Hi,

It looks like there are a few here with the Trex 300x and I'm wondering if there's any advantage to connecting the ESC's separate data cable to the Spirit unit via the TELEM-UNI cable. I know that Align (Hobbywing) bigger 'v4' ESCs have the advantage of telemetry, but does this little ESC have it too? I've successfully used the Hobbywing program box for setup / features but don't know if the signal wire outputs information in-flight.

Cheers, Andy

Andy- not related to your question but can I ask you to try something please?

Are you using the esc and servos that come with the heli?

Can you run the bec test please? Did it pass? Mine always browns out.

Hi, yes, using the standard ESC and servos. And yes, running the BEC test just now had it fail 2 out of 3 times. When it fails, it doesn't just stop but the swashplate pumps up and down about every 2 seconds (and the tail servo doesn't respond). Must be a fail-mode in the unit. Mine's a uSpirit (micro) and the ESC feeds direct to the unit (AUX). The unit then powers the SRXL2 receiver via single connection.

Tomorrow I'll do the test with the the tail linkage disconnected to see if it is binding. The swashplate seems pretty free so I doubt it's that. I'll try to measure the battery current when the BEC test is on, using a watt-meter in the main battery line. I'll also use my Hobbywing box to try different BEC voltages if poss. I do have a spare Castle 35A ESC to try as a substitute BEC, but no suitable motor connectors so can't swap it out fully yet. I'm still in the setup stage but was hoping to hover it in the garden in the next day or two. Seems I need to resolve this issue first - thanks for the info!

Cheers, Andy

Mine also fails (spirit 2), but I get a complete brownout. The receiver disconnects from my transmitter etc.

I've had this issue from new, I've not flown the 300x or the spirit 2 yet. I changed the ESC and changed the servos under warranty, but it still occurs.

There are tons of videos of these flying just fine on YouTube, so I concluded that the Spirit BEC tester is really hammering the servos in a way that normally doesn't happen in flight.

I then, on the bench, set up rescue, and engaged it. That test also caused a browns out.

I then put the 4 servos on a servo tester, set to move them at full speed continuously, powered by the Align 25A ESC - The servo tester eventually browns out after about 20 seconds.

I also replaced the ESC with a Talon35 (3A bec) and the same thing happened.

So to conclude: 3A BEC is not enough for this model. Change the servos for different ones or change the ESC for one with a bigger BEC.

I've tried 4x KST215mg servos and they pass the BEC test every time.

Change the ESC for the 40A version which has a 7A BEC. The 25A version is only 3A.

I've decided to change the servos for KST215mg (because i use these on my Gaui x3's) and also change the ESC for the 40A/7A version.

Align should have known the the BEC was under-rated. They also should have noticed the elevator servo rod is 5mm too short!
This is a real let-down by Align.


(sorry for hijacking your post )

As far as I know, the 25/40A plat v4 escs do not have telemetry. Only the bigger models.

EDIT: See here:

http://www.manual.spirit-system.com/ind ... ted_models

jjuk,

Thanks for the link which answers the question - I'd missed that!

Re: the BEC test - I discovered a lot of binding / friction in the tail of the 300X which was solved with careful lubrication. The system then passed the BEC test but I agree the ESC's BEC output appears marginal. For me, I doubt it will be an issue as I don't fly 3d and witnessing the BEC test it looks like it would satisfy the needs of Alan Szabo jr. with Parkinson's.

Cheers, Andy

any BEC with only 'almost enough' power will fail some day most likely... when dust has weakened the lubrication and you are in trouble & push rescue (which is demanding on BECs). switch to better BEC or try at least to integrate a capacitor as integrated in many Hw ESCs package by default (i.e. one 4700µF parallel to BEC)... this should cut the peaks a little - even it will not resolve problems of a generally weak BEC. as it's about BEC: better safe than sorry

_________________
cheers
Michael

I have a new (standard setup) TREX 300x with only 5 flights on it. Spirit 2 fitted.
With the ESC BEC set to 6 volts the BEC test passes. With BEC set to 7.4 volts in the ESC the BEC test will sometimes report as a fail but test completes without indication of a brownout or disconnect.

that's a clear indication for a BEC on the edge as current hv servos are known for clearly higher amp peaks in hv use (peaks are seen during change of direction... and as faster they are, the higher the peaks) => peaks @ 6v are barely within BEC's limits... 7.4V too much. bec can likely fail... i.e. during high load @ rescue.

just try a capacitor (4700µF, 10V better 16v, Low ESR) parallel to the BEC... and retry the test. maybe it's enough... of course a stronger bec woud be better.... at least i would stay @ 6v

_________________
cheers
Michael