Starting my second RC build.

[E-racer]

I caught he EV bug about a year ago when I completed this build: http://endless-sphere.com/forums/viewtopic.php?f=35&t=20732
After a year of thrashing on this ESR w/ 80-100 and Kelly I found the setup to be VERY reliable. In fact I used 3 sets of SLA's (thank you batteries plus warranty) without one issue from my motor or controller. I am sold this is the driveline for my next EV.

Next I toyed around with what I want to actually accomplish with my next build. I am in college and my campus is about 4 miles away so I want to be able to comfortably commute on w/e I build. I thought about building my own frame, then I thought I had decided on converting a XC mtn bike. After alot of mental deliberation I came up with my final plan. A downhill/free mtb bike setup for the street/urban riding. This way I can comfortably ride to school and be able to drop stairs, hop curbs, rip through the dirt to pass ppl ect... After a good bit of searching through bikes I decided on this 2005 Kona Stinky. It is setup with the following components:
-Marzocchi Drop Off Tripple
-Fox DH3 rear
-Hayes 9 Brakes
-Sram X7 running gear
-Maxxis Hookworm 2.5" (sweet i dont have to get tires!)


Now for the power train. I use my toys often, no show queens here, and I dont like to clean/detail/rebuild stuff. This build will be BEEFY so I dont have to service it often. After I completed my E-scoot (ESR750 w/ brushless) I opened the deck maybe 6 times in a year, 3 of those times were to change the batteries. On this Kona I will be using the following components for the power train.
-Kelly 48201 sensored (carrying this over from my ESR)
-2X Turnigy 80-100B (in tandem on a common shaft)
-Custom 2:1 reduction box with straight cut gears incased in oil (I will be machining this part)
-Chain drive through the brake rotor mount (Combination rotor/chain ring I've heard ppl call it a Sprotor before)
-Custom brake caliper adapter with idlers for "Sprotor" setup (cnc plasma and some macining)
-10X Turnigy 6s 5000mah Long Packs for a 12s5p 44.4V 25ah pack
-Cycle Analyst (large Screen standalone model)
-Hyperion 1420i 14s 20a balance charger
-2X Hyperion EOS Sentry Cell monitors on board.
-Full LED light rig for brake light, turn signals, running lights, Backlights ect. (I plan on making a circuit to control all of these)
-2X 55w halogen driving lights for headlights

I will be gearing this bike similar to my ESR for a gear ratio/motor max speed of 55mph. My ESR fully loaded weighs over 90Lbs w/o rider (due to SLA's) this bike should weigh 75ish maybe push 80. With Li-po's and the tandem motors it should be a good bit quicker than my ESR (WOOOOOOT!)

[ev_nred]

looks like a solid build!
just got a few questions and comments instead of having 2 motors why not have one big one? (180kv turnigy) also isn't it impossible to run 2 motors on 1 controller?
cheers,
Jacob R

[def215]

looks like a solid build!
just got a few questions and comments instead of having 2 motors why not have one big one? (180kv turnigy) also isn't it impossible to run 2 motors on 1 controller?
cheers,
Jacob R

i thought the turnigy 80-100b was one of the biggest with the 130kv rating

but ive seen your esr and im pretty sure you can handle this project without a problem. is the motors in tandem gonna be like a siamese motor setup with one common shaft or will they be side by side and mated together with a sprocket of the same size and chain? id like to see what you come up with.

[AussieJester]

also isn't it impossible to run 2 motors on 1 controller?

Not with brushless motors it isn't brushed you can have multiple motors one controller. That sais however, running two brushless motors on a common shaft i believe is possible?

*subscribed...best of luck with the build...

