Something's Wrong With the Home Made Electric Dirt Bike Project - Part 7 

It's the pole sync. Basically, the controller needs to be set to sync with the magnet position of the motor. That is universally true with any brushless system. The speed control is fine and the motor is fine. Just needs the correct settings. You need the exact properties for that motor

65V is near dead for a 72V battery. The controller will also have a low voltage cutoff setting. A fully charged 72V LiFeP04 will be closer to 80V. Charge your batteries before using them, gotta take care of your lithium batteries.

You might be dropping the voltage of the battery below cutoff when hitting the throttle, it did it before you went to drive it @19:30. You could be losing voltage through a bad return connection to the motor. Maybe run a dedicated neutral wire from the hub bolt to the main return lug. Also using a passive voltage monitor with a voltage over time graph would make the troubleshooting easier. I love troubleshooting this stuff, good luck brother. We deal with these kind of shenanigans regularly in electronics. Its all part of the dopamine rush you get when its optimized.

That reverse switch looks pretty dangerous if you accidentally flip it while riding.

I had that same problem with a mid drive motor. I canged the pole angles in the motorcontroller software and it started working.

A good rule of thumb for matching electronics is to overspec the battery for the controller, and overspec the controller for the motor. The motor is the most resilient part, then the controller, then battery is most sensitive. Also, check the BMS on the battery and what the amp cutoff is. If you are pulling more than the BMS will allow, it will cut out. Then you'll have to adjust the controller amp settings to just below that and reduce the acceleration rate so you don't hit peak amps so fast. It is a lot of just running the vehicle up and down the road to find the settings that work.

You need to put a protective cover on the reverse switch before loose clothing or anything flips it while your moving.

The front brake hose on usd forks goes on the inside of the fork to protect it from damage - hope ya get it 'running' well, looks madness.

You did a great job considering this is your first outing on serious kits. You’ll get it and learn along the way.

10:50 - I'm seeing nothing but a very happy man right there.... I think he might have fallen in love at this exact moment, as did I when I played around w/ my first fast ebike before I rode it and got addicted. LoL Edit: I think the slipping in the axle is causing the hall sensors to freak out and make that stuttering of the rear end... I found an Endless Sphere post about testing the hall sensors by disconnecting the phase wires and spinning the wheel and testing the phase wires for weird voltage to show that the hall sensors are working correctly. A few videos in and it says to check the continuity of the phase wires to make sure they're not broken.... Also check for moisture in the motor case, that can be helped by drying it out and putting Statorade inside the motor to help heat build-up and moisture.

based on my experience working with motor wheels, I recommend tightening the halves of the dropout between themselves with a bolt, or putting a clamp on them. considering the power, I would advise you to make a bracket from a c-channel beam with tightening screws to select the halves of the dropout. the main idea is that the grooves on the motor shaft have as large a contact area as possible with the corresponding dropout surfaces and the dropouts should be maximally fixed against expansion. Maybe if you have someone you know who owns the Delfast's TOP3 with a new dropout amplifier (it can be recognized by the 3 bolts sticking out of it), see how it is arranged on this bike. suitable as a starting point.

Lots of good suggestions here for an electronic fix, but try the mechanical first. Put your gopro on the rear swing arm to see if the wheel is torquing/twisting/bending spokes and hitting the swing arm. It could also be the magnets inside the wheel trying to lift out of their pockets under high load, they are often only glued in, it is Chinesium after all.

Make sure your phase current wires are not loose in any way. Keep up the good work! I'm sure you will get this going soon!

You need to make sure regeneration is off because that chatter doesn't sound good! Keep at it and messing with it until you dial it in! Awesome job bro!

I have been involved in electric transport for a long time and I can say that there can be several reasons for this behavior of the motor. To a greater extent, I am inclined to believe that you have the wrong combination of connecting phases or hall sensors. You should not rely on the automatic detection of the controller, since not all controllers can correctly determine the phasing on the motors, especially on powerful motors with low winding resistance. If you understand what we are talking about, then you can first check the correct operation of the hall sensors, the circuit is simple, connect three diodes to the outputs of the halls and slowly turn the motor to watch, the diodes should light up alternately, but they should never burn all three or not burn all three, at 120 degrees they light up in a chain 1-2-1-2-1-2 shifting in phases. Next, you need to check the idle current of the motor, it should be small. And finally, download the connection table of combinations of phases and halls and check the correctness of the connection by enumerating all combinations. If you need help write how to contact you. Good luck in job.

