check that out. It would be very useful!
Click to expand...

Starts on pages 55 of the VP-X install manual. Section 6.12 Trim configuration and 6.13 Flap configuration.
 
I don't plan to have it tied to either (VP-X is too expensive and Dynon not convenient).

I'm using the coolie hat on my Infinity grips, along with this 3 axis trim relay.

After flying a bit, I may opt for a speed controller to slow the trim action and disable flaps above a certain speed.
 
The trim controller in SkyView:

1) Protects against broken / shorted switches
2) Provides priority for the pilot input
3) Allows you to use simple, low current switches like those found on most grips
4) Adjusts the speed of your trim based on airspeed so it's never too sensitive or not sensitive enough
5) Gives the Dynon Autopilot the ability to auto-trim when the AP is engaged

The VP-X trim controller does a lot of what the Dynon controller does, but it's really #5 that means you should use the Dynon controller if you have both a Dynon and a VP-X. Auto trim when using the AP is pretty awesome.
 
Thanks

dynonsupport said:
The trim controller in SkyView:

1) Protects against broken / shorted switches
2) Provides priority for the pilot input
3) Allows you to use simple, low current switches like those found on most grips
4) Adjusts the speed of your trim based on airspeed so it's never too sensitive or not sensitive enough
5) Gives the Dynon Autopilot the ability to auto-trim when the AP is engaged

The VP-X trim controller does a lot of what the Dynon controller does, but it's really #5 that means you should use the Dynon controller if you have both a Dynon and a VP-X. Auto trim when using the AP is pretty awesome.
Click to expand...

Thanks (Dynon Avionics). I love it when manufacturers comment.
I wish they would use a name. Makes me feel like I'm at a restaurant yelling "waitress". I always address people by name.
 
Larry,
We have a couple people that respond under this account, and when it's a bit more than a simple support issue we do tend to use our names, but we aren't in the habit of doing that always. No particularly solid logic in when we do and when we don't.

We appreciate the feedback. We'll try to do better.

--Ian Jordan
 
So, does the Dynon AP servo see load on the control surface to automatic send trim inputs, and do all the trim wires to to the dynon and then the hat sw?
 
Wires

bret said:
So, does the Dynon AP servo see load on the control surface to automatic send trim inputs, and do all the trim wires to to the dynon and then the hat sw?
Click to expand...

Brett
I have a drawing if you want to see where all the wires go and what color. It's based on Ray Allen servos and Tosten grip. Send me an e-mail.
I don't know how it senses but every wire goes to a Dynon pin. Hat switch wires and trim wires. I assume since it controls the hat switch inputs, minor adjustments are initiated by the EFIS.
 
The Dynon auto-trim is a good reason to use the Skyview system versus the VP-X system, especially if you are using the Skyview auto-pilot. It was not to difficult to rewire to the Skyview system if you have already wired it to the VP-X. In my case though, my aircraft is still under construction and the front skin is not in place.

Frank Huber
RV-7A under construction
 
bret said:
So, does the Dynon AP servo see load on the control surface to automatic send trim inputs, and do all the trim wires to to the dynon and then the hat sw?
Click to expand...

Bret,
The Dynon Servos do as you say- they detect the load on the controls when the AP is engaged and flying the plane.

All the wires from your trim switches individually go to the AP control panel, as well as the two motor wires from the trim servo. Trim position wires still go to our EMS unit or the VP-X.

--Ian
 
Trim position wires/flap control

dynonsupport said:
Bret,
The Dynon Servos do as you say- they detect the load on the controls when the AP is engaged and flying the plane.

All the wires from your trim switches individually go to the AP control panel, as well as the two motor wires from the trim servo. Trim position wires still go to our EMS unit or the VP-X.

--Ian
Click to expand...

Ian (thanks for signing)
Is there any benefit or down side to running position wires to the EMS? At the very least it seems like it would keep things neater. All the trim wires are going to a Dynon box.

Next question
Any benefits over VP-X for flap control? Given the higher load, I would prefer them on a VP-X circuit.
 
If I am not using the Dynon AP control, is there any benefit in wiring the trim to the EMS or EFIS? I like the idea of auto-trim but the AP control is apparently required to use this feature.
 
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VP position on this is to run the trims through the Dynon for position input and power through the VPX for circuit protection. The Dynon support guys are great and I'm glad to see Ian has jumped on this. My apologies for being late to the thread.
 
Larry,
We'd suggest the trim wires to the EMS not the VP-X if you are using the Dynon for trim. Just cleaner and simpler overall.

The VP-X flap control is probably superior to anything Dynon can do right now.

Raymo,
There's no place to wire your trim motors to the Dynon systems without the AP control panel.
 
I have both SV with AP and VPX. As the Dynon chap said, use the SV interface. Ive also got the separate SV AP module and wiring the trim hat switches to this was a breeze.
 
