250w hub motor scooter mod log

Hey cotemar, glad you're enjoying my build. Just curious, have you measured the top speed and range of your scooter, or are these specs posted on a website? They seem a bit embellished, that's why I'm asking.
onto your questions.
1)Yes I'm currently using the hub motor that came with the scooter. It's rated at 36v, but can take more voltage than 36v which is how I'm getting the high top speed. When you run a motor at a voltage higher than it's rated, that is called over-volting the motor.

2)Yes the two batteries are connected in series. When they are fully charged they are 25v, so pack voltage hot off the charger is 50v.

3) Yes the balancer (charger) is pretty fast. You need to have a powerful power supply running the balancer in order to charge your batteries at a high amperage. I have a 750w pc power supply at home that I run my balancer with, I typically charge at 3-5 amps (not too crazy). At work I have a 120w power adapter that only lets me charge at 1A which is super slow, luckily I'm there 8-12 hrs a day. The two large wires are where the main power comes from, the smaller wires are the balance leads, current is bled from these wires to keep the cells balanced while charging. If you search lipo balancers on the forum I'm sure you will find someone explaining it much better than I am.

4) Not sure what you mean by custom. He sells controllers that come in different sizes (number of MOSFETs). They are all programmable, so you can set parameters in the firmware like low voltage cut off and phase current to give a few examples. The size of the controller you need depends on the amount of current you want to push, Lyen would be able to answer any questions you have regarding his controllers. I have bought about 4-5 controllers from him and they have all performed very well, he provides excellent customer support and is very quick to respond to questions.

5) Yes it is entirely possible (and encouraged) for you to modify your scooter. I would recommend a lyen controller and 12s of lipo to start. But, it really depends on your goals and your budget. We are all here to help, so definitely start a thread and we can walk you through it and answer any questions you may have. Hope this helps.
 
shortcircuit911
I have measured the top speed at 19 mph on a flat road with this Booster model. I have only had these for a few days. Yesterday I went 6 miles at full throttle for the whole trip and up a really steep hill the speed was only 13 mph. It still had 90% battery when I was done with the trip. I agree that you will not be able to do a 22 mile trip at 19 mph, but will have to try it to see how far we get.
Our last models where the Master, which only did 16.4 mph, but they had the 8.5 Ah battery.
We regularly did 22+ miles trips if you kept it =< 15mph

Thanks for answering all my newbie questions.

I will have to buy some parts from Lyen to get started.
My goal would be to make a 25mph top speed with a 25 mile range.
A 25/25, BUT keep the weight under < 30 lbs
 
well good news and bad news. I noticed my pack wasn't charging all the way to 50v the past couple of days, the voltage has been getting lower and lower, and top speed, and torque don't seem the same anymore. I checked the cells with a cell log and both packs had a .3V deviation between cells :eek: . I really don't want to start a fire, so I think I'll retire those cells.I'm really not surprised, these packs are 5 years old and were abused on my 6500w e300 project however, I may keep them around for some light duty projects. The good news is that this is forcing me to get all these new parts installed on my scooter. I was checking measurements and 2 6 fet controllers won't fit under the deck with the 2 lipos. I tried a few different arrangements, one with the controllers mounted to the frame and the other with both lipos in the back side by side, and I didn't really like either. I've decided that I'm going to make an entirely new battery box/ center of the scooter. I have a bunch of 16ga sheet metal, so I'm going to experiment with that. 16ga is thinner that what the frame is made of now, so I'll have to add supports, or just get thicker stuff. I marked up a piece I had and plan on cutting it on the bandsaw and bending it on the brake. I will also try and get it welded or at least tacked to see how it looks. Hopefully I can come up with something I like. It looks like its back to the balance board for the morning commute, I'm hoping to get this thing complete by new years. The new tray will be much bigger and will have the extra room to go to a 16-18s pack if I want. And since it's $10 more I might just go with 2 9fets since I dont have to worry about space. I plan on getting the disc brake parts ordered soon as well as a bunch of other stuff I want to add/change. I'm going to have a huge pile of bad ass parts to put on this thing soon! Can't wait to get started on the battery box!
 

