Could my motor break from testing without speed controller.

[Liam.great98]

Hello
I'm 15 years old and building my first electric bike. I ordered the 24v 250watt MY1018 motor on eBay and it arrived really fast so i was all excited. My throttle and speed controller were ordered online too, but they haven't arrived yet. I already have my batteries, they are sealed lead acid 12v, 12Ah and I'm putting them in series for 24v. I was really excited when the motor arrived yesterday, so i wired up my batteries in series and connected the motor by touching the wires from it to the spade terminals on the batteries. Now, i am positive i did this right. The batteries were properly connected in series and i measured about 25v. But when I touched the wires, there was a bit of a spark. I pulled the wire off immediately. The motor and all the wires were NOT hot or anything, the only thing was the spark. The motor was clamped down because i was expecting it to lurch forward. This didn't happen. I was filming at the time, and upon analysis the bicycle sprocket that comes attached to the motor did indeed turn about 5 degrees. After this, I measured with a continuity meter from one wire on the motor to the other, and the circuit was closed, which is good. I would like to know if I did something wrong. Why was there a spark, why didn't the motor lurch forward? Does it NEED TO HAVE the throttle and seed controller? It's a brushed motor, so it should work when connected straight to the batteries, right? I'm hoping someone can reassure me that i didn't just kill my brand new motor. Thanks.

 

[Thud]

You will get a spark anytime you touch live wires to something that will instantly draw current (like your motor)
I doubt you have done any damage other than a spark erosion at your contact point.
Id try it again but only on 12v to watch the motor spin. (Smaller spark for the same jollies quotient)

Have fun.
T

 

[Liam.great98]

Thank you for your reply. Are you sure the motor would be able to spin on only 12v? It is designed for 24v, and it is a geared motor. Would it be able to rotate the gears on such low voltage?
You seem to know what you're talking about. Thanks, I'm clearly new to this!

 

[e-beach]

Hello
I'm 15 years old and building my first electric bike. ......... I would like to know if I did something wrong. Why was there a spark, why didn't the motor lurch forward? Does it NEED TO HAVE the throttle and seed controller? It's a brushed motor, so it should work when connected straight to the batteries, right? I'm hoping someone can reassure me that i didn't just kill my brand new motor. Thanks.

Hey Liam.great98!


I am not an expert on the MY1018 motor, but it is a brushed motor so you should be fine if all you did was momentarily touch the wires to the battery. The spark you saw was the closing of the circuit. BUT, you did do something wrong in not waiting. You need to get all information on what could happen to your new motor setup before you make that spark, or risk loosing all your hard earned money and have to buy a new motor. Just wait for the other parts before proceeding.

Now, that is not to say that all of us on this board have never made mistakes, we all have, but we would rather you ask questions then waist your money by prematurely blowing up your motor before you can put it on your bike.

Also, can you post the video on youtube and attach it via the youtube button cuz we would love to see the video?

Edit: Thud is correct as well.

Welcome to ES!

 

[gogo]

Ya, he knows of which he speaks. Have fun. And post video.

 

[Liam.great98]

Alright, I will post the video tomorrow morning. Thanks again.

 

[Liam.great98]

Hey
Here's the video attachment. Good thing I was filming at the time. I understand that I'll get a spark whenever I connect something that will instantly draw current, but this spark seems kind of excessive. Like a lamp, or even something that draws more current like a vacuum cleaner, doesnt make a spark that big if you turn on the switch and then plug it in. A massive spark doen't shoot out from the outlet.

 

[Liam.great98]

Here is the youtube link. It's not my real account, it's just a bogus one that I use for videos that only need to temporarily online like this.
http://www.youtube.com/watch?v=zre3d1VGGws&feature=youtu.be
Good thing I was filming at the time. I understand that I'll get a spark whenever I connect something that will instantly draw current, but this spark seems kind of excessive. Like a lamp, or even something that draws more current like a vacuum cleaner, doesnt make a spark that big if you turn on the switch and then plug it in. A massive spark doesn't shoot out from the outlet.

 

[e-beach]

Nice blue spark! :lol:

Maybe there was something flammable on the wire, like a bit of oil or solvent or something. Or maybe a bit of the wire itself vaporized.
I once vaporized the tips off the probes of one of my volt meters on a 36v battery.
I accidentally let them cross while measuring the voltage. That was a big spark....and smoke.

BTW, post where you are from in case there is a local expert in your area you want to talk to. Also, if you feel like editing your previous post, hover your mouse pointer over the youtube button to see what info you need to imbed the video in your post. You have a bit more info inline then you want at the moment. I think you only want this: zre3d1VGGws&feature=youtu.

Did the motor move with a 12v battery?

 

[justlooking]

seen your video, its normal to get a spark with electronics, and even bigger sparks with higher amps draw,
if you connect the wires and hold them there, you will find that the motor will spin up ok ,
its the same as leaving the light on a car turned on a connecting the battery, you will get a spark.if you have a electronic thing and turn the switch on, when you plug it in there will be a spark , but you wont see it because it will be in the plug socket,

 

[Liam.great98]

I changed my location, now it says I'm from Burlington ON. I haven't tested the motor on 12v because I'm worried it isn't a good idea. The controller has "under-voltage protection" so I assume that's because the motor isn't supposed to have less than 24 volts. Are you sure it will work on only half the voltage they say it needs?

 

[justlooking]

The controller has "under-voltage protection" so that you dont use to much voltage from the batteries and Finnish them off, if you use to much it will end the life of the batteries

 

[Ykick]

Your DC brushed motor will spin fine 0-24V. The controller acts somewhat like a light dimmer to regulate voltage/amps in order to drive the motor at various speeds.

