AXN Floater-Jet (aka Cloud Fly) - Page 100 - RC Groups
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Dec 18, 2009, 01:50 AM
Registered User
Further examination of the H40A ESC shows that it uses TWO LM317T voltage regulators to implement the BEC. These are 1.5A devices, and as they are connected in parallel, the total BEC current available is not 2A as stated in the user manual, or 1.5A as stated on the HobbyCity site, but 3A

It's quite amazing that this ESC sells itself short! Not only can it deliver more motor amps that it's rating, but the BEC is over-specified as well. I guess it's down to it's larger size and thus there was less need to miniaturize as much.

The LM317Ts are connected across the incoming power supply, and apart from the supporting circuitry shown in the datasheet linked above, that's all there is to the BEC.

LM317T regulators are fully protected against over current and thermal protection.

Quite how a stalled HXT90 could "overload" a pair of LM317T is beyond me. Maybe the battery was no good and could not provide enough voltage to power the receiver / servo tester being used.
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Dec 18, 2009, 01:52 AM
Registered User
AJBAKER : what I see is that you repeatedly make statements that you cannot back up, and when you are called on them, resort to attacking my credentials rather than my arguments.

So I repeat : what is bad about the design. Or was that just a guess?

Oh, and the reason it's not off topic is that you are suggesting solutions to a problem that are wrong.

(And reporting my postings to a moderator doesn't change anything. Hiding behind a moderator is a feeble ploy. )
Last edited by beautox; Dec 18, 2009 at 02:51 AM.
Dec 18, 2009, 04:05 AM
Argue for your limitations
ajbaker's Avatar
Quote:
Originally Posted by beautox
AJBAKER : what I see is that you repeatedly make statements that you cannot back up, and when you are called on them, resort to attacking my credentials rather than my arguments.

So I repeat : what is bad about the design. Or was that just a guess?

Oh, and the reason it's not off topic is that you are suggesting solutions to a problem that are wrong.

(And reporting my postings to a moderator doesn't change anything. Hiding behind a moderator is a feeble ploy. )
First, I suggest learn how to play well with others. This topic is closed.

Meanwhile, back to the thread. Has anyone used gyros on this yet? I have had one on the pitch since it was maidened. Now, that I have many flights on it, I am wondering if it has any value. For several of my planes, a gyro is unnecessary. But, Like is cousin, the Wild Hawk - on that one it is needed IMO.
AJ
Dec 18, 2009, 04:39 AM
Registered User
Launching the CF does require quick reactions as it tends to pitch down under full power.

A gyro would be helpful for beginners. Or for anyone who lacks confidence in their flying abilities.
Dec 18, 2009, 04:56 AM
Registered User
Quote:
Originally Posted by beautox
Talk about not wanting to admit you're wrong...

You see, the "problem" has already been fixed. By setting HIGH timing (as it was clearly a timing problem).

Given that, when I initially tested this, there were no servos connected, how on earth do you reckon that the BEC is failing? Amazing.

By the way, I've been flying the plane successfully now for a few weeks.
There is an issue beautox, why do 98% have no problem , we heard sofar in this thread that only you and lonzar had this issue.
A lot of people who bought the CF assembled it and fly with it, without having the knowledge how to program the ESC so using low timing.
Dec 18, 2009, 04:56 AM
Argue for your limitations
ajbaker's Avatar

Gyros


I need to be clear in my question. Has anyone used a pitch or roll gyro on a CF airplane? I am looking for feedback on their experience.
AJ
Dec 18, 2009, 04:58 AM
Registered User
jaccies: I'm using a non standard ESC and motor (as I have explained in several posts). I would guess that the stock ESC and motor work fine together.
Dec 18, 2009, 05:01 AM
Registered User
Quote:
Originally Posted by beautox
Launching the CF does require quick reactions as it tends to pitch down under full power.

A gyro would be helpful for beginners. Or for anyone who lacks confidence in their flying abilities.
or use up-thrust
Dec 18, 2009, 05:13 AM
Good Better Best quest.
olmod's Avatar
Quote:
Originally Posted by jaccies
or use up-thrust
I have added 2 deg and it made very little difference to the nose down power launch,
but a local has used an undercarriage with great success.
Dec 18, 2009, 05:42 AM
Registered User
Quote:
Originally Posted by beautox
Right, my Watt meter arrived today and I performed some tests. Using a 4.75x4.75 prop, on high timing at max throttle it was drawing 24.1A at 11.4V, which makes 274W
On low timing the point where the motor cuts out (roughly half throttle) when the throttle is opened fast is somewhere between 6.3A and 9.1A (V=12.1)
So you can see that a 40A (50A burst) ESC is nowhere near overloaded.
On a related note, has anyone measured the Watts that a stock motor consumes at full throttle?
see post, it is 230Watt
Dec 18, 2009, 05:44 AM
Registered User
Quote:
Originally Posted by olmod
I have added 2 deg and it made very little difference to the nose down power launch,
but a local has used an undercarriage with great success.
I added 2 shims of 1,5 mm thick at the above 2 screws, and it helped a lot
what is an undercarriage , any pictures??
Dec 18, 2009, 05:51 AM
Registered User
230W - that's with the stock prop I suppose? Is that 5x5?
Dec 18, 2009, 06:01 AM
Registered User
Quote:
Originally Posted by beautox
230W - that's with the stock prop I suppose? Is that 5x5?
yes correct 5x5
Dec 18, 2009, 07:57 AM
Crashing in Melbourne
Quote:
Originally Posted by ajbaker
I need to be clear in my question. Has anyone used a pitch or roll gyro on a CF airplane? I am looking for feedback on their experience.
AJ
I have a gyro on pitch - makes for very stable flight.
I still had issues with hand launching - my reaction either not quick enough or over compensated.
Once I fitted the undercarriage - a single glider wheel in my case - launching has been a breeze. This has meant that I can keep both hands on the controls and don't fumble.
Dec 18, 2009, 08:05 AM
Good Better Best quest.
olmod's Avatar
Quote:
Originally Posted by jaccies
I added 2 shims of 1,5 mm thick at the above 2 screws, and it helped a lot
what is an undercarriage , any pictures??
Ill get some pix sunday if the weather is ok.