I think you should ask yourself if you are comfortable passing control of your trim and flaps to a multi-purpose piece of uncertified software with no effective cut-out. I know both Dynon and Vertical power have a fine reputation for building reliable products, but just because you can do something does not mean you should. Failure (runaway) of trim or flap control at cruise speeds could make life rather too interesting.

From my perspective these 2 functions are things I will assign to single function systems to ensure reliability. My flaps are currently actuated with a large handle, and will be controlled by a simple switch directly to the motor. I currently have a manual trim, and will have a single purpose box to vary the trim speed with flap position that can be switched off easily. I don't think auto-trim is very useful in RVs - the trim force over the entire speed range is typically low, so the autopilot servos rarely run out of authority. Manually trimming is not a huge overhead to prevent some of the failure scenarios possible with an integrated (simplex with unknown failure monitoring) auto-trim and autopilot.

David - you might like to ask the LAA their view on auto-trim using the autopilot.

Pete
 
penguin said:
I think you should ask yourself if you are comfortable passing control of your trim and flaps to a multi-purpose piece of uncertified software with no effective cut-out. I know both Dynon and Vertical power have a fine reputation for building reliable products, but just because you can do something does not mean you should. Failure (runaway) of trim or flap control at cruise speeds could make life rather too interesting.

From my perspective these 2 functions are things I will assign to single function systems to ensure reliability. My flaps are currently actuated with a large handle, and will be controlled by a simple switch directly to the motor. I currently have a manual trim, and will have a single purpose box to vary the trim speed with flap position that can be switched off easily. I don't think auto-trim is very useful in RVs - the trim force over the entire speed range is typically low, so the autopilot servos rarely run out of authority. Manually trimming is not a huge overhead to prevent some of the failure scenarios possible with an integrated (simplex with unknown failure monitoring) auto-trim and autopilot.

David - you might like to ask the LAA their view on auto-trim using the autopilot.

Pete
Click to expand...

Hi Pete, I'd like to respectfully disagree with your value assessment of autotrim.
I developed an autotrim controller that works with the SkyView systems as a separate stand alone box. If the EFIS fails, it works as a standard trim controller with speed scheduling determined by flap position. It also has fail safe/recovery mode. This agrees with your premise.

However, I think your assessment of the servo motor authority over the RV speed range is incorrect. Before Autotrim, I was getting constant demands for manual trim intervention from the Dynon Autopilot in my Harmon Rocket. With my autotrim controller, I can change throttle settings and let the autotrim take over. I can even engage the autopilot with large trim offsets so that the servos slip and my autotrim controller will converge to neutral.

This means that I can use smaller, lighter servo motors and I have a lot fewer distractions in the cockpit.

My SOP is take-off, level off at 2000 feet (about 30 seconds later in an HRII), slap on the autopilot and let the trim take care of itself while I tidy up the cockpit.

I would never go back to manually controlled trim with an autopilot. An autopilot without autotrim is so last century.
 
vlittle said:
I developed an autotrim controller that works with the SkyView systems as a separate stand alone box. If the EFIS fails, it works as a standard trim controller with speed scheduling determined by flap position. It also has fail safe/recovery mode. This agrees with your premise.
Click to expand...

vlittle: Can your autotrim controller be used on a NAVAID servo or a Trio GOLD standard servo?

:cool:
 
GalinHdz said:
vlittle: Can your autotrim controller be used on a NAVAID servo or a Trio GOLD standard servo?

:cool:
Click to expand...

No, it controls trim motors only. It interprets the SkyView serial data stream, integrates auropilot servo force vectors and makes trim commands in two axes.

It works only with Dynon SkyView systems. The fundamental difference with the Dynon control head and my box is that mine is remotely mounted and takes no (or minimal) panel space. I developed it about a year before Dynon rolled out their unit because I was impatient and enjoyed the challenge.

I don't know what algorithms Dynon uses for their controller but the math I used for mine required a high speed processor with critical hand-coded operations. I published the algorithm in the datasheet, if anyone is interested. It's all based on an open source hardware platform, but this particular code is proprietary. Dynon was helpful in pushing me in the right direction, even though they had their own development underway.
 
penguin said:
I think you should ask yourself if you are comfortable passing control of your trim and flaps to a multi-purpose piece of uncertified software with no effective cut-out.
Click to expand...

You can disconnect the Dynon trim control by pulling your trim breaker, the same one you'd pull if your switch broke and the servo kept moving.
 
dynonsupport said:
You can disconnect the Dynon trim control by pulling your trim breaker, the same one you'd pull if your switch broke and the servo kept moving.
Click to expand...

Isn't that the same way you would disconnect a runaway trim in a certified system? :D

vlittle said:
No, it controls trim motors only. It interprets the SkyView serial data stream, integrates auropilot servo force vectors and makes trim commands in two axes.

It works only with Dynon SkyView systems. The fundamental difference with the Dynon control head and my box is that mine is remotely mounted and takes no (or minimal) panel space. I developed it about a year before Dynon rolled out their unit because I was impatient and enjoyed the challenge.

