CroBorg Commuter

[Alan B]

It appears similar to the dicta that I bought for about $7 or so. I'm not sure it is as good in quality, and the delivery time from dx is pretty long. I think I bought mine from Amazon.

[Alan B]

Made up a different "temporary" battery pack. This one has 12S 8AH and 15S 8AH both in the same pack using 2x 6S and 3x 5S Zippy 8AH batteries. The pack is 6x6x8 inches and fits nicely in the upper battery storage area. It is a bit too wide for the side panels but not in the way for pedaling.

I just took it for a spin with 12S. It was still gently accelerating at 26 mph on the level, and on the 10% grade it made 11-12 mph with no pedaling using the 12 FET controller.

The 24 FET controller had one shorted FET which has been repaired and it will be back from the doctor shortly.

[Alan B]

Brought the rig to work today (on the vehicle, didn't ride in), and showed it off at the noontime safety display. They had some bike vendors, etc. It did well, no popped FETs this time.

Lots of interest from folks.

Another news flash - the Regen IS working! It didn't seem to be the other day when I installed it, but it is now. I do feel a shifting the first time I apply it, so it may be loosening the nuts. I just tightened them, I do think they shifted a bit. So that's not good.

[Alan B]

Last time I tested the regen the battery was set up for 22S, probably too high a voltage for regen to work on this 12 fet controller the way it is set up. Now at 12S it works..

[Alan B]

Working on the battery layout. My original plan just doesn't quite fit. Very close but not enough room for the wiring. This was based on fitting 6x2 of the 6S 5AH bricks into the upper compartment. If there were no wires on the packs they would fit, but that would defeat the purpose of having them.

So on to plan B. The pack will be made up of three modules, each having four 6S 5AH bricks in parallel. These modules will be wired in series for 18S or about 70 volts at 20 amp hours, or about 1.4 KWH. Two of these modules will fit in the upper battery volume. The third will half fill the lower battery volume, leaving about half of it for a charging system or other.

[hjns]

Hi Alan,

First of all, very nice thread. I am about to pull the trigger on a Cromotor, and I learned a lot by reading your whole thread.

Regarding the regen - what kind of torque arms are you using? The inevitable wobbling of the axle will loosening the nuts in no time. With double Ebike.ca torque arms on each side of the axle, my HT3525 (when it was still working) would still wobble between accelleration and regen.

Brought the rig to work today (on the vehicle, didn't ride in), and showed it off at the noontime safety display. They had some bike vendors, etc. It did well, no popped FETs this time.

Lots of interest from folks.

Another news flash - the Regen IS working! It didn't seem to be the other day when I installed it, but it is now. I do feel a shifting the first time I apply it, so it may be loosening the nuts. I just tightened them, I do think they shifted a bit. So that's not good.

[Alan B]

Thanks for the comments.

No torque arms at this time. The Greyborg frame dropouts are specified to handle the Cromotor if it is all the way forward into them. They are Chrome Moly Steel and quite thick.

I have NordLock lockwashers installed, and it did not transition over a step on them, but it did move a little, so I think it is a problem. I will probably add the Kiwi torque arm and then I could oppose the free play in the dropouts vs the torque arm and eliminate the motion. In the meantime I am going to reduce the use of regen and tighten those nuts frequently.

I do have a problem in that there is no room for a torque arm unless I take the disc adapter off the motor which I will do. The newer Cromotors have longer axles so you will have more space.

Kiwi is working on a new disc with a thinner adapter that might work for the rear, I want a rear disc brake which won't fit right now. He needs 3 more orders to make them.

[gensem]

Be carefull if you are using heavy moped wheels and tires with a strong brake/regen. You gotta make sure you have the axle well fitted specially on the disk side, otherwise the axle might move a little when you are in the air and hit the brakes hard.
Its alot of energy to deal with.


PS: its a general advice not related to the warp frame only.

[hjns]

Can you post a link to a thread with that new adapter ...
Well appreciated

Kiwi is working on a new disc with a thinner adapter that might work for the rear, I want a rear disc brake which won't fit right now. He needs 3 more orders to make them.

[Alan B]

Can you post a link to a thread with that new adapter ...
Well appreciated

Kiwi is working on a new disc with a thinner adapter that might work for the rear, I want a rear disc brake which won't fit right now. He needs 3 more orders to make them.

viewtopic.php?f=6&t=25459&p=602057#p602057

scroll up about half a dozen postings in the above thread.

