getting the Cholo ready for the road p.1

Still waiting for my batteries and Sevcon Size 6... so not much has changed regarding the power train of the vehicle. I have decided to spend time and money getting ready to get the bike road legal. I bought a bunch of stuff including: new brake pads, new rotors, new brake fluid, a new gauge cluster, rear view mirrors etc.

I am still looking for a ZX6E front fairing (can't find a decent one on ebay/the interwebs). I also made and added a spacer to the motorshaft and a shaft collar so now the sprocket is axially constrained on both sides and I dont have to depend on the set-screw/locktite for any constraint on the sprocket. I also got to use some sweeeeet new lathes (Proto trak) and after using them it will be extremely hard to go back to any other lathe.

brand new brake pads and brake fluid!

hacking into the tach

using a function generator to hack the tach into showing me current

the tach responds... now to hook it up to an arduino to show it in real time

The tach normally runs of the signal from one of the ignition coils, you can fake a coil signal by any periodic signal (sine, square) etc of around 5V-12V, i used a function generator and then an arduino. Turns out every 20Hz is aprox 1.2kRPM for this bike (it'll depend on how many cylinders your bike has, mine had 4). It turns out if you use 12V you get the full range of the tach. With help from my friend Jacob we hooked up a hall current sensor that Charles gave me to an arduino. The arduino brings in the voltage from the sensor and then sends a pulse of a frequency that corresponds to the current into the tach. I offset the 0 current position on the tach to be about of a third of the way into the tach so I could also show negative currents and thus show much current I'm regening. Next step is to print a new sticker for the tach that says "current" instead of RPM! I am also planning to hack into the fuel gauge to show battery charge or voltage and also hack into the temp gauge.



I decided it was time to get into 3d printing so i decided to start printing some lug covers for the high current terminals on the controller and motor. After a couple of iterations I got a pretty satisfactory lug cover.

v2 and 3 of the lug covers, more coming soon!

I also replaced the speedometer cable and tested the bike in the hallway, I got up to 20mph! I don't want to go any faster than that indoors! I am still waiting for the bracket to mount it to the frame as well as headlights and other parts.

Next steps is to start wiring all the brake lights and turn signals. I might add a 12V battery and DC/DC to the system so that I dont have so drain all the power for auxiliaries from the sevcon. I am also trying to use as much of the old harness as possible (junction box, switches, connectors).

I'm Riding Cholo!

Hey folks, its been long since the last update. This was a busy semester (but my last, yay!). I spent the last couple of weeks debugging the sevcon controllers to work with my AC-20.

I rigged up my testbed in the EVT room.

EVT test room

making sure to keep tires off the ground

Sevcon espAC with the bike

in the process of testing cholo ride, I had to revive two dead cells in this pack

putting the controller into the bike!

bike with zip tied batteries (better batteries and battery mounting coming soon!)

blown fuse!!!! during some auto-tune testing

power supply+espAC for autotuning

After struggling with the sevcon for a couple of hours Dgonz and I finally got this to happen!

Finally we waited for sunny sunday to do this:

I rode it around campus for a bit (i didn't want to ride too much given the bike is totally not street legal right now). Lots of fun! I Still need to mess around with the settings and fine tuning of the motor to get 100% of the motor potential. Currently I have a 72V 15Ah LiFePO4 pack (1kWh), I am hoping to upgrade this to 5kWh soon. I am also waiting for a sevcon gen4 size 6 to arrive to finish the bike.

[a more comprehensive update for the sevcon troubleshooting will be coming soon! in the meantime follow this as it is the best online tutorial that I found, credit to dgonz for all the sevcon help]

Cholocycle - Motor and Motor Mounts

Camilo and Victor spent lots of time making the clamps fit perfectly:

camilo staring at the clamps

victor posing for the camera

We then made renderings for the motor and its mounts (for prettiness sake)

rendered motor mount (soooo pretty)

The AC-20 finally arrived!

sexy motor!

Shout-out to Travis at http://emf-power.com/ who sold us the AC-20!

When the motor arrived we checked the laser cut clamps with the actual motor and then it was time for some waterjetting!

good fit!

waterjet pieces!

Roberto did some post machining on the water jet pieces, he drilled and tapped holes for the starboard clamp.


We also machined the sprocket with its bolt circle and its bore.

With the pieces waterjet and post machined it was motor mounting time! Roberto and Jacob spent part of their friday night putting the motor in. It took a while but it came out great!

the chain is on!

Our next big challenge is to get our Sevcon Gen4 driving the motor. Stay tuned for more updates!

A really big thanks to our friends at elmoto.net especially the folks that responded to our thread (big shout-out to Noah Podolefsky and Ted Dillard for their resources on AC-20 motor mounting.

Dismantling, cleaning, and welding CholoCycle

Hey guys, a lot has happened since our last blog post. We bought an AC-20 Motor which should arrive very soon. We also got a AC motor controller from SevCon.

     When we took the engine off CholoCycle we realized several things. We had a lot of space for batteries, several anchor points to mount stuff, and sadly, one of the previous owners had tried to cut the frame :(. This meant we had to dismantle the frame so we could take it to an experienced welder who can weld aluminum. Thanks to Scott from the Central Machine Shop for helping us out! 

Someone tried cutting the frame

Before

The first thing we did after taking the fairings and seat off was to make a mock-up of our motor. We conveniently found a PVC pipe that was around the same diameter as our motor.

Motor model fits pretty well

Motor model picture from top

Motor model picture from the chain side

While we were looking for the best place to mount the motor we realized how dirty the frame was. We had three options to clean the bike:
1. Bring a bucket of water and rags to the shop and wipe it down.
2. Roll it home and hose it down.
3. Roll it next door to D-Lab and shower it..... literally

Our Spanish friends are helping us wash choloCycle

Yup, it's going in the shower; Hmm, Camilo doesn't want to get his shirt wet.

Look at that Spanish ingenuity

Working hard. I should be a manager.

Squeaky Clean! :D

Now that CholoCycle is clean we cut out cardboard to make a quick model of the aluminum plate we would use to mount the ac-20.

Quick cutout of one of the motor mounts

Zip-tied motor model in place

First motor mount in place; third anchor point needed.

Much better picture of the motor mount. Oh Hai Roberto

The first two anchor points for the motor mount were not hard to find. The only problem with them is that they are not coplanar. This means we will have to make a spacer for at least one of those mounting points. More on that later! For the third mounting point we are thinking about welding a piece of c-channel (or maybe L-bracket) onto the side of the frame. We would then bolt the motor mount onto that c-channel so the mount is removable.

C-Channel welded on red square

There goes the front wheel....

Back wheel and swing arm are off too..

Time to take to the welder...

Who came up with the best way of carrying the chassis? Roberto? or...

 Or me? Lol at Dgonz and Nancy in the background

After taking apart the frame we also made new battery mock-ups. We settled on two different configurations. One in which we have the two batteries mounted side by side vertically. This means we would have to cut the cross-arm that joins the two sides of the frame. The second configuration would not require us to cut off the cross-arm. We would place them on top of each other in a criss-cross pattern. We still don't know which batteries we are getting but it seems that all the batteries will have the same width and height. For this reason we think that the vertical configuration would allow us to use longer modules.

Vertical Battery Configuration

Vertical Battery Configuration Side View

Criss-Cross Battery Configuration

Criss-Cross Battery Configuration Top View

Looks like the Sevcon Controller is arriving tomorrow and the ac-20 will arrive very soon too. More to come in the next couple of days!