Eboost -kepler friction drive review and testing

[BikeFanatic]

Thanks for the replies i will try foam over the Mic next time

I do recommend Lipo. either two 5 series bricks or two 6 series, the high discharge rate ones like 20-25C discharge rates as this motor can pull alot of amps. I cruise at about 25 amps but peaks of 75 even 100 amps.

I get away with the 15C 5 series but i am cheap. a single brick w.ill cut out if i nail the throttle

 

[tritonwow]

Thanks for the replies i will try foam over the Mic next time

I do recommend Lipo. either two 5 series bricks or two 6 series, the high discharge rate ones like 20-25C discharge rates as this motor can pull alot of amps. I cruise at about 25 amps but peaks of 75 even 100 amps.

I get away with the 15C 5 series but i am cheap. a single brick w.ill cut out if i nail the throttle

It looks like if you'd paint (or annodize) the F drive blue to match the frame the unit would "dissapear".

 

[Kepler]

Hi Ann. Great job on getting the drive built and setup on the folder. The drive really suits folding type bikes that’s for sure. Sorry the seat post diameter gave you grief. Very difficult to cover all sizes but it looks like you have it covered. 30.4mm seat post is an unusual size. I was sure the one I sent you would close down enough to suit but obviously it didn’t quite do it. I can turn up a custom sized adapter for you if you like and send it it out to you.

I find the simple servo tester interface is quite hard on most grip tapes simply because it can put so much power down so quickly. The new interface I have under development is much more gentle on the drive and i can get quite a few hundred km's out of the tape before it wears through.

The interface also improves the range on the drive quite dramatically. I use 2 x 5S 5000mah pack and get a safe 25 kms range using assist as soon as soon as any real peddling effort is required.

I know I have been talking about this interface for quite some time but I can assure everyone that that it is coming very soon. Most of the logic is now finetuned and its now a matter of packaging it up as effectively as possible.

Anyway, I don’t want to hijack Ann's thread going on about the interface and all it's new features

Great to see the videos of the drive in action too. Well done

 

[1121790]

I've got the drive attached to my bike, but the battery goes flat in a couple hundred meters. I tested the battery before setting out and it was indeed at 18.5v. I'm using a new Turnigy 5.0 and I have to change the pack before I've gone half a kilometer while pedaling. I tested it and now it's at 13v.
Here's a video of this morning's commute. This is the second battery, the first behaved similarly. I don't let off the throttle at the end, the motor just slows to idle. The altoids tin holds an arduino, I couldn't get the servo tester to work at all.
[youtube]f_sSrqfUuko[/youtube]

 

[BikeFanatic]

Hi Kepler,
thanks for the comments, you can jump on my thread if you like.

I have been using the carpet tape with 60 grit coarse sandpaper and NO Issues so far. And my sister said it was too beta for her that I had to work the kinks out. But I dont have an issue I think she is Nailing the throttle
and thats why it gives her trouble but not me. I am enjoying using the bike though, so much fun and so light
everyone who rides it loves it. I would be interested in the new throttle interface, when it is ready. I like having a spare. Right now in Northamerica it is winter and not so good for riding, but I ride anyway, just less pleasure trips.
I will give it to her again in the spring, she wore quite the grin when riding around NYC. I want to try it with a mountain bike too.

 

[BikeFanatic]

1121790,

I think you battery may be the issue, this drive pulls allot of amps , are you using a watt meter ? I am crazy to use a 5 amp hr 15 c pack on this thing, but I do , and I see the drop after a few miles, but the other day I got 6.5 miles from one pack and I use LVC of 3.50 per cell.

You see this drive can pull up to 70 amps and if your pack can not handle it maybe you are hiltting the controller cut off.
Do you have a watt meter?
BTW hobby king has some 25 C lipo for 40$ plus Shipping of course, where do you live?

 

[spinningmagnets]

I appreciate the info about the double-sided carpet tape working well. For sandpaper, I am going to try out the carbide-grit cloth-backed wet/dry industrial sanding belts...It may be a few weeks but I will report as soon as I have any info on how they turned out.

http://www.mcmaster.com/#sanding-belts/=9xqndt

Kepler....let me get this straight...you're going to work out the bugs BEFORE you sell the gadget?..and then, your going to charge a reasonable price for a product that has features that users want....AND...it will work on other systems different than your own??

