Monday, October 4, 2010

Drive Line Improvements.




I got the Sram 3x9 drivetrain installed, and then tried to attach it to the mid drive. No joy. The mid drive cogs are too wide for a narrow 9 speed chain. So I disassembled a wheel in the garage that had a 7 speed cluster on it. The slot was still to narrow to go on with a quick release, so I had to hack up a quick release and get some washers to make this whole thing fit in the really tiny access compartment. I bought a surley chain tensioner but now I can't adjust it, so I'll have to make a tool so that I can reach in there and tension the chain. Now if you look closely, you'll see that the chain tube is protecting the electrical wiring, but the chain actually has to go AROUND THE WIRING. This can't be efficient. I want to find a way to run the chain without tubes. Maybe that idea about hacking all the bits of automotive grade electronics from the velomobile is a good idea....

The freewheel (yes it was a freewheel) is a 7 speed. This will allow me to adjust the gear ratios once I get everything running and depending on the planned terrain. Since you can't mash on the pedals in this velo, I'm going to need a way to get really low gearing for some of the hills around San Diego.

Lighter is better

The velomobile weighs about 210 pounds empty. I got to thinking that this is a bit heavy considering that most of these things are around 70 pounds empty and without any electrical. At any rate, I decided to remove all attempts at motorizing this thing as it adds weight and as far as I can tell only slows me down when I pedal. Even the new motor did this. I'm thinking if I strip it down I can get it under 100 pounds -- ideas for stripping it include:
  • Pulling the mirrors and replacing with bicycle equivalents
  • Removing the horn (replace with a bike horn)
  • Removing turn signals (replace with bike signals)
  • Removing the struts and hinge for the canopy and making it slide forward rather than lift up
  • Removing some key bits of fiberglass
  • Removing the ventilation system
  • Possibly replacing the full canopy with a cloth top for a heads out sort of velomobile

Sunday, July 11, 2010

Drivetrain improvements

Okay so after my motor fix I've been thinking long and hard about how to get an acceptable gear range in this thing. The aerorider only had an 8 speed drivetrain and it was geared high which doesn't work for a hilly area like san Diego. So I went to replace the cranks with some campy 10 speed cranks I had in the garage. The crank bolts weren't even tight. After searching for my crank extractor for an hour I gave up.

Saturday, June 5, 2010

Commuted by trike last week.

Since I had to go on blood pressure medicine last week, I decided enough was enough. Since my current work schedule does not allow me to work out at lunch like I used to, I built up my catrike trail for commuter duty until I can get the aerorider functioning. I doubt the SLA batteries are going to have the range I commute anyway, but just in case. I rode to work two days last week. My commute is 40 miles round trip. Hopefully the velomobile is faster than the catrike because it takes too long to get to work right now.

The dc-dc converter works at 48 volts.

The dc-dc converter on the aerorider is flagged at 36 volts of input. I finally decided to try and fire it up. It works at 48 volts. None of the magic smoke came out. I tested it with the headlamp, horn and blinkers. Then I went to remount the blinker switch in the left handlebar.... I messed up the switch doing it :(, so now off to radio shack to get a new switch. I also ran the throttle wire through the body, and mounted the controller on an existing stud in the fiberglass. It will rattle, so I'll need to put something under it to protect it.

Sunday, May 16, 2010

It rides again!

I bought a conhismotor from conhistmotor.com and got the velo running again. Took it out for a spin. It's got a touch more power than the 500 watt motor did. The new motor is 48 volts and 1000 watts rated. The new motor can get me up the hill from the house a little better than the old one. Now to get a new freewheel and configure the rear shifting to support a 9 speed drivetrain.

Monday, March 22, 2010

Vic made me post this.....


Wow, the last post was feb 6th....
I've been too depressed. My dream car is up on blocks. In frustration, I gutted every electronic component to start over with modern electronics, batteries, and motors.
I had to research electric motors and find a manufacturer that could meet a few requirements.
1. Push 400 pounds up a 15% grade (that's 200 pounds of velo, and 200 pounds of lard). I live on a 15% grade, so the 15% part is important.
2. Allow for a reverse -- it's not like you can put your feet down and go backwards.
3. Cover 70 miles without a charge (this is more of a battery issue than a motor issue)
4. Not run through the body -- many motor solutions use the crank system to drive them. I plan to use an internally geared hub for shifting. They typically can't take much power, and the monocoque construction of the velo bends when I press with all my might -- bad news for powering through the drivetrain.
5. Sustain 20 MPH over the bulk of my ride.

I found out that when I was pedaling with the old motor system, I was actually fighting the motor when my power output was in excess of the speed that the motor could drive the velomobile.

The new motor will probably have the same problem, but if I am pedaling faster than the motor, what I need to do is cut the power and pedal on my own power.

After talking with everyone and their mother about how to power this thing (every ebay seller, every internet ebike seller, etc), I'm planning on getting a BMC motor from:
http://www.electric-bikes.com/betterbikes/bmc.html
Whenever I can save my pennies to pay for it. I'll get a large capacity LiFePO4 battery direct from China at a place that seems to have good reviews at endlesssphere.com. In the process, I will have to change the power side of the drivetrain -- I have parts coming for that which I will show in another post. Basically, in the middle of the velomobile there is a transfer case of sorts. I'm going to mount an internally geared hub in there and affix a cog to the disk brake side of the transfer hub, and the motor. The other alternative is to mount two hubs in the middle with a crossover chain, but I don't think it will fit.