Running a Novak GTB on 3S?

[SidewaysLS4]

My 1:10 speed buggy is running a GTB/3.5R setup, pulling 85 amps at speed (so far gps'ed @ 63mph, working on tires/best gearing still). I'm really thinking about going 3S for the same/more wattage at less amps (will use a selection of lower KV motors already on hand for this of course). Thing is...I'd hate to just bail on the GTB for a MM, so I looked up what the GTB is made of...

Mosfets at rated at 30v, BEC regulator is rated at 26v. Who knows what else is in there and the ratings on those parts, but I think I got the main stuff covered, so it should work. I also improved the GTB cooling via some simple cooling improvements I learned from my water-cooled hot rod computer hobby, so temps shouldnt be too much of an issue. I'll use a 'SmartStop' for lipo cutoff duties. The only thing I'm wondering about is what is sequencing the motor and its voltage rating, along with the sensor system, so I look to you guys for some advice...

Anyone try a GTB on 3S? Any thoughts on this?

[himalaya]

replace the capacitor, its rated at 10V6800uF, you'll have to change it to a 16V rating capacitor.

sensor system uses BEC regulated power, and consumes very small current.

So change the capacitor, and GO AHEAD.

[lutach]

Could you take some pictures of the components that makes the GTB tick ? A picture of the MOSFETs and the brain board would be very nice.

[lincpimp]

Originally Posted by lutach

Could you take some pictures of the components that makes the GTB tick ? A picture of the MOSFETs and the brain board would be very nice.

If my camera was here I could do that... I will open one up and see if I can read the numbers...

[lutach]

Originally Posted by lincpimp

If my camera was here I could do that... I will open one up and see if I can read the numbers...

Thank you lincpimp.

[MetalMan]

I would be more worried about the 3.5R on 3s than the GTB... Although the GTB sure would have a heck of a time handling that power I imagine.

[lincpimp]

Originally Posted by MetalMan

I would be more worried about the 3.5R on 3s than the GTB... Although the GTB sure would have a heck of a time handling that power I imagine.

Originally Posted by SidewaysLS4

I'm really thinking about going 3S for the same/more wattage at less amps (will use a selection of lower KV motors already on hand for this of course).

I have wanted to run a 13.5 or a 10.5 motor on 3s for a while. I did try the 13.5 in a pede with a sidewinder, but it lacked the torque of a similar kv s can motor...

[MetalMan]

If it makes any difference, I run a Trinity 13.5 on 3s 4000mah Lipo in my XTM X-Cellerator (great truck) with a MM. For the tight track I drive that truck on this combo is great.

[SidewaysLS4]

Cap...forgot about that one, gonna check it, thanks!

While on the ancillary items subject...stock fan needs to go as it is direct off the battery, need a 12v unit vs. the 5v used by Novak...and use the spacers if improving thermal conductivity to the heatsink issues...no spacers = burnt up fan, lol.

Here is what was hiding in my GTB...

Mosfets

BEC regulator

I didnt break apart the board sandwich, so beyond these two is just a few supporting smc's. Who wants to crack open their GTB to see what's on the other side? :)

[lutach]

Originally Posted by SidewaysLS4

Cap...forgot about that one, gonna check it, thanks!

While on the ancillary items subject...stock fan needs to go as it is direct off the battery, need a 12v unit vs. the 5v used by Novak...and use the spacers if improving thermal conductivity to the heatsink issues...no spacers = burnt up fan, lol.

Here is what was hiding in my GTB...

Mosfets

BEC regulator

I didnt break apart the board sandwich, so beyond these two is just a few supporting smc's. Who wants to crack open their GTB to see what's on the other side? :)

Do you happen to have a picture to see how everything is up in there?

[SidewaysLS4]

Originally Posted by lutach

Do you happen to have a picture to see how everything is up in there?

No photo, sorry

[himalaya]

GTB uses MOSFETs from a variety of vendor, IR, ST, and Vishay.
Here are pictures I took about a year ago when repairing my GTB, which got strangely burnt BRAND NEW.





Or you can go read this thread, sorry it's written in Chinese.
http://bbs.rcfans.com/viewthread.php...8222&highlight=

[lutach]

That is awesome, thank you.

[SpEEdyBL]

A while back I actually emailed novak about this question except using an external bec instead, and they still said not to do it as it would damage the components inside the esc. But maybe they didn't understand the part about using the external bec. Either way if you do try to put 3s on the gtb, you must use an external bec. The linear bec of the gtb can't handle much more voltage of 6 nimh cells. That's why its not even rated for 7 cells ni-mh.

[lutach]

This is kind of funny.