Just some shrink wrap and it’s done, hopefully rideable tomorrow
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It’s done, almost
Was a whole saga to finish, and in the end I’m more confused than before
Here is the situation, tried to get FlexiBMS data to show up on FreeSK8 app, not working, first I updated its FW, was on the pretty old version 0.6, newest is 0.18, still nothing, time to regretfully open the VESC case that was already sealed with silicone.
Turns out I had wrongly wired swapped the signal wire that turns on my front light with ones of the CAN wires, the big plot twist is that even with it swapped, switching on and off the front light always worked, which makes no sense and I can’t explain, I tested continuity multiple times, taking notes of what goes where and one of the CAN wires was definitely going to the light, I gave up trying to figure out how it was working
In the end, even with all wiring and settings right I still can’t get the Flexi to show up, so either I fried the CAN ic by having the wires swapped all this time, or the wires plus two connectors have too much noise/losses or I would have to try and remove the termination resistors, all of them are too much work to fix and will be left for the future me
In the end I installed the battery permanently and I’m letting it balance overnight
As a side note, maybe one day I will cut the shrink wrap in the correct length, but that day wasn’t today
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How I had missed riding this board, specially since it has battery that can deliver the power
I’m never going back to belts also, dead quiet and smooth, biggest issue before was full throttle or full brake at really slow speeds, always had belt skipping due to the small pulley I used, now I know I can trust in it
The motor sounds awesome and there is definitely more torque than the 6355 from before, and this is running with setting that should result in less torque at the wheel
I need to change two of the tubes, one the thread is gone and I can’t pump it, and the other it’s punctured right where the valve meets the tube, third one that this happens, don’t know if that is a thing with MBS wheels
But overall really nice, it was really windy day and two of the tires were at 40 psi or less, the other two at 60, and even so resulted 13 Wh/km, the previous setup with 6355 motors I averaged around 12 Wh/km, so I can say it’s pretty much equivalent but here I have way more headroom to increase the current
Will have a week or more of rain starting tomorrow so I will get around in changing the tubes and getting ready to do a range test
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Board is done been a few days, for now
Been riding it when I can and it’s really nice, at first I was thinking the Hypertrucks might be too wide for off road use, but didn’t seem to be a problem, and on sand, it’s even better, the width make it way more stable and you can keep the board straight and just focus on not getting bogged down, which not always works, let see how the 9"s handle that
The motors have plenty of torque, I’m running then at just 60 A, which should give me around 18 N.m of torque on each wheel, the previous setup in theory gave me 22.5 N.m, but there is no comparison.
I could get stuck like above and the wheels wouldn’t turn even at full throttle, now I can dig myself deeper and deeper and make a sand fountain without even going full throttle
Another interesting point is consumption, it’s the same, within margin of error. This was something I was really worried about, I don’t have a big pack, so any range lost is a big deal.
Just speculation at this point, but there is a few things that together could contribute, like belts vs gears, and while the motor is significantly bigger, the gear ratio is lower, so I’m trading core losses for copper losses due to higher average currents to keep the same torque, but as a counterpoint, the motor resistance is also quite low due to it being big, so my copper losses aren’t higher and overall I end up where I was before efficiency wise, but with more torque (and room to increase if needed) and no problems with overheating when needing lots of torque in short period like would happen with 6355
All that aside, got my first damage already, light support broke because I forgot to change the perimeters and infill when printing, and since my printer is also broken and I can’t figure out why, I put my title to good use and repaired it using rubberized CA glue plus barbecue wood sticks as dowels
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Man it’s beautiful where you live !
