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Old Nov 14, 2012, 02:10 PM
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Melbourne Australia
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Quote:
Originally Posted by FlyBillyFly View Post
Just curious...Are you using a Park Receiver...or Full Range....Park Receivers are not good for Funjets....you git out of range in a hurry..

Oh...there is a squabble among us at the field....running only 2 servos we have a split on whether or not to use a separate UBEC even on just two servos and over 3 cell.....I do for my own peace of Mind...The recommendation that i've heard is over 3 cell use a separate UBEC..I do....and since your running only 3 cell....seems to me you have a reception problem...
...Billy

I had used an AR500, but when it went wild on me and crashed, i replaced it with an AR600. These are full range receivers according to Spektrum, and both those receivers came out of models that were flown at far greater distances than where the funjet was at when it went down.
I will trial an AR7000 just the same.
One of the guys I fly with is suggesting the servos cant do the job. Theyre HS 65MG's, which Ive seen as a good, commonly used servo on the funjet.
The thing I say to counter that idea, is that if it did i snap loop on its own (which it did), then BOTH servos have flipped the ailerons in the same direction at precisely the same time. What are the chances? But then finally, the crash was caused by just one servo having a fit, and sending the plane spiralling.
Damn frustrating but I WILL get a funjet flying reliably at some point in time. I'm just not sure how many I'll have to go through
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Old Nov 14, 2012, 02:12 PM
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Melbourne Australia
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Quote:
Originally Posted by War Machine View Post
After a few crashes I use a separate pack to power the Rx and servos. That way if you fry your lipo or esc you can at least (hopefully) land in one peice. 370mah 2s and HK BEC. Or you could use a 2S LIFE pack with no BEC.
Thats another idea.......I'll look into that. But would a ubec be any less reliable? Coz l have a couple laying around.
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Old Nov 14, 2012, 02:16 PM
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Melbourne Australia
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Quote:
Originally Posted by yellowcolorado View Post
If you really want to eliminate the problem, remove the Spektrum gear from the equation all together. When I bought my first RTF radian with a dX5, I had 3 brown outs, I sold that gear and went to ASSAN for years with 0 and I repeat ZERO problems. I wanted telemetry and have within the last 4 months went to FRSKY, once again with 0 issues so far.
Ive used spektrum gear on all my models, from small park flyers to helicopters and 60 size nitros. Never a problem. This is a completely foreign problem and I'm more inclined to think its a power supply problem. Im going to swap the RX out again though, to an AR7000 and see how i go.
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Old Nov 14, 2012, 02:20 PM
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United States, CA, Los Angeles
Joined Jan 2012
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I don't necessarily think AR600 receiver is to blame per se. I fly all of my Funjets and flying wings with AR400s with no problems. But with a high-power system like a Funjet, you really need an external BEC (Dimension Engineering), especially if you have a cheap ESC.

When you're gunning the Funjet at full throttle, the battery voltage sags and hits LVC, or worse - total cutoff to the servos. I had this happen with a stock Funjet setup with their Multiplex 37 ESC. I then switched the ESC to an Exceed Proton 60 and set the LVC cut-off to low.
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Old Nov 14, 2012, 02:20 PM
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Newmarket, England.
Joined Aug 2006
689 Posts
Quite a bit of research has been done on the brownout or lockout phenomenon.

2.4 ghz tends to require a more consistant voltage to keep the receivers happy.

Therefore,in most cases the problems encountered are usually the BEC section of the ESC not delivering enough amps and volts to feed the servos and receiver.

There is no guarantee with any 2,4 ghz system that it will be problem free from lockout or brownout but designs change.

Hitec now use receivers which have a separate port to allow voltage to be supplied to the receiver section only and the servos supplied with the voltage from the BEC. This must say something for their research.

In my experience, the use of a separate bec, or installing a ubec is not worth overlooking. all of my planes has one fitted.

Even the factory fitted units like the Parkzone radian, for instance, uses 6 digital servos and a 30 amp esc which only just has enough headroom to supply the necessary requirements from the inbuilt BEC.

It's also paramount to know and understand how long you can fly WOT and land before the BEC is starved of what it needs, long before the Low Voltage Cutoff section of the ESC takes over.

By then the peaks and troughs of current supplied by the BEC may be well under what the receiver requires.

This is the UBEC which I use. The weight added is nelgligable.
http://www.4-max.co.uk/ubec5Ahv-3.htm

Clearly there are some very good ESC's which a have the ability to diddle around with the LVC and determine if tyou need to set it to low or high to allow enough headroom for the BEC section to cope with consistent supply to the receiver. no doubt these work very well as stated.

Personally I still prefer to use a separate BEC.

There were indeed reports that the AR600 and AR400 receivers from Spektrum were poor performers but possibly the problems all along have been the choice or the factory installation of the ESC ? however all of my lockouts were with the AR600. The AR400 worked perfectly for the rest of the season this year so far.