[Alan B]

Evening Ride

Took the CroBorg out for a beautiful evening spin after work. Not a great cellphone pic, but it was nice to get out and enjoy the great weather we are having.



This motor is really docile at 12S / 48V. It glides along at 25-27 mph effortlessly, and climbs 10% grades at about 12 mph. The throttle is not touchy (like it was at 22S) and it is really pleasant to ride. It is really tempting to make a 12S/24S switching system for those moments you want to "go fast", and run 12S the rest of the time.

It is not too hard to make a series/parallel system, but I don't think I want to deal with the issues it brings. It would be a good match for the battery setup because two 12S 4P battery setups would fit nicely giving 12S 8P 48V 40AH for just under 2 KWH of battery.

I don't want to run at 24S normally because it is too close to the voltage ratings, there is not enough margin. With a 12/24 system it would not be at the 24S setting much, and the stress would be reduced.

It would certainly change the character of the machine from docile to wild. I think though I want something in between for every day. 12S is too docile, and 24S is too wild. 18S sounds really nice.

I may be able to fit a "backup" 18S pack in the extra frame space based on three of the 6S 8AH Zippys. That would bring the total pack up to 70V 28AH which is 2KWH.

I picked up some Corrugated plastic sheet at Tap Plastics today. I will be working on the main battery pack very soon.

[Alan B]

Vehicle Bike Racks

I've been using a Swagman 2-bike hitch mount rack. A couple weeks ago I decided to review the ratings of this rack. 70 pounds total, 35 pounds per bike. Amazon failed to mention that when I was shopping.

http://www.amazon.com/Swagman-Cross-Cou ... B0001VO1YY

I must have missed that when I bought the rack, as that is not sufficient for ebikes. My EbikeE is the lightest ebike I have at 50 pounds, the mountain bike is 65 and this CroBorg is, well the back wheel is 33 pounds, not sure what the whole thing weighs yet... But expecting closer to 90 pounds...

I've been limiting the rack to one bike when carrying the CBorg, and I don't have the full battery set or cover panels or accessories onboard yet.

But it is time to look for a stronger rack. I found some dual-dirt bike racks that are rated for 400 pounds per bike that should do the trick.

http://www.discountramps.com/double-mot ... arrier.htm

What are other folks doing?

Controller Repair

I should get the 24 FET controller back today. One FET was shorted. Seems strange, I'm going to write that off to infant mortality. With 4 FETs in parallel in each bank, most failure modes would affect all four FETs in a bank. Further testing will show us whether this was a fluke or there is more to it.

[Alan B]

Simulation Runs

I did some simulations using the ebikes.ca simulator.

12S Lipo 48V
23.5" moped tire
200kg system weight
40A controller (12 FET)

flat ground: 27 mph
10% grade: 12 mph

These values agree pretty well with what I have been seeing.

Now change the controller to 24 FET:

Controller: 100A

level: 27 mph
10%: 18 mph

Now change to 18S Lipo:

18S Lipo 67V

level: 35 mph
10%: 27 mph

And then on up to 22S Lipo:

level: 45 mph
10%: 36 mph


Again, 18S looks like a nice place to operate.

[fractal]

Vehicle Bike Racks

I've been using a Swagman 2-bike hitch mount rack. A couple weeks ago I decided to review the ratings of this rack. 70 pounds total, 35 pounds per bike. Amazon failed to mention that when I was shopping.

http://www.amazon.com/Swagman-Cross-Cou ... B0001VO1YY

I must have missed that when I bought the rack, as that is not sufficient for ebikes. My EbikeE is the lightest ebike I have at 50 pounds, the mountain bike is 65 and this CroBorg is, well the back wheel is 33 pounds, not sure what the whole thing weighs yet... But expecting closer to 90 pounds...

I've been limiting the rack to one bike when carrying the CBorg, and I don't have the full battery set or cover panels or accessories onboard yet.

But it is time to look for a stronger rack. I found some dual-dirt bike racks that are rated for 400 pounds per bike that should do the trick.

http://www.discountramps.com/double-mot ... arrier.htm

What are other folks doing?

