New Featherweight Build

Slight problem with my featherweight. Every time the removable link is inserted both motors go into full forward for a second or so.? Also the battle switch for the weapon seems to fire by itself when going either full reverse or full speed. Any ideas why this might be?

Also after a few minutes in operation one of the speed controller seem to begin to smoke, which in my experience is usually a bad thing. It my be due to my pretty poor attempt at wiring (lots of lekky tape) or maybe something else?

we will need a bit more info

components your using and do u switch your tx on before your robot ???

No problem

Electronise 43HVR
Drill Motors
BR6000 receiver and DX6 transmitter

Anything else needed give me a shout. I was only running it on 12V instead of 24, which makes me think adding the extra power may amplify the problem.

I have tried turning the tx on before and after fitting the link but it jumps forward either way.

Is the forward drive linked to normally closed section of the electronize relay?

Quite possibly mate, at the risk of sounding like an idiot, how I would know if that was the case?

I was going to say check the trim levers on the transmitter first of all, but if the motors are only surging forward for a second then it won't be that. It could just be the nature of the speed controllers, as I have used Electronizes before and had that 'problem' occur.

Are you powering the receiver from a battery eliminator circuit? If so, that's another reason why they may spin briefly; when you're plugging in the link, that is the first time that the receiver is taking power, and often receivers can take a second to pick up the proper signal (i.e. neutral stick, no wheel movement) once power has been applied. In theory, this shouldn't happen if you're powering your receiver from a separate battery pack, because the arming up procedure should go transmitter -> receiver -> robot so your receiver should be settled before power is applied to the motor controllers. If you are using a separate battery pack and the same thing happens, it might just be the way the speed controllers are.
The best thing to do when arming up in any case (in your room, outside, in the arena etc) is to lift your robot off the ground with something - in the arena I tend to rest one edge against the wall - so that when you do plug in the link and the wheels spin, then at least they're not touching the ground and are able to make the robot move.

I'm not 100% sure on the battle switch auto-firing but I can offer a theory (assuming your receiver is powered by a BEC): at full forwards or full back, your robot is drawing the most power from your batteries, meaning that there could be a drop in power going to the receiver. This could be disrupting the radio signal to the battle switch, which could inadvertently cause it to fire. But without seeing the wiring up close, it's difficult to tell if that is the issue.

As for the smoke coming out of the speedo, yeah you're right, that's generally not good :proud:
Might be a faulty speedo, there could be a tiny shaving of metal inside the speedo that is shorting out a couple of components or you could be exceeding the specifications of your speedo (which might be the case but seems unlikely considering that you don't seem to be overloading the motors/speedos to any degree)

That's all I can offer at the moment, hope it's of some help!

Cheers Jamie, it is a help.

The ESCs are powering the receiver through a method which you inadvertently helped me with, just by chance, by reading an old post by yourself when I was having trouble when I first put it together. Connecting the two spare wires together on one of the controllers.

I suppose this answers your other suggestion already, but there is only one power supply in use. I have been lifting it up off the deck when inserting the link, I wasn't sure if that would be allowed in an arena setting but if thats all fine and it isn't a symptom of a greater problem then I could always just leave it.

As for the smoke, it hasn't done so since so it was possibly just a small piece of metal. Its also running at only half the recommended rating at the moment so I cant see it being overloaded, and as I said it has been working since. Hopefully just a one off thing.

Yep, sounds like the speedo.
NST has the same problem, that is, the right hand drive activates on inserting the link and settles after a second or 2. I had to do the same thing Jamie suggested, just lift the wheels off the ground until it settles.

In the rush of the build its not something i sent any time fixing or investigating but i think it was the speed controller (sabertooth). I'm currious to know if other people using the 10 amp model have the same problem (or don't) and will stand corrected but IMO Its not a fault on the speedo as such, just poor design of the circuitry.
Tiberius on the other hand never glitches, as the programming in the Wotty speed controller cleverly designs out this issue.

I have the same thing with Satanix when you plug in the link and it goes for a few seconds until it binds, I think the trims were off when I bound it though.

hmmm smoke is never a good thing with a speedo. If i were you I would disconnect the power and open up the speedo to make sure nothing has been shorted inside it. When it comes to wiring up a robot for the first time I know that the temptation is to do it quickly and tell yourself that you will do it properly next time. A lesson I learned a long time ago, if it's worth doing then do it right first time!

I think the running for a few seconds is an inherent thing with the spektrum gear. Never had it with futaba 40 meg radio equipment but occasionally get it with the spektrum. I guess it's a small reminder to treat the machine, what ever size, with the utmost respect when it comes to arming up and operating.

Cheers guys,

My plan today was to assemble the wiring correctly and hope that stopped most of the problems, most notably the smoking speedo, but the snow has prevented me for getting the bits I would need to do the wiring properly. Hopefully tomorrow I can get the bits and keep you posted on its progress.

that sounds like a failsafe issue. If you are using the BR6000 set your stick to neutral position and re bind the rx. should stop it now.

Cheers for the ideas guys, I tried to give them a try today and the battery is refusing to charge, repeatedly telling me that there is a connection break instead. Very annoying.

I have connected the charge lead and terminals to the charger and it still says this. Am I doing something wrong or is there something up with the equipment?

what charger are you using and the battery ????

maybe a connection between the cells within the pack has come loose

The battery is the Zippy 2200 and the charger an iMax G6

Battery type is a LiPo sorry I don't think I specified that earlier. Still haven't been able to solve this problem, thinking possibly its a case of trying out a new battery. This was the first time i've had to charge them though so don't think it should be dead.

Quote:

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Originally Posted by Anttazz

Battery type is a LiPo sorry I don't think I specified that earlier. Still haven't been able to solve this problem, thinking possibly its a case of trying out a new battery. This was the first time i've had to charge them though so don't think it should be dead.

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It could be that one of the balancing wires inside the LiPo pack has come loose. This problem is a known issue with some brands of LiPo. It will charge without balancing probably but I don't recommend that. Best thing is to measure the balancing wires and see if there is a loose connection and repair it, or use another LiPo pack.