Thud Does A 6FET ecrazy man mod......

[Thud]

MWkeefer,
Thanks again, I modded onother 6fet this afternoon & tried your settings. It seems to hold true on the 116 chip also. I am getting 8650rpms with no load at 46v
Thats about 300rpm improvment. My no load current on the 80/85-170 is right at 7 amps.
I have added monster heat sinks to these baby controllers. Should help if I get into a thermal situation.


this is all bolted to the outer case after lapping & adding artic ice hea sinking compound. (stuffs kinda pricy)

here is the 1st one with 10gage wires & a monster heat sink bolted right on the fet's

been a long weekend of modding controllers & meanwell's. Nice now every thing is working

[Jeremy Harris]

Looks good, but I'm afraid that I doubt if those big heatsinks will really make a significant difference. When you look at the thermal resistance across the whole system, from FET junction through to the air around the controller, the big issue under extreme conditions is right at the FET. The standard case is probably OK if you can get a really good thermal junction between the FETs and the heatsink bar (i.e. chuck away the really crap silicone rubber insulator and use either thin Kapton or mica).

Jeremy

[amberwolf]

If it helps any, I don't see enough of a thermal difference between cheap white heatsink paste and expensive SuperChillAbsolutZeroBrand to be worth the money. The only differences that have mattered were the ability to remain creamy and not dry into a paste that shrinks away from mated surfaces, leaving airgaps.

If the heatsinks are well-lapped and have a flat-fit already, then it *really* doesn't matter, as long as all the compound is applied only to the scratches in the surfaces, and not a whole layer between them (since bare metal to metal will always be better than metal to any compound to metal).

[Thud]

Thanks for the input Guys,
I have a roll of kapton inbound.
(you have to admit, the monster heatsink look industrial)

[Jeremy Harris]

Thanks for the input Guys,
I have a roll of kapton inbound.
(you have to admit, the monster heatsink look industrial)

It does that, it looks pretty mean and it may help out a with overheating a little bit. It'd be nice to find a big finned case that is easy to use, rather than the extrusion with end caps that they come with as standard.

I've not used any of the alloy boxes that these controllers come in (in fact, I just bought a batch of bare boards from Keywin last time) as it's hard to get big cables, bigger capacitors etc inside the small case. My controllers are built into big, sealed, diecast alloy boxes, with neoprene gaskets on the lid to keep water out. This makes it much easier to work on the controller and gives a bit more space around the components, as the wires aren't all bunched up inside.

Jeremy

[gwhy!]

I thought I will post up a picy of my modded 6 fet, It also really helps where mine is located on the bike you get a very good air flow over the heatsink from the tyre.

6fet re-housed controller.jpg (34.36 KiB) Viewed 317 times

[mwkeefer]

Thud,

These turned out well... I see you equipped your race ride with one.

That increased RPM of 300... it should have been higher, but really it depends on the sag your seeing off your pack... with 3P I doubt you will see much if any sag no load.. there I wonder what was your battery voltage at that maximum no load speed?

My experience has given me on order of 3x that RPM increase no load so about 900 on a 230kv motor at a given voltage... obviously each motor has their sweet spot for maximum efficiency which unless I've misinterpreted a bunch of stuff, changes at each voltage potential.

I will be setting up halls on a Turnigy Aerodrive XP 170kv shortly (within a week or so) and will report back the optimal settings I can acheive there... it should be more akin to your setup if I recall from earlier and other threads.

-Mike

[Thud]

Mike,
I was only running a single 12cell pack & the voltage was down to 44v near the end of my tinkering this weekend.
The bike will be 3p for certain. & I really need to keep a better Log of all my program settings.
Baby steps.
Well be seeing if 6 FET's can handle the abuse from the smallest of the "big" Turnigy's.

[FastDemise]

I'll give this thread a bump since it has good information. I'm curious what's the most power that has been pushed through a 6fet. I'm running mine stock with no internal mods minus some thicker power and phase wires. I sealed up the controller and filled it with mineral oil on 18s Lipo @ 50amps. The controller barely gets warm even after 8-10miles of full throttle on my 9C 2808. So 66.6V * 50A = 3.33kW peak. Just wanna ask if anyone has pushed more so I can feel confident pushing up the amps to 60amps or greater.