TinyTwo Speed Controllers

All things antweight

Moderators: BeligerAnt, petec, administrator

Post Reply
Roboteernat
Posts: 109
Joined: Fri Oct 05, 2012 12:37 am
Location: Eastleigh, nr Southampton
Contact:

Re: TinyTwo Speed Controllers

Post by Roboteernat »

So... I got my stuff out again to build a new antweight, not that I have yet competed with anything, nor built a bot worthy of the arena!

But I plugged in my N2LVHP board to a 2s 350mah zippy lipo and smoke started to appear... I strip the heat shrink back to see if there is damage and although I cannot see any, the smoke is coming from the central side of the lower motor controller chip on one side.

Will check the wiring but I don't think it's a shorting issue, although the black wires sheath has shrunk with the heat...

IS there a likelihood I can repair it? I cannot trace the chip Used to perform a repair... Sad as it's not really been used much, and no battles!

And an action picture! https://flic.kr/p/v8KV2R
Some projects done: Wirelessly controlled mechanical hand/arm
Heavyweight: Short Circuit
Antweight robot : Locking wheel nuts, dell-apidated bANTtry...
Featherweight : Wanna Choppa, CASPer
Check out http://www.Roboteernat.co.uk for more details
Rapidrory
Posts: 1160
Joined: Sun Nov 24, 2013 9:54 pm

Re: TinyTwo Speed Controllers

Post by Rapidrory »

Yeah, I'm afraid that appears to be a problem with the HP version of the controllers; I've had 3 reported to die like that in the last few months (compared to almost no dead regular N2LVs despite having sold more)

If you're not running 4 HP motors then the HP controller isn't actually needed. You can convert it to an LP controller by removing both the chips from the dead side, and then take the top chip off the working side and solder it in place of the dead chips. Quite a fiddly job, but can be done if you use a pair of tweezers... If it doesn't work I'm afraid you'll have to ship it back to me for repairs; the driver chips are only available through one supplier direct from china in batches of at least 200.
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
Roboteernat
Posts: 109
Joined: Fri Oct 05, 2012 12:37 am
Location: Eastleigh, nr Southampton
Contact:

Re: TinyTwo Speed Controllers

Post by Roboteernat »

Hi Rory, thanks for getting back, do you know what it could be the cause, if it's the drivers themselves or the negative wire just touching the positive side of the capacitor in between as the heat causes the wire sheath to creep?

I'd like to get it repaired so I can use it again, will check the specs of the lower one to see if it will be ok, as I'm only using them for 2motor bot atm, but got the 4 for future upgrades, I have the kit, but if it's too fiddly how much would it be to get to get you to repair for me?

Thanks
Some projects done: Wirelessly controlled mechanical hand/arm
Heavyweight: Short Circuit
Antweight robot : Locking wheel nuts, dell-apidated bANTtry...
Featherweight : Wanna Choppa, CASPer
Check out http://www.Roboteernat.co.uk for more details
Roboteernat
Posts: 109
Joined: Fri Oct 05, 2012 12:37 am
Location: Eastleigh, nr Southampton
Contact:

Re: TinyTwo Speed Controllers

Post by Roboteernat »

I took off the motor controller chips and took one from the other side making it the lower powered version, still shall be adequate for my needs...

Here are some images from the take apart, shows the lower chip seems to have suffered a heat failure, possibly due to the piggyback nature of the chips.
Also it could be that the negative wire had been heated against the chip, melting the protective coating and shorting out, causing the chip to blow, although this is far less likely option.

https://flic.kr/p/vC7cZY
https://flic.kr/p/uHpaPs

And the final board:
https://flic.kr/p/vnQtkY

Looking forward to getting my new bot built. Will let you know Rory how it goes and if it is still working, otherwise i may have to send it back to you for repair :) or buy a new one!
Cheers
Some projects done: Wirelessly controlled mechanical hand/arm
Heavyweight: Short Circuit
Antweight robot : Locking wheel nuts, dell-apidated bANTtry...
Featherweight : Wanna Choppa, CASPer
Check out http://www.Roboteernat.co.uk for more details
Rapidrory
Posts: 1160
Joined: Sun Nov 24, 2013 9:54 pm

Re: TinyTwo Speed Controllers

Post by Rapidrory »

Ah well done on getting the mod to work :)

Yeah not entirely sure what it is that causes them to die, whether it's the chips somehow getting out of sync with the other one, with one driving high and the other driving low or whatever.. It's unlikely to be heat related as they have thermal shut off that should prevent that.. Either way I have barely sold any of those boards, so may well discontinue them except in exceptional circumstances..
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
Rapidrory
Posts: 1160
Joined: Sun Nov 24, 2013 9:54 pm

Re: TinyTwo Speed Controllers

Post by Rapidrory »

I've finally got around to rewriting the firmware for my ESCs (Something I've been meaning to do for about a year). The main improvements are that it now has 1024 discrete speeds rather than the previous 32, and it now reaches full speed at about 90% stick travel rather than 75%. This makes for smoother and more precise control, though having driven with my previous firmware on all my bots it's going to take some getting used to! I'm going to upload it to a few of my bots and try it out at the weekend to see how it performs in a contest, then if there's no issues I'll switch to using the new version for all new ESCs.

On a related note I've just moved into a new house at uni which so far lacks any proper work bench, and I have quite a backlog of orders, so any new orders might take a while to complete at the moment.
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
Roboteernat
Posts: 109
Joined: Fri Oct 05, 2012 12:37 am
Location: Eastleigh, nr Southampton
Contact:

Re: TinyTwo Speed Controllers

Post by Roboteernat »

Sounds good RapidRory,
are we able to get the new firmware into previously bought controllers? perhaps a prepaid envelope or something to you?

Thanks

Nat
Some projects done: Wirelessly controlled mechanical hand/arm
Heavyweight: Short Circuit
Antweight robot : Locking wheel nuts, dell-apidated bANTtry...
Featherweight : Wanna Choppa, CASPer
Check out http://www.Roboteernat.co.uk for more details
Rapidrory
Posts: 1160
Joined: Sun Nov 24, 2013 9:54 pm

Re: TinyTwo Speed Controllers

Post by Rapidrory »

Just coming to the last of the 200 NanoTwo ESC PCBs that I originally got made. Since I'll soon need to send off for a load more, I was wondering if there are any changes to be made in the design.

The main one I'm considering is dropping the 6v regulator in favour of a 5v regulator. The 6v regulator was originally put in to get the best power out of servos, but considering most people now use 7.4v servos if they want a powerful flipper, then the benefit of having a 6v line becomes somewhat moot, especially since it adds 5 extra components to the board to get it to work. The 5v reg would still be able to drive servos fine, just with a little less force.

I'll also probably make a few extra tweaks to make them easier to built/ more robust. Just wondering if anyone had any other suggestions for improvements?
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
Max
Posts: 105
Joined: Tue Oct 08, 2013 3:14 pm

Re: TinyTwo Speed Controllers

Post by Max »

Maybe it isn't an issue for other people but I felt easier access to the full unregulated battery power would be useful. ie a set of pads parallel to the battery connection to solder on wires for brushless escs, servos etc.
Rapidrory
Posts: 1160
Joined: Sun Nov 24, 2013 9:54 pm

Re: TinyTwo Speed Controllers

Post by Rapidrory »

Not a bad shout... I was considering making it so that the BEC could be dropped out giving 7.4v on the RX pins, which would allow for HV servos, but not sure about how I'd do something easily for brushless ESCs... I'll look into it though.
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc
Post Reply