stuart macrory Posted December 3, 2007 Share Posted December 3, 2007 HELLO ALL IM NEW TO RC AND WAS LOOKING SOME HELP.I BOUGHT A FUNJET AND RAN IT ON THE RECOMMENDED POWER SET UP WITH A 11.1V 2100 MAH 25 C LIPO.I HAD 3 FANTASTIC FLIGHTS BUT THEY ONLY LASTED 3-4 MINUTES UNTIL THE LIPO LOST ALOT OF POWER.ON THE 4TH FLIGHT IT FLEW GREAT AS USUAL BUT AFTER ABOUT 3 MINS OF FLIGHT TIME IT LOST ALL POWER NOTHING WOULD WORK AT ALL,OF COURSE AT THIS POINT I WAS IN A VERY FAST DIVE!!(YOU CAN GUESS THE REST)IT WAS LIKE AN EXPLODED BEAN BAG AS IT HIT THE DECK.SOMEONE TOLD ME WHO KNOWS A BIT ABOUT RC THAT I SHOULD NOT FLY IT FLAT OUT FOR LONG PERIODS OF TIME,I HAVE TO ADMIT THAT WHEN I FLEW IT ,IT WOULD BE FULL POWER 90% OF THE TIME,HE SAID THAT I HAD OVER WORKED THE BATTERY AND IT HAD JUST CUT POWER.IS HE RIGHT?? ALL THE ELECTRICS STILL WORK AND I HAVE ORDERED A NEW FUNJET BUT COULD NOT BARE TO SEE IT KAMIKAZE AGAIN.THANKS FOR YOUR TIME. Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted December 3, 2007 Share Posted December 3, 2007 What motor and ESC were you using Stuart? Sounds like an loss of signal if nothing worked rather than a loss of just battery power. We had the same problem documented with our review model - we put it down to the receiver being too close to the motor/ESC. We put the receiver up at the nose and the problem seemed to cure itself. Quote Link to comment Share on other sites More sharing options...
stuart macrory Posted December 3, 2007 Author Share Posted December 3, 2007 im using a multiplex bl-37 37a speed controller and himax 2700 ha2828 motor. i had battery up front with rx just behind,its the only way i could get cg right,what do you think? Quote Link to comment Share on other sites More sharing options...
stuart macrory Posted December 3, 2007 Author Share Posted December 3, 2007 also do you think there is any truth in what a friend is saying regarding constant full throttle being too much for the battery? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 3, 2007 Share Posted December 3, 2007 Without a wattmeter to check the current consumption on that setup it is not really possible to say with accuracy.The actual motor recommended for this setup is the 2825-2700, NOT a 2700 -2828, which incidentally I could find no reference to anywhere!As for not flying it flat out all the time, that all depends on the points above. If you pulling too much current due to a bigger prop, then the ESC may well be seeing a severe drop in voltage from the battery and triggering the LVC, which will cause the motor to stop.You do not state which propellor you are using, and THIS is the single most important thing when using brushless motors and Lipos. Quote Link to comment Share on other sites More sharing options...
stuart macrory Posted December 4, 2007 Author Share Posted December 4, 2007 the prop is an apc5.5 x 4.5,i also got this in the multiplex box with the motor and esc,the box did have a sticker on the side with funjet on it.the motor is a 2825-2700 sorry for any confusion on that one. Quote Link to comment Share on other sites More sharing options...
Mark Jones Posted December 17, 2007 Share Posted December 17, 2007 Hi i test flew my funjet a few weeks ago on the same motor 2825-2700 and prop,but with a 2200 lipo. Flew round most of the flight on 50-75 % power for 7 mins. it only used 1300 from the lipo. Quote Link to comment Share on other sites More sharing options...