Controller Repair

I should get the 24 FET controller back today. One FET was shorted. Seems strange, I'm going to write that off to infant mortality. With 4 FETs in parallel in each bank, most failure modes would affect all four FETs in a bank. Further testing will show us whether this was a fluke or there is more to it.

Hey Allan, I got this rack for my bike : http://www.ragepowersports.com/motorcycle-products/scooter-dirt-bike-carrier/
It works great!!! I use it for my commute. I bring my daughter to day care and then leave my car at the park and ride for my wife to pick her up at the end of the day. At the park and ride, I hop on my bike and away i go! I would not use it on a car, it would be too low. On my Santa Fe its ok. I'll take a picture tonight for you to see!

[Alan B]

Good to hear that it is working for you. I believe Rage makes the double dirtbike rack I linked earlier (previous link was to a reseller):

http://www.ragepowersports.com/motorcyc ... s-carrier/

I would like the capacity for two bikes. Vehicle is Toyota 4Runner so should be high enough hitch.

Any challenges tying down an ebike to a dirt bike rack?

[fractal]

Good to hear that it is working for you. I believe Rage makes the double dirtbike rack I linked earlier (previous link was to a reseller):

http://www.ragepowersports.com/motorcyc ... s-carrier/

I would like the capacity for two bikes. Vehicle is Toyota 4Runner so should be high enough hitch.

Any challenges tying down an ebike to a dirt bike rack?

Its really easy and solid! No problem whatsoever! You can adjust for different wheelbase lenghts. Even if the shortest adjustment on the rack is still too long, that poses no problem at all.

[Alan B]

That sounds really good. Looking forward to getting that rack, most likely.

I see the 24 FET controller package was supposedly delivered. Something to look forward to when I get home!

[fractal]

Hey Alan, check out my rack! Its really a good solution for heavier bikes. I'll post more pics on my build thread.

[Alan B]

Nice!

[Stevil_Knevil]

Hey, nice rack ..but that's cheating..

[Alan B]

Controller Woes

I sure am glad I bought a 12 FET backup controller. It is working great!

I reinstalled the returned 24 FET controller and did testing with the wheel in the air. Worked great at the lower power settings that were left in the controller when it was returned to me, so I reprogrammed the default settings. Those worked great too with only the load of the heavy tire/wheel, and it did about 39 mph at 60 volts no-load.

I put it on the street and it popped on the first gentle acceleration. Something appears to be preventing the FETs on that phase from properly sharing current, perhaps.

The 12 FET is back on and working well, so we can continue to work on the battery pack.

[Alan B]

Battery Modules, or Fun with Coroplast

I cut the coroplast with a bandsaw and chopsaw, then scored the back side and folded into a pair of "U" shaped pieces to make boxes around the battery blocks and used 3M strapping tape and Gaffer's tape to make up three protected battery modules. Each contains four each 6S 5AH Turnigy Lipo batteries.



If I wired all these batteries in series it would be 300 volts!

A better plan is each module to be paralleled to 20 amp hours and about 24 volts, so 72 volts 20 amp hours total.

[Alan B]

Trial Fit

I put the covers temporarily in place. The good news is that the cover under the chainring can be fitted with the crank installed. It is touching the chain slightly but that will improve when installed and chainring spacers are added. The not so good news is:

As often happens when we try to pack things into a tight space, it almost fits. I am going to have to repackage the batteries to slim them slightly. The coroplast is adding too much width. It can still be used where it is needed to protect batteries from frame mounting flanges, but on the side the covers will be the main protection.

[Alan B]

Weight

Did more work on battery mounting. More on that later.

Did a bathroom scale weight of front and rear wheels. It wasn't easy to get the digital scale to cooperate, might be some error.

Greyborg, Cromotor, 12 FET controller, Cycle Analyst, 12 each 6S 5AH Lipo - about 1.4 KWH, Schlumpf crankset, rear shock, front suspension forks, chain, dual front brake, cloud9 seat, no rear brake

44 pounds front wheel
63 pounds rear wheel
107 pounds total

not including side panels, some wiring, and 24 FET controller (this is with 12 FET)
no headlight
no kickstand
no onboard charger

So call it 120 pounds estimated full up.

[shorza]

An easier way to weigh it is to lift the bike while standing on the scales. Then subtract your weight from that figure.