I will be using either Hitec or futaba next year though but still employing a separate BEC.on my FJU




There's an excellent thread here which has an XL Spreadsheet with a superb calculator to help determine your flight time at WOT.
http://www.rcgroups.com/forums/showthread.php?t=703489
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Old Nov 14, 2012, 02:31 PM
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Staffs, UK
Joined Apr 2009
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Spektrum seem to get a pretty hard time IMO.

ONLY time I've had range issues was with a chinese copy of a 6110E, and that went out of range at about 100yds. However I didn't know it was a copy, and sent it back to HH complaining of the prob. They actually replaced it FOC.

I've used 6110E's and AR500's (6200's too) to the range of my vision on sub 1mtr models, never had a prob. This was using the internal Bec's and before I didn't mind dropping lipo's down to LVC (on high setting tho...3.2v per cell). Most of this was on 3s BTW.

What I would say is anyone who uses Spektrum to send their RX's and TX in once a year for servicing. My RX's usually get sent back when the antenna has frayed (pretty regular then...). HH Uk have NEVER charged me for servicing or repair on anything. Actually I've never paid for return postage either. Very good customer service IMO.

However, I'm open to the fact that other users have had probs with Spek, just I haven't, other than the above.

But I wil be honest and say that I use MPX for all of my molded gliders, FJU and Dogfighter now. Most of my Spektrum has been moved on, only a Halfpipe 48, Alula and a Blade 450 3D are left on Spek, but only because I decided to SERIOUSLY reduce my fleet because of lack of time to fly.

BTW,the reason I use MPX is because the DX7 wasn't a good enough radio for full house sailplanes. I would have happily bought a JR and used Spek, but the MPX came for a great price 2nd hand.

Just my 2c.....
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Old Nov 14, 2012, 02:33 PM
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Melbourne Australia
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Quote:
Originally Posted by Left Coast DJ View Post
I don't necessarily think AR600 receiver is to blame per se. I fly all of my Funjets and flying wings with AR400s with no problems. But with a high-power system like a Funjet, you really need an external BEC (Dimension Engineering), especially if you have a cheap ESC.

When you're gunning the Funjet at full throttle, the battery voltage sags and hits LVC, or worse - total cutoff to the servos. I had this happen with a stock Funjet setup with their Multiplex 37 ESC. I then switched the ESC to an Exceed Proton 60 and set the LVC cut-off to low.
Im using the stock multiplex kit, with the BL 70 esc. I was flying it gently at the time as well. Im baffled, but Im going to use the external bec now.
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Old Nov 14, 2012, 02:38 PM
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Melbourne Australia
Joined Aug 2010
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Quote:
Originally Posted by soundcheque View Post
Quite a bit of research has been done on the brownout or lockout phenomenon.

2.4 ghz tends to require a more consistant voltage to keep the receivers happy.

Therefore,in most cases the problems encountered are usually the BEC section of the ESC not delivering enough amps and volts to feed the servos and receiver.

There is no guarantee with any 2,4 ghz system that it will be problem free from lockout or brownout but designs change.

Hitec now use receivers which have a separate port to allow voltage to be supplied to the receiver section only and the servos supplied with the voltage from the BEC. This must say something for their research.

In my experience, the use of a separate bec, or installing a ubec is not worth overlooking. all of my planes has one fitted.

Even the factory fitted units like the Parkzone radian, for instance, uses 6 digital servos and a 30 amp esc which only just has enough headroom to supply the necessary requirements from the inbuilt BEC.

It's also paramount to know and understand how long you can fly WOT and land before the BEC is starved of what it needs, long before the Low Voltage Cutoff section of the ESC takes over.

By then the peaks and troughs of current supplied by the BEC may be well under what the receiver requires.

This is the UBEC which I use. The weight added is nelgligable.
http://www.4-max.co.uk/ubec5Ahv-3.htm

Clearly there are some very good ESC's which a have the ability to diddle around with the LVC and determine if tyou need to set it to low or high to allow enough headroom for the BEC section to cope with consistent supply to the receiver. no doubt these work very well as stated.

Personally I still prefer to use a separate BEC.

There were indeed reports that the AR600 and AR400 receivers from Spektrum were poor performers but possibly the problems all along have been the choice or the factory installation of the ESC ? however all of my lockouts were with the AR600. Teh AR400 worked perfectly for the rest of the season this year so far.

I will be using either Hitec or futaba next year though but still employing a separate BEC.on my FJU




There's an excellent thread here which has an XL Spreadsheet with a superb calculator to help determine your flight time at WOT.
http://www.rcgroups.com/forums/showthread.php?t=703489
All good information, and consistent with some of the suggestions from guys i fly with. What bothers me about this being the possible cause is that l chose to use the stock multiplex system, so that l wouldnt have to worry about problems like this. Anyway Ive got a couple of ubecs and l will use one. Im convinced its a power failure problem somehow, but not 100% sure.
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Old Nov 14, 2012, 02:41 PM
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Newmarket, England.
Joined Aug 2006
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Quote:
Originally Posted by feefo View Post
Spektrum seem to get a pretty hard time IMO.

