Botbitz 85a esc..... in a heavy?

[teamstorm]

Ceri - Yes.

Lots of detail here

http://www.teamstorm.com/storm2/speed.htm

[Mouldy]

They say that they can hold 85a true current but I wouldnt use them, got my Roboteq which does me quite nicely

doesnt that comment make this thread kinda pointless?

I've been impressed with the botbitz escs... use them in diablo without fault on some 500 size whyachi drives, and in 720 on the 700size motors, i blew a motor and the esc was still fine... if a tad warm.

I think a tz85 would run a bosch 750 powered heavyweight.... maybe not for very long though as Ed said- the heat would melt it... the fets are lightly pressed against a heatsink with a bit of compound to transfer heat.. in the big esc's the fets are bolted to a heatsink- much more positive.

However i'd like to see if someone could hack something like the castle ice 200a, capable of up to 300a with current limiting....but then before hacking there £200 isn x 2 = £400 ish... plus all the development time etc... just buy a wotty.

[typhoon_driver]

So what would be the issue in bolting the esc to a large lump of metal in the bot and making sure the fets are well connected to it?

[PJ-27]

There's always another weak link.....

@ Dave, How did you manage to blow a 700 size motor? Honey Badger hasn't even been in a fight yet!

[marto]

I wouldn't recommend them in a heavy, but that being said if your drive train is very tame then maybe...

Check out the graphs here.
http://www.botbitz.com/manuals/TZ85A_Manual.pdf

Of course the will never do 85A indefinitely but its really a question of how long you NEED to pull 85A for.

BTW these tests were conducted @ 12V most bots run considerably higher voltages which means more power running through the ESC which will contribute to the heat. Keep in mind this is a $65 controller, which was intended for featherweights.

And I did this to it


Yes those are clamps.

I have worked out a way to pair 2 x TZ85as together to make a custom ESC. Aim is to use it in a pair of middleweights at some point in the future. 3x increase in FETs and will have custom heatsink. If it ever gets built you may be able to have your Heavy Hacked Hobbyking ESC.

For updates on our dev we are most active @ www.facebook.com/botbitz

Steve

[marto]

Just a quick heads up that I am working on a 150A version for some middleweights of ours.



So might be possible to use it in a Heavy soon.

Steve

[typhoon_driver]

I'd like to know what the actual current handling capacity of these is beyond the hobbyamp figures as there is no way in hell it's actually 85A continuous. Granted I've bought a couple to play wtih and i'm sure they will be fine in a featherweight but just from their size etc I get the feeling they are around the 20 to 30 amp continuous range for 5 minutes.

[shakesc]

even in a featherweight beefing up the heatsink is no bad thing

[craig_colliass]

From the specification given for these controllers they could work if used in tandem.

The maximum voltage at 25v may be a little restrictive as many people use a little more than that.

Quote from Specifications.

1 Specification
This ESC has been flashed replaced with custom BotBitz firmware in order to allow it
to be used for brushed motors. (Brushless motors will no longer work)
ESC do not have current or temperature limiting and overcurrent and situations
will result in damage to the ESC.
1.1 Current Capacity
€ 200A burst <1s
€ 85A for 1min
€ 60A for 2min
€ 40A for 3min
For more information see the graphs in testing section.
1.2 Voltage Limit
Max Voltage 25V
Lipo: 2 - 6S
NiMh/NiCd: 5-18S

[plargen]

with that spec you could probably use them with wheelchair motors as most are 300w or less