Problem; Scorpion XL going spaz!

If I put the flip channel into Ch 5 in order to run the robot inverted, will that still solve the problem ?

Id be surprised if it didnt.

What motors are you using? Make sure the motors are not shorting each other out.

I remember when i first put my EVs in my metal robot and forgot that the motor casing is connecte to one of the motor inputs (negitive normaly) bit like wipe motors... and it did funny things. Sometimes the sidewinder shut down, and sometimes one side wold fly into full fowards.

Be interesting to know what happens if you take the motors out of your robot and place on the floor and then test.

I know its not an XL but im sure the the software might be a bit the same. Now my sidewinder just cuts out and all leds flash letting me know there is a short somewhere.

Mr Stu

afaik the problem is already sorted (according to Daves text message anyway). Still good advice, I didnt know that actually.


(Message edited by leorcc on June 16, 2008)

Ahhhh! Mr Stu, that might not be Daves problem but it may well be BOOM!s problem. I transferred the motors from Testbot where they worked fine (plastic) to BOOM! (metal) where they started failing. I will give that a try.

Cheers

Andy

Yeah one terminal in the EVs is connected to the motor casing which in turn bolts to my metal chassis shorting the motor outputs together.

This was a major problem with Rexs Robot Challenge with people using wiper motors.. yes they were being taught to use in wooden bots.. but soon as they started making thin metal chasiss they didnt understand why the speedos were blowing.

Dissconnect one motor and test, then connect other motor and then problem appears. Thats how i found it out. Even Chis from Robot Power was like wow cool fault finder that the Robot Power Software is very smart.

Mr Stu

dont want to start a whole new thread for it so ill ask here,

got a new spinner bot with a brushless motor and 6 a123 cells powering it all with a scorpion XXL on the drive. i had troubles to start with with the BEC not being enough and causing the weapon to jam on and lock everything up. not good.

using a S-BEC now and disabled the on board BEC which has fixed that but now while the weapon is spinning up initially for about 3 seconds, it causes the voltage to drop to about 15v for 3 seconds which makes the status light go out on the scorpion and no response from it until the voltage picks up and it works great again.

so it seems like the voltage bounced between 21 or so and 15 which is either side of the 16v they recommend you cut the HV jumper at.

question is - what does the HV jumper control? have a suspicion it is something to do with the 5v regulator so now im using a bec i was contemplating just rejoining it and seeing if it works better with the voltage drop.

the controller should work okay through the drop as its rated down to 4.5v but yeah i think the HV setting is causing it problems.

any ideas on what i could do here? no ones seemed to have this problem in australia quite yet.. and you guys seem to use the controllers a fair bit :)

aside from that the XXL is going great!

cheers guys

Got a decent pair of 12v SLAs or similar kicking around that you could temporarily lash up to the controller just to confirm that voltage drop IS the problem?

6v seems an excessive drop...So Id suspect that one or more of your cells is duff.... or you could add in one more cell.

Note that Ive tried the XXL on 8 A123 Cells ( 2 off 4 cell packs ) without encountering any magic smoke AND had much the same problem as yourself with a homemade pack in which Id fudged two cells .. they appeared to charge fine but under load their capacity to supply was greatly reduced.

So ..Probe each individual cell rather than looking at the pack voltage.

Hey Guys

if the power to the receiver runs through all of the RC cables, why would you need a BEC lead in the first place ? and wouldnt 3 lots of whatever the BEC is producing do harm to the RX ?

Im getting a seperate BEC so I can run my gyro and switcher as well, but just to get some confusion out of my head...