ONLY time I've had range issues was with a chinese copy of a 6110E, and that went out of range at about 100yds. However I didn't know it was a copy, and sent it back to HH complaining of the prob. They actually replaced it FOC.

I've used 6110E's and AR500's (6200's too) to the range of my vision on sub 1mtr models, never had a prob. This was using the internal Bec's and before I didn't mind dropping lipo's down to LVC (on high setting tho...3.2v per cell). Most of this was on 3s BTW.

What I would say is anyone who uses Spektrum to send their RX's and TX in once a year for servicing. My RX's usually get sent back when the antenna has frayed (pretty regular then...). HH Uk have NEVER charged me for servicing or repair on anything. Actually I've never paid for return postage either. Very good customer service IMO.

However, I'm open to the fact that other users have had probs with Spek, just I haven't, other than the above.

But I wil be honest and say that I use MPX for all of my molded gliders, FJU and Dogfighter now. Most of my Spektrum has been moved on, only a Halfpipe 48, Alula and a Blade 450 3D are left on Spek, but only because I decided to SERIOUSLY reduce my fleet because of lack of time to fly.

BTW,the reason I use MPX is because the DX7 wasn't a good enough radio for full house sailplanes. I would have happily bought a JR and used Spek, but the MPX came for a great price 2nd hand.

Just my 2c.....
Yep I agree, I think Spektrum do have a lot of bad press, usually at the fault of something else. Personally I find that the AR600 is VERY voltage sensitive and since fitting the UBEC on the planes with it fitted, zero problems.

The reason for my change is due to a complete clearout of everything that I have except my FJU and I have the opportunity to buy a different 2.4 system which i'd like to try as opposed to Spektrum.

I find that the quantity of counterfit units on the market is intolerable.
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Old Nov 14, 2012, 02:55 PM
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Staffs, UK
Joined Apr 2009
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I'd tend to agree about voltage being the under-lying prob, simply saying 'brown out on Spek again' is an easy option when pilot error (not checking equipment properly or even a moment of numb thumbs) could be the prob.
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Old Nov 14, 2012, 03:42 PM
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Melbourne Australia
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The irony of it all is that the guys said it was the most beautiful loop I'd ever done!
I left it a while before I told them that it wasn't actually me that did it
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Old Nov 14, 2012, 03:56 PM
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Newmarket, England.
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Quote:
Originally Posted by Maccanaut View Post
The irony of it all is that the guys said it was the most beautiful loop I'd ever done!
I left it a while before I told them that it wasn't actually me that did it
See if you can do a loop as well with a new UBEC

It's clearly the cheapest way to go and sad it is that you went the MPX route trying to eliminate future probs and potentially it hasn't paid off yet.

If the UBEC cures or eliminates the same issue then thats a good thing although not really what you wanted after spending the $ on the quality products.

I just read the spec on the BL70 and it really has a low amp BEC at only 2.5 MAX !!....In comparison most of the cheapo stuff has at least 3 amps with a 5 peak (Stated), now depending on the servos, this may well be the issue. Without connecting a meter in line you'll never know but even on 2 servos, if they are digi ones, then throw in the mixing, I would bet that the UBEC will change things for you.
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Old Nov 14, 2012, 04:47 PM
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United States, CA, SF
Joined Mar 2008
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Quote:
Originally Posted by Arcteryxxx View Post
AR7000 / 7010 are the best Spektrum receivers IMO.
+1

AR6200 receivers are full range too, but I wouldn't trust that either for high power stuff.
I don't even want to get into that debate again. There is a "Dark cloud" over it....and others.
How many times have we seen simple change to AR7000 take care of issues????


Ofcourse, issues are not always related to receivers but for models that people really care about, I don't see going below AR7000.
Does not make me right, but that is my view.


Gryphon
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Old Nov 14, 2012, 04:58 PM
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United States, CA, Los Angeles
Joined Jan 2012
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Any full-range Spektrum DSMX receiver will do. As I said above, I fly with AR400s and have had absolutely no problems. I don't see a need to spend $100 for a receiver to fly a plane that only uses 3 channels.

I route the longer antenna of the receiver through the hole in the Funjet fuse on to the groove in the wing and tape it there. And with an extra BEC, you should not have any problems.
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Old Nov 14, 2012, 06:15 PM
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United States, AK, Anchorage
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Sorry for generalizing all your FJU problems to Spektrum. Chances are you just need a UBEC. I fly most of my planes with an external UBEC as well. Funny thing is, I dont use an external UBEC on my Ultra. It's run with a CC 100A lite esc and I run it on 4 cell, so I will chance it. Spektrum does charge so much more for a 7 or 8 channel receiver than some of the other brands.
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