The Rocket | 4wd hummies hubs | 4x chaka vesc | 10s4p LG HE2 li-ion | CNC milled veneer pressed deck

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… :wink:

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…

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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. :grimacing:

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.:slight_smile:

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.

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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.

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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.

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for sure. i cut off my fuse so no more blowing that thing.

@evoheyax Are you running this in FOC? Would you mind sharing your settings, if so? :heart_eyes:

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)

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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:

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very nice! how did you remove the bearings? I was thinking about ceramic bearings for my all weather board, but the bearings were in there pretty tight, didnt want to break anything. did you work with heating/cooling or just brute force/hammering?

It was a 2 man job for sure. It required a 2 pin spanner, an arbor press, 2 people with a lot of force, and I even CNC milled a tool out of steel to get the little bearing off. It was a lot of work the first time, but it’s easier now that we’ve done it. That high heat expoxy is way stronger than needed. Red locktight from here on out.

Quite a voyage! I hope the board is presently working great. Do you still have Hummie Hubs in this build? I’m about to start on a small build with FOC, Torqueboards VESCs, 12s1p, and Hummie Steel Hubs, but your experiences here have me worried about heat. I actually thought the steel hubs fixed this problem.

Do you think I’d also run into heat issues at 200-ish lbs? Or maybe have any advice on ways to mitigate it? For example, if I could limit the board to 15% grade or 15MPH, that’d be fine. I just don’t want it melting my bearings.

Everything’s working great. Only issue I’ve had since the new car tire rubber has been bearings. I would just watch how your riding. Weight has a factor for sure. Hummie weighs 50 pounds less than me and doesn’t have the heating issues like I do.

I also ride very aggressive. Quick stopping, and quick accelerations always. That eats up more amps and generates more heat. I also ride with a heavy backpack, so my riding weight is closer to 220-225 lb.

I also ride long distances at mostly full throttle (5 miles). And I have lots of hills on my route. Stick to flats and riding aggressive for shorter distances or a bit less aggressive for longer distances.

OR, just go quad :stuck_out_tongue: IMO, I need quad motors with these motors in order to get the performance I need with out real heating issues.

The real beasts will be his new motors. I will upgrade this board to 4wd with those sooner or later with a higher kv.

Do you have any video of this beast in action???

If you look above, there’s a short clip maybe 20 posts above of being ridden by hummie. He didn’t push it’s limits though by any means, so it doesn’t really show it’s power, just more or less that it works, haha.

But I am working on getting videos together. I have 3-axis gimble coming this week so I can get more videos of this board.

Check back in a week or so, and I should have some new videos posted :stuck_out_tongue: