:Newb: 50v20ah Rear Mac 8T Build.

[ihategeeks]

The previous build was a 9CRDD 1965 schwinn typhoon, unfortunately due to the brake being linked to the hub, I had no way of stopping without welding something to the frame, which I didn't want to do. Or I had to go FDD, which I really don't want to do.


Different bike means new priorities.
http://i.imgur.com/f4Dgve6.jpg
Now with full suspension and a lighter frame I'm going with the agility of a geared hub over a direct drive.

Overview of planned purchase (open to suggestions)
Most of these parts will be purchased from Cellman, to save on shipping cost and hassle.

Performance Goals.
http://i.imgur.com/qCLkf8j.jpg
compared to a BMCv2speed using a ping 52v-20amp Running a 4110 40amp controller on 26 in wheels.

Mac 8T
12 FET 40A IRFB 4110 Controller. (worth it?)
Upgraded Phase Wires + Temp Sensor (worth it?)
Full Twist Throttle (or is half better)
Ebrakes
26 Alex DM24 CNC
CA-DPS
Universal Rear Torque Arm
16S 20Ah A123 AMP20, 3.3V, 20Ah Nanophosphate Lithium Ion Prismatic Pouch Cell 40amp BMS (worth it to get the 80amp BMS?)
300w Fan Cooled 58.4 5A Charger.


Still Needed.
7sp DNP 11T-28T Freewheel
A way to mount the controller and battery to the frame.
Volt Meter
Front tire upgrade.
Bike Tune with new freewheel.

Future.
Front Disc Brake
New Rear pads
Lighting.
Mirror.
Better Peddles.

Questions.
Am I forgetting something critical?
Are there places to cut back without losing performance?
Is the battery charger going to work with the battery? (that charger should work and charge completely in 4+ hours? )
Are Cellman's kits plug and play with these parts?
Does anyone know what my mounting options are with that battery size? (I am unsure of the dimensions) 8.8kg
What kind of preventative maintenance should I preform on the MAC 8T?
What kind of weather proofing tips are there for the controller / motor / battery?
I've gone over the dimensions of the battery / controller / and frame triangle, and it appears I should be able to put everything in the triangle, are there reasons to not do that?
Does anyone have a good solution to hang the controller from the seat, or seat post? In the best interest of compartmentalization.
The A123 battery has a very high C rate, in what ways can I best utilize that?
Is hooking up the temperature probe plug and play?


I <3 this forum.

 

[dogman dan]

You will want to monitor temperature closely if you run 40 amps into a Mac, or a 9c,,,,, And use it. If you only draw 25 amps anyway, no big deal, but if you go climb steep hills with that fast winding, it will sure heat up.

What do you want? Go faster on street? Put 72v on the 9 c you have, and give it 40 amps.

If you want to ride steep single track trails, you REALLY picked the wrong motor.

 

[ihategeeks]

You will want to monitor temperature closely if you run 40 amps into a Mac, or a 9c,,,,, And use it. If you only draw 25 amps anyway, no big deal, but if you go climb steep hills with that fast winding, it will sure heat up.

What do you want? Go faster on street? Put 72v on the 9 c you have, and give it 40 amps.

If you want to ride steep single track trails, you REALLY picked the wrong motor.

I never acquired the 9C motor. Previous build was never attempted, just spec'd it out. (same as this one,but with a quote requested from cellman) I tend to be very meticulous before buying things.
Which is why I have so many questions left to answer.
Also, from all of my research on the 9C, 40 amps shouldn't be put through it.

Which is why I wondered if the MAC 8T with upgraded phase wires could take 40 amps

What do I want? I want everything of course I want the best compromise between speed , torque, distance, and robust build I can make that will give me 30+ on the flats, 15+ range at WOT, and can still cut up some hills or run though the dirt. Sometimes I want to tear through town offroad, sometimes I want to commute, sometimes I want to run half throttle for 30 miles assisted to get to the the 3 next towns.
I expect that I will stay under 1200 watts the majority of my riding. With some bursts of power to beat up occasional hills.
I'm not trying to drive up a wall for 2 hours, I just want some all around punch on a bike that can adapt to many different localities. My city has both long flats and some rolling grades under 5, a couple long 5's, and one very short and very vicious 20 I can peddle up unassisted but often slips the chain on most bikes I have attempted it on. Geared hubs appear to be the best in traffic with their ability to free wheel start, or more off the line acceleration.
tl;dr, the goal is to be good at many things, not best at any one thing.

 

[ihategeeks]

Got a response from Cellman today

The build
-----------------------------
Mac 8T
12 FET 40A IRFB 4110 Controller. (worth it?)
Upgraded Phase Wires + Temp Sensor (worth it?)
Full Twist Throttle (or is half better)
Ebrakes
26 Alex DM24 CNC
CA-DPS
Universal Rear Torque Arm
16S 20Ah A123 AMP20, 3.3V, 20Ah Nanophosphate Lithium Ion Prismatic Pouch Cell 40amp BMS (worth it to get the 80amp BMS?)
300w Fan Cooled 58.4 5A Charger.
--------------------------------


Cellman recommends I go with the 40a 3077 instead of the 40a 4110. Reading around here it should run cooler. Would not have even considered that.
Also, he says he is getting new 58.4V 5A chargers for 60USD. 12 bucks cheaper. And that my shipping will be cheaper than what is on the website. (that is with the battery).
Rare is a vendor that will actually down sell you into the more robust package.

 

[neptronix]

Yep, he's steered you in the right direction. Get the 3077 controller, it does indeed run a little cooler.

50v is a good voltage on an 8T in a 26" wheel.

If you are going to be conquering long and steep hills, then a temp sensor setup would be a worthwhile purchase. You will be able to cut the power before you take the motor over the edge.

