Ohio race bike.....controllers...I hate them all!

[Thud]

PM sent Lyen,

Any thoughts On my Shunt Mod? too much?

 

[recumpence]

I am glad the 160 is holding up for you.

Bear in mind, those can be blown too. It just takes a bit more to do it.

My PK Ripper is geared for 50mph right now and will accellerate with a grown man leaning over the bars and still no issues.

The main thing is to find the sweet-spot for these setups.

Oh, the sync issue is related to that motor. An Astro will not lose sync at all. Of course, that just means it will continue to pull untill you draw 400 amps and POOF, there goes the controller.

So, you could also go to twin motors and controllers. I garrantee you will not be able to hang onto it with that setup (as me hos I know).

Matt

 

[Lyen]

PM sent Lyen,

Any thoughts On my Shunt Mod? too much?

Just sent you another PM requesting more info to give you more accurate answer(s) and resolution.

 

[rhitee05]

Aparently I am not totaly jinxed by the electronic gods.(my camera decided to cooperate after a world class cussing out )
here is a pic of the damage. you can't see it but one of the legs is burned completely through:

If you burned through one of the FET legs, that suggests either your shunt mod was too aggressive or you need to reduce the phase current limit in software (or both). The legs pop just like a fuse if the current is too high. IR's recommendation is 75A continuous, you can get away with higher in short bursts. For your 18-FET that would be 225A continuous. It's a completely separate matter if your cooling is up to that kind of power...

 

[liveforphysics]

Copper wire is a little extreme for a shunt mod... That one little thin strand of copper could have lower resistance than all those bars of shunt metal combined. Copper conducts 20-30x better than some of the common shunt alloy options, so a thin bit can make a big difference!


The problem with these controllers is the FET packages. TO-220 case fets were originally designed for applications under 20amps... Since then, they've been made with extra thick legs, and the silicon has become very low resistance, but it's all a bit of a band-aid solution for a package that simply isn't suited to high currents.

I should have a controller functional in a week or two. The problem with the first one though is it's not at all an easy to manufacture design. In fact, it's more like an extremely time consuming hand built sort of thing, but it will be good enough to get testing done for proof of concept work.

 

[AussieJester]

If these aren't too costly Luke? you can pencil me in for one when/if you start selling them?

I don't think i am going to even bother with an infineon TBH too many people having issues
with them not just with rc motors either...

KiM

 

[gwhy!]

LoL @ Warranty claim... Think you have 2 chance there Thudster... none and f**k all buddy hehehe...

I wonder after seeing this will GWhy still be flapping his gums that his lil 6FET will run the 80-130 Turnigys to 8000watt as he claims it will.. :lol:

Best of luck Thudmiester

KiM

Nope Im not flappin Im still confident 7-8kw on paper maybe 6-7kw max real world all from my baby 6fet 8)

 

[mwkeefer]

Thud,

From those PICS it's worse than just a LEG blew on a fet - based on the BLACKENED {metallica songs get caps, they run better} areas I'd say the entire high side of B phase went poof... Still totally fixable, alcohol swaps are your friend and will clean the components, the sink and the PCB right up of all that CHAR so you can fix the 2-3 blown traces, replace all the fets (most likely even if the gate + source || drain aren't shorted they took damage and wouldn't have the same performance as new - matched FETs).

The shunt mod is an issue... your not only decreasing the shunts resistance with copper but tied 2 of the 4 into parallel anyway which would again half their resistance - this means you have 3 shunt resistors now in parallel but all the current is going to pass through the soldered one (path of least resistance) and yep... POOF.

A better option would be to tack a parallel resistor onto the existing trace running from far side of shunts to the MCU... I don't remember which resistor it is (knuckles?) but it's in the forums, a little math and you can get this perfectly setup so that the parameter designer values are exact offsets or multiples.

The other thing I am unsure about is phase current multiplication and the effect on a 12 Pole (is it 12 or 8) RC motor - you may want to dial it back to 2x or even 1.5x the primary current and then do a test rip... bump it a tad and test again until you find the correct sweet spot... by doing this incrementally and then testing each config for perhaps 2 min of hard riding you can monitor the motor temperatures at various speed and current levels on the Infineon and make the chance of blowing it up much lower - that's how I tune every build (begin with 10-20A primary and 1.5X for the phase and dial, test, repeat).

Hope it helps!
-Mike

 

[Thud]

Thanks guys,
Lyen has offered to repair the controller for very reasonable & I just may take him up on it.
I see where tying down the 2 shunts may have clamped the current a bit more than expected. I wish the ellectrical MOD guru's had a better grasp of documentation so mimics like myself can benifit from their expertise.

Mwkeefer, I had the current levels programed at Batt 50 & the phase current at 80 when I smoked this unit. (I can only assume I was pulling a bit more :lol: )

I will pull the fet's & change out the blown ones & see if the controller lives, If it requires more love than that,I will ship it off to Lyen to get it back to "stock" & start over.