Attachments

  • image3 (7).jpg
    image3 (7).jpg
    47.6 KB · Views: 4,807
  • image1 (15).JPG
    image1 (15).JPG
    47.3 KB · Views: 4,807
  • image2 (11).JPG
    image2 (11).JPG
    59.3 KB · Views: 4,807
Well change of plans (again). I was going to make a new battery box and decided it wasn't the way to go. To do it the way I was thinking would require me to really compromise the the strength of the frame. To make it strong again would add too much metal (weight). A while ago Aidan made a suggestion to use angle iron to raise the deck height, I'm going to borrow some of this idea. Instead of angle iron I'll use strip steel, and instead of welding to the side of the battery box I'll weld to the top. Essentially what I'm going to do it weld strip steel to the top of the battery box (butt joint), this should give me an additional 1 1/2" of clearance for the lipos. Everything should fit under the deck now, and I will add as little weight as possible. I weighed the scooter the other day and it came in at 33 lbs. My goal has been to keep it under 40lb, which is going to he close with all the new parts coming in. I've been on ebay all day ordering stuff for the overhaul of the scooter. I was able to pick up the following:
(2) watt meters
(2) disc brake rotors
(2) disc brake calipers
5' 10 ga silicon wire
more andersons, throttle pin connectors, crimpers, and some extra 22ga wire

I think all I need to get is the controllers from lyen and I'm good to go.
 
Didn't make as much progress as i wanted to this weekend, the wife and kid got sick so garage time was limited. I did manage to get the scooter stripped and the steel strips cut to length. I was planning on TIG welding them, but that will take too long, and I'm going to grind the welds down so I can powedercoat the frame when I'm done. I'm planning on getting the steel strips MIG welded to the frame tomorrow after work. I also want to add another bead adding more support between the neck and frame, might as well since I have it apart. I'm planning on welding up the holes from the db25, and anderson connectors. I will cutout new ones in a better location. I want to wait until I have every single part to start making harnesses and connectors. I want every cable to be just long enough to cut down on wasted space under the deck. ALL wiring will be re-done, especially the high power stuff, I have top of the line silicone 10ga wire for that. The other wire I made my harnesses out of was too stiff and didn't have as many strands as the silicone wire does. My goal is to get the battery box done by next weekend, and to get the watt meters modified so that I can mount them on the handlebars, I'll keep you guys posted.
 

Attachments

  • image2 (13).JPG
    image2 (13).JPG
    57.6 KB · Views: 4,773
Well the motors came in today along with the controllers. I think I officially have all the parts that I need to make this thing happen. I was able to take the frame to the shop I do fab work for work and welded it. It came out ok, still needs some more grinding. The battery box is going to be crammed with electronics! I'm hoping I can make everything fit nicely, it's going to be close. The seller I got my motors from said they offered a fork, he did t say it was a rear fork. I'll see if the motor will fit the e300 forks, if not I'll have to make my own. I was thinking it would be done by New Years, but I think it's going to take longer. There is a lot of fab work left along with a lot of wiring, it's hard to find spare time. UFC 194 is this weekend, so I doubt I'll have time, but we'll see. I'm going to take my time with this project. I like to overbuild things so I can ride like an A-hole. I'll post pics and updates as they come up.
 

Attachments

  • image2 (14).JPG
    image2 (14).JPG
    62.3 KB · Views: 4,763
  • image1 (19).JPG
    image1 (19).JPG
    60.4 KB · Views: 4,763
This things seriously cool. Have you monitored temperature at all? Just wondering how close to glowing you're getting the hub internals with that sort of power boost...
 
Thanks Ohbse! I checked motor temp a while ago and it was only 90F on a 75F day so it really doesn't get too bad at all.

Got a few minutes to work on the scooter today, more specifically on one of the watt meters. My plan is to have them on the handlebars, so they need to be modified. If I were to run power wires up the the bars the inductance would be way too high and I would get voltage spikes that could cause damage to my electronics. Instead, I plan to de-solder the lcd screen from the shunt and make a harness between the two boards. This harness will be 22 ga wire or even ribbon cable. The only unknown is how long can this cable be without adding too much resistance that the screen no longer works due to voltage sag. Worst case scenario is that I can only get 6" extension and the lcd screen gets mounted out of the battery box. Mounting them to the handlebars would be ideal, but outside of the battery box works, I just need to be able to monitor power consumption easily. I need to put some more thought into the front forks. The e300 forks are a bit too tall so the wheel looks goofy in there. Another option is to use the rear fork I bought with the motors and weld a stem to it. I not sure how the rear fork would hold up to riding, it might be fine but it would be taking a load 90 degrees out of phase than it was designed for, hope I explained that ok. The last option is to just make my own fork. I still haven't decided what to do but I hope to have the front end done by next weekend. I plan to mount the rear wheel this weekend and maybe have the watt meter sorted out. I did a quick mock up with the rear fork on the front and it doesn't look bad, it also provides more ground clearance than the stock fork, I may go with this option.
 