I can tell already that you don't work for Microsoft.

 

[Kepler]

Hi Kepler,
thanks for the comments, you can jump on my thread if you like.

I have been using the carpet tape with 60 grit coarse sandpaper and NO Issues so far. And my sister said it was too beta for her that I had to work the kinks out. But I dont have an issue I think she is Nailing the throttle
and thats why it gives her trouble but not me. I am enjoying using the bike though, so much fun and so light
everyone who rides it loves it. I would be interested in the new throttle interface, when it is ready. I like having a spare. Right now in Northamerica it is winter and not so good for riding, but I ride anyway, just less pleasure trips.
I will give it to her again in the spring, she wore quite the grin when riding around NYC. I want to try it with a mountain bike too.

I have been testing 80 grit cut from a length of belt sander material and am finding this to be very robust. Very little wear so far. Much better then the grip tape I think.
I can understand your sister having a little trouble with the drive. I think this first release best suits the enthusiast. The interface makes a huge difference to how the bike rides. I think your sister would like the drive much more with this setup. The interface will be available very soon. Also will have a better damper material available soon with much better rebound properties. I will post a video of the interface in action over the next few days to prove it does exist

 

[Kepler]

Kepler....let me get this straight...you're going to work out the bugs BEFORE you sell the gadget?..and then, your going to charge a reasonable price for a product that has features that users want....AND...it will work on other systems different than your own??

I can tell already that you don't work for Microsoft.

Got to take care of my friends a ES I would never have had this oportunity if it wasn't for you guys. (group hug )

 

[1121790]

I think you battery may be the issue, this drive pulls allot of amps , are you using a watt meter ?

I am not using a watt meter, though I do have an arduino attached already. Should I just buy one of these until Kepler's arduino-based interface is ready?
http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=10080&aff=70668

I am crazy to use a 5 amp hr 15 c pack on this thing, but I do , and I see the drop after a few miles, but the other day I got 6.5 miles from one pack and I use LVC of 3.50 per cell.

Have you got photos of your battery pack? I'm willing to throw more battery at this thing, but don't know the best way to connect a larger pack. I'm using:
HXT63-74-200 HXT 63-74 200kv Brushless Outrunner
T5000.5S.20 Turnigy 5000mAh 5S 20C Lipo Pack ( 2 of these but connected one at a time)
ECO6 HobbyKing ECO6 50W 5A Balancer/Charger w/ ac
KF-100A TURNIGY K-Force 100A Brushless ESC

You see this drive can pull up to 70 amps and if your pack can not handle it maybe you are hiltting the controller cut off.

If I am hitting the controller cutoff, should the battery be useful later? At what voltage should I stop using the battery?

BTW hobby king has some 25 C lipo for 40$ plus Shipping of course, where do you live?

I live in the U.S.ofA. Should I solder a connector to use both T5000.5S.20 batteries simultaneously in parallel?
Photos follow:

 

[Kepler]

I noticed you said the battery was at 18.5V. This is not a full charge for a 5S 18.5 V pack and probably not even half. 21V is fully charged (4.2V per cell) I typically get 10km out of a 5S 5000 pack which is about the same as what Ann is getting.

 

[Kepler]

The standard cutoff in the ESC is quite low. 3V per cell. I prefer the highest setting in the esc of 3.4V per cell. This can be changed using the throttle. You will need to read the instructions of the ESC carefully but it can be done. Its a good idea to get a watt meter so you can monitor the voltage and how many ah you are using. Even if you don’t use it all the time it is a must have tool for the ebike enthusiast.

The interface measures volts / amps /ah and has a low voltage cutoff that does more then just cut off when the low voltage threshold is reached. It looks at how long the load has been applied, the amount of load the drive is under and then averages all this information out. This allows the cut out voltage to be set quite high and still avoid nuisance cut outs under higher current draws. The interface we have the option of attaching a full feature LCD display, a simple Sunding bike computer, or running stand alone.

 

[maydaverave]

Hi Kepler,
thanks for the comments, you can jump on my thread if you like.