stuart macrory Posted December 17, 2007 Author Share Posted December 17, 2007 what connector do you use on the battery,esc etc,ive a feeling my power cut may have been from a bad connection.thanks for reply Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted December 18, 2007 Share Posted December 18, 2007 Best use 4mm gold banana plus Stuart Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 18, 2007 Share Posted December 18, 2007 I would not personally use banana plugs............. as they do not offer good contact area. Much better to use 4mm ( or 2mm will be fine for this application ) gold caged connectors, sometimes known as bullet connectors. Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted December 18, 2007 Share Posted December 18, 2007 Actually that's what I meant Tim - the male bit is a banana isn't it? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted December 18, 2007 Share Posted December 18, 2007 Well strictly speaking no. In my days as an electronics student ( OK... it was while ago ) a banana plug had a single spring wire let into a slot in the side of the connector stub. This afforded a reasonable contact area for it s design purpose which was mainly low current /voltage applications, and as they were simply alloy or steel construction, there resistance - especially after repeated insertion and removal, was quite high, they also tended to discolour and even rust slightly over time.This projection along one side only is what led to its naming as it sightly resembled a banana, although none that I have ever eaten!Furthermore, many of them had / still have grub screw connections for the cables, although the version above does offer both solder bucket / screw. Even the later ones as shown in the first picture do not have a "fully floating cage" - as do the better gold bullets illustrated. The floating cage allows a better contact because as it compresses, it is allowed to expand lengthwise along the shaft of the connector. In turn this allows it to sit flush along the connector pin so increasing the effective surface area. Furthermore, the revolving action of the cage provides less wear on the female connector as the plug is inserted and removed, plus of course, they are gold plated for maximum resistance to corrosion, and use solder bucket style connection for minimum electrical resistance and maximum security. Of course, all these little factors can make a difference when we start using high voltages and even more so, high currents.Phew.....all that just for a bloomin plug Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 18, 2007 Share Posted December 18, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Mark Jones Posted December 19, 2007 Share Posted December 19, 2007 I use 4mm gold connectors in all my electric joints never had a bad momenthope the weather is flying stuff this weekend funjet is waiting to be had lots of fun with Quote Link to comment Share on other sites More sharing options...
stuart macrory Posted December 19, 2007 Author Share Posted December 19, 2007 thanks for all the help,ive ordered 4mm connectors,hopfully be flying for weekend. Quote Link to comment Share on other sites More sharing options...
Dominic Else Posted January 4, 2008 Share Posted January 4, 2008 Out of interest Stuart did you buy the power set separately or buy an RR version? I'm interested as i am about to purchase a funjet but am buying the same motor etc individually to save on costs. Happened to notice last night that you can buy a standard APC prop and also an APC pusher prop in the 5.5 x 4.5 size.Wondered if i have bought the right one?! Quote Link to comment Share on other sites More sharing options...
stuart macrory Posted January 4, 2008 Author Share Posted January 4, 2008 hello i bought the power set seperate but the prop comes with the set,you just have to make sure you wire the motor the right way round,and put the prop on the right way round also. Quote Link to comment Share on other sites More sharing options...
mark smith Posted January 4, 2008 Share Posted January 4, 2008 Hi all funjet fansMy set up is not as powerful as the MPX recomended power set but it is a lot cheaper!I'm using a Tower-Pro A2409/12T and a HiModel 25A esc, this is a £36 combo deal from BRC, and an APC 6x4. On a 2250 3s I get about 12-15mins depending on throtle use.The performance from this set up is not balistic, around the 65 mph mark on a low fast pass and the vertical tops out at about 300ft but this is still a fast plane and the jet like flying characteristics are unafecterd.There are some other advantages of using this set up, as mentioned I get longer flight times and as the motor is only 68g, some 70g lighter than the MPX 2825, this means the battery does not need to be shoved up in the nose and can be move to the middle of the plane nearer to the COG which improves handling.Set up Spec.Tower-Pro A2409/12T pusher(200w) KV 1570, APC 6x4 current draw 9.4AAs you can see this is a low power set up but you could get a lot more out of this motor as it is rated for 20A continuouse current so you could use a APC 6x5.5 or 7x5 and still be under 20 amps.Happy Flying. Quote Link to comment Share on other sites More sharing options...
Dominic Else Posted January 5, 2008 Share Posted January 5, 2008 Thanks for the tips guys. Am looking forward to putting it all together! Mark, I will look into your set up as it would suit my post christmas budget a bit better!I am looking to get a pretty fast set up so i can get bugger and better each year! will let you know how i get on.Dom Quote Link to comment Share on other sites More sharing options...
craig mortimer Posted January 5, 2008 Share Posted January 5, 2008 did you set your throttle to zero after the plane lost all control?i don't know how the multiplex esc works, but usually if the LVC kicks in you have to move the throttle to off to re-set the esc. i cant remember if you lose power to the servoes or not when this happens. you should get some more power after re-setting the esc. if your lipo is a cheapie then the 25c rating could be ambitious. i've read somewhere else that your setup should draw about 28-30 amp at full throttlegood luck with it, one of these is going to be my next plane Quote Link to comment Share on other sites More sharing options...
Dominic Else Posted January 21, 2008 Share Posted January 21, 2008 p.s! Just noted that re. my previos statement that it should have read "bigger and better each year". Not what it does read! Sorry guys! Dom Quote Link to comment Share on other sites More sharing options...
Keith Lewzey Posted January 24, 2008 Share Posted January 24, 2008 Hi GuysJust for some alternative ideas on Funjet power trains have you had look at the thread my son Jonathan has set up in this section of the forum titled "I need Speeeedddd" ?Interesting what you guys have said above aswell. Keith Quote Link to comment Share on other sites More sharing options...
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