I do have a quite strong suspicion that standing below axle causes wobbles to be more violent, and I am moving back to standing inline with the axle, just an fyi. I’ll definitely update my thread once I have the time to swap back to being inline.
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Thank you I appreciate you letting me know, I have been keeping up to date on the forum with the latest deck height ideas and no front bushings.
Even though the gasket had another cm to tighten up I have had to use risers for clearance. One thing I am not 100% on is unlike dualities or airs etc my hangers pivot around a point higher up than the axles, I am not sure if I focus on the axles or where it rotates around.
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I think you should focus on the point on the kingpin where the distance is shortest between the axis going through the axle and the axis going through the kingpin. Let me know if you need help visualizing what I am trying to say 
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As in the furthest inside part of the kingpin right?
I don’t think it’s worth too much effort to figure out it’s not going to change the plan of switching to 8” or CST C190 (edit got confused I mean the 190mm CSTs from Trampa) keeping the top of the deck below the kingpin (roughly inline with the axles/slightly above for clearance on 7”) and keeping an eye out for a cheap heavily used Deathwish.
I’ve also shortened the wheelbase to 93cm and made a standing platform extension for more leverage. It needed extra holes drilled in the stainless which was hard going with a hand drill and a blunt bit.
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It’s the green dot on this picture that counts.
The blue line is perpendicular to the kingpin and perpendicular to the axle.
At 93 cm axle to axle you wouldn’t run enough truck angles to loose extra leverage there too, so probably it will feel relatively good.
If you swap to a mountainboard deck eventually you should aim to extend wheelbase just enough so that green dot is inline with the standing platform height.
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Another Spintend blows up.
I was just running motor detection, the motor on that side froze, and it blew. Luckily I had my hand on the loopkey and pulled it fast.
I can replace the fet the pcb underneath it is fully intact, I can replace one of those other little chips there are solder pads under where it was, but there is a crater where another used to be, not sure if it was 100% necessary. Could it live again this way?
Alternatively does anyone know of a cheap Ubox that’s blown up on just one side or has an intact power stage pcb?
Alternatively I might be able to reverse engineer a couple new pcbs from jlcpcb or somewhere because they only have a 2 digit number of components on the whole power stage. But why could this have happened?
Spintends would suit what I want to do for a
race-ish board in the future
Next up.
I want to go to esk8con maybe in 2 years, so I will need a different battery I can fly with. I believe some airlines allow 20 batteries up to 99Wh on the carry on, so a 20S7P with realistic Wh numbers is perfect and fits well. Being able to disassemble it will work perfectly with how I want to use an offset stack, make the series connections in the awkward space in the middle and use copper instead of nickel tabs due to how I am connecting the corner and not middle. Can I just bolt together each copper tab?
I can hear “What if it flexes?” I router a slot in the deck for steel.
VESC + inrunners?
20S is too much for my controllers and a waste on my motors, so I will change to 17S/18S/19S8P which will unfortunately take another 6mm of clearance in a turn. I could take this as a good excuse to swap the mosfets for some stronger higher voltage ones like DSU011N08N3A (data sheets linked) instead of FDBL0150N80 The rest of the controller is good for 18S if not more, and I am pretty sure these Uboxes have been used on 18S in Kalys and the mosfets are 80v. Encoders, short wires, fast gearing, extra capacitors and charging a little lower can’t hurt. More on this + rheostatic braking later.
And customisable kv.
A normal charger and bms is new to me and actually really expensive, I have been getting compact adjustable volt/amp charging at 1.3kw from 2 server power supplies I got for <€20 and LiPo chargers I already had.
I want to compete in drag races and maybe borrow a racebox at esk8con.
17-19S8P of Bak 45D (tabless 21700s) will handle more than enough amps, a Ubox will do 110 battery amps per corner for a second, with 110T mod 1.5 gears I can gear down lots, so maybe I can set some good 0-30mph times without much max torque. I am pretty confident if I get it tuned decently or use encoders I can run 150A motor or more, my 63100s are very well battle hardened and the Spintend is rated to 180 and has been used much harder by some. Don’t get me wrong normally that much current will have momentary spikes to like 270A which would be a fatal blow to the flipskies but with encoders I can get it down a lot.
Build format + enclosure
I am going to wet lay CF my own enclosure so I can fit the extra thin and narrow pack down to the curve of the cell.
I have been doing the CAD to make sure it might fit under a Deathwish which would be great for the extra standing platform but I do quite like how brackets look and I can get a lot of drop without ending up 5ft long. I think the Trampa 8x4-3" slicks will be great.
Did you know an offset stack with a bottom cell moved to the top is actually better in a turn than a normal offset or an overall smaller wider single stack? It will be a max of 40mm tall and 126mm wide at the tallest part. I am tempted to do a wide single stack which is worse in a turn but good for ground clearance.
