Deadband more than Before???

[rchaas]

Setup:

E7, Xera 4530-500
HeliJive
Vbar 5.3 blueline
12S
JR/Spektrum (satellites, digital center)

So, i am switching back to HeliJive governor (funky startup sounds/behavior with VBar gov and HJ). I reset the HJ to mode 1, then mode 4 (auto bailout feature enabled at hold 15%), throttle curve 0-100.

When i go to take out the deadband, i noticed that the HJ activates at 58% ATV on low end throttle!

Previously, it was always at 82%. Is this a quirk of VBar 5.3 or is something wrong. It just seems like a very short spread with loss of resolution for governor to be using -60 to 60 as opposed to -82 to 82.

Appreciate your thoughts.

[MrMel]

If you do it via VBar you need to have the VBar powered else you get zero throttle range.
I use a separate RX to program.

[rchaas]

Vbar is powered for the adjustment but i am using the transmitter ATV to adjust.

So use a spare JR receiver without Vbar?

[rchaas]

error

[MrMel]

Vbar is powered

yes, but is it powered all the time (not using BEC but a valid buffer pack), the Vbar failsafe will kick in otherwise, and can interfere.

[rchaas]

BEC is disabled and I'm using a separate receiver pack. Should I reenable the BEC for programming purposes?

[MrMel]

Nope, then it should work correctly, make sure you have 0-100 curve and 100/100 endpoints when starting, and no throttle trim.

[Groucho_]

I never needed to program any compensation for deadband on my helijive...

I just set mode 1, then I set mode 6 and according to Jlog my TX values and helijive values are almost identical. They're 1% apart.

So if I have 39% throttle on the TX, the helijive reads it as 40%

[rchaas]

MrMel,

I have checked and double checked, ATV 100/100 on Vbar, throttle curve 0-100, no throttle trim. Any other suggestions? It is repeatable, but the deadband is much higher that it was on any of my other HJ's.

You think this one needs to go back to Kontronik for a checkup, or shall i just fly it?

[MrMel]

Use separate receiver to program it if you have one as im unsure if anything changed in that aspect in 5.3

[rchaas]

will try a separate receiver without VBar.

[rchaas]

I tried a separate receiver, no Vbar, same result. Deadband eliminated at -55-+55.

However, when i reprogrammed without enabling auto bailout, the deadband went back to the usual -82-82!!

Aha!

I hadn't tried the HJ auto bailout feature before, so was never confronted with this. To be sure, I'll describe how I am programming auto bailout:

before programming mode 4, i leave the throttle curve at 0-100 and enable hold, at +15%. After 4 beeps in HJ program mode, I raise the stick. I hear 3 beeps, then switch into hold, and I hear three more beeps, then four beeps and the phone ring, signifying auto bailout enabled. Is this correct? After programming in this way, the deadpand results in 55-55 throttle ATV active range.

When i reprogram mode 4 and do not switch into hold, I hear the second three beeps and the four beeps, but no phone ring. After this, the deadband is back to 82-82.

So, i guess i am not going to use auto bailout (I rarely bail from autos anyway)

Interesting.

[dl7uae]

I'm not sure if my understanding of "dead band" covers with yours.

The H/JIVE is also starting to commutate at 12% of throttle, as the JIVE does.

There is a difference regarding the "uplift" throttle./.PWM which is a bit higher with the H/JIVE.

Look:

JIVE mode 4


H/JIVE mode 4

[rchaas]

What I am referring to is, after programming mode 4, with or without auto bailout, with ATV at 100-100, the motor starts to turn ("commutate" as u say), not at -100 or -90 but at -56 with auto bailout enabled, and at -82 without.

So, one must move the stick quite a long way on first spool up. I am not sure how this might effect inflight performance, once the gov has engaged. Maybe not at all.

[MrMel]

Originally Posted by rchaas

What I am referring to is, after programming mode 4, with or without auto bailout, with ATV at 100-100, the motor starts to turn ("commutate" as u say), not at -100 or -90 but at -56 with auto bailout enabled, and at -82 without.

So, one must move the stick quite a long way on first spool up. I am not sure how this might effect inflight performance, once the gov has engaged. Maybe not at all.

You must do something wrong when you program it.
With AR bailout you need to do the first stick movement from -100 to +100, not use the throttle hold with 15% or whatever you have in the first movement when you do mode 1

See my video if unsure.

[dl7uae]

at -82 without

This is 9% on a scale 0/100. This is not really possible if the JIVE is understanding the throttle pulse 1:1. Start at 12%, stop below 10%. So -82 should be the value at which a spinning motor stops.

but at -56 with auto bailout enabled

22% on a scale 0/100.
Well... What was the agreed bailout throttle value by setup? (15% should be fine)
Based on the above 9%, the bailout seems to be 13% (22-9).

OK, not surprising. With bailout the agreed 2nd value for OFF is acting as an offset to the throttle seen in the input by the JIVE.

[rchaas]

So the JLog supports what I am finding.

MrMel,

I have watched your video repeatedly. The first movement is throttle stick from -100 to 100. After the confirmation tones, I enable hold switch. I get a second set of confirmation tones and then the four beeps with phone ring. I am not programming incorrectly.

Thanks for the all the input and help!

[dl7uae]

(That was "SAC", another development by me, not JLog, but anyway. But, right, JLog is embedded in SAC.)

Only the 9% instead of 12 (-82 vs. -76)...

As said: The bailout throttle value is always an offset to the input throttle. That is why, so that the JIVE can distinguish between zero and bailout "zero". Btw: The JIVE will initialize with both values, zero and bailout. The 1st spoolup after initialization with bailout throttle will be a slow one. Only, you have to be careful in using bailout for zero to avoid a fast spoolup with the heli on ground. Means, to wait at least 15 seconds between spoolups. In this respect it is more safe to use zero (0%) on ground and bailout for an AR on the hold switch. But this is sometimes difficult to do with hand-held transmitters, needs a 3-stage-switch, extra mixer or whatever. If you sacrifice a flight phase, it is easiest.

Find here JIVE modes demonstrative and H/JIVE bailout. The text is in German, sorry, try the built-in translator of the site.

Tom

[rchaas]

The translator is not very robust, and I only have a little German. However, it seems the author has a profound disagreement with MrMel about the whole "deadband" issue.

I think that for now, I"ll leave the AR bailout mode off, and fly it like it is...which is quite good mind you!

[dl7uae]

Okay, however.. I cannot see a reason to pass on the bailout.

The "dead band" thing is not important here, although it is mentioned in the title of the thread.