Attachments

  • image4 (3).JPG
    image4 (3).JPG
    55.5 KB · Views: 4,722
  • image3 (8).JPG
    image3 (8).JPG
    33.5 KB · Views: 4,722
  • image1 (20).JPG
    image1 (20).JPG
    59.7 KB · Views: 4,722
Seems like a lot of effort! Have you considered using a cycle analyst with a single external shunt? Probably get more accurate results plus all the other killer features.. Unless you specifically want to know what each motor is pulling I guess.

Did you have a link for three motors you bought?
 
It is a bit of effort, but i like to hack things lol. I did think of the cycle analyst but wanted to see what both motors are pulling. Maybe after I get everything dialed in I'll go with a CA because they're badass.I was able to cut the fork stem off the stock forks and the tabs off the fork I bought, it still needs some more grinding. The stem didn't have much material left under the bottom bearing cup, so I may look for another to weld on there, I'll possibly try the e300 fork stem if its the same diameter. I will also try and solder some ribbon cable onto the lcd of the watt meter meter and try to connect the two boards with a 6" extension between the two, hopefully that works.


Motor: http://m.aliexpress.com/item/1736511255.html

I contacted the seller and asked for the fastest spinning 8" hub they had and he sent me an invoice through paypal. It was actually cheaper than the listing price in the link above, so I'd suggest contacting the seller if you plan on buying a motor, or are even curious about customized motors because they do that as well.
 

Attachments

  • image2 (16).JPG
    image2 (16).JPG
    50.6 KB · Views: 4,738
I was able to cut the fork stem off the stock forks and the tabs off the fork I bought, did some grinding and got the top of the fork flush on the disc sander. I drew up a quick part in CAD and cut it out on the waterjet, its basically a centering plate for the stem. I really didn't like the quality of the stock stem, and length would've been an issue when welding it to the new fork so I hacked the e300 up (there wasn't much left to hack). Luckily the dimensions of the bearings and stem were perfect! I'm so glad I didn't throw that thing away. I'm going to skip the gym tomorrow morning and go work on the forks before work. I should be able to cut the stem off the e300 fork and get it welded to the fork that I bought. Then I have to turn down some stock to make a stop for the bottom cup of the bearing race. Usually there is a machined feature on the stem (I have to cut above this feature on the e300 fork) so I need to make one. It shouldn't be too hard, just another thing on that's pushing a test ride back even further. If i can get the front end done this week that would be huge. I need to get some button head M6 bolts for the brake rotor because the mockup bolts I installed stick out too far and hit the frame. A few washers are also needed for the rotor side of the hub to space the rotor bolts out a bit from the frame. As always I'll keep you guys posted on progress.
 

Attachments

  • image1 (1).PNG
    image1 (1).PNG
    115.1 KB · Views: 4,698
Nice progress! What do you think the all-up weight is going to be for this beast?

Have you seen this thread about remote mounting the shunt on a watt-meter?

https://endless-sphere.com/forums/viewtopic.php?f=2&t=21976

Just another option for getting the display where you want it. And you won't have to come up with a separate housing.
 
Thanks Apache, I'm hoping to come in at 40 lbs, but I think it'll be a bit heavier, we'll see. Thanks for the link I may give that a shot soon, kinda scared because lots of people in that thread were getting false current readings, its worth a shot though. It was cool meeting you the other day, hope you enjoy the hub, can't wait to see your project.

Have had very little time to work on the scooter, been super busy with work. Got the fork welded and mocked up. The front tire is really close to the down tube of the frame, should've put more rake on the front end. May just add some spacers under the head tube to lift the front even more. There is way more ground clearance, but it's taller in the front than the back which I don't like, I'm open to suggestions, may just redo the fork, not sure yet. Pics as promised.
 

Attachments

  • image2 (18).JPG
    image2 (18).JPG
    63.8 KB · Views: 4,652
  • image1 (20).JPG
    image1 (20).JPG
    59.7 KB · Views: 4,652
  • image1 (23).JPG
    image1 (23).JPG
    55.7 KB · Views: 4,652
How about notching a slight "V" in the top of the down tube, fold it up and reweld?