All I am looking for is the performance of at least a KX60 for a duration of 25-30 minutes.
Is this too much to ask for a racing "bicycle"?
Right now I leaning toward a dual motor set up Like the big road racers are using. Matt has proven them capable of some real power....I suppose its on Me to see if they are really durable in a set up that will truely stress them.

 

[dontsendbubbamail]

Thud,
Did any of the solder on the power traces melt? The reason I ask is because I thought that you had to beef up the traces whenever you draw more than the stock power levels. I had a 12 fet and just programmed in a higher current level without modifying the shunt or power traces and melted/burned a power trace in two.

I know your frustration because I have had my share of problems with these controllers. The 6 fet controllers just don’t seem to work for me. I have two 18 fets that are working great, but my application is electric assist and not all out power.

When you beef up traces, one thing I have noticed is that most people focus on the bottom of the board. On the 18 fet controller boards the fets has some ground buss traces on the top of the board. These are fed through a matrix of through holes in the ground buss from the bottom. I can only remember one picture where someone actually used wire on the bottom of the board to jumper from ground to the fet leg with the trace on the top of the board. My soldering skills are not up to the task of getting the wire soldered to the little pad without shorting to something.

Bubba

 

[AussieJester]

]
Nope Im not flappin 6-7kw max real world all from my baby 6fet 8)

GWhy.. $US1 dollar bet....? paypal aussiejester@hotmail.com

KiM

 

[gwhy!]

]
Nope Im not flappin 6-7kw max real world all from my baby 6fet 8)

GWhy.. $US1 dollar bet....? paypal aussiejester@hotmail.com

KiM

But I dont have a 130kv motor I have the 180kv motor so if what luke has said in another thread that the 180kv will even be more stress full for a controller I think you stake should be higher than mine for the bet :wink:

 

[AussieJester]

But I dont have a 130kv motor I have the 180kv motor so if what luke has said in another thread that the 180kv will even be more stress full for a controller I think you stake should be higher than mine for the bet :wink:

Luke has known to be wrong bets a buck

p.s is the 180kv motor a version 2 with skirt bearing? if u wanna sellz it ill buyz it?

 

[gwhy!]

But I dont have a 130kv motor I have the 180kv motor so if what luke has said in another thread that the 180kv will even be more stress full for a controller I think you stake should be higher than mine for the bet :wink:

Luke has known to be wrong bets a buck

p.s is the 180kv motor a version 2 with skirt bearing? if u wanna sellz it ill buyz it?

Yes it is the v2 with the skirt bearing ( But I have removed the bearing cos it was sucking 1A of current!! ) I want to hang onto it for now KiM as I need to test my controllers with it to win the 1 buck bet

 

[Thud]

I wan't to see 6kw pulled,for at least 15 second durations back to back for 20 minutes........
$1 dollar to the 1st guy who pulls that off with any infineon (or any rc controller for that matter)
Call it the thud challange!

 

[AussieJester]

Yes it is the v2 But I have removed the bearing cos it was sucking 1A of current!!

:: putz for finger and thumb to forehead to symbolise a "L" ::

WHO frocking CARES GWhy we is trying to build frock killing machines get with the program ::HICCUP:: I'm soz buddy yes i am intoxicated BUT I STILL try to spread the good word... :: group hug::


KiM

 

[gwhy!]

Yes it is the v2 But I have removed the bearing cos it was sucking 1A of current!!

:: putz for finger and thumb to forehead to symbolise a "L" ::

WHO frocking CARES GWhy we is trying to build frock killing machines get with the program ::HICCUP:: I'm soz buddy yes i am intoxicated BUT I STILL try to spread the good word... :: group hug::


KiM

:lol: I care,,,, the heat man, its a killer. The motor runs hot as is with no load ( I think its a really bad mechanical design flaw with the v2 motor ( I dont mean the skirt bearing but the way the motor is put together) ).

Thud,
yes Im up for that :? But I will be doing it first with my smaller motor cos from day one I have never been totally happy with the larger motor. But when the small motor survives 6kw I will try it with the larger motor, then just keep upping it until it blows up ( or not, upto 8kw )

 

[deVries]

But when the small motor survives 6kw I will try it with the larger motor, then just keep upping it until it blows up ( or not, upto 8kw )

Hi Gwhy, wow, with all this high $ kw talk, :lol: then I can safely assume at 3-4kw with my Hyperion motor you'd bet the farm that your Infineon 6fet will work even at extended slow speeds 48v?

The Hyperion is rated at 75A continuous with short peaks at 85A, but the magic smoke trouble is in the phase currents shooting way up at slow speed under load for a several minutes -then poof or poof with hard acceleration.

 

[gwhy!]

But when the small motor survives 6kw I will try it with the larger motor, then just keep upping it until it blows up ( or not, upto 8kw )

Hi Gwhy, wow, with all this high $ kw talk, :lol: then I can safely assume at 3-4kw with my Hyperion motor you'd bet the farm that your Infineon 6fet will work even at extended slow speeds 48v?

