Testing/Review of the Spektrum module for the 14MZ

[Finless]

OK I have a 14MZ but have not been using it as I put all my stuff on 2.4 using a DX7. I have been DIEING to get back to using my 14MZ and am waiting for Futaba FASST. BUT my local hobby shop (Rob's RC Hobbies in Garden Grove Ca) got in a Spektrum module for the 14MZ and he let me borrow it for some testing.

Below is my review video of this module and it's performance on a eCCPM heli.

Review of the Spektrum Module for the 14MZ (60 Megs) (http://video.helifreak.com/?subpath=finless/other&filename=14mzspektrum.wmv)

In the end I will wait for Futaba's FASST system for my 14MZ as I didnt buy a $2K radio for degraded performance. The DX7 is better than a 14MZ with this module. My testing puts in just a bit better than a 9C in FM PPM mode though.

Bob

[ballwall]

i see the site has a new look but now for some reason i click on the link to view the videos and it says to login in but im already signed in ?

[Finless]

i see the site has a new look but now for some reason i click on the link to view the videos and it says to login in but im already signed in ?

They will be fixing that today so hang tight.

Bob

[ballwall]

thank you i was getting worried lol

[WillJames]

They will be fixing that today so hang tight.

Bob


Thank you Bob for responding. I am tired and my php is not up to standards as it should be today, I mean look how long it took me to fix the DNS this morning. :(

I will be working on it ASAP or if you are at Home, call me Bob if you want to hack some php. hint hint hint.... :)

[Finless]

Thank you Bob for responding. I am tired and my php is not up to standards as it should be today, I mean look how long it took me to fix the DNS this morning. :(

I will be working on it ASAP or if you are at Home, call me Bob if you want to hack some php. hint hint hint.... :)

Will I am in the office but if this is not fixed yet I will be glad to see if I can fix the PHP code in the afternoon when I get home. I just need the login to the sever again where that file is stored as I do not remeber anymore.

[WillJames]

Video server will be fixed ASAP thank you!!

[flymo]

Hurry up..........................!

[MrMel]

Waiting here too, to see if you came to the conclusion because of the same reason as I did... :)
I got some VERY strange results with the 14MZ & Spektrum module.

[JKos]

Hey guys,
I'm seeing some funny stuff too. It doesn't help that the 14MZ's latency in PPM mode has some oddities to it (wider than expected spread) which then impacts the perceived performance of the Spektrum system. But that isn't the cause for the eCCPM interaction issues, just increased total latency.

Finless,
What channels on the AR7000 were you using for the swash servos? I tried to follow in the video, but...

Also keep in mind that with the AR7000 you'll get 1024 resolution but with the an AR9000 you'll get 2048 resolution.

Here's the channel mapping from the 14MZ Function page to the outputs on the AR7000...
14MZ -> AR7000
1 -> 3 (Elev)
2 -> 4 (Rudd)
3 -> 1 (Thro)
4 -> 2 (Aile)
5 -> 5 (Gear)
6 -> 6 (Aux 1)
7 -> 7 (Aux 2)

The channel output order on the AR7000 when used with the DM8 module is: Rudd, Elev, Aile, Aux 1, Thro, Gear, Aux 2

I think you should use the Elevator, Aileron, and Aux 1 channels on the AR7000 for the swash servos to preserve their grouping on the rx outputs. That would mean using "channels" 1, 4, and 6 on the 14MZ. So a full mapping could be...
14MZ "channel" -> Function -> Output on AR7000
1 -> Elevator -> Elevator
2 -> Rudder -> Rudder
3 -> Throttle -> Throttle
4 -> Aileron -> Aileron
5 -> Gyro -> Gear
6 -> Pitch -> Aux 1
7 -> Governor -> Aux 2

- John

[MrMel]

I tried mine in real flight the other day, it felt wierd, if you did 10 tictocs, all of the sudden it went out of whack during 3 of them.

Finless was using correct channel assignment (switch Elevator and Gyro on the receiver cables)

[JKos]

The best combination I have found thus far is using rx channels 1, 3, and 4 for the swash which are 14MZ channels 1, 2, and 3. In this configuration it acts more like it does with the AR9000 in which the swash behaves just fine about 5/6+ of the time and dances a bit for a short time.

But note that this is really only good for testing purposes as using ch 1 on the receiver for anything but throttle is not good.

- John

[Finless]

Hmmmm interesting. I already returned the unit to my LHS but I bet I could borrow it again.

JKOS tell me why the 9000 has 2048 res since the PPM signal out the buddy box port is really NOT going to change? That makes no sense??? That is like watching a 320x200 video on a hidef TV... You cant MAKE UP "dots" or pixels that dont exist!!!

Also I wanted to know what it was going to be on the AR7000 as if I am going to go buy all new RX's for my helis I might as well go buy FASST! It's gotta be good with existing RX's! FASST better be there too or it will not get my approval!

As MrMel said I went with what the Futaba groupings are for 2048 G3 as it is well documented having ail/elv/pitch on 4,5,6 is best. I found it interesting how that mapped on the RX though so I can understand what your saying a little bit. Your saying the latency is in the RX remapping and not coming from the PPM train is part of the problem?

Bob

[LITHIUMSTATIC]

:clappp:banana:noteworthy

[MrMel]

Hmmmm interesting. I already returned the unit to my LHS but I bet I could borrow it again.


Dont bother, even though its better its still equally bad when it goes out of sync, meaning sometime when you fly you will experience what I did the other day.

"WOW, did I hit the wrong stick or what"

[Finless]

Dont bother, even though its better its still equally bad when it goes out of sync, meaning sometime when you fly you will experience what I did the other day.