Thanks for the hub motor. I'll start my own build thread once I find some time to to work on it.
 
Thanks for the suggestion Apache! Ended up staying away from cutting the frame, went a different route.

I was able to get some work done on the front end. I ended up cutting up the stock forks to reuse the sides. I cut a square around the drop outs and welded them on to the new forks. I put about a 25 degree angle on the piece before I welded it to get the center of the wheel off center to the steering tube. The mod worked (with some shims above the fork) and the tire has about 1/2" gap from the frame. I'm still not happy with the forks to be honest, they have the clearance I need, but they're ugly IMO. I'm going to keep them on for now so I can continue with the build, and will probably just make my own (possibly on the waterjet), because it is such a unique size.

Today I snuck into the garage for about an hour and got some work done. I made the y harness for the throttle (to control 2 controllers with one throttle). I also cut all the phase and battery wires in half and crimped anderson connectors on them. My goal is to get both motors spinning this weekend! I still need to make a series harness for both lipos and a parallel harness for the controllers. I plan on hooking up my multi to the controllers and checking no load wheel speed with my laser tachometer, then I can find the kv of the motors, hopefully they're the same.

There is still a lot of fab work to do, but hopefully I can get this thing moving under its own power soon, really can't wait to see what the top speed is. I also plan on hooking up the regen and playing with those settings to add more braking power/increase range. Hope to be back soon with lots of progress.
 

Attachments

  • image1 (25).JPG
    image1 (25).JPG
    70.4 KB · Views: 4,605
  • image2 (20).JPG
    image2 (20).JPG
    67.1 KB · Views: 4,605
  • image2 (19).JPG
    image2 (19).JPG
    69.8 KB · Views: 4,605
  • image3 (10).JPG
    image3 (10).JPG
    66.9 KB · Views: 4,605
Got the power harnesses made out of the new 10 ga silicon wire and got the electronics wired up. In the process of wiring everything I managed to plug my throttle into the controller with the polarity crossed and burned out the throttle. I also think I burned something else out in the controller because the + and - of the hall sensor outputs of the controller are reading 2.8V. The blue, yellow, and green wires are reading 3.5V, a few of the wires may have touched while I was trying to get the hall sensor/ phase wire combo correct. I'm pretty pissed about this because its a rookie mistake and it could've been avoided had I paid more attention. I sent a PM to Lyen letting him know what happened, hopefully he knows what wrong with the controller, because I have no clue. I hooked the other controller up and both motors run smooth. I was kind of pissed because I checked the no load rpm of the motor and it was only 1,148 (the seller said they would spin over 1,500 rpm @ 48v. Luckily there is only a .2 kv difference between the two motors. Hopefully i can get the other controller fixed by next weekend and can go for a test ride, it really sucks seeing this thing torn apart for so long.
 
I watched your video. It looks fast, but then the camera is a couple of inches off the ground so that makes it look really fast. Do you know what your top speed is with the setup you had when you made the video?

This is a cool build. I wish I had access to a tig welder and breaks and various machining tools like you do. If I did, I would build an all aluminum frame and precision machine a lot of the parts. Because of my equipment limitations, there's lots of stuff I can't do. Maybe since I have been a wood worker most of my life, I should make an all wood scooter. That would be cool! It wouldn't be impossible, but certain things would have to be rather bulky and over sized to handle the loads on them. I'm thinking of getting into carbon fiber and building an all carbon frame. My scooter currently weighs around 90 pounds. I think all carbon could get it down to 40 pounds. Drop outs, bearings and bolt locations would still have to be steel, but all carbon forks and tubes and boxes would work for everything else.

Watch out on your dual motor build. Not all controllers (even identical ones) apply power to the motors exactly the same. One motor may pull much harder than the other if timing isn't just right. In your controllers are their setting for acceleration ramp up or throttle levels? I have been using Kelley controllers and they have options in them that make acceleration very linear or have a more exponential curve and more. On linear, you can crank the throttle and the speed controller delivers max power to the motor from a dead stop. On the maximum curved slope, you can crank the throttle, but the speed controller will only deliver like 5% power and then slowly ramp up to full power. My controllers also have a percent throttle option in them. Effectively what it does is allows you to have the throttle partly engaged before the speed controller recognizes the throttle input. If your controllers start the motors at different times despite having the exact same throttle input, something like that may get them tracking more closely.