The Hyperion is rated at 75A continuous with short peaks at 85A, but the magic smoke trouble is in the phase currents shooting way up at slow speed under load for a several minutes -then poof or poof with hard acceleration.

4kw is what i run my motor with ( around 75A limit ) ( but it is a different motor ) my phase current setting on the controller is around x2 battery current , the controller dont get warm, the motor gets warm'ish but noting to worry about and has showed no signs of popping. When I first setup my controller I had it set to 100A battery and x2.5 phase and this was seeing peaks of 5kw with a fresh battery I only backed it off slightly because of the motor was getting a bit to warm for my type of riding ( its a 3250w motor ) some of the hills I was chugging up (20%+ grade) would pushing 4-5kw into my poor small motor for the duration of the hill but the controller stayed at ambient temp , So yes I think it will be fine on your setup,, betting a farm maybe not yet, until I have fully tested upto 6-7kw with both the modded 6fets that I run.

 

[amberwolf]

There's three things that I think are a problem with high power levels on the average controller, which boil down to getting rid of the excess heat in the controller. There are other issues too, but the heat makes most of them worse really fast. I have no direct test data to validate any of this, it is educated intuition combined with several years' experience of what fails and how in various types of switching power supplies (and stuff that has helped prevent future similar failures, as well as what I've seen of designs that don't fail that way to start with) as well as the little experience I yet have with motor controllers (since I have only been really working with them for about 3 years or so, with any understanding of what was going on inside them, most of that understanding being very recent in the last few months).

1: FETs can't get rid of heat in their die fast enough due to TO-220 package limitations. Not a lot to do about that without moving the FETs to an external board using TO-264 or something like that.

2: Heatsinks themselves are three separate thermal barriers, because there is that gray rubber electrical insulator, and then the mounting bar, then the actual case's heatsink.

3: Caps get damaged by the heat, and/or aren't sufficient capacitance and/or low-enough ESR to start with.


#1 can be dealt with by moving to the external FET board with TO-264 instead of TO-220. Depending on it's physical design, and the heatsink design, some of the #2 issue can be eliminated, the rest minimized. If the FETs that must be electrically isolated from each other are placed on their own externally-exposed heatsinks, and a controller-wide mounting bar is not used, then direct FET-metal-back to metal-heatsink contact can be used with very minimal thermal grease to fill air gaps (preferably very little, if the extruded aluminum heatsink and the back of the FET are lapped to a polished surface). That would probably help heat removal tremendously, even if the heatsink itself is still only air-cooled, as long as there is sufficient airflow to continue removing heat and making a large thermal gradient at the fin-to-air surface.


Short of doing all that, #2 could still be dealt with by leaving out the gray rubber pads and using Kapton tape and very minimal thermal grease, again just enough to fill the airgaps and scratches. Lapping the heatsink and FET backs would help, too, but not nearly as much as if you were going for direct metal-to-metal contact, I'd guess.

If the TO-220 FETs are mounted to the heatsink not only by the tab but also by a clamping bar across the plastic front surfaces, this will increase "flatness" to the heatsink itself, by evening out the pressure across the back surface of the FET. It might not make too much difference with Kapton but it probably would make at least a little with the gray rubber.

#2 can also be helped by eliminating the mounting bar "middleman", and directly securing the FETs to the externally-exposed heatsink, preferably one better than just the outside of the controller case; one that has a LOT of surface area with lots of very thin very long fins, with air being pulled thru them by a fan.


#3 can be helped by using more caps, with lower ESR, in a paired triplet of sizes, from say 1/10000th of the nominal main value to 1/100th to 1/1. Meaning, if normally you'd put a 1000uF then instead you put two 0.1uF, two 10uF, and two 1000uF. This is only necessary on the main input caps and the phases, where the caps are rapidly drained and refilled during switching. On the MCU section and low-voltage rails it is probably not necessary. This has been suggested by others here on ES in regards to this; but I cannot remember who it was to give credit.

Personally I would also prefer to use caps rated for a voltage at least 30% above the maximum the controller is designed to run at, and I would also use only Panasonic or Rubycon caps (from my own experience with leakage failures of other brands in many applications over the years since 2001). I'd ensure that all caps used are rated for at least 105C, as well. If it was possible to get away from electrolytic caps completely, I'd rather do that, but I don't see how.

Fan-cooling the interior of the controller will help keep the caps cool, and extend their lifetime as well as keep their ESR down during operation. Keeping the ESR down will help the FETs stay cooler because currents in them can be reduced a little.

 

[recumpence]

I pull way over 6kw from my Castle controllers for more than 15 seconds. They are up to it. But, that is only at full throttle to keep the phase currents down.

Matt

 

[swbluto]

I pull way over 6kw from my Castle controllers for more than 15 seconds. They are up to it. But, that is only at full throttle to keep the phase currents down.

Matt

Do you mean controller heat? Phase currents definitely don't go down at higher throttle.

(It seems LFP's miswording is misleading way too many.)

 

[recumpence]

I mean overall, they work with that much power for that duration. However, beyond about 8kw, you really can only pull power in 3 or 4 second bursts.

Matt