Antabuse (aka DieSulfiram)

[razerdave]

It's better to have thinner stuff on top because ants don't much attack from the top. I built Baby Hell and Bulletproof with 6mm side panels with the wheels inside, and 1mm top and base plates. Seems to have stood up OK thus far .

[JamesDavies]

Dave- is that 1mm polycarb of HDPE? That sounds like a good plan...

[razerdave]

Bulletproof is polycarbonate. Baby Hell is 3d printed nylon. 1mm HDPE is a bit too bendy for a base.

[JamesDavies]

Okay. I think I'll go for some 2mm polycarb for the base and top then. Then see what weight I have left for the sides. How do you fix the polycarb together in Bulletproof?

[razerdave]

M2.5 bolts through the lid and base and tapped into the 6mm edge of the polycarbonate.

[JamesDavies]

The polycarb arrived today. Got it all cut out now. Just need to fix it together. While I was cutting out one of my batteries (which wasn't plugged into anything at the time) started smoking. It warped a bit and this is the result. Any idea what happened?? It wasn't plugged into anything and hasn't been for at least 24 hours (except for 2 seconds about 30 ins before when I tested the drive). IMG_1370.jpg

[epicentre]

Do I see two exposed pins on the left-hand side of the image? You probably accidentally dropped or knocked something metal into the battery, causing it to short the pins for a split second (which is all it takes). NEVER leave pins exposed on LiPos. At an absolute minimum always cover them with electrical tape, but preferably use plugs that only have one exposed pin, and one socket.

[harry hills]

I see what happened there. you've somehow removed the connector that the battery plugs into, and bared the pins. these short circuited the lipo and caused your smoked battery. PLEASE be more careful with lipos.

[JamesDavies]

Looked at it and that is it. The connector came off with the battery and the pins must have touched. I'll reinforce it with tape now so that can't happen again.

[epicentre]

Looked at it and that is it. The connector came off with the battery and the pins must have touched. I'll reinforce it with tape now so that can't happen again.

As this is your first LiPo failure (most of us antweight builders have had one at one point or another), do a Google search for how to safely dispose of LiPo batteries.

As Harry says, you cannot be too careful with LiPos. I've soldered up loads of LiPo packs and cells in my time, and yet I still triple-check every single connection, solder joint, and socket by eye and with a multimeter at every single stage of the process. I also always keep anything metal far away on my workbench to where I'm working on them. Always cover anything that's exposed, and be very careful if you're ever cutting a wire to or from a battery while it's connected. I know a few people who've thought it was a good idea to cut both battery wires at the same time, only for the wires to short through the cutters they were using and go pop.

[JamesDavies]

Thanks for the tips. I'll take more care when removing them in the future... And try to be super careful to avoid shorts...

[duff]

I seem to remember you have to put them in a bag of salt and pop them...? As Scott says though, I'd double check with Google. Personally I've never had a failure (very unusual, I still have a few 10 year old kokam cells which seem good), but I seem to remember someone mentioning the salt thing before. I think the key is, when handling them, always assume they're about to explode or catch fire if you do the slightest thing wrong.

[Max]

Looked at it and that is it. The connector came off with the battery and the pins must have touched. I'll reinforce it with tape now so that can't happen again.

Just to confirm you can't use that battery again it must be disposed of, never use a lipo that has swelled or looks at all damaged. Sorry if you already realised this but better to be safe than sorry!

[JamesDavies]

Yes- so far I've been treating them very carefully. I'll have a look and dispose of them safely.
I wasn't planning on using it again But thanks for mentioning it anyway

[JamesDavies]

IMG_1371.jpg
Remade the chassis in polycarb.