On the subject of watt meters. Look in my thread for the watt meter I am using. I'm using a remote 100A shunt that is very close to the motor controller (5" of wire), the monitoring wires are very low resistance cable and then I am using 2 pairs of conductors for the load side and ground side on the shunt. I have done a comparison test with dual meters (one at the speed controller and the one on my handlebars) and they are pretty darn close to the same. when I swapped the meters and tested again, the difference followed the meter, not the wire length. That tells me that the meters were not calibrated the same;. On my shunt which is in the battery box, I have a 3" long cable that terminates in a deans T connector. That's the monitoring connection. The same watt meter reads virtually identical on the end of the short lead as it does on my handlebars on nearly 3 feet of wire. Find yourself an old network patch cable, you probably have several laying around in a box. Cat5 cable is very low impedance wire. It has to be to get a network run that's 300 feet long. This is exactly what I used for my watt meter. The wires in the cable come in twisted together pairs. Use a set of twisted pairs for the load side and a twisted pair forthe ground side. That should work really well and then you can use a watt meter like I have. My Kelly has a function where you can set the maximum current draw. It has a built in watt meter and limits current load to what you set it to. My watt meter and the setting in the controller are usually pretty close to the same.
 
Yup GoPro was in the forks super low to the ground so it looks faster than it is. I got it to go 20-21 mph with the the rear hub on 12s.

I'm pretty fortunate to have access to so many cool tools, just wish I had more time to use them. That's cool you work with wood, I terrible with wood but managed to make my deck. A carbon scooter would be sweet! I'd like to make a scooter from scratch in the future, that should be a fun project.

Thanks for the heads up on the controllers. I measured the KV on both motors and they were nearly identical with the same controller, hopefully the other controller behaves the same way. There are two speed setting I can play with in the software so hopefully I can sync both motors nicely and have a badass scooter, I'd like to hit 25 (faster would be better but wheel size is the limiting factor). I still haven't heard from lyen, maybe he's on vacation or something, I might post something in the tech area, maybe its something I can fix.

I saw your watt meter and I really like it I think I will order one because the one I have it too much of a pain to deal with. I saw the link in your thread so I'll get one on order soon. Thanks for your input EG you have some really good ideas and skills so the advice is much appreciated.
 
Well my second controller is still not working, but Amberwolf has been pointing me in the right direction, I just jest need to do few more checks with my meter to pinpoint the issue.

My goal for the weekend was to get the scooter to the point where I could go for a test ride. I reached my goal today and was able to ride a dual motor scooter in 2015, I can die a happy man.

PROGRESS: I pulled my 12fet lyen from the shelf and decided to hook it up in place of the 2nd 9 fet just to be able to go for a test drive. The front wheel is still spinnging about 5-8 rpms slower than the rear wheel, not too bad, it could be worse I guess. I received a new throttle from electricscooterparts.com and wired it up (correctly this time) to both controllers. I have to say it's pretty cool seeing the front and rear wheel spinning at the same time!

TEST RIDE: I took it easy at first, mainly because I had no brakes, and also because there was no deck, and controller were sticking out of the battery box. At low speeds the motors are a bit noisier than I thought they would be, they quiet down once you get up to speed. I went around the block a few times just to cycle the battery a bit and get a feel for the performance of the scooter.

PERFORMANCE: I have to say I'm pretty pleased with the acceleration. It definitely pulls harder then the single rear hub I had previously. This thing feels like a rocket (more so because standing space was awkward and limited. The top speed according to a speedometer app on my phone is 23.6 mph. I was hoping to get at least 25mph out of both motors, but fell a bit short. I could always bump the voltage I guess. I unplugged the front wheel just to see what performance would be like and it was definitely not as torquey as my other hub motor (same controller and voltage were used), the top speed of just the rear motor was about 21 mph, so I'm getting much more torque, and another 2 mphs or so running the both motors. Like I said its a bit noisy at low speeds, but if you listen carefully you can hear them both winding up, and it sounds pretty cool. I hooked my watt meter up and went back out to see what the performance was like going up the hill in front of my house. Both motors together pulled 3,287 watts, and 75 amps.

ISSUES: I noticed the lipos were a bit warm when I got back from my test ride, they are 10c so I need to be nice to them and not get carried away with the current. If the ratings on the battery are true (I doubt they are) I'm not stressing it too bad (12ah X 10c =120 amps continuous) but warm lipos are not something you want. I'm having quite a bit of trouble getting the heardset to stay tight. The nut doesn't seem to be backing out, but the forks have play in them after pushing and pulling of the handlebars a few times, this is super annoying and needs to be addressed immediately. Battery box space is going to be super tight on this thing. I'm hoping I can make everything fit, switching power connectors may help with saving some space because the andersons are making it hard to route the power leads to the controllers, I can explain more later.

