Pretty much everyone learned tons by brought things from China… Glad to see you accomplished your homework mate!
The MKV #1 | sensored 6374 | VESC | Koston deck | Lipo 6S 10A | Psychotiller's enclosure
coming from a long rc background there isnt an issue in the previous motor you stated you buyed. if it spins in the other direction, you need to switch any 2 wires connecting the motor to the esc. this will solve that.
I think there is a issue because it was working, spinning in the right direction, and (they are color coded so I’m 100% sure) I didn’t switch the cables. Also I can guess that is damaged because when it starts it does like 1/10th of a turn in the right direction, then starts spinning on the opposite one as long as it gets more electricity. I think it’s an internal magnet/electrical problem but yes, I may be wrong.
Edit: also they’re sensored motors, I think I should change the order of the sensor wires as well if I want to invert the motor.
Yes unless it suddenly spins on the other directions when you ride on it, then thats a huge mess right there
I bought a scale and weighted the board, right now is around 5.9kg, I guess with the new board will be lighter, but adding another 6s lipo to reach 10A will do a +750g, so let’s see, this w/e I will do another update with the solution mounted on the new board.
Also I measured the max speed commuting to work using a GPS tracker and it’s around 29km/h, I will do another measurement with another realtime app instead of a tracker.
Finally, here’s the “exploded” hub motors pictures, as you can see the glue that holds the magnets melted and the magnet moved and caused the motor to fail, those two can be pushed easily around.
Wow this is such a great shot, so lucky I went for the other chinese hub motor. I opened them up and it looks very solid with more magnets compared to yours.
Not doing real street test yet, but so far I am very happy with the bench test performance.
@makevoid ! you should make a huge shout out to the DIY communities and warn them about this particular flaw on that hub motors . skaters could get THROWN off board if any of those magnets break free .
@laurnts ! yours is better .
I’m starting to make some videos like this:
check more on the other thread: http://www.electric-skateboard.builders/t/makevoids-vidz/2408/3 or on youtube: http://youtube.com/makevoid/videos
Big update, finally I decided to mount everything on the new deck and also, big surprise :), @psychotiller 's enclosure arrived!
Unfortunately the other 6s pack is still somewhere in between China and me, also I ordered a vesc, a battery voltage monitor and an anti spark switch from the german esk8 shop but they didn’t arrive yet, so I had to do some workarounds to switch the thing on. Also I’m waiting for the vesc from enertion because I want to make a comparison between the two (also to have one backup vesc if one fails).
Here’s a pic of the old setup and the new deck still untouched.
Then finally the new build, mkv 2.1
As there’s no switch yet I have to plug the battery cable (which I extended) by hand, I also made an extension for the motor cables so I could push the enclosure as far as possible to balance the weight. Unfortunately the deck is curved and the enclosure, even if it’s somewhat flexible, is leaving some spaces at the sides so I applied some tape for now but I plan to put some foam or similar. I am very happy so far of the outcome, the enclosure helped a lot, will do a test near the beach tomorrow and hopefully a video.
Get some of this stuff! it works great!. http://www.ebay.com/itm/4M-157-Seal-Universal-Car-Door-Rubber-Weather-Hollow-Strip-D-shape-Weatherstrip-/131734781851?hash=item1eac013f9b:g:ezgAAOSwKtlWnenH&vxp=mtr Or add a few screws along the sides. It’ll suck up to the shape of your deck.
Thanks man, the enclosure made everything look more professional, it protects esc and battery from splashes and made the board more stealthy. I will get the rubber stuff and put two or four extra screws as long as the new esk8 stuff arrives! I also thought about taking an hairdryer or another heat source to make the abs bend a little bit more but maybe that’s too much.
@psychotiller I got the rubber, sticked it under the enclosure, got longer screws and now it’s also more silent, very good tip.
On tuesday the new lipo will arrive so I will switch to 2x6S totalling 10A, that will give me 15 miles of total range, which I look forward to try.
I also got a voltage/wattage/amp monitor thing and I mounted it temporarely (I’didn’t even made proper adapters yet) to do some measurements, I want to measure both boards, right now the watt power readings on the first one were:
~200Wp > starting ~450Wp > riding at normal speed ~830Wp > after riding at top speed + braking hard, and that was my peak power drain
I will also do a long ride and see if the amps consumed are actually 5A total or much less.
2 days ago I was riding and I broke so hard that my motor was almost blocked, probably that explains the +800W of power drain, all because I have a bad ESC that I couldn’t program.
I knew that operating the brake on the controller needed extra carefulness because after a point when pulling the throttle in reverse position, the motor just stops, and I just had recalibrated the throttle range of my controller so it was more sensitive, because at the beginning it was calibrated poorly and I didn’t figure out the correct procedure for chinglish reasons. The downside was that the hard-breaking point was now reached before than I expected and I tried it just once at low speeds, I was too excited that I could ride after 2 days of late work which didn’t gave me free riding time. When I went out I screwed up but I’m still alive Also the VESC should arrive next week and it will be a very happy news for my body.
In the meantime I switched the hub motors to the longer deck, mounted the battery near the front trucks so that the weight is more balanced and put the ESCs + RX in a small spray-painted lunch box, here’s the pic:
I still need to fix the cable and the switches but the effect the leds do from the inside the box is quite cool. Also the longer deck will help my gf riding it easier because she was scared by the shorter one.