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Thanks man, the picture makes it pretty, and not saying it isn’t, but it’s a bit sad that there are barely any forests around, only some small patches now and then where it’s required by law, the rest is just sugar cane crops, you can go in any direction for maybe 100’s of kilometers in any direction and it’s all you will find in 80 to 90% of the terrain, but sometimes you came up in some gems
Not related to the board but just a sneak peak at the region, for the past of almost two years since everything closed down my mother and I have been going out on the weekends and exploring what we can find
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There is a first time for everything, and today is the first time I ran out of juice to get home
Did a few random riding in the woods and decided to take the really long way home, bad idea, 5 km from home the board stopped in a big hill, lowered the cutoff values from 33/31 to 30/29, that gave me not even 1 km more, dragged the board for a bit until the top and rode until the bottom, after that had to drag it again and then the rescue was available to come get me, was about 2 km from home
All this time I had the Freesk8 app checking the cells voltages, that damn group 1 keeps going down too much, on the 33/31 cutoff it was ok, but after going to 30/29 it plummeted
The thing is a need way more range for me to truly enjoy this board, double would be ok but ideally I would like to triple it to 90+km so I can truly go on adventures. Will do some quick maths to see what’s is the best route to do that, I’m really thinking in just slapping a bunch of hoverboard packs, for the price I paid the cells I can buy 10 hoverboard packs, or 1580 Wh, versus the 550 Wh I have now
There is no way for me to put 10 on the board, but I can put 2 easily, 4 maybe, and maybe another 6 in a backpack, or all in a backpack so the board still look clean
I could do this the right way, new enclosure, but more cells from a guy that is now selling some 2170s, but that would be way more expensive to get the same range and way too much work, this board will get left behind in a few months, so I really want to ride instead of having it down on the bench
Any inputs appreciated
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Amazing build, really loving the hypertrucks, their design looks is slick 
. Im not a fan of batteries in backpacks, falling would be a big risk i think with the weight of the packs. Plus lugging around that weight in a backpack that will slosh around while riding offroad 
what if you make a bigger top mount enclosure and just use that for big adventures? Then when you do more casual riding swap back to the normal one.
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That’s a really good point, specially if the goal is to ride for way longer, 10 kg on the back wouldn’t be nice, my legs are absolutely trashed from yesterday ride, really rough roads with lot of rocks
Another advantage of having way too much battery is that I can run lower pressures on the tires, I ride with 60 psi for now
But I think I’ve found a way to make the hoverboard battery works without backpack. I’m trying to fix my little cousin one, so I have one on hand to mock it up
First, on top of the enclosure I can fit 4 easily
Then at the front and back of the enclosure I can have 2 or 4 depending how I orient them
I’m going on the conservative side and assuming each pack can give me 10 km extra range, so I might start with just 4 on top for 70 km and then go to 6 for 90 km and maybe 8 for 110 km
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Nice! If you can come up with something to quick attach and detach them it would be a pretty good solution 
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For sure, I bought some dual lock Velcro that might work, but going that way I need something that only connects the two packs if they are around the same voltage, I don’t trust myself to always make sure of that before conencting
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Yeah id need that as well I know myself…
but how would you do this though?
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I’m thinking an Arduino and a relay, when you plug it in it measures the both voltages and only close the relay if the diference is under a certain value
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Thats clever, nice!
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But I’m thinking I will stick with 4 in a nice 3D printed case
I was looking is most routes I would like to do, the longest being around 90 km that is to visit my grandpas, around 90 km, but most would be sub 60 km, with a bit more if I do some loops and explorer the sun places, so 70 km range sound good, specially considering that my average speed off road is just 16 km/h, the day will end before the battery. And on my grandpa one, will be a whole day riding, and certainly I can stop midway to charge a bit
At least now my printer is fixed, this little fucker was the responsible
For some reason the printer was simply resetting mid print or even with just the bed and extruder hot doing nothing. With the Arduino being fed over USB I was getting a bed thermal run away error, which made no sense since I triple checked all wiring, thermistor contact and all that
With the 5V removed and being fed over just USB it finally works, at least on this 3h print with no filament, previously it always faulted in less than an hour
And to be honest, the printer being down is the reason I ran out of battery, the last thing I tried to print 2 weeks ago was the case for the DC/DC converter, if that had went well I would already have the range extender installed and would have got home yesterday
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Charge and ride setup done, just need to stick some Velcro to it
Still have to finish designing a case for the battery and also stick it in the board
The case isn’t that well sealed but the converter itself has 3 really generous coats of conformal coating, probably would work under water
Full range test only next weekend probably
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Range extender done, I was a little afraid that the dual lock Velcro would be weak, but now the problem is the opposite, I can’t take neither the battery or the dc/dc converter off 
, the adhesive start peeling off, maybe there is some technique that I’m missing, and I really need to take it off since it’s the same battery that goes into the ebike
Speaking of the battery, I made a case for it since I’ve been improving the ebike and want it to be rain proof
Also the last 2 tires arrived, so I’ve been improving the adapter ring, not all doing well but I’m printing the fifth revision now and hopefully it’s the last one
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I usually stick a plastic ruler between the velcro, pushing it in from the side. That way you get the velcro open with minimal adhesive tear.
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Nice, will try that, thanks
And in other update, there still some ghosts in my printer, went to print the second spacer and again turned into a spaghetti mess, I had never before had layer shift happen in the 5+ years I have this printer, I’m starting to suspect the power supply is dying, and that was what was causing the arduino to reboot
At least the fifth version is perfect
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