TO DO: There is still a lot to do to this thing, hopefully I can knock it all out quickly, spare time is hard to come by these days. Here's a short list of what needs to be done before I can start commuting with this thing again. Get headset to stop coming loose, cut motor wires shorter (they're about 2ft too long), get new watt meter, fit everything under the deck, cut out a hole for the db balance connector and andersons (charge plugs), notch holes in frame for motor wires (for better routing of the wires), get 2nd controller working,fab disc brake caliper mounts, make new deck (optional). These seem to be the obvious things that I need to fix, I'm sure there's a few things I'm missing.

Hopefully in a month this thing will be done. I feel like I reached a huge milestone today, its just the details that remain. I made a quick video (sorry for the quality I was holding the phone while riding). https://www.youtube.com/watch?v=Ztwd6qjhzN4
 

Attachments

  • image1 (27).JPG
    image1 (27).JPG
    52.8 KB · Views: 4,426
first of all sorry for my bad english, i'm french. :D
second of all, this is a really cool project and a source for my future Mod so thank for posting your Mod.
i have a question about how do you wire the lipo and the Controller in order to be able to recharge without disconnecting, I have been looking for some idea in order to simplify the recharge process which is now, not practical at all.
if you could help me on that by telling me how did you done, it would be great :mrgreen:
 
Val0:
Charging and having your speed controller hooked up at the same time is not a problem. Most speed controllers have a disable/enable option on them that you get to by the key switch. It doesn't disconnect the speed controller from power, just puts the controller in a low power mode where it wont run the motor. If your speed controller doesn't pull much current when disabled, you can leave it hooked up for months and it will just draw on the batteries a little. My Kelly controller, when disabled pulls 20mA. It has to provide 5v to the key switch so you can enable it so that's where the 20mA is going. Decent mosfets have infinite resistance when turned off so the current draw through them should be negligible with the controller off. You should be running a watt meter inline with your speed controller and batteries anyway so you will easily be able to see how much your controller is pulling on or off.

One of these little meters will do the trick and they are small and really inexpensive. You will need to get a better shunt since the one that comes with the meter is only for 50 amps.
http://www.ebay.com/itm/131630345531?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

This is the shunt I am currently using, but I'll need to get a bigger one. 100 amps is enough for right now, but I intend on going with a much larger motor later that will pull 160+ amps. My speed controller will handle 160 amps continuous and the rest of the electrical will do 200 amps. Once I'm running on the Zippy 35C 8000mah packs I have on order I'll probably want a bigger shunt. My system is good for 200 amps except for the fuses and the shunt. Anyway, this shunt will do it for most folks going with a small scooter EV. 100 amps is a lot! I've been running this meter for a couple of months now and I just leave it on. I have nothing turning it off and it draws a few milliamps. I can't even tell it's on all the time.
http://www.ebay.com/itm/New-100A-75mV-DC-Current-Shunt-Resistor-Panel-For-Digital-Amp-Meter-Analog-Meter-/351103422226?hash=item51bf650f12:g:94MAAOSwq5lTqmsP


Hey 911...
I think your motors are fighting each other to some extent. You wont double your top speed with 2 motors instead of one, but torque should be significantly better. Whatever your top speed with a single motor is, well that's about all the faster you will get with 2 motors. 2 motors will just give you more acceleration until you reach the top RPM's for the motors. Hub motors are what they are, you can't gear them so the higher torque is translated into more speed. They spin only as fast as they can spin. Anyway, get your motors in sync so they track RPM wise as closely as possible. Considering how you are using 2 different speed controllers, that's probably going to be difficult since they most likely have different mosfets, programming and have different power curves as a result. Getting the motors in sync will make the whole system more efficient too and will probably give you a higher top speed and more torque. One of the things you can do keep the controllers in sync permanently is take them apart. They have an internal clock circuit for timing everything. Disconnect the clock circuit on one controller and use the clock circuit from the other controller to run both. Look at 2 identical digital watches that are set exactly to the same time. Give them a little time and they will get out of sync. Speed controllers are like the watches. The only way to make them switch motor fields at the exact same time is to use the same clock signal for both controllers. Do the speed controllers and motors have hall sensor capability? If they do, you should definitely use it. A lot of motors don't have halls built in, but they are pretty easy to add. There are a dozen threads on here that will tell you how to add them to hub motors.