KiM

[ev_nred]

thanks for the info! so if it not on one shaft then it is impossible rigth

[E-racer]

I assume you could get any setup to work that locks timing wether it be a common shaft, timing belt, or chain as long as you time the motors together. Due to the backlast in chain and belt setups the only way I want to attempt the twin motor on one controller is on a common shaft. The reason I am doing the twin motors as opposed to higher voltage is my controller's E-Rpm limit. My controller is good for 40,000 E-Rpm so 40,000/7poles=5,714.3 Rpm. 12s= 44.4 V so 44.4 X 130kv= 5772 RPM Perfect! Hopefully the twin motors will draw more power in tandem than just one motor giving me more POWA! But if it doesn't work out as well as I want, dividing the load over twice as much copper should keep motor temps down and hopefully combining the torque will pay off. Also the twin motors will be more ascetically pleasing in my design. Just FYI the 130kv and 180kv are the exact same size. The 130kv is an 8 turn (for torque) and the 180kv is a 6 turn (for higher RPM) the power spec is listed slightly lower in the 130kv due to the higher internal resistance of the 2 extra turns (windings).

[nieles]

be careful when you power the 2 motors up for the fist time.

with 2 motors in paralel the total resistance will be half. the controller already has hard time dealing with 1 motor, let alone 2 motors

[Byte]

Looks good! I"ll be following this build.

[recumpence]

You cannot run two brushless motors off one controller. It will not work. You need two controllers. You can run two motors to a common shaft. But, you must run a separate controller to each motor.

Matt

[etard]

Two of those motors on one shaft will also be very long, stick out, and look funny IMO. Why not start with one but leave room for two later if money time and necessity allows?

-2X 55w halogen driving lights for headlights

Why not go for LED lights and have a dc to dc convertor onboard? It will only use maybe 20 watts total.

Great choice on bike, I look forward to see what you come up with on the build.

[AussieJester]

You can run two motors to a common shaft. But, you must run a separate controller to each motor.

In my above post I stated you can run two motor on not too a common shaft, which makes
it possible to run one ESC (varified this with Liveforphysics to be 100% sure) Theres video of a go cart on youtube
with 4-5 Turnigys on a common shaft, thing flogs too. Would indeed make for a loooong motor setup...Matt is right that
running too a common shaft two esc will be required.

KiM

[E-racer]

You cannot run two brushless motors off one controller. It will not work. You need two controllers. You can run two motors to a common shaft. But, you must run a separate controller to each motor.

Matt

I have tested two motors. When timed together, my one sensored controller powers the two motors just fine! Thanks to some members on the board I figured out how to time the motors dead nuts!

Two of those motors on one shaft will also be very long, stick out, and look funny IMO. Why not start with one but leave room for two later if money time and necessity allows?

-2X 55w halogen driving lights for headlights

Why not go for LED lights and have a dc to dc convertor onboard? It will only use maybe 20 watts total.

Great choice on bike, I look forward to see what you come up with on the build.

The motors wont stick out any longer than one would. The gear box will be mounted between the two motors. So the gearbox is centered with the wheel and there is a motor on the left and right side of the box with a shaft through it. Ill post my 3D models pretty soon so you can visualize it.

The running headlight (for daytime) will be LED. But the night time real headlights will be halogen (I like to be able to see! and I ride at night alot)
Thanks! I think the Stinky should be a great platform!

[neptronix]

Why not go for LED lights and have a dc to dc convertor onboard? It will only use maybe 20 watts total.

That is about right. One magicshine light uses 13w and produces about 600-800 lumens through a DC-DC convertor at 8.3v.

26 watts vs 110 watts, maybe more like 125 watts after you factor in dc-dc convertor losses.

[LI-ghtcycle]

You cannot run two brushless motors off one controller. It will not work. You need two controllers. You can run two motors to a common shaft. But, you must run a separate controller to each motor.

Matt

I have tested two motors. When timed together, my one sensored controller powers the two motors just fine! Thanks to some members on the board I figured out how to time the motors dead nuts!

Two of those motors on one shaft will also be very long, stick out, and look funny IMO. Why not start with one but leave room for two later if money time and necessity allows?

-2X 55w halogen driving lights for headlights

Why not go for LED lights and have a dc to dc convertor onboard? It will only use maybe 20 watts total.

Great choice on bike, I look forward to see what you come up with on the build.

The motors wont stick out any longer than one would. The gear box will be mounted between the two motors. So the gearbox is centered with the wheel and there is a motor on the left and right side of the box with a shaft through it. Ill post my 3D models pretty soon so you can visualize it.