Finally I want to plug the wattmeter onto this thing as well to see the various consumptions and do a test when going uphill. Last but not least I noticed that running the hub motors with the sensor cable unplugged makes the problem of one motor not being able to start from still, disappear… very interesting. I will do some tests and measurements next week and keep you guys updated, a cool test would be recording a quick run with speedometer+power meter data.
Two of my friends, attracted by a video I posted, wanted to get an e-skate too and they asked me what’s the minimum budget, I pointed out @onloop’s video ( https://www.youtube.com/watch?v=6yBgsT65UPg ) and then started putting down a BOM (bill of materials) with prices and everything.
Here’s the result: https://docs.google.com/spreadsheets/d/12XYKZhs7IkBiTNniIc3gyUE7a4pvkk4sOGjK85dNeWI/edit?usp=sharing
There is a base build starting from ~510 USD plus all possible addons to arrive at a very similar build like mine, do you think that I should suggest other parts to my two friends? Thanks in advance
I would stick to ZIPPY Flightmax because the Multistar one feel a bit weak.
Thanks a lot for the tip!
Spreadsheet BOM updated
I haven’t tried HK lipos so I don’t know yet but my friend will soon
vesc + anti spark switch from esk8.de
Testing, so far motor moves ok controlled by the laptop USB serial connection & keyboard, motor movement and control is so much different than the other 2 ESC I tried
smooooth, now I need to swap it with the old esc, make the hole for the switch in the enclosure, set up the new remote and test-drive/test-ride it
You could be the first person to ride a using a computer keyboard … Looks way more fun than a hand controller lol
After testing and configuring the vesc and the new receiver, I put all the new elctronics into the enclosure, made holes and fixed battery charge port, balance port and switch that goes to the anti-spark pcb.
I rode the board few meters and both acceleration and braking are awesome, the vesc is on another planet compared to the other ESCs, starting from still is now much smoother, I don’t think I will need any push at traffic lights anymore. Can’t wait to try it!
I’m still waiting for another 6s lipo which is still stuck in china as now I would like to double the range to reach new places and to be able to come back without pushing i’ll end up getting other two 6s from somewhere else like hobbyking…
Also I recommend the remote, is very compact and seems to have no issues at first
I have two lipos so with 10A I can get long rides finally, the vesc was a game changer, why was? well… something happened… but first…
Here are the two Lipos, with the blue tack and enclosure shape and pressure they don’t move, the vesc is in the space in between them but I’m open to suggestions on different positionings
That overall gave me around 60 km worth of smooth rides and commutes, I was very happy until I did a ride over a long and very wobbly terrain that probably caused my motor mount to move a bit and tightened the belt too fast, that with the non perfect alignment of the wheel because of the irregularity of the mounting holes (bought a drill finally to fix it, also bought a new enertion pulley and I’m waiting for that to arrive) caused friction, more current draw and heat. I guess that that’s the main reason that made the vesc fail.
E-sk8.de suggested’s repair guy said that it could be a DRV chip, I’ll probably send it there for repairs, I tested quickly the vesc bypassing the caps (connecting the battery directly to the vesc) and the problem seems the same, I bought spare DRV chips and caps that should arrive this week but I think I will not be able to change the DRV myself if it’s that the culprit .
Here’s the video of me running the motor, with the arrow keys it basically doesn’t move, first I do a motor detection, then accelerate with the controller and using a very low current (3-4A), this is the behaviour, the braking instead works, what do you think it could be?
Of course with another ESC the motor is fine, I’m currently riding with an FVT 6s. I’ll probably send it to be repaired to the german repair center suggested by esk8.de if I can’t figure out and fix myself the problem. “faults” debug command in the BLDC terminal gives no error messages.
thanks to anyone that can give me a hint
edit: I suspect is my motor because it’s still overheating with the mechanical part fixed and if I pull the wires gently a bit it starts clogging even with the FVT ESC, will do an inspection soon, also I have other two motors to test the vesc with, a thing that I’ll do soon too.
Yes, I found out that is a motor problem, by pulling the R-Spec wires when I have the FVT ESC plugged accelerating, it makes the motor clog a bit, so I guess there’s some partial shorting that is generating all that heat, also the upside is that the VESC works! I have to re-heatshrink it again and keep it ready for when the motor arrives!
Edit - update:
I replaced the RSPEC+ with the sensored 6374 from esk8-de, the motor detection is ok, I’ve also tweaked start RPM a bit more and it seems to start better, I still haven’t tested it on the streets because I had to go on holiday and I couldn’t bring it with me. I also ordered a sensored cable so I’ll try it sensored as soon as it arrives, I’ve read on endless-sphere and on another forum that sensors helps not only smoother startup but also braking as well and I’m willing to test the difference asap.
Here’s a pic I posted on another thread of my boards MKV2 and MKV1 side by side:
I actually bought a similar motor from DIY Electric and had the same problem. the magnets didn’t have enough glue so they just popped off and gave the motor a lot of resistance. I saw someone else just epoxy them back in place so I gave it a try. It worked, but I think the spacing between the magnets is slightly off. Now the motor hardly has any startup torque, but will still go about 23 mph tops with my 10s battery. Also the threading on the motor and bolts can strip very easily. Never buying these cheap hub motors again.