"WOW, did I hit the wrong stick or what"

Hi MrMel and good to see you on the Freak along with JKos...
I trust JKos and his numbers as everything he has said to date as shown true for me on real experience!

However this random "going out of sync" is just WIERD and you saw it in my video. If that continues even on the mappings John is asking me to try then sorry I aint going to put this on a $2K radio! As i said int he video I didnt buy a $2K radio for that kind of performance........

John, I am going to borrow the unit again and try what you ask BUT I wont do it on a AR9000 as i WANT to see how it will work on a 7000. Again if I am going to buy new RX's I might as well do it on a Futaba solution..... Dont you agree?

Bob

[flymo]

When is the 12z/14mz FASST module due out?

[MrMel]

Late Aug/September is the date listed, so with current knowledge about how much its normally delayed it probably coming out at december..

[HFG]

Hey Fin ! From my understanding of some of the protocals on the higher end Futaba is that if some of the channels dont change significantly from frame to frame it will repeat some of the channels that have large changes. This allows any quickly changing channel to have a higher priority over slower changing channels. This might explain why you are getting more interactions on the swash when you add rudder inputs.

[Finless]

Hey Fin ! From my understanding of some of the protocals on the higher end Futaba is that if some of the channels dont change significantly from frame to frame it will repeat some of the channels that have large changes. This allows any quickly changing channel to have a higher priority over slower changing channels. This might explain why you are getting more interactions on the swash when you add rudder inputs.

If that were true why dont I see this on the same radio with a G3 RX?
Something is very different on how PCM 2048 works and how the PPM train is put out the trainer port. That is the only conclusion I can come to. My G3 2048 RX never did ANY of this stuff.

Bob

[JKos]

Finless,
> tell me why the 9000 has 2048 res since the PPM signal out the buddy box port is
> really NOT going to change?

The PPM stream out of the buddy box port is at least 2048 resolution, maybe higher. When the DM8 connects with an AR9000, it sends the pulse widths of the PPM stream in 2048 resolution. When it talks to an AR7000, the AR7000 can only accept 1024 resolution. So, the transmitter isn't changing what it does, it's just a difference in how the connected system can use the provided data.

> it is well documented having ail/elv/pitch on 4,5,6 is best.

This is due to how G3 works. Half the channels have simultaneous pulses, then the other half of the channels have simultaneous pulses. The output pulse groups are seperated by half the frame period. Keeping the three channels used for the swash in the same group is what is key, actually. I found nothing particularly special about 4, 5, and 6 when testing G3. As long as all three are kept in the same group it really doesn't matter much which of the channels in that group are used.

> Your saying the latency is in the RX remapping and not coming from the PPM train is
> part of the problem?

There is a more to the story than is immediately obvious. It has to do with a certain characteristic of Futaba PPM streams.

> Something is very different on how PCM 2048 works and how the PPM train is put out the trainer port.

Bingo. It appears PPM operation was not a high priority during 14MZ development. For some reason the latency has a spread of about 35 ms. That is just "not right" as the spread shoud be one frame period (as it is on every other radio I've tested in PPM mode). I didn't believe it at first, but that's what it is.

Don't bother borrowing the system again just as MrMel said. It still goes through the wobbles at times but it just makes it good when it is not in that state.

- John

[Finless]

Thanks for explaining John. Makes sense.

Yes I understood about the 14mz and "groupings" 456 was default so why change it.....

Couple of questions.

1) Will the DX7 be 2048 with a AR9000? I did feel a loss when I went grom G3 to DX7 with AR7000. If yes I mat have to go get a AR9000 :)

2) So your aying if I set up for channels 1,4, 6 I wont feel the paddles STEP similar to a 9C? I understand the wobble but I wont feel a step? Or do I need to try the AR9000 to get rid of that too?

3) I have "heard" that to get the full 2048 with FASST I will need the 14 channel FASST RX? Is that confirmed or do you know yet?

Bob

[HFG]

Finless,
> tell me why the 9000 has 2048 res since the PPM signal out the buddy box port is
> really NOT going to change?

The PPM stream out of the buddy box port is at least 2048 resolution, maybe higher. When the DM8 connects with an AR9000, it sends the pulse widths of the PPM stream in 2048 resolution. When it talks to an AR7000, the AR7000 can only accept 1024 resolution. So, the transmitter isn't changing what it does, it's just a difference in how the connected system can use the provided data.
d.

- John

The PPM signal from the buddy box is just a time coded system. The module can be triggered at any clock rate it wants to to obtain any resolution it wants. Of course you cant generate NEW data but if the clock rate is faster then the PPM resolution then the LSB will just be garbage from jitter.

[JKos]

HFG,
True enough. What I'm saying is that the buddy box output (PPM output) of the radio actually is at least 2048 equivalent resolution.

Finless,
> Will the DX7 be 2048 with a AR9000?

No.

> So your aying if I set up for channels 1,4, 6 I wont feel the paddles STEP similar to a 9C?

It seemed good to me during the good times but the wobble stage is still unacceptable.

> I have "heard" that to get the full 2048 with FASST I will need the 14 channel FASST RX?
> Is that confirmed or do you know yet?

I don't have any info on that. Haven't they been advertising 16,384 resolution for the existing FASST system?

- John

[Funky]

Great vid Bob. I would love to see the same tests on a 9303 w/ Spectrum module. I have been considering buying the module to convert my 9303. Does anybody you fly with run the 9303/spectrum? Is it only the 14MZ or is it all Futabas that have this problem when running a Spectrum module?