Chopper bike with 93% eff motor

[Bluefang]

Needs to be removable for me atleast so the neoprene fabric was perfect as it is waterproof in full sheets and stretchable Just need to get it cut and shut to make it work a lot better for my purpose and decide on a color

 

[Bluefang]

Yay, pretty much all the final parts i needed to finish off the bike arrived today or could be modified today.

Managed to get the wetsuit maker to modify my cover the way i wanted it, now held on with 2 zippers at the front and a large bit of velcro for the back around the controller etc. After i orgainized for that to be done i recieved some normal bike chain and single speed adapter for the hub, also got a 19" motorbike rim which i laced on to the DH hub and got a 100-90-19 sized tire put on it, cleaned up the front hub already on the bike and laced a black DH rim 35mm wide onto the front for a Hookworm to run on. Only finished everything just as i was going out tonight even after doing handyman work for some friends so i only have some pics of it currently and have not been out to test ride it yet.




View attachment 1

 

[Bluefang]

Well had a interesting trip tonight on the bike, finally got it all worked out and working properly, hooked up the bike chain and decided to ride to tennis even tho the weather looked bad. Got there ok, showed off the bike, played the tennis and then it started to rain.....heavy. Was a great test of my wetsuit cover over the batteries which managed to keep everything perfectly dry, only thing to remember is when taking off the wet cover, wipe it off first as some drops fell on the battery pack. I desperately need to build some fenders for the bike.....way too much water getting picked up from the road.

Pulled a few high speed runs with the bike, i have not setup CA properly yet so i cant say how much power its drawing or speed but speed wise i was passing cars on a short run along a 80km/h road, its wicked fast to top speed . I have the bike charging and working on setting up my micro video camera so next time its light outside and i can ride the bike i ll take some video of it. The chain wore in abit and has stretched slightly so i ll tighten that up again as it was jumping again when i was showboating on hard take offs.

 

[hydro-one]

Love it! Cant wait to hear more details!!

 

[Ariane]

Love it! Cant wait to hear more details!!

+1 well done

Good day!
Black Arrow

 

[gensem]

Now make it run fastl... and time it!

 

[Bluefang]

Thanks for the positive comments, it receives a ton of positive responses from some very random people so far and i have only been able to be out riding it a few times. Managed to catch my neighbor to get him to video a quick run of the bike but he kinda had no idea how to use a Video camera etc so he only captured 1 run out of 4. Its not as fast as it could be yet as i am still waiting on my V3 CA to arrive and i have not modified the controller at all yet. The motor never makes it past slightly above ambient, as in i can barely feel a temp difference. Atm it seems to also be hitting the current limit on the controller so i have to roll on the throttle at low speed to not have it cut out completely. Atm my micro video camera is dead and i have one on order to get some ride video.

Mudguards are next on the list.....then V3 and modding the controller....then smallest rear sprocket i can get, a chain tensioner to get more sprocket wrap and i ll take it to a drag strip for some fun. Atm even with the length of the bike and the weight all lowish and to the front, the mini-monster can make the front wheel feel light just before the point that the controller trips...great now, soon to be AWESOME.

[youtube]KhjQwLOR2iA[/youtube]

Help John, how do i mod the controller so a) it doesnt trip b)i have 3x the power?

 

[Bluefang]

Still have not got a proper video camera but i taped my phone to the bike for the trip home from work at midnight last night and this is some small cut outs from it. Only rolling on the throttle as the controller is cutting out atm on high amps and something has moved again allowing the chain to slacken abit.

[youtube]4faYhL0rQBI[/youtube]

 

[John in CR]

I've gotta get you a pic of what I did for a sprung idler using a derailleur and part of a skateboard wheel. It pushes the chain more open and aligns it with the rear sprocket along with taming the dancing chain for a smooth feed onto the sprocket teeth. It took my chain drive from unusable to near silent and no problems since, even when torque made my wheel shift a bit in the drops.

Right at the end of the last video, leaving the stoplight finally gave me a sense that she's pulling pretty good. Yeah, a shunt mod to push the cutout limit higher, and then controlling the current with the CA should cure the cutouts and give you the ability to dial it in. A little less than in my pic here http://endless-sphere.com/forums/viewtopic.php?f=2&t=31643&p=458366&, should do the trick as long as you're sure the CA3 already has full control. Dial it down quite low first to prove full control. Then mod the shunt. Then take the CA higher incrementally.