Here's the halls I am using. They are commonly supported by just about any controller out there and work well. You can add halls to just about any brushless motor there is.
http://www.ebay.com/itm/161184227133?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Halls get you several things over a sensor-less motor.
1. Motor position is not determined by the pulses coming from the field winding's. The speed controller always knows the motor position so it is able to get it spinning in the correct direction immediately with much less cogging. The controller always knows the position of the armature even when the motor is not spinning and as a result is able to power the field windings correctly every time. You may not notice it, but in a "hallless" motor, the controller may bump the motor backwards slightly before getting the rotation correct. This is the controller getting an initial pulse to determine proper direction. The controller has a 50-50 chance of getting it right so from a dead stop so only half the time it will it bump the motor backwards and then spin it forwards. If you always kick off from a stop, then you are giving the controller those initial pulses it needs to determine direction.

2. Halls make the motor more efficient than a "hallless motor". The speed controller since it accurately knows the armatures position will always fire the field windings at the correct time. It's kind of like top dead center on your cars engine. If you fire the spark plug while the cylinder is still on the compression side of the stroke, then the engine has to overcome the downward force of the piston to maintain rotation. This is called pre-ignition and it kills engine performance. If you fire the spark plug after top dead center, then compression is being lost in the cylinder and as a result so is efficiency and power. At top dead center is the ideal time to fire the spark plug. Compression is highest and all explosive energy created in the cylinder is used to drive the piston into the down stroke. Brushless motors work similarly. You want power applied to the correct field windings at "top dead center" for that winding.

3. You mentioned that your motors are noisy at low RPM's and then things smoothed out. That's probably cogging or the motors fighting each other. Halls in the motors and controllers that are locked in sync will probably overcome a lot of that.

It sounds like you have made some good progress on this "upgrade".

By the way, those 10C batteries are not very good. A lot of people have bought them for quad and octocopters and they will run the machine, but they tend to suffer from sagging issues (loss of or reduced battery power). That 10C rating is more like 3 or 4C and the batteries are not very good quality either so their life spans tend to be short before a cell in the pack goes south. It's not an uncommon thing that people pull the packs apart. and then rebuild them out of the good cells. It may be that your battery packs can't deliver the current you need to run at full speed so you won't really know how fast you can go using them.

I was thinking about your balance charging port using a DB9 connector. The pins don't need to handle tons of current to balance the cells and if you don't care about charging your cells in 30 minutes or less, then you can always charge at a lower current and integrate everything into a single D style connector. Use a DB15 connector from a VGA port. You now have enough pins to have balance for both batteries a single connector. For your dual 6S solution, you need 2 6S balance charge ports. That's 7 pins per balance port and a DB9 only has 9 pins. The DB15 has 15 pins so for the same amount of real estate, you get all of your balancing into a single connector. Obviously charging power will still need to be a better connector.
 
Thanks apache! That was definitely a morale booster taking it for a spin, it's all improvements now.

Electricgod, thanks a lot for the links I ordered the same watt meter as you along with the higher current shunt, should work for my setup.

Val, glad my posts are helping you, that's what it's all about. Your english is fine I understand what you're saying. The lipo system can be simplified. The first step for me was to get a 12s balancer (I think I paid like $120 or so for it). The next thing I did was to use a DB25 connector and soldered the balance leads to the connector (ground to pin 1, then went in order on the balance wires. -,cell1,2,3,4,5,6,-1,2,3,4,5,6) so I'm only using 14 pins of the 25 pin connector, hopefully that makes sense. The last part is to make a Y harness for the battery output. This harness lets you send power to the controller, and the other leg of the harness lets you have another plug available for charging. I use anderson connectors so there is a retainer you can buy that lets you bolt the plug down, I bolted mine to the battery box next to the balance port for easy charging. It sounds like a lot, but it can be pretty easy to do, just take your time. I took a few pics for you, hopefully they explain what I did.

I got some spare time today and got a few things done today. I shortened the motor wires quite a bit (3ft in the front, 2ft in the rear!) that should give me some more space in the battery compartment. I also drilled another hole in the battery box for the wires of the front motor to enter the battery box in a better location. I pulled the front end apart again and made a few tweaks and filed a small tack weld I made that may have been causing issues with the front end. Hopefully I hear from lyen soon so I can get both controllers mounted under the deck, I really want to get this thing done! I have also started fabrication on the rear disc brake caliper mount, I should be able to knock that out by next weekend.
 