18:18 If you crash or brake hard and get shoved up towards handlebars, those switched could damage the family jewels.. 😬 Something to think about! 👍

From brushless rc experience when you set up an esc you have to teach it where full throttle is by holding it at full throttle then turning on the esc then cutting the throttle down to off, this will tell the esc what range the throttle has. But as it has an auto tune I am not too sure, the other thing it might be is the 'c' rating of the battery packs. C rating relates to how much current the batteries can burst too, if the C rating is not high enough then the batteries wont be able to deliver the amps the esc is calling for. Are you sure the BMS boards are rated to pull the high amps the esc is needing?

I bet your neighbors partially approve of your electric projects. The sound is 180 degrees off what a 2-stroke belts out.

Front brake routing goes around the inside of the fork. We didn't wait decades for Hondas patent to run out to go around the outside.

Get a multimeter. Set it up for ohms. Disconnect all power sources. Check out the resistance of the throttle.

try changing the phase angle on the controller and as for the torque arm i used stainless steel for mine to stop the axle eating away at it good luck buddy looks great cant wait to see it finished

Love your work but that switch will cause a castration during an accident. I am a biker and love motocross. I and everyone else have found out that the tank becomes a seat frequently. Be careful

At least the neighbors are happy with this project :)

I am a builder myself. Thank you for sharing all...! Congratulations for your achievements, we know why we are the people not getting lost on TV or arcade..

when this is all done, you should go and paint match everything to the original colors of the bike, i think it would look so good

The front brake hose is supposed to be routed on the INSIDE of the fork leg, not on the outside.

At least you’re neighbors will be happy with no noise 😂

If it is only on acceleration and not on fix speed I think you can use supercapacitor to help with the peak current demand when you accelerate, but your work is awsome, big fan!

A LOT of builders run the sensor wires and the motor phase wires together in a bundle to have a neater appearance. Common mistake. Inductance and the magnetic fields around the phase wires will affect the signals from the 5V hall sensors. Separate them as much as possible. A couple inches is usually all it takes...the three fat motor phase wires can be bundled, and the five skinny hall wires can be bundled a couple inches away.

On the end of your swingarm where you slide the axle in, you need to drill holes in the end of it and put a tie link to hold the ends of the aluminum together. If you go back and look at the video, you can see the spaces are opened up and starting to separate, which is why you had the axle start to twist. Its not that the axle nuts were coming loose, its that the space was opening up and allowing the axle to slowly start to twist.

All I can say is, I’m glad it’s you that’s working on that ebike and not me. I would’ve pulled my hair by now. 🤣🤣

do not give up, you will succeed, the bike turned out Greetings from Russia

I know that orange motor cable is well Insulated but if it were me I'd be putting even more protection on it just incase you catch it on anything. With that sorta current It pays to be careful!

Sounds like the controller is loosing track of the rotor position, usually they use Hall effect sensors or a sine/cosine encoder. If it doesn’t have those and it’s a sensorless then it might be loosing position causing it to do that weird jerking

3:38 listen when he flicks the switch, something in the background turned off at the same time. That was good timing.

I had the same problem with a kelly bldc controller it turned out to be the settings for the hall sensor angle. you will need a pc to change that . all the blue tooth apps only change general settings

Weld those steel tabs to the axle shaft. Then cut the back of the aluminum mount off the end of the swing arm so the axle can slide in from the back. Finally, tap the swing arm from the side to accept bolts through the holes you have in your new axle tabs in front of the axle. The longer the tab the stronger it’ll be and a bolt in front and behind your axle would be ideal.

Scrap that idea and build a tube swing arm something that isn’t so soft and can hold the axle in place or add bolt stops like a standard swing arm even though there used for chain adjustment but I’d assume they would help hold the axle in place better.

Hey mate, thought i should point out that you'll need to install steering stops on your chassis. they physically limit the amount of handle bar turning radius so when in a crash the triple clamps/fork assembly stops before making contact with the chassis. also i believe the squeaking sound is coming from the rear shock as the old mate before you who did that ghetto paint job didn't cover the chrome shaft, that will destroy the main dust/oil seals. pretty easy to remove the rear spring and remove the paint with some paint stripper. sick videos, refreshing seeing someone actually thinking outside of the box when it comes to a bike build.