John

Here's my skateboard wheel + derailleur idler hack. I think the spring is strong enough to handle your 218 chain.

 

[Bluefang]

Found the cause of my chain losing tension this time was due to the motor mount bending slightly....its bending 6mm steel plate on a very short leverage lol. Managed to solve that by running a adjustable bracing bar out of M10 threaded rod inside a 1mm thick tube from where the motor axle is in the mount to the rear axle. Will still shrink the rear sprocket and install a tensioner.

Modded the shunt, covered about <50% of it in copper and now it seems that ~200ohm is about the right figure for it on the controller. I dont really have a great way to test that value so i am going to split the wires out from the V3 and run a external calibrated shunt so i know the correct power draw of the system.

The Cycle analyst V3 is a awesome piece of kit, now that i have figured out what was causing some problems on my first ride(the controller was cutting out if i came to a complete stop after riding for a minute or more, turned out to be the Throttle out was set slightly high causing the controller to fault for some reason...).
Its set to be slower then the bike has been before the mods but with the shunt mod and V3 adjustments its much easier to ride. The V3 is running in current mode that took afew runs to get dialed in right but now limits the bike smoothly to the point you think its just a low powered bike rather then a mini-monster.

 

[John in CR]

Send battery current through your DMM, and after accounting for the current draw at 0 throttle, dial in the shunt value in the CA until actual no load current equals CA reported current. Using Ohms Law gets you there quickly.

Note- You have to switch the DMM's plug to be able to measure that couple of amps, so don't forget to switch it back when done or you'll get an unpleasant surprise next time you measure voltage. Take if from someone who's vaporized probes that way. Turn the throttle slowly too, so current doesn't spike beyond the DMM's capacity.

I can't wait to get some CA3's on some bikes myself. Starts that depend how I twist the throttle has been my key missing ingredient.

John

 

[Bluefang]

Hitting a few problems with the Controller/V3, V3 seems to work perfect but it also seems that the controllers don't really take the Value of the output voltage and match it to the motor power perfectly. I still have low speed surges where once i have turned the throttle enough to get the bike moving it then does nothing for a small twist of the throttle and then it hits with a chunky change. While its much much better then before where it was almost throwing me off that back of the bike its not very smooth for very low speed riding.

I may not have CA dialed in right but i am using it in pass thru mode atm with a limited max throttle output. Also running 3 resistors on a magura throttle to get a parabolic curve on the throttle so it should have a very soft, smooth start and once you hit about 50% it starts really adding the power. It still has a choppy start on the bike, not enough to visually see but more of a feeling. Once past like 30% power its much smoother and really goes hard.

Already have the shunt installed and working so its all good Rode the bike home thru very heavy rain and gusts of wind, made it with ease even running at 70km/h to keep up with cars so i didnt get stuck in troublesome spots. The wetsuit fabric cover is doing a great job

 

[John in CR]

Let us know when you hit settings that work well. You might want to use the 3 speed switch for very slow speed stuff, especially in wet conditions.

I've never used the CA for any current limiting, but the approach I'd take is to use the CA to dial current and throttle ramp up to a very tame and smooth level. Then work my way up using the different options.

What's the highest current you've managed to pull so far?

I keep coming back to thinking some kind of manual friction clutch could be the easy route to precision luanch control. I'd much rather clutch plates bear much of the waste heat during the first revolution or 2 of the tire. I think it might be more efficient overall too by having the motor operating at a much higher efficiency, as well as enable stronger start.

 

[Bluefang]

Well i have it all working almost perfect. Finally figured out what was causing all my trouble with the V3......My motor is too powerful. The bike accelerated too quickly to the speed limit and it auto lowers the power but it does not show up as a limit on the CA screen so all i had to do was change the speed limit to something crazy(don't want it) and lower the gain settings till they pretty much do nothing and she is running sweet

On a side note the controller and motor are not taxed at all even running 10 acceleration runs from one end of my street to the other the controllers case where the fets are mounted is still ambient and the motor is only just warm........holy shit.....Still have no idea what power its using as i have tried to use a external shunt with a plugin CA so i have a accurate value, connected the blue wire to the battery side of the shunt and the white to the controller side, tried swapping them as well but it gave a negative then too. I ll get it eventually.