 

[melodious]

You may need to upgrade the Cycle Analyst to a v3. It has the temperature/amp algorhythm that weans your amps as your motor temp increases. Not 100% sure on this as I don't have one (yet) and the general daily buzz on some of the threads here revolve around this topic.

50+ page thread on the v3 CA
newer thread on experimenting on different cooling strategies*
older thread but just as relevant on different cooling strategies using drilled holes and air fins*

*Big boo boo edit: this applies to direct drive motors only. Not geared hubbies. Putting holes in the geared hubbies like your MAC is asking for trouble from grit & debris.

 

[ihategeeks]

You may need to upgrade the Cycle Analyst to a v3. It has the temperature/amp algorhythm that weans your amps as your motor temp increases. Not 100% sure on this as I don't have one (yet) and the general daily buzz on some of the threads here revolve around this topic.

50+ page thread on the v3 CA
newer thread on experimenting on different cooling strategies*
older thread but just as relevant on different cooling strategies using drilled holes and air fins*

*Big boo boo edit: this applies to direct drive motors only. Not geared hubbies. Putting holes in the geared hubbies like your MAC is asking for trouble from grit & debris.

so v2.3 will work with a temp sensor but won't automatically throttle down like 3.0?

 

[sabongi]

AFAIK CA v2 doesn´t have a temp sensor!

 

[footloose]

Are Cellman's kits plug and play with these parts?

I purchased a similar setup from Paul recently.
Key differences: 10T motor (chosen because of local hill situation), 9FET 3077 controller, Samsung NCM 14S/6P 12.6Ah battery pack (chosen for lighter weight).

The setup is as plug-and-play as humanly possible. Nearly impossible to get it wrong. Find two connectors that fit, plug them in together. Repeat until you are out of connectors. He has used different form-factor for each connector, so you really can't mis-wire the setup... at least, I couldn't find a way. Then 5 minutes of setup programming for CA, and you are good to go.

 

[footloose]

... plus of course endless speculation on whether you can find a better routing for wires, mount point for batteries / controller, etc etc etc... :wink:

 

[ihategeeks]

... plus of course endless speculation on whether you can find a better routing for wires, mount point for batteries / controller, etc etc etc... :wink:

I'm waiting on a invoice from cellman now, so I probably got until may before I get it. I need a paint job, front tire, new brakes, lighting, mounting for battery and controller, I have the dimensions of the battery, and I wanted to do a Falcon EV bag, but I am not sure that will fit. If not I can probably fabricate something that will mount into the frame. What I don't know yet is where I can put the controller because I don't know how long the wires are going to be. Optimally, I want the battery in the frame, and the controller on a seat mount , or in the frame as well. Rear wheel is out because of the suspension, and I don't trust 20 pounds bouncing on just a rear wheel frame.

 

[melodious]

I remember reading that either cellman or ping are planning on making frame bags similar to falcons. Might be worth a mention to cellman towards your purchase.

 

[-dg]

Are Cellman's kits plug and play with these parts?

I purchased a similar setup from Paul recently.
Key differences: 10T motor (chosen because of local hill situation), 9FET 3077 controller, Samsung NCM 14S/6P 12.6Ah battery pack

I had the good fortune to get a test ride on this build. Impressive. This was in an area where every street is a 12% grade and it whisked me along (with good pedaling) around 18mph up climbs I didn't expect to go up at all. Very strong. It was a noisier than my wife's SWXK but not objectionable. [ps: don't tell the owner that it was still making 400 watts assist at 30mph on the down slope].

 

[alfantastic]

Go for the MAC 10T, as it's a good compromise of speed, torque and ability to climb steep gradients without overheating.
I've been running one with Cellman's 9fet 3077 and a Ping 48v 15Ah battery and the performance on hills is amazing.
Plenty of punch and if you are willing to pedal a little, will climb the steepest of hills.

If I were to build another bike, I would probably upgrade to Cellman's 12fet 40A controller and a capable C rating battery, as I reckon this motor can handle it.

 

[ihategeeks]

Prototyping the battery size in the bike frame :?

http://i.imgur.com/6IZvSLX.jpg
http://i.imgur.com/lhAcOxF.jpg
http://i.imgur.com/ej8gOIq.jpg

Seems a bit wide.

 

[bionicdan]

Is that box exactly to his size specs? Looks bigger, maybe your bike is tiny lol. Racks that mount on the seat post only are often rated for 10kgs (pack is 8.8kgs) so might be ok if you arnt downhilling.

Or on its side on the cross bar if you can make a bracket/shelf. I have previously just used straps and bungees to secure 20ah 24v pings on top of my crossbar with no mishaps. You loose the option of standing over the bike at traffic lights though and have to get off backwards.

Your pack would only over hang width wise by 2cm either side unless you made a tray.

http://www.ebay.co.uk/itm/Bicycle-cycling-bag-pannier-carrier-bike-rear-rack-fender-mudguard-reflector-/130838327903

I have the 40a 3077 12fet on a 10t paired with a 16 cell 10ah saggy headway pack. I opted for a half throttle as I have a big heavy downhill bike I like to pound down hundreds of steps sometimes. I do not trust the strength of a full width plastic throttle while doing this. My pack acts like an 8ah pack with my setup and would like to try a cellman battery like yours instead.

I got no instructions on connecting the temp sensor and when I did get a reading it never seemed to change with my 10t winding, 3 degrees outdoor temps and 12s lifepo4. Now its summer it has started getting warm if I run 16s so might hook it back up. I think I had to add the connector to the controllers hall block myself from an old broken controller. One wire goes to positive or negative of the pack and the other to the spare wire on the hall block I seem to remember. On an 8t winding at 48v on a 40a controller I would say the sensor was a must have unless you live on flat lands.