I have been using the carpet tape with 60 grit coarse sandpaper and NO Issues so far. And my sister said it was too beta for her that I had to work the kinks out. But I dont have an issue I think she is Nailing the throttle
and thats why it gives her trouble but not me. I am enjoying using the bike though, so much fun and so light
everyone who rides it loves it. I would be interested in the new throttle interface, when it is ready. I like having a spare. Right now in Northamerica it is winter and not so good for riding, but I ride anyway, just less pleasure trips.
I will give it to her again in the spring, she wore quite the grin when riding around NYC. I want to try it with a mountain bike too.

I have been testing 80 grit cut from a length of belt sander material and am finding this to be very robust. Very little wear so far. Much better then the grip tape I think.
I can understand your sister having a little trouble with the drive. I think this first release best suits the enthusiast. The interface makes a huge difference to how the bike rides. I think your sister would like the drive much more with this setup. The interface will be available very soon. Also will have a better damper material available soon with much better rebound properties. I will post a video of the interface in action over the next few days to prove it does exist

Has anyone tried dry wall metal sanding screen? Or for that matter any kind of metal screen should give a good grip and long life.

 

[Hillhater]

I tested the battery before setting out and it was indeed at 18.5v. I'm using a new Turnigy 5.0 and I have to change the pack before I've gone half a kilometer while pedaling. I tested it and now it's at 13v....

Well 13v is very bad for that pack (2.6v per cell) or maybe you have a bad cell ? .. running that low will kill the pack .
As Kepler said, fully charged you should be at 20-21v ..unless you have a bad cell or two !!
And yes...get that wattmeter.

 

[1121790]

I tested the battery before setting out and it was indeed at 18.5v. I'm using a new Turnigy 5.0 and I have to change the pack before I've gone half a kilometer while pedaling. I tested it and now it's at 13v....

Well 13v is very bad for that pack (2.6v per cell) or maybe you have a bad cell ? .. running that low will kill the pack .
As Kepler said, fully charged you should be at 20-21v ..unless you have a bad cell or two !!
And yes...get that wattmeter.

I'll get the wattmeter, but I can't blame the battery so readily. These are my first LiPo batteries and I obviously have no idea how to charge them. I don't know how to detect a bad cell. The manual that came with the Eco Six charger would be laughable except for the fact a mistake could result in an explosion. From what I could find using the manual and the forum, I set it to read the following:
LiPo CHARGE
0.5A 18.5V(5S)
I then press the start button and the display reads:
R: 4SER S: 5SER
(CONFIRM: ENTER)
I press Start again, not knowing what R:, S:, 4SER or 5SER mean and after a bit it beeps, reading
VOL SELECT ERROR
Which the manual helpfully says means "Voltage Select Error"
What other voltage could I possibly select? I can't set it to 21V, as everyone recommends, only 22.2V(6S), which I don't do for fear of damage and/or explosion. The battery says 18.5V, the charger says 18.5V, so I've no choice but to press Start again, and it usually finishes in two hours. The battery then lasts two minutes.

 

[Grinhill]

Hey there, the "4S" means that your pack voltage reads about the same as a 4S pack, which is very low for a 5S pack. This may happen following a very deep discharge. The second number means the charger is set to 5S, as it should be. This is sort of a safety thing so you don't accidently charge a 3S pack up to a 6S voltage.

Grab a multimeter and check the voltage of each cell on the balance connector (skinny wires). They should all be about the same voltage between adjacent pairs of wires (around 3V).

If any are very low compared to the others, this could mean a sick cell.

Otherwise, charge it up! You may need to charge it a couple of times if it's really low.

EDIT: check out this thread on Lipo if you haven't already - http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=9170&start=0

 

[BikeFanatic]

Thats it you over discharged your battery. So the charger sees 4 series.

Now you have to fool the charger in order to charge the pack. I have done this myself. I am a noob with Lipo
just less than a year experience. If you want my non expert advice here it is. but maybe ask advise in the battery section
so someone with more knowlege can help.

the charger saying R- 4 series and S- 5 series means the charger "see's four series voltage but user requested 5 series charging

I think if you charge at a low current 0.5 amps or less, and set the charger for lipo fast charge
then you only have to connect the red and black wires not the white multi plug.

charge as 4 series until the voltage jumps up to normal like around 15 volts should jump up quick like a few minutes.
then restart the charger in balance mode 5 series. when charging in balance mode 5 series hit the forward arrow key and it will show individual cell voltages. hopefully your cells are close to even and not out of balance. charge at a low rate
like 0.5 amps or less and stay with the battery while charging.
you know lipo can be dangerous if you over dishcharge then charge fast. cells should be 3.50-4.2 volts each and no more
and no less.