I want to use these typically 16S VESCs on 18S so I plan to find a ubox already used for 18S with rheostatic braking stuff included from an old Kaly for the front controller (long battery leads and most of the braking). I am hoping to get one from a Kaly XLR that also has those adjustable dampeners that tighten at speed w/ the VESC servo plug.
This is what it looks like under a Haero Bro which is a good bit shorter for example, so doable with a custom enclosure but I might loose access to an inner truck position or 2. It would be great to get the files for a Deathwish 42 I made some rough ones myself from pictures but proper ones including concave would be awesome. I am pretty sure there used to be a Deathwish 45 one of those would be great. If I can’t fit 2 Uboxes lengths and 9x 21700 lengths and 2 motor widths between the hangers it might just need a top mount VESC box.
Gears and motor mounts
4wd will be great for the extra top end power and no longer always skidding on the brakes, I already have 2 extra sets of motors I just need to trade for some lower Kv’s. Reckon throttle and brake simultaneously with a dual trigger will do a burnout or instantly explode?
I may as well make spur gears because 3 sets of belts will pay them off, I am lasercutting motor mounts anyway, I want more torque than speed on high rpm motors w/ 8" plus. I also made my 80T pulleys way too heavy.
Largely because of Project Endgame not accelerating faster with more amps and how I think it’s because of radial forces messing up gear alignment or something in the wheel hub or motor, I want to make the gears as big as possible to reduce the radial forces, slow wear and achieve big gear ratios for inrunners. I am designing the motor mounts to fit the base of the spur gear and I think I should have a bearing inside the spur gear as well. I think lasercutting from 2-3 mm Hardox 500 and stacking layers is going to be best. Will probably be 110 tooth mod 1.5.
I am cheap, lasercutting gears anyway and need the c2c smack in the middle of Idea mid and large sizes. I will buy some 20x20 clamps from Boardnamics unless someone has cheaper, measure the hole spacing and make some plates that bolt on.
This is largely inspired by the earlier Raceboi, I am ripping off some of Split Decision with the split angle drop brackets atm and then doing the same enclosure process, as well as the Dream Chaser truck and deck combo. There are a few things I would not have thought of without Bog Roosh like an extra internal layer for battery waterproofing, adhesive on loose motor wire strands and the headlight foot switch.
But first I want to rack up a few thousand kilometres.
Rated to 180A phase 110A batt 18S / side, has been used to much more by some, possibly plus an improved Alu pcb, cheap, servo outputs, rheostatic braking, and I don’t think there are any really more reliable options available and if I can make and replace power stages easily it wouldn’t be an issue to kill some.
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Just as im considering picking up a pair of Dual ubox Aluminum Lite. I’ve been running a solo ubox alu lite in my converted Onewheel Pint for the better part of a year and have had zero issues with it hence my interest.
That said I have zero idea how similar the Alu Lite/Dual Alu Lite and the Dual Ubox actually are alas, sorry for your loss lol.
If you’re considering going to go to the trouble of reverse engineering/replacing the power stage board why not reach out to sprintend and see if they have replacement power-stages? They advertise the separate power stage as a “repair” benefit on their store front so it’d be odd to me that they’d tell you to pound sand unless the version of your hardware was deprecated (this is also a fairly optimistic and non-cynical perspective).
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They are really different, those are much newer, are based on 100250 instead of 75300 iirc and the pcb design is quite different. Just keep firmware and the configurator the same version from the start, fully compatible ones and simple.
Thank you that sounds brilliant I had no idea, could you show or let me know where on the website it is? I am on an older version of their VESC but I was thinking of that as a good thing because they might be more likely to send me files for the powerstage. If I can make them cheap I think hot swappable power stages might be the closest we get to VESC reliability. The one issue of I’m struggling to find somewhere to make a thick enough pcb.
alternatively, @Skyart I think I remember something about you having a burnt Ubox with an internal receiver sliding around, still have it laying around?
You might want to take a look at the FOCKing thread (github) (its DIY from the ground up inspired by CheapFOCer and based on the MP2-ESC). The design is effectively modular. Power stage, MCU, and V-Supply are all on their own modules. So while I doubt “hot swap” is likely, having modularity and spare modules that are easier to swap is likely doable with such a design.
Edit: Though, in my experience(lol) the power stage tends to be the more expensive part of the board on DRV-based designs. This might not be so much the case anymore but when I did my own batch of CFOC1 & 2s the bulk of the cost came from the FETs. Now we’re pushing more volts instead of stupid amps part selection might be more economical but I’ve not compared. Food for thought.
Regarding the Ubox dual Alu Lite if you scroll down they say “Replacable single board” as one of the changes between the Ubox V2 and the Dual Alu Lite.
