Im open ideas of how to improve on my designs. I want to get the production of this board to a place where I can fesebly make 20 of these boards to start with. And your switchs look very simple, yet effective. I’m always interested in simple.
The Rocket | 4wd hummies hubs | 4x chaka vesc | 10s4p LG HE2 li-ion | CNC milled veneer pressed deck
1 Like
Cells generally become more and more unbalanced over time. Check again after using it for a couple months to see the deviation.
And that would explain a lot. My cells actually became more balanced today without balance charging and I full drained twice today.
Yeah its about as simple as they come lol. Now it isnt perfect because there is still some drain leakage though it is incredibly low and for EBoards its pretty much irrelevant. For example when the switch is plugged in and in the off state a small amount of current is let through the switch though its so low that I had my board sitting around “down for repairs” for over a month and the battery voltage never went below what it was at before, ~3…8V per cell for “storage”. Anyways its very simple and works pretty damn well and ive used it for many other applications not only my EBoard but other high current applications, like my lab bench PSU that has a similar MOSFET switch using a 3034 fet instead. And if your ever interested in ordering in small bulk like 10-20 contact me and ill see if I could do it, though no guarantees, remember im just a single person compared to other groups like Enertion, DIY, etc. Also if you were ever planning on selling your boards like making the 20 of them like you stated I would highly recommend that you use a BMS just for ease of use to consumers, maybe talk to @longhairedboy and see what he has to say about it cause he is always using BMS’s.
This is so sick. So, so sick. and it gives me ideas.
So you were saying you were riding with laptop connected to the board and re cording your screen to measure the results right? Does the VESC interface over USB or what port do you use to get readings off of it. I was thinking you could have some sort of Arduino connected to it 're cording the information an SD card so you can look at it later on. I might actually look into some thing like this in the future though I would have to know a lot more about the VESC in the first place.
I rode my last build, which was my back 2 motors and vescs, and same battery minus 1 p (so 10s3p, same cells), with my laptop running the bldc program recording the screen of the active sampling. Its sketchy to say the least, because I have to keep a cable connected via the usb port on the vesc. I have to keep it in one hand while I control the board with the other, and i’m 6’ 1", and the cables like, 3 feet long. So not something II look forward to doing again, but I need to get a look at whats happening.
I want to write code for the vesc, but I wish vedder documented his code better. There’s not a lot of info of whats where, how he decided to split different things up, even what these variables mean, as looking through the code, he named some variables likes like gstd (don’t know if that’s a real variable name, but my point is some are just abbreviations I simply don’t know). I need to spend a lot of time and ask vedder a lot of questions before I can try to write anything. It’ll help to learn actual C this semester too, I know objective-c and c++.
ahhh, programmers… 
Here’s a quick video of hummie riding it up a 3% grade hill. Not much, and it doesn’t show the torque, but more videos to come…
2 Likes
uhm, i dont get your balance issues - 4.2 vs 4.185 is already a pretty significant difference in my books. my batteries never showed any of that kind of drift, not even my very first 1.5yo evolve battery. youll have to use a charger with adjustable end of charge voltage. 
That’s not very much IMO. It’s easy to balance up with a regulated power supply. And it doesn’t matter too much since I have more range than I need. I think 4.2 and 4.12 is a fair amount, 4.2 and 4.0 is way too much. But .05 even is not very much in my mind.
All inside the deck - nice work.
Too fast for me though.
What would be your ideal top speed?
I’m thinking of making different configurations that would suit better to different riders.
UPDATE: I have been working on finding better techniques to make boards, and believe I have found a solution to my problems. I’m in the process of designing a press so I can reduce the gluing to one session, one 24 hour dry time. the outside shape is easier to cut out with a band saw. And the battery compartment can be cnc milled, after gluing and drying. This would allow me to make multiple boards in one week, instead of 1 board every week and a half. I just need to find the time to build the press.
1 Like
Update: up to around 150 miles, probably more on the board. A few issues to note so far:
Back 2 bearings can still get to 226 F if I ride for more than 6 miles without stopping. This is too hot for the bearings, and thus the back bearings are starting to dry out of oil. They are only rated to 210 F while every thing else is rated to 300 F. So i need higher heat bearings and high heat oil. I also am thinking of rewinding the back motors to 80 kv to match the front and in hopes of fitting more copper on the stator.
I also have some slight delimitation on the last layer of the board on the nose and tail. Not a big deal and easy to fix. And it’s from not being careful when I sit the board up and dragging it. Everything else looks good. My next board, I will round the edges which should solve this.
2 Likes
Update again:
So I figured out if the vescs are compacted enough, I can fit can upgrade to 12s4p. So I’m having chaka make his special quad vesc design. This will mean my max speed should be about 30 mph, and acceleration will become insanely fast, as I will run 72 amps at 12s instead of 72 amps at 10s (@Jinra, we will have to race again we I’m done with these upgrades). I will also have more range, as I will be up to 500 Wh.
2 Likes
for sure. i cut off my fuse so no more blowing that thing.
What settings are you looking for. For the FOC mode settings, you need to based on your motors, as everyone has a slightly different motor. Some are 90 kv, some are 80 kv, and even a motor rated at 90 kv for example could be + or - a few kv (like 93 kv or 87 kv).
In terms of general settings, it depends on what battery your using (max amps you can pull, 12s vs 10s). At 10s, you want up to 50 amps on the battery side for these motors. I run the motor amps at 80 regardless. To set your battery cutoffs, use this chart:
for regen, I think 12 amps is good between the motors, so if dual, 6 amp per motor. I use 3 amps per motor since I have quad. Everything else, I have left the same as default. The remote you have calibrate, since we’re using a mix of remotes (right now, I’m messing with the mini trigger. Was using the steez before)
3 Likes
It’s been a while since I did any updates, and a lot has changed. so heres an update:
- I cooked the lubricant out of my bearings (even with 4wd, I still hit 250 F+)
- As a result, I decided high heat ceramics would be a better option. But we needed tools to crack the motors off and I had to wait over a month for ceramic bearings to arrive.
- I decided I was done with 10s, and I wanted 12s. I ordered a few more cells, and now I’m up to a 504 Wh 12s4p.
- I decided to go back to the carvon v2’s in a dual drive.
- The carvon v2’s were good and bad. The overheated the vescs very quickly, but I was able to do 38 mph officially, and I believe I hit speeds of 40 mph+ at times when I wasn’t recording data. This deck handles high speeds like a champ, not even a bit of speed wobble at 38 mph.
- But I had to take many breaks to cool down the vescs with the v2 carvons, so they were not practical. I have since decided I will make another deck with a 4wd carvon v2’s. Details on that will go into a new build thread when I’m closer to finishing that board.
- @hummie and I were finally able to crack the entire motor apart to replace with ceramics. While I waited for the tools, I order a special request quad vesc from @chaka. This was necessary, as I could not fit 4 vescs with caps with a 12s4p battery. Since I already upgraded the battery, this had to be done to reduce foot print.
- We replaced the bearings with ceramics two weeks ago, and I got my quad vesc this past weekend.
- I also replaced my battery screens with individual cell readings. So no more math, just look and see how the cells are doing. As you’ll notice in my picture below, the 2nd p needs balancing, the rest are pretty good. To balance, I simply take off the lid, and unplug the balance cables that go to the balancing port on the screens on the lid. I charge through the balance cable the p that needs balancing with a regulated power supply.
With out further a due:
19 Likes