Unfortunately with all my playing around i have come to the conclusion that my 32S battery is above the cut off for regen, so i have none. Very temped to get another 4S and solder the shunt again to really turn the bike into a green monster, on really hard accelerations with the battery fully charged it still cuts out so i need to do the shunt mod anyway

I ll upload video once is on youtube

 

[jmygann]

have you given up on the Nuvinci hub ?

 

[Bluefang]

Haha sorry mate I have gone way past the level that Nuvinci hubs can handle even from the disk brake side. It has a down hill 150mm hub with a 12mm axle to handle the power still waiting for the vids to load on YouTube.

 

[Bluefang]

[youtube]Md2gIxQfHEo[/youtube]

1 part of the uploaded videos, not much in the way of action Kinda limited on speed due to been local streets need to fine somewhere empty to test out the top speed properly

 

[jmygann]

Haha sorry mate I have gone way past the level that Nuvinci hubs can handle even from the disk brake side. It has a down hill 150mm hub with a 12mm axle to handle the power still waiting for the vids to load on YouTube.

but if the power was controlled , (say to 750-1000 watts)the Nuvinci Hub would be okay ?

thinking of its place in a "street legal" bicycle ... 20mph

https://www.facebook.com/photo.php?fbid=438562029545685&set=a.141857095882848.26984.141856995882858&type=1&theater

 

[Bluefang]

Should be fine. I am using a Nuvinci Dev kit with a 9C hub motor as a mid drive thats probably doing about 4kw+ peaks so easily more then you will do and it survives. Disc brake side may be abit risky but some minor mods and it should be ok.

 

[Bluefang]

The sprocket is a hardened steel go kart sprocket thats ment to mount on a clutch. Noise wise its reasonably quiet, the chain is almost silent and most of the noise comes from the motor itself but its completely drowned out by the wind at anything over 20km/h. The motor i am planing to push as far as possible maybe 30kw peaks

 

[John in CR]

The sprocket is a hardened steel go kart sprocket thats ment to mount on a clutch. Noise wise its reasonably quiet, the chain is almost silent and most of the noise comes from the motor itself but its completely drowned out by the wind at anything over 20km/h. The motor i am planing to push as far as possible maybe 30kw peaks

Let's get you to the 14kw the controller is supposed to be delivering to you first. I don't think you're getting to 10kw input yet. I've stuffed 30kw peak into a much less efficient motor, pushing a bigger load, and geared to a much higher top speed of 95kph, and I don't think you can load the motor down enough to ever see that kind of power draw, even accelerating up a steep hill. I think we'll be banging up against saturation issues well before 30kw at this voltage, so the only way to see that kind of power is with much higher voltage. Your low 1.3A no load at 125V including the power to drive the centrifugal fan effect proves that the motor can take plenty more voltage. We aren't anywhere near the mechanical limits of the steel shell at 2k or even 3krpm are we?

John

PS- That motor sound we hear I believe will mostly be cured by a sine wave controller. Then it would be down to chain noise and air flow noise due to the ventilation.

 

[Bluefang]

Yup, your right John. I finally figured out why my CA was reading funky amps and it was due to me not moving the ground wire for the CA when i moved the shunt wires to a calibrated external shunt. Now it seems to be reading accurately and its indicating that my peak draw is 6.5kw with a almost flat battery just hitting the cut off voltage. So with a full battery i am probably still way under 10kw...........this thing is going to be crazy if i can even just get it up to the right levels that the controller can handle easily let along above that.

 

[thewmatusmoloki]

Nice build mate
Looks like your up to speed....
Whens the next GC group ride then ?

 

[Bluefang]

once i have it running at top acceleration without cutting out .....so soon

I ll be pulling the controller and rear wheel apart on Saturday morning to rework the wheel. I laced it with 2nd hand spokes as they fit perfectly but sometime between deciding i was going to use them and using them i managed to loose a spoke and the wheel is not quite perfectly centered due to that. The controller i ll get photos up and see if someone smarter then me can tell me how to change the current sense cuircut to 2x the cut off point for now. The V3 can control the power easily now that it set up properly. Tested it tonight on my ride to tennis.

 

[hydro-one]

So how is the bike performing ? have you cranked up the amps and got that front wheel in the air at all? mabye a drag race/timed accel run?

heat?