It's pretty easy to test hall sensors just have everything on and and plugged in then connect the negative voltage meter probe to the black negative wire on the hall plug and then test the 3 correct wires and if the hall effect sensors are good they should read voltage when you spin the wheel slowly and then not read in certain positions and usually the blue green and yellow wires are the signal out hall effect wires on the hall sensor plug, if all the hall effect sensors check out then you probably need to set the degree angle and amount of poles in the controller settings to match the specs of the motor.

Make sure to put a really stiff spring on kickstand so it doesn't come down during a jump... Stay safe

I would say it is probably the controlleror sensor. Seems like it is losing what position the motor is in . Don't know if that motor and controller is sensorless or not. But that might be your problem. Bldc motors need to know the position of the rotor at all times. Check your wiring.

t's the pole sync. Basically, the controller needs to be set to sync with the magnet position of the motor. That is universally true with any brushless system. The speed control is fine and the motor is fine. Just needs the correct settings. You need the exact properties for that motor

I absolutely love your episodes! Great to see a longer one now as well. All of that electronics is a bit different from gas powered stuff, but fun to see something “different “

I think it might be a good idea to put a kick stand switch linked to the brake switch so you can't move with the stand down Unlike a running engine you can't tell if it's on or not. All it takes is some nipple head to twist the throttle while it's on the stand.

A good rule of thumb for sizing circuit protection is your load x 1.25 Your 300 amp might not be big enough, 260 continuous isn't it's max, it's just what it can do sustained, it can put out higher when starting out, it's called inrush current. That can be limited in your programming though. Battery voltage doesn't go down to zero. It's a range, a 72V battery is actually full at around 75V and dead at 60 something volts depending on what cells are in it.

GRIN TECHNOLOGIES is king at these types of problems

Dude I'm gutted for you, I feel ur pain, I really wana see that bike fly, don't give up

Having the reverse switch where it is might not be the best idea... If you accidentally hit it while going forward it's not gonna end well... Stay safe

Is there a setting for the regenerative breaking maybe that could have something to do with the chattering

That wheel spinning sounds like a spaceship

what i like most about this whole build is that its actually full sized. all the E bikes are so small its like riding pitbikes

Is it just me or did anyone else find his constant reving it and the back tyre hitting the floor grip their shit....?

the battery is all wrong , check the low voltage cutoff on the controller settings . odds are its set to 60v or higher, as you draw from the battery voltage sag occurs , hitting the controller Lvc. You need a battery capable of 1000a discharge to run a 600a controller. This WILL SOLVE the cogging issue also.

Yep I agree with the battery is too small. I always go more volts than I need. As long as your electronics can handle it I would go 96v on this build.

The motor is cogging need to add some capacitors inline with the battery to the controller which will help during high voltage dump

Probably a voltage cut in the esc. In high rpms you pull alot of amperage so voltage may drop. Check your settings on what type of battery its programmed for

looks like the BMS is limiting the current output from the battery. You can get a battery designed for higher current or add a capacitor bank in parallel between the battery and the ESC

This is why I much prefer mid-drives to hub motors, mid-drives you only have your chain to worry about but hubs it’s endless things can go wrong, I hate having all that power at rear of bike as u get a slight issue metal starts peeling lol, I find mid-drives much more sturdy and hassle pain free, a good solid motor bike chain on a mid-drive u good to go.

That's right, you have to change the cables of the hall sensor.

Titanium plates and axle my dude. I can't imagine the torque that axle has to endure, if there is ~any~ slop it will confuse the controller because it'll think the wheel is moving faster or slower than it should, so it compensates.

Have you tried the regenerative breaking ? Maybe disabling that will fix the issue.

You are a manufacturing genius!

Food for thought. How about a car (ala Ariel Atom style) with 4 of those motors, one at each wheel. That would be a very interesting build. God bless and stay well.

Check the speed controllers motor timing. Too much leads to jerking and motor heating. If there is decree numbers, start with 10decree. Also charge the battery, it should indicate clearly for low voltage cutoff.

