Antweight help

[Max]

Do I need to have a fuse and power light or is it not necessary at this size?

[duff]

Yeah, rules state you'll need a 50 amp maxi fuse and a 9 LED lamp.



Naaaahh, just messing with you. No fuse or power light needed. But the led in the receiver effectively acts like a power light anyway.

[Max]

So now looking like I can just about get it in weight (will I get away with being like a gram over as not too sure about the accuracy as my scales!
But the bad news is that I fitted the lightest switch I could find and I think it's welded itself together, so I thought about replacing it with a removable link made from male and female header pins like this:


Do you guys think this will handle the amps?

[Mega Masher]

Not a great idea, but drill some holes in the carbon fibre and hdpe, or the wheels?

[duff]

That's absolutely fine in terms of sticking to the rules. But it might fly off in battle. Maybe ever-so-slightly bend the pins so the jumper is a tight fit. It will definitely handle the amps.

[Max]

Damn, looks like I wired the battery in the wrong way round! I don't have the parts at home to try to change it around at home so will have till tomorrow at school to rewire and see if the sabertooth still works. Does anyone know if a reversed battery normally breaks it or if it has reverse polarity protection?

[harry hills]

Chances are it's cattled

[limpet]

I blew a sabretooth, I accidentally touched a wire across it. I contacted Dimension Engineering and they replaced it free of charge, they even paid return postage from the US. Fantastic customer service.
Its probably worth pointing out that I initially asked them where I could get the components and they offered to repair it if I returned it, I wouldn`t just ask outright for a replacement.

[Max]

It has broken, but a new one has been ordered and should be here tomorrow. I may try to contact dimension engineering but I got it from technobots not directly from then and have removed all the screw terminals and shortened the wires so not sure how happy they will be to fix it!

[Mega Masher]

Btw, when I said not such a good idea, I didn't mean the removable link idea, I meant my ieea of drilling holes in everything
Just to make sure It didnt seem like I'd said the wrong thing.

[Max]

Right sabertooth has been replaced and all kinda works now, only problem is that the robot occasionally decides to move completely randomly without me moving the sticks on the transmitter or it decides to go full power backwards and I have to move the stick forwards to get it under control. When I then pulse the brushless motor on for a second the drive seems to fix itself. When the brushless is on a red light also lights up on the sabertooth.
Does anyone know what might be causing this?

[plargen]

you might need an external bec i had something similar with my BW, when i used the servo weapon it would start to dive off and the external bec solved that

actually on second thought have you tried a bigger battery and have you disconnected the bec from either the sabertooth or brushless esc

[razerdave]

The drive issue sounds like a trim issue. It's probably worth your while to check the DIP switches are in the place you want (some of the steering and mixing functions can be messed with).

Red light on the sabretooth can be caused by all sorts: rogue signal, voltage drop (which can also explain the drive randomness), or conflicting BEC's (both the sabretooth and the brushless have one, you need to disable one or the other.
The other option is the battery simply can't hack it, needs a bigger one.

Dr Weston, robot diagnostition at your service. .

[Max]

The drive issue sounds like a trim issue. It's probably worth your while to check the DIP switches are in the place you want (some of the steering and mixing functions can be messed with).

Red light on the sabretooth can be caused by all sorts: rogue signal, voltage drop (which can also explain the drive randomness), or conflicting BEC's (both the sabretooth and the brushless have one, you need to disable one or the other.
The other option is the battery simply can't hack it, needs a bigger one.

Dr Weston, robot diagnostition at your service. .

I don't think it's the trim as it drives fine then randomly it starts ging backwards, I've chopped off the red wire from the brushless esc leaving just the sabertooth's (though maybe if I used the brushless esc one instead it may not cut out?) could be the battery although it doesn't seem to explain why it would suddenly go into full reverse. I'll check through everything and see if I can spot a fault, with try with some other parts to see what's causing it.

[razerdave]

Bulletproof and other robots of mine have gone 'off the rails' due to a sudden voltage drop; loses power to the RX and takes a stab at what signal it got given. It could well be worth trying the BEC on the brushless esc rather than the sabretooth, I've seen a few occasions where something drawing so much power (usually a servo, but it has been brushless motors) it causes the BEC on the drive ESC to falter.