Attachments

  • image2 (4).JPG
    image2 (4).JPG
    37.7 KB · Views: 4,400
  • image2 (23).JPG
    image2 (23).JPG
    61.1 KB · Views: 4,400
All this time I thought you were running your packs in parallel. More voltage is better than more current.

I found a sort of wireless watt meter on ebay. NO cabling required to the display except power. LOL! It would need some minor modifications to get it to work at higher amperage. The shunt is for 25 amps. You will like that watt meter. It has a couple of zeroing options in it. You can set fully charged and fully discharged and a few other options.
http://www.ebay.com/itm/221753693933?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

R/C motor connectors are compact and handle lots of amperage. I use 8mm bullet connectors for the motor and all power connections. I found several sizes of the bullets on ebay (both length and diameter). The shorter ones I use on my motor fields. The longer ones I use for power. Castle creations says the short ones are good for 300 amps. I'm unsure if I will ever put 300A through one of them and I am skeptical they will handle it. I would trust the long ones for 200 amps continuous. Also, they are gold plated so no worries about corrosion. You solder your wires into the end with the hole in the side and then put heat shrink over the whole thing. They work really well, don't come apart easily and can handle whatever you can throw at them.

8mm%20Bullet%20connectoirs_zpsz31qkkqr.jpg


Here's something else that may interest you. AGU fuses come in some pretty high amperage ratings. I'm currently running one of these 4-way fuse blocks and 4 30 amp fuses. Since my current demands are going up, I just bought 60 amp fuses. Each of my 4 battery packs are on an independent fuse. You can get AGU fuse holders in single fuse types too.

http://www.ebay.com/itm/4-Quad-4X-AGU-In-Line-Fuse-Holder-Distribution-Block-Stereo-Audio-Car-30A-100A-/251962512423?hash=item3aaa22d427:g:6F0AAOSw~OdVV6hI

This project is coming along great. I can't wait til it's done. I'm sure you are learning things as you go...like the rest of us!
 
EG, thanks for the replies man its really good to get feedback from other members. I completely missed the second half of your other post. Its very likely that the motors are fighting each other, I haven't come up with a clever way to check individual wheel speed. I tried twisting the throttle 1/4 way and checking the wheel speed with the laser tach, but I couldn't hold the throttle steady to check both wheels, perhaps I could play with the software. I knew that two motors wouldn't double my speed, the goal was to use 2 so they could spin as close to their no load speed as possible, and have killer acceleration. Based on the test I did the other day my theory was true, one motor gave me 21 mph and both motors gave me almost 24 mph, what's left now is firmware tuning to get the motors closer in sync.Both the 9 fet and 12 fet have 4110 MOSFETs so the switching properties should be similar, some of the other settings may have some deviation. You bring up an interesting idea with the internal clock, unfortunately I'm not too familiar with the clocks on these controllers, so I'll ask lyen when he responds. The motors have hall sensors, sensored commutation is definitely the way to go. I'll look into the noise a bit more, I want to say that when I ran the rear motor it was a bit noisy, I'll re-check that.

I knew when I bought the batteries that they weren't going to push crazy current, it was the capacity that sparked my interest. I want to see how they perform, and if I'm not happy I'll get some 20-30c cells. I predicted this setup would pull 3,000 which is half of the max power these batteries are rated for.We'll see how they hold up.Sorry for the confusion with the DB connectors, I originally thought I could run a DB9 but later realized I needed more pins. I went with the 25 just in case I want to run 18s later. I only had a pic of the DB9 so I posted it for Val so get a better idea of what I was talking about.

Bullet connectors are pretty sweet. I used to run them on my e300 I put an outrunner on. The only thing I didn't like was soldering the connectors on. If these andersons keep giving me trouble, I may incorporate a few bullet connectors in the battery box and keep the andersons on the outside for charging. That wireless meter you posted was pretty sweet, I wonder if they will work with the motor noise. I scrolled to the bottom of the link and found higher current wireless models so that would be interesting to see on a scooter. A fuse would be a good idea, especially a reset-able one. I was thinking of using a 3 speed switch when the project is done and limit everything on the fly, that's a ways away though.

Thanks again for the replies, you bring up lots of interesting points and links to cool parts! Keep em' coming!
 
Back
Top