I used depth as my control. i assumed the thing was a solid block of aluminum up to some depth. I was very careful to not go to deep. I think i used a drill stopper. might have used tape.
you need to not get it wrong, you need to be careful.
I think i tried to use the hole pattern from the castles xlx2, but i think measurements were wrong so ti’s it’s own pattern. i relied on depth not placement to avoid electronics concerns.
I don’t think width is a concern.
I should have warned you to be very careful not to cross thread them either. and I apologize. I didn’t transfer the pattern to the board well so those holes were off making it very finicky to get bolts started.
wonder if it’s using thermal pads or paste. either way if you can find a replacment that’s the extra cautious way of going.
Chances of hurting the fets are incredibly minimal. Warm up the casing a bit and pull up with even force once all screws are out. DONT USE THERMAL PASTE, get a thermal pad. With the way the fets are mounted backwards, with the metal side facing out. This side can be directly connected to the drain or output of that phase and result in a real bad time if they short through the aluminum casing, the thermal pad provides an actual barrier while still facilitating heat transfer. In contrast, thermal paste can move out of the way and fill air gaps while letting metal still touch where it can.
I think this is the time to throw it in an ultrasonic cleaning bath with isopropyl while I have the electronics out anyways… It makes sense anyway Right?
Luckily the facility I’m liquidating out in Arizona has a lab and happens to have a ultrasonic cleaner & iso
I just powered the board briefly
as far as lingering voltage in the caps / mosfets after being powered down with the batteries removed is there a way to handle this properly?
Is there a proper way to drain?
Or is it just a waiting game?
Are there other components that might hold power
That might be hiding sparks?
I guess the simple solution is to probe caps using my multimeter aswell as mosfets
(which I will have to figure out what they look like and how to properly measure due to the other potential mosfets I’ve seen in my life that usually have 3 prongs?)
to see if they retain voltage at all as is.
And if they do I might have to find a resistor in the facility somewhere tmr & see if I could drain the residual power by probing each component that contains power.
Idk just thinking out loud could be a totally different angle to all of this
I would like to put these Vescs through absolute hell & run hobbywing inrunners on them or do 4wd with 6495s in the rear and 6485s in front from SKP. Still undecided.
In theory I could potentially push these foccers up to 400A phase amps that is if I properly upgrade traces / component hardware limits
So I’ve been told anyway… definitely could be quite the learning experience and a wild experiment
I will have to look into gnarly liquid cooling to complement the passive heatsink. Potentially ditching the stock heatsink and making a completely custom one if needed
Luckily I have an extra set of little foccers with heatsinks that could make water cooling pass through ports in
as a start when it comes around to it
(not such a far fetched dream)
Estimated ERPM is 109,200 at 20s
Which is still under the 150,000 limit but I’m not sure how dangerously close that is or what would put it over the edge.
That estimate was Utilizing EZRUN MAX 56118 SD G2 650KV motors since that’s what all the cool people are running nowadays
It will be really hard to push 400A from a 6 mosfet focer.You need a tronic or something similar.
I got in a group buy for mp2 vescs, i will pay ~120$ for two. They can do 20s 250 amps. Maybe there are some better mosfets for them
I second Tronics, X12 in the bareboard bundle were cheaper than lfoccer, don’t take up much more space and are much beefier doing 400-500A and 6awg phase wires. Also better than G300 imo although they don’t come with a case.
I was looking at swapping fets on VESCs one possible issue is more powerful mosfets often having a higher gate charge and especially at high erpm it’s more work for gate drivers, I’m not sure if it would contribute to how VESCs have been dieing lately with high erpm and funny stuff.
Would a spintend be any good as a platform for modifying?
I believe they have been used up to 300A per side on inrunners, will let you set 400A per side, 2 separate pcbs, copper rails above the mosfets which are all on one side for cooling unlike D100S or something. It also has 12v outputs you can set to turn on and off based off esc or motor temperature. I know it’s rated to just 16S but apart from the mosfets it’s good for at least a couple more volts since they use the same thing for their other VESC.
I had been guessing ratings were motor current generally, that makes me more optimistic. I actually don’t understand why VESCs can do more motor amps than battery amps if it’s just more heat generation from voltage or duty cycle or it will legit die immediately.
I think absolute max current might be the max setting for it in VESC tool. It’s at the limit for current measurement too and it’s also an awful big number for those little mosfets.
MY PANT POCKET FEELS REALLLL CRISPY RIGHT ABOUT NOW.
(Burnt wallet)
In the meantime while those are coming I will have to make some more headway on that project of mine (shrinking the mt12 guts) into a more manageable size for use of a pistol style remote.
I kind of miss the pistol / trigger style remote
Plus it’s a learning opportunity.
I still have to determine whether the guts of the remote can run without the screen.
If it does need a screen at a constant in order to properly run I may consider sourcing a smaller screen if possible.
My take? The inrunners already have massive amounts of iron losses at 16s, so I wouldn’t recommend going higher than that.
You can overheat the motors without some form of active cooling. The temp sensors also don’t work on these motors with VESC because of Hobbywing’s proprietary digital protocol for temp sensing. You can make your own, but getting reliably accurate readings without being inside the motor will be hard.
Also, while ERPM values remain below the threshold, consider actual RPM; you will be at well over 50k when these motors are rated for 12s operation, and a fully charged batt will get roughly 28k rpm. 16s is already well over that, and that was a gamble I took with sacrificial ESC testing to see if the motor would grenade itself going higher than the rated voltage. It did, and it did it fine, but that was 16s. You’re in uncharted and potentially costly waters going into 20s.
Spinning the motor to that high of an rpm will require some insane gearing to keep it to reasonable speeds (e.g., 1:15), which will require some creative thinking and playing around to get it right. That high ratio will already provide you with insane amounts of torque, so much that it won’t be very controllable.
All in all? I don’t say all of this to be a downer, but rather just my 2 cents and maybe prevent a lot of headache and wasted money, if you do go through with it all, would love to see your progress and how it all turns out!
They are quoting motor current. They mention battery current being 2/3 of motor current, but they never gave me an official number when figuring out my build. I have them set to 200 batts per side.
From what I’ve found, these Tronic X12s are rated very conservatively, too.
The 100v (24s) model uses 4x Infineon IPTC017N12NM6 on each phase, and the MOSFETs themselves are rated for 120v and an output of 331a EACH (of course, with adequate cooling). To help with cooling, these MOSFETs are TOLT style, meaning they dissipate heat directly through the top of them rather than having the black shell that heat has to get through first. I hope that more high-power VESCs take note of this and implement this style of MOSFETs.
The DC bus also has 12x 150v capacitors and is rated for 140v spikes, so it can handle pretty much anything I have been able to throw at it. I’ve hit over 24KW per side, and they still only got to only 34 degrees Celsius MAX
might work too 