I dont think they mention it in any of the other listings though I haven’t really looked all that closely at anything outside of the Alu Lite and Dual Alu Lite. Its also possible im misinterpreting the statement. But hey, the worst they can do is say no.
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I can use those pin header things if I were to be swapping frequently.
That’s surprising it’s just mosfets, shunt resistors and capacitors, if something was very expensive I could move it across. I can get FDBL0150N80 for not too much. The most expensive, or at least hardest to get and make is the really thick pcb with copper rails soldered on.
On a side note can I swap mosfets for ones with a few more V of headroom and slightly lower RDSon, similar gate charge and threshold etc or is some calibration stuff going to be messed up?
.
Yeah one here or there isnt a huge deal, and when im talking about expense in context to DIY the expenditure is relative to the cost of the whole unit. So if 1 unit is 60 bucks and the power-stage alone costs 40… there ya go. Granted, having glanced at the FOC_King BOM the fets used there are under a buck a piece so YMMV.
In context to a “repair” or “rework” kind of situation for an off the shelf design, costs are significantly lower relative. 5-3.5 per fet isnt horrible if you’re swapping a few out on a power-stage when the cost to replace the whole unit is 200+ dollars.
Also for what its worth, I am realizing that the majority of my time assembling DIY ESCs was done during peak covid which may explain why my experience may have been atypical.
Not familiar with the design of the power stage or the internal of any ubox if im being honest. I know most of the DIY ESCs that I’ve fumbled around with have used conventional sizing (1.4-2mm) any significant thermal or conductive mass is provided by soldering on copper/alu busbars or just applying oodles of solder to the main current rails.
I am not the right person to ask this, I have a hard time finding BOM replacement parts without significant research and guidance.
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There’s one side and the other side of the powerstage is very near completely blank.
I actually haven’t checked with a callipers yet, but with a ruler it’s at least 3mm, probably 3.2mm or about the same as a small screw driver. At least where the copper rails are directly on the other side I have not been able to de-solder the larger pad of a mosfet from this.
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Some of us have a loop key out of necessity and not for emergencies 
I updated firmware and while I can use my power button to turn on my vesc it won’t turn it off so I added a loop key instead. I tried other buttons and so many fixes but gave up for the easy fix
That aside, if you can afford it, then I’d say get a tested known working VESC that can handle your specs first. Then work on repairing and testing the one you blew up. Even if you fix it there is a chance it will blow again on the other side so better to have two options vs just one.
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I like to have absolutely nothing connected to the battery in storage for safety (paranoia really), there are then far fewer chances for a short to happen especially for sketchy VESCs and no parasitic drain as a bonus.
I think G300 is the only VESC that is currently available and hasn’t proved to have major faults but they are too big and expensive. I think a spintend can run great and encoders will help everything with high current. I know it might be a foolish choice but getting the front spintend ahead of time might be worth it for getting back on the road, or 1wd.
YES got the drain pad de-soldered. It was impossible with a 650C heat gun or 2 soldering irons but with a little Sn42Bi58 solder around the edges it came off immediately.
Of the 2 little things missing I am pretty sure one is a pull down resistor between gate and source and the other is a resistor between the driver and the gate. @Davewesh does that sound right? And is there anything else I need to know like replacing other mosfets to keep them all from the same batch?
Thanks
Charging fast is very loud. 1300w instead of 1100w will probably be even louder. I had no idea these PSU were so loud before using them closer to 1.5kw max. It makes me nervous too.
I don’t think any place to stop and charge is going to put up with this😂
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the pwm output testing setup. Hopefully the 0.5A limits will help protect the measure+power devices, vesc and pc.
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The converted psu and cell tower rectifier chargers use high static pressure fans, but not necessarily good ones. You can get noctua replacements but i never have any issues when charging at 110v (half wattage and usually 1200w or less to not trip circuits). I have a one based off the delta 2000w psu and one based off the huawei 4850 rectifier which will do a little north of 3000w and both are loud when running on 110 at or near 50% of its maximum wattage. Also, you should be able to use class2 ev charging stations to really dump some amps. Just need an amazon adapter
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Thanks I might swap the fans then. The main time I would want to charge fast is a stop on a long ride and that’s the main time I want it quiet.
I am in Ireland so we can get quite a bit of power from plug sockets. We got >4kw from a random plug socket all day long helping heating the house during construction.
Plus with group rides not existing on this land mass 
combined draw isn’t an issue.
Where did you get those chargers from? Alibaba? I like this I could charge at 20S 50A with the next pack but idk how to order on alibaba.
https://www.alibaba.com/product-detail/Modified-Battery-Charger-Adjustable-72-101V_1601373319136.html
This looks nice but I would have 6 esk8 related apps.