The running headlight (for daytime) will be LED. But the night time real headlights will be halogen (I like to be able to see! and I ride at night alot)
Thanks! I think the Stinky should be a great platform!

Well, sure if your going at those speed, you NEED a set of halogens!

I love my MS, but it doesn't have the right reflector for that kind of distance, it's the cat's meow at 20-30 MPH, but I imagine much faster and you're out-running your headlight.

I'm sure there are similar lights with the cree P-7 LED set-up with a reflector that isn't going to diffuse it so much, I'm sure there is an LED light that would rival a halogen's performance, but I haven't looked for one yet.

[StudEbiker]

I think you should consider a couple of Cycle Lumenators instead of the auto halogens. If they're enough (some might say more than enough) for Ypedal's RC bike, then they should be enough for all but the most extreme bicycles.

[NickW]

You can, of course use leds and get however much light you need, but it's going to be pricey.

even a pair cree MC-E, or SSC P7 is probably only going to get you slightly better than a single 55W car beam best case.

Realistically, to get similar brightness to a pair of 55w bulbs, you're going to need around 4 of them driven close to their rated current (most commercial stuff isn't), and with adequate cooling to make them last.
The cycle luminators are a pretty darn nice light, and are already set up for ebike voltages, but you are talking ~$300 for probably a bit less light.

Personally, I wouldn't want to give up >100W to lights and would go with an LED based setup, but given the price difference I could certainly understand why someone would go halogen if they have the range to spare.

[E-racer]

I use these 48V H3 bulbs in my headlights http://www.lightexports.com/servlet/the-2053/H3-Fog-Auxiliary-Halogen/Detail

No dc-dc converter required. I will have one 5w LED headlight for daytime running. So during the day my headlight is only 5w. At night the low beam is one 55w and the high beam is both for 110w. I like to be able to see at night and dont care abt giving it 55w. And I like the construction of car fog lights, mine are aluminum cased. http://www.amazon.com/Navigator-NV-534-Crystal-Rod-Light/dp/B001BB3IRO Killer deal at only $35 and its very easy to add a LED to them. I make my own mounts for them.

[E-racer]

1st stage reduction.

[x88x]

Hmm, interesting. I haven't seen one done that way before. Are you going to fit a true shared axle or just join the two?

[E-racer]

true shared. I will be removing the turnigy shafts. My own custom one will go in. I am also removing the skirt bearings, and I will only have one shaft bearing per stator (all the way outboard). the gearbox has its own two center bearings. making 4 total bearings on the shaft.

[x88x]

Nice! I look forward to seeing that.

[E-racer]

Fancy Rendering for your enjoyment.

[E-racer]

More.

[AussieJester]

Have you seen Rodgahs Kona Stinky with dual 3220 Astors? Here's the last video before he stripped the bike down, might want to take a look how well that goes with so much power on a short wheel based bike before wasting money on twin motor setup Either way, Placing the motors on the swinf arm IMHO is a bad move, Rodger mentioned to me the flex he felt from the rear swing arm when lacerating with his setup, add to that the bad placement of weight over the rear of the bike to impact on handling, the less weight there the better, you wont keep the front wheel on the ground with this much power, it will be ridiculously overpowered, and not in a good way....all the best anywayz.

KiM

[E-racer]

To each their own. I know my DH bike needs more power than my scoot (1 80-100 similar gearing @48V). I'm worried the twins at 12S will be underwhelming and have plans to go to 24s at some point. If you can't keep the front wheel on the ground you aren't leaning far enough forward. I am gearing this for 60mph (my scoots geared for 52mph) I definitely don't think it will be to overpowered with that gearing. I am going to be running clip- on bars instead of mtb bars. This will lower my body a good bit. I'm really not concerned with adding 10lb of motor/gearbox above the wheel in fact my batteries are being mounted pretty high as well. All together motors, batt, and controller weigh under 45lbs. My Stinky is an XL someone 250lb's could ride it and I only weigh 165. The swing arm is definitely sturdy enough to hold those motors up there and with the 4link setup it will be even sturdier.