As JL mentioned low or under voltage protection is more about protecting the battery than the motor.

 

[Thud]

Your motor will function perfectly fine on 12volts. It will just run at 1/2 speed. As long as there is no apreciable load on the motor it will free spin for years on 12 volts.

Under voltage protection is to protect the power transistors inside the controller(fet's or prolly more correctly: Mosfet's)
If the battery voltage falls too low to power the logic section or the low voltage/ gate drive section (the magic ellectric stuff that turns the transistors on & off really fast) it will fail & the controller will fry the fet's.....& on a brushed controller, that is typicly in "runaway" mode.

A very bad condition.....it is recomended to have a battery inturupt contactor that is independantly switched & accesable to an operator of any vehicle you may pilot.

But congrats on displaying the fortitude & waiting.......i am a big kid with my toys & hasta plays! :lol:

 

[Liam.great98]

Thanks Ykick, but since it is a gear reduction motor doesn't that count as a load? Or is it lubricated enough to still work?
I'm currently figuring out how to mount the motor and chain and stuff. I'm keeping myself busy with that stuff until the speed controller stuff arrives.

 

[Ykick]

Not sure about your gear reduction but that's low concern IMHO. The gear started to turn when you saw spark so it appears to be worth holding the wires on a for a second or two longer. The Spark is merely the many coiled wires inside the motor charging up, so to speak. After the initial inrush of electrical potential it should turn. The lower the voltage the less spark. It would likely turn on 3-6V just fine.

 

[gogo]

I understand that I'll get a spark whenever I connect something that will instantly draw current, but this spark seems kind of excessive. Like a lamp, or even something that draws more current like a vacuum cleaner, doesnt make a spark that big if you turn on the switch and then plug it in. A massive spark doesn't shoot out from the outlet.

I like your reasoning process and reconciling of information. The difference you observe is partly due to the nature of direct current as compared to alternating current. The 'spark' as you plug into an AC outlet alternates between, and goes to zero through the two conductors 60 times a second. With DC its a continuous sustained spark on a single conductor.

A PWM DC motor controller limits the flow of electrons using a high frequency chopping up of the supply to the motor very similar to AC, except the polarity doesn't alternate. A battery connecting to a load, in comparison to AC or a PWM DC controlled flow, doesn't have much to limit the spark.

 

[Liam.great98]

Update! Today I got bored and tried running it on 12 volts. Again, there was a spark, but this time I held the wires on and it ran! It ran very nicely too. This bike is going to be amazing

Here is the original footage. You can see how the first time there was a spark I pulled it away, and the second time when I held the wires on there wasn’t even a spark. I’m not sure why. But this is good, because it is the first time I’ve seen this motor spin. I’m a little relieved, as it was >$100 after shipping.
http://www.youtube.com/watch?v=U1IJi46PhoM

 

[Thud]

 

[Liam.great98]

I've mounted the motor on an aluminum bracket, and I have to decided now if I want to mount it in the middle of the frame, or on the bottom, in front of the pedals. I've attached a picture. I could only use 2 of the three screws because of the position of the gearbox.

 

[Liam.great98]

For anyone who's interested, I'm documenting the build on my blog. You can find that by going here:
http://nerdbag.blogspot.ca/

 

[e-beach]

I've mounted the motor on an aluminum bracket, and I have to decided now if I want to mount it in the middle of the frame, or on the bottom, in front of the pedals. .......

If you put it under the frame you will leave more room for a battery pack. Having it under the frame and your battery pack in the triangle of the frame will make for a good low center of gravity and optimal handling. BUT it will leave the motor open to getting knocked if you unexpectedly can't control what you are going over....like an unexpected pot hole.

Putting it in the triangle will protect the motor and leave a good center of gravity, but will move your battery pack somewhere else causing some, instability in the handling compared to the under the triangle mount style.

Battery weight is a handling factor.

If you decided to put the motor in the triangle, then mount you battery pack as as low as possible to offset the possible instability caused by the battery weight. Panniers hanging from the back rack are an option.

 

[Liam.great98]

I ended up getting a custom steel bracket. I wasn't happy that it was being held on with only two screws with the aluminum bracket and I also wanted to mount it differently on the bike. I'm putting the motor in the triangle and the batteries on a homemade pannier rack thing on the back of the bike.
You can see how I'm mounting it here:
http://nerdbag.blogspot.ca/2013/09/electric-bike-update-steel-motor-mount.html
The chain isn't going to be nearly that long, the motor will be way lower and the bracket will be parallel to the top bar of the bike. I just didn't adjust the chain length yet.

 

[e-beach]

I ended up getting a custom steel bracket. I wasn't happy that it was being held on with only two screws with the aluminum bracket and I also wanted to mount it differently on the bike. I'm putting the motor in the triangle and the batteries on a homemade pannier rack thing on the back of the bike. You can see how I'm mounting it here:
http://nerdbag.blogspot.ca/2013/09/electric-bike-update-steel-motor-mount.html
The chain isn't going to be nearly that long, the motor will be way lower and the bracket will be parallel to the top bar of the bike. I just didn't adjust the chain length yet.

If the batteries are going in back just keep them as low as possible and if you can do it put 1/2 on each side of the rear wheel for balance.
You are right about lowering the motor. Realistically you only need a gap of about 3 chain widths between the motor gear and the chain-ring gear. That way even if the chain comes off and try's to doubble-up it won't get jammed in between the two gears. The biggest concern is to make sure you have enough teeth on the motor gear engaged to give you proper performance. If the chain is too long you should consider a chain tensioner. An old rear derailleur could work.