Scorpion XXL

[Anttazz]

I found an old receiver battery that I thought was busted in a mixture of HW electrics waiting to be reassembled and it seems to be a vast improvement. I still have to nurse the throttle up to full whack but it does get there after a few seconds, but that might be something to do with the battery not being charged for the last 10 years. I did also try the 2 motor thing and it worked better, but not properly before I added the receiver battery, it would go faster than with the 4 motors before it began to stutter but still stuttered before getting to full throttle.

Will probably look at getting a better receiver battery and getting it tried out with that as it seems to have fixed the problem. Is there anything specific I should be looking for in a receiver battery? I have never really had to use one before.

The failsafing is still not playing though, I may have to rebind the transmitter and receiver and see if that is the problem. Also only getting forward and reverse drive at the moment, but i'm sure thats a problem thats easy to fix once its all working.

[woody]

I'd also check your main batteries ... stick a meter on them whilst they're underload ...see what the voltage sag is.... I've a feeling that one pack is fudged.

[Anttazz]

They seem ok Woody, 11.something v when under no load and between 9.2v and 9.6v when running full tilt.

[razerdave]

You said the BEC wasn't working, generally speaking the XXL's BEC is utter testicles when used with Spektrum, thats why I used a seperate one (and why the BEC loop was cut on the XXL when I sent it to you).

As for current limiting, it may well be because it was with my Speed 900's, but that was due more to my motors than the controller.

[Anttazz]

The BEC was working to a point, but not well at all so I agree with you there. I charged that battery a bit and it seems like its getting better the more charged it is, but it is still very jumpy. The one I found has a max charge of rate of 900mA so takes ages to charge. Think I will have to get a battery ordered along with my new batteries for Daiske. Should I just get any reciever battery or am I better with a specific rating or anything like that? Also, is 4.8v NiCad the way to go on that front?

[woody]

You could consider a BEC ...I've one of these ...OTT on the voltage but it gives the possibility of going mad should you ever wish to.
http://cgi.ebay.co.uk/UBEC-5A-8-40v-SBE ... 564298d0ea

[Anttazz]

Look like a good shout Woody, it talks about being for Li-Po's, does that matter that i'm using NiMH? I shouldn't think so, but thought I should ask.

[woody]

volts is volts ...Use it on any battery type combo in the stipulated range

The BEC is the part that drops the battery pack voltage (7.4v, 11.1v, or whatever) down to 5v or 6v for use by the receiver and servos. It's called a battery eliminator circuit because it eliminates the requirement for you to use a separate 4-cell NiCd or NiMh receiver battery to power them.

The BEC is usually incorporated into the ESC, so that simply plugging the ESC into the receiver is all you need to supply power to it. But often the built-in BECs are insufficient to deal with all the servos you have, or the high voltage of a 4S and upwards LiPo pack, so you can get a stand-alone BEC to do the job.

Stand-alone BECs are usually the switching kind, so they can deal with higher voltage and current than the linear kind which are usually built into the ESCs. SBEC, UBEC, and other terms have become generic terms for, usually, switching BECs. But it's always wise to check the BEC's specs, irrespective of what the manufacturer calls it, to make sure it is switching if you want high-power and/or high-voltage use.

[blazerbotics]

Have you checked the calibration? We use the XLs on our P2D and if the trims get knocked, they 'over travel' and it cuts out when you get to the end of the travel on the stick.

[Anttazz]

Sorry Alan I didn't see your post there, I will check that tomorrow when I get the chance.

I got hold of that SBEC today and still getting the same sort of problems, the motors begin to turnoff and off quickly, but I suppose that is just a case of decreasing the amount I move the stick or the acceleration on the transmitter (however that might happen) and that will fix that if it is unavoidable for the moment, the more worrying thing is the failsafe playing up, its still driving the front 2 wheels forward when I switch the transmitter off and I have tried binding the transmitter again with no joy. Is this something the XXL was also known to cause?