I confess to have overdischarges to 3.0 volts a cell and no harm done. i charge my lipo in a metal box. supervised.
So I would like to send you some individual cell monitors from hobby king, and maybe a cell alarm too that shows the individual cell voltages. can you PM me your address?

 

[1121790]

It turns out I never fully charged the battery. I'd always stopped at 18.5V, thinking that was the maximum voltage. I checked the cells using the ECO6, and the difference was 0.01V on a couple of cells after balancing, which I assume is acceptable. I used "Fast Charge" for two hours at 0.5A, switched batteries and repeated until the charger read 20.99V on both batteries. The difference is amazing and the commute was enjoyable, even in 1C weather. After changing the Electronic Speed Controller to "Slow Start" and raising the signal frequency to its highest level using the throttle I had fewer sync problems when the motor screamed and didn't turn.
I have to replace the circular pad that the motor and pivot arm hit, though, as the violence of the earlier sync problems permanently compressed the pad. I can flip it and get some use out of the other side, but eventually I'll have to cut another. What is that stuff made of?
Thanks very much, folks, for your patient help.

 

[BikeFanatic]

GREAT,
I am glad you got that going, the bike looks great, have fun out there!

 

[Kepler]

It turns out I never fully charged the battery. I'd always stopped at 18.5V, thinking that was the maximum voltage. I checked the cells using the ECO6, and the difference was 0.01V on a couple of cells after balancing, which I assume is acceptable. I used "Fast Charge" for two hours at 0.5A, switched batteries and repeated until the charger read 20.99V on both batteries. The difference is amazing and the commute was enjoyable, even in 1C weather. After changing the Electronic Speed Controller to "Slow Start" and raising the signal frequency to its highest level using the throttle I had fewer sync problems when the motor screamed and didn't turn.
I have to replace the circular pad that the motor and pivot arm hit, though, as the violence of the earlier sync problems permanently compressed the pad. I can flip it and get some use out of the other side, but eventually I'll have to cut another. What is that stuff made of?
Thanks very much, folks, for your patient help.

Good to here. The rubber is just 20mm sheet rubber mainly used for insulation. I am experimenting with better rubbers now.

In regards to charging, those batteries can be charged at 1C no problems. Thats 5A. That is a 50W charger so the best it will do is around 2.5A on those batteries. Just set it to fast charge at its highest setting. and do a balance charge say every tenth charge.

 

[LI-ghtcycle]

Wow, good stuff here! Glad to see some K-Drives out there tearing it up! I'm going to be testing out some belt sander belts soon, but after reading this I might see if I can get the wet/dry version, didn't think of that when I bought what I have, but if I have things ready soon enough, I'll just give this stuff a try.

I am very encouraged that a small folder with such a small diameter wheel is making such good speed! I have been making pretty good speed with 4S, but just around 20 - 22 MPH when my bike was as much of a tank as E-Bikes get (read 76lb tank!!! :lol: 110 lbs fully loaded with cargo!! :faint: ).

Well I have wised up and stuck with the original plan and kept things light, so I should be no more than 35-40 lbs (with 18AH's of 4S, three 25-50C nano LiPo packs) and then I will expect to see much higher speeds with half the weight.

I will see what it does with 6S too soon, just haven't decided what set-up I want to use yet battery wise.

 

[1121790]

The seat-post mount broke this morning, where could I get another?

 

[spinningmagnets]

I believe Kepler said it was a music drum-stand clamp?...
http://www.steveweissmusic.com/category/drum-racks

 

[Kepler]

Never seen one break before. How did that happen? Was this from normal operation or did you accidentally drop it on the clamp? I will organize one for you if you like.

 

[1121790]

Never seen one break before. How did that happen? Was this from normal operation or did you accidentally drop it on the clamp?

I started out on my trip, heard the sound that means the drive is misaligned, pulled the drive into alignment with the rear wheel, turned the handle to tighten the clamp and it snapped.
I think I'll use some leftover carpet tape and 80-grit on the inside of the next clamp to help keep it from rotating around the post.