"This thing" counter: 539

IM Really Really Impressed by the fact that it needs so "few" Parts to Work even my 99' LC4 needs alot more chanenigans holy cow..... im really IMpressed.

Drill and tap the rear of the swing arm to clamp down on the axle to help with the axle twisting.

cant wait to run 5kw w the far dirver setup on my little razor mx650 build. Keep it up brother this thing is insane!!

using a breaker and switch is the best way to do it, I blew up a few blocks on my mini kelly controller which is why i got the far driver setup and a qs165.

Good luck. I don't know crap about these yet. So this is my first go around too

This is a real high power! I opened this video and was very frightened by the sound)

Your quality non vulgar content is supreme amigo!

Every time you plugged in the wires I was waiting for sparks to fly. Lol

Well, at least the grumpy old neighbor can't complain about an electric bike being too loud. Speaking of which, another electric project could be another buggy. But using an ME1616. It's a watercooler motor, 96 volts DC, 88ft/lbs of torque (without gear reduction), 6000 max rpm, up to 73hp (20kW to 55kW). It seems to scoot a crosskart pretty well.

Could just be a throttle tuning issue but testing with an almost flat battery is no good great project as always 👍

Heya so awesome for having a go at this level build ,lots of us been waiting for someone to take the lead especially with this motor the torque is just unbelievable ,cheers

I used to forward remote control helicopter a lot and have come across this issue in the past with brushless motors. Loose magnets was almost always the cause. Just figured I would throw that out there for you.

The back tire is wobbly just letting you know 👍

Pop a pinch bolt in the back of the dropout too chris, stop the alu ever spreading, do it on all my build,,, love the work

Put the front brake line on the other side of the fork so you don't rip it off if you have a get off, super badass keep up the good work!!!

Don't use those throw switches for range mode and forward, reverse. Those only take a brush of whatever to throw and you don't want that happening when you're not expecting it during a ride it could lead to a crash.

you built a machine! i built a 60v ebike . amazing how much they are the same, yours just weighs more

There is an imbalance in the rear wheel. Bring it to me, I'll center it for you.

Hardened steel for the torque bracket and stick a bolt through the fork of drop in ends to keep them from opening under twist torque

I'm curious if that hubmotor and controller have an option for regenerative braking. if it does maybe it's trying to activate it without it wired into the controller. maybe it's just take more research and development. maybe the manufacturer of the hubmotor and controller might have some answers for you. that hubmotor is sort of strange. it seems like it should have a torque arm that mounts to the swingarm. instead of having to rely on the axle to hold the hubmotor in place.

Братан, не сдавайся, Воронеж смотрит за тобой.

this is the best electric bike ive seen holy crap

I don't know jack about electric powertrains. But here's a comment for the algorithm. 👍

Check your pole pairs in the settings for that QS motor should be at 16 pole pairs. Plus check if your field weakening is on if it's on turn it off and test.

Interesting build, thanks for sorting out all the unknown issues for the while builders. I had Send-Cut-Send water jet torque plates out of stainless, it was worth the money not to burn up drills and mill cutters.

My favorite journeyman. I’m in WNC too

You have a battery close by.... use a fan blowing out, maybe two. Blowing out will keep the dust out.

Super cool much much cooler bro 👍🔋✅😎 now that it's all the pieces are put together on the dirt bike runs better sound so much good job keep up the good work 👍😎 keep tinkering with tools 👍😎

Seems like what hsppening is the plus from the controler is getting ahead or behind the magnets which is trying to turn the wheel backwards until the rpms slows enough to put it back in sync. Hence the the jerking or antilock brake effect. Im an electronic hobbiest so i have not played with controllers like this but i would look at phase angle settings or as others have said shielding the hall effect wiring.

Got that right , just like a RC car , if your battery is low your low voltage cutoff kicks in and kicks you out , ,enough said

That's what the thumping is...the axle is is rotating...make the axle adjustors thicker...use a steel collar on rear axle swing arm.

I don't know a whole lot about brushless sync settings, but there is absolutely no way those cables are moving 280amps.... You could have a power supply issue. That thing needs 120mm2 cable 😊✌🏽

It’s a Low voltage cut out and the kick back is the motor generating charge from the rotation of the wheel

I suggest you can use a water cooler for a gaming pc. You can cold down the electronics. And put the radiator outside.