I don't know what algorithms Dynon uses for their controller but the math I used for mine required a high speed processor with critical hand-coded operations. I published the algorithm in the datasheet, if anyone is interested. It's all based on an open source hardware platform, but this particular code is proprietary. Dynon was helpful in pushing me in the right direction, even though they had their own development underway.
Click to expand...

INTERESTING. Can I use your box with a SkyView system, an old TRIO Altitude hold and a Ray-Allen electric pitch trim?

:cool:
 
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Breaker

dynonsupport said:
You can disconnect the Dynon trim control by pulling your trim breaker, the same one you'd pull if your switch broke and the servo kept moving.
Click to expand...

Trim breaker?
Now I'm confused again. The initial question was whether to connect to the Dynon or the VP-X. The recommendation was to hook up all the wiring to the Dynon. I looked it up and drew the wiring diagram according to the Dynon install manual. All the wires go to Dynon connectors. There is no breaker shown.
Maybe the Dynon EMS has a breaker or in my case, a circuit on the VP-X. If the latter, a switched VP-X circuit would power down the EMS. Please explain. What did I miss?
 
Larry,
All circuits in a plane have circuit protection. So in your case, we mean turn off the circuit on the VP-X that drives pin 9 on the SV-AP-PANEL.

This circuit protection device is shown on Figure 117, Page 18-7 in the install manual. This does not power down all of SkyView, the EMS, or even the SV-AP-PANEL. This just removes power from the circuit that can move the trim motor.
 
Thanks

dynonsupport said:
Larry,
All circuits in a plane have circuit protection. So in your case, we mean turn off the circuit on the VP-X that drives pin 9 on the SV-AP-PANEL.

This circuit protection device is shown on Figure 117, Page 18-7 in the install manual. This does not power down all of SkyView, the EMS, or even the SV-AP-PANEL. This just removes power from the circuit that can move the trim motor.
Click to expand...

Ahhh. I haven't gotten to the panel drawings yet. That explains it.
 
vlittle said:
Hi Pete, I'd like to respectfully disagree with your value assessment of autotrim.
I developed an autotrim controller that works with the SkyView systems as a separate stand alone box. If the EFIS fails, it works as a standard trim controller with speed scheduling determined by flap position. It also has fail safe/recovery mode. This agrees with your premise.

However, I think your assessment of the servo motor authority over the RV speed range is incorrect. Before Autotrim, I was getting constant demands for manual trim intervention from the Dynon Autopilot in my Harmon Rocket. With my autotrim controller, I can change throttle settings and let the autotrim take over. I can even engage the autopilot with large trim offsets so that the servos slip and my autotrim controller will converge to neutral.

This means that I can use smaller, lighter servo motors and I have a lot fewer distractions in the cockpit.

My SOP is take-off, level off at 2000 feet (about 30 seconds later in an HRII), slap on the autopilot and let the trim take care of itself while I tidy up the cockpit.

I would never go back to manually controlled trim with an autopilot. An autopilot without autotrim is so last century.
Click to expand...

Hi Vern - I did say in RVs ... clearly more use in an Rocket with its greater stick forces. Still not on my wish list!

For Dynon, I won't be using a breaker to switch off anything I might want to disable in flight, I think that is poor advice.

Pete
 
Pete,
You are welcome to use a switch as well, but you are going against general airplane implementation. You only ever need to pull this in the case where the software or hardware fails and causes your trim to move uncommanded. This is basically the exact reason pull-able breakers exist, for the very rare cases that you need to disconnect something in flight that is never done normally and you need to turn just it off. We absolutely don't think you should be turning off the trim controller on a normal flight, so a panel switch for it is overkill and in fact adds complexity to the system which is almost always a bad idea.

Unless you are going with all very old radios, transponders, etc in your plane, the request to turn them off from the front panel is a request to software, not a hardware switch (if they even have a power switch, which many certified boxes don't). So if you distrust software, you very much need a way to switch each box off individually. Again, in most planes this is done by having breakers for emergency situations. If you think having certified software is the solution, then you haven't paid much attention to the huge stack of AD's on certified devices. As was once told to me by someone with tons of certified software experience - "I'd much rather fly in a plane with 1,000 hours of real world experience and no certification than a plane with level A certification on the first flight".

If you consider trim runaway a critical condition, we highly suggest you have a way to disconnect your mechanical trim switches as well. A mechanical switch can break and fail and leave your trim moving just as easily as software can fail. Ironically, this is something the software protects against in a software based trim controller.

All that being said, Dynon doesn't think you need a breaker or switch for the trim controller in an RV. You can fly an RV with trim at the extreme, the chance of failure is very low, and a simple electrical system made up of automotive fuses has a lot of nice benefits. The great thing about experimental planes is you can actually choose for yourself.

--Ian Jordan
Dynon Avionics
 
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