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Interesting stuff.

My crash seems to have sparked some heated debate. I intend to use only 6v UBECs in the future on all my leccy models, and if I'm correct I can modify my BEC ESCs (in my Ripmax Spit / 3 std servos) to allow me to use a UBEC, can't I?

Jetsome - where do you get Polyquest lipos from?

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Yes....simply remove the red ( +ve ) wire from the 3 wire lead from the ESC to receiver - this stops power being fed from the ESC to receiver but still allows the throttle signal pulses through. Plug your UBEC power lead into the receiver "battery" socket.

PS As I have stated many times... I do NOT think brown out was the cause of your crash. You state quite clearly that the throttle closed as the problem started - this is signal failure of one form or another NOT brown out.

IMO ( see lengthy post above in response to Scott ) small foamies and the like are perfectly OK on most ESC BEC units, provided all other aspects of installation and equipment used is up to scratch.

Paranoi seems to be spreading throughout the Spektrum land about brown outs and becs and so on.... totally unjustified in many cases, ESPECIALLY as there are now many perfectly good ESCs which contain an onboard switching regulator that are equal or indeed better than some standalone BECs!

I for one have no intention of purchasing UBECs for my lightweight simple foam models to simply make the existing ones surplus weight, and introduce yet more PPOFs

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You're probably right. Do you think then that the 33a ESC with BEC unit on my Ripmax Spit (which has only 3 servos) is likely to be sufficent?

Don't worry I won't blame you if it goes wrong.

As for paranoia, I am still intent on continuing down the 2.4 route, and as my insurer has agreed to pay up, I may be looking for a JR DX9!

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Shaun Chant wrote (see)

You're probably right. Do you think then that the 33a ESC with BEC unit on my Ripmax Spit (which has only 3 servos) is likely to be sufficent?

Don't worry I won't blame you if it goes wrong.

As for paranoia, I am still intent on continuing down the 2.4 route, and as my insurer has agreed to pay up, I may be looking for a JR DX9!


Personally YES. I cant say it any more clearly than I already have - explained in detail above, the results I have experienced in almost 2 full years of DX7 flying ....100s of flights with ESC becs and not a single problem EVER.

I never said YOU were paranoid and the new JR set is gorgeous.

What more can I say I know I am not just lucky...

My final words on your crash.... ( I am probably lying about this being the final words  )

SIGNAL LOSS OF SOME SORT.

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Timbo - forum moderator wrote (see)
My final words on your crash.... ( I am probably lying about this being the final words  )

SIGNAL LOSS OF SOME SORT.

Agreed it was probably signal loss of some sort.

DSX9 question - confirm it will work happily with all Spektrum DSM2 rx? (inc AR6100)

PS - I'll be ordering another Sea Fury....

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Yes, and also DSM1 rcvrs too...such as the underated and excellent performing AR6000.

Better luck with the next fury.  Could I suggest maybe testing the replaced receiver in a real cheapy chuck about first until you are happy again. Also, did you ever confirm the TX aerial positioning during the final flight? 

Plus.. ( see I told it was my last word on  it  ) - I am still puzzled about the figures you showed for the different battery packs - higher internal resistance alone should not have resulted in such a huge difference between between delivered current - could you run another test with same rig, but use WOT for say 1 minute runs and let us see the results?

Nowt to do with your crash I suspect...but has raised a further question nonetheless.

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Aerial position - I usually have it in the half bent position, so I must assume this was the case on the day.

Battery tests - sure I can repeat the test. Do you want discreet 1 minute runs, or a WOT run until stop with data every 1 minute?

Of possible interest, when I recharged the two packs the Electrolite took 2150mah and the Mystery pack took 2094 mah. Both are rated 2200mah and 25 - 30C

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They are considered top class packs - and some may argue ( me included ) that as good as the cheap packs are in terms of VFM what about their overall lifespan...that has yet to be properly ascertained. EG: I have 2 x 2000mahr 15C KOKAM packs which are now over 4 years old, have been pushed hard, never balanced ( these were supplied with no balance plugs in those good ol' days ) and they STILL perform pretty well.

I wonder if my latest £11 / 2200 / 25C jobs will be as good

Shaun...  a single 2 minute discreet run each at WOT will be fine... I just want to see why one is so poor at delivering current compared to the other. Open the go stick full from kick off and leave it alone until 2 full minutes have passed, then shut off throttle completely in one swift move.

Ensure each pack is properly peaked on the charger before testing.... and obviously use exactly the same conditions for each test.

Record the V A W at 30 second intervals ( thats why I filmed my tests before I got the eagle tree logger ) 

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jetsome

    i assume you are aware that polyquest, flightpower, hyperion and sharkpower from Puffin are all enerland cells thus if you find another of the mentioned cheaper than polyquest buy em. incidentally i rate these cells very highly and i'll not use any other at the moment....... yes i have some cheapo packs but the enerland stuff is 2nd to none

nasa

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Shaun Chant wrote (see)

Comparison results. Timbo asked me to conduct some 2 minute tests at WOT. Here are the results

http://i94.photobucket.com/albums/l92/winchweight/2mintests.jpg


Ah... now that's a bit more like it. I suggest the reasons for the substantial differences in the earlier test was down to imprecise throttle settings - thereby comparing apples with oranges. Unsurprisingly the cheaper "mystery" packs do not hold their voltage under load quite so well as the excellent Electrolite cells, and this results in lower amps and therefore Watts.
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Timbo - forum moderator wrote (see)
Shaun Chant wrote (see)

Comparison results. Timbo asked me to conduct some 2 minute tests at WOT. Here are the results

http://i94.photobucket.com/albums/l92/winchweight/2mintests.jpg



Ah... now that's a bit more like it. I suggest the reasons for the substantial differences in the earlier test was down to imprecise throttle settings - thereby comparing apples with oranges. Unsurprisingly the cheaper "mystery" packs do not hold their voltage under load quite so well as the excellent Electrolite cells, and this results in lower amps and therefore Watts.
But interestingly they are much closer in performance after 2 mins than at the start!
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That is not uncommon...many packs actually increase their current flow by quite a margin after a short period - the cells warm up, internal resistance drops, and away they go and If one pack starts off with higher internal resistance, then it is likely to improve slightly more than the other.
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This latter stage of the thread is not really looking at the original problem of the crash - we have drifted off slightly ( as usual ) into the aspects of receiver failures in one way or another. I think it is fair to say we pretty much agree it was signal failure....but Shaun tried a few tests at home and one thing lead to yet another !
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