Miscellaneous Projects
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Winter Project January 2013 - Electric ATV

A long overdue project is the Electric ATV I promised my oldest son in 2010.

















Winter Project January 2013 - Long Wheelbase Electric Bicycle

Another long overdue project is the practical electric bicycle to be built with my youngest son.













Kraig took the Linear out for a 6 mile spin after at least 7 years out of service...it's so much more comfortable and enjoyable that an upright!   Nick wanted upright handlebars because it looks cooler (Kraig agrees it looks cooler), but eventually I'm sure we'll go back to underseat steering because it's so much more comfortable.

Nick was really unstable on his first ride, I had forgotten that it takes some practice to learn how to ride the Linear.  We'll get him to a parking lot so he can get it down before putting him on the street.  On this note, I think it's easier to learn how to ride the Linear with upright handle bars than with underseat steering, so this will be a good evolution for Nick and also give us some more time to work on projects as we modify the bike to make it more comfortable and efficient.

It's surprising how much the front suspension fork smooth's out the ride and how much difference 4 inches forward or back with the seat makes for the front suspension - Nicks legs are shorter than Kraigs and so rides with the seat more forward and it makes a huge difference in the dampening.

We have a friend who says he'll donate some Lion Batteries, so the project is moving along.  With Earth Fair done after this weekend, I'll be able to work on this project some more. We can't wait to get the batteries on board and take this baby for an electric spin!





Used batteries donated from a friend on May 4, 2012. They are Elite Power Systems 20ah batteries abused in a 48Volt prototype Trail 70 project. They probably have less than 30 recharge cycles on them, but some very abusive. 3 of the 12 volt modules are holding a charge with each cell at exactly 3.33 volts each. One of the 12 volt modules (4 cells) are at 0 volts. 2 of the 16 balance boards seem dead (no LED light).

The cells weigh in at 6.25 # for each 12 volt module for a total of 25# for 48v x 20ah = 960 Wh of power x 70% = 672 Wh / 25 Wh/Mile = 27 mile range.


May 5, 2013: Here is recharge station setup outdoors to attempt to slowly bring the dead cells back to life. Using a variable power supply and keeping always under 2.5 amps, voltage was slowly increased to 3.3 volts. The voltage will be held at 3.3 volts until the cell holds a charge.

SOLAR FURNACES bigdish.jpg
The satellite dish solar furnace shown above causes a wooden two by four to burst into flames in less than 15 seconds. The energy from the noon-time sun is said to be about 1,000 watts per square meter. Eye-Protection and extreme caution are required!

There is truely nothing new under the sun...here is a link to a 1916 Magazine article on a working solar furnace.

"When you're one step ahead of the crowd you're a genius. When you're two steps ahead, you're a crackpot." -- Rabbi Shlomo Riskin (Feb. 1998)
TEST MOUNTING Sept 2009 deadoak.jpg
The day began like any other. I spend two hours tuning an electric vehicle and doing some road testing...then moved on to something potentially more exciting.

I've wanted to mount that solar dish on the south side of my house to do some trials heating water for heating my house in the winter. But, I needed a 3.5 inch diamter post to mount it on. I thought I'd have to purchase one. But, speed is more important than perfection when doing experiments and I'm learning I can find everything I need quickly and for free if I just open my eyes and let myself be creative. So, I wandered for a few minutes finding myself in the woods behind my house next to a small, dead, oak tree. What a perfectly simple and free post!
Putting it together assem.jpg
At first, I thought I might assemble the dish on the mount in the air, but that was not the way to do it.

Mounting it
maggie.jpg
First the dish gets assembled, then you get good looking friends to help lift it into place.
Using It
mmellow.jpg
While I was practicing aiming the dish, my son had some fun cooking marshmellows...

Here are lessons learned through this experience:
  • Dish with mounting bracket attached to it is too heavy for one person to mount. 2 or 3 people are required
  • Oak pole is not strong enough. A nice 3.5 inch diameter basket ball hoop steel pole would work great
  • My mounting point was 1 foot too close to my house, but the mounting height was perfect
  • The walkway provided by the old hot tub deck worked great for being able to mount and service the dish
  • Aiming is critical to power output. The dish must be pointed right at the sun for the focal point to be on center
  • The dish mount has the nessesary adjustments for aiming at and tracking the sun, but electronics are required to keep it aimed perfectly and declination would need to be manually adjusted once per week.
  • Aiming and surface imperfections on dish are critical to not reflecting sunlight into neighbors yards and houses
  • Dish provides a nice shade - Totally unexpected learning - It was a very hot day and the sun was beating down. I was sweating like a trooper, but when I went behind the dish to aim it, it was cool. So, any solar heating system has the benefit of providing heated water AND shade!
  • Digital garden hose timer might provide a cheap way to turn water flow from dish on and off. These have a manual on/off switch and an automatic timer operated on/off.
  • Since aiming and surface reflection are so critical with this dish it makes me conclude that flat, non-reflective systems are a simpler and probably less expensive solution. The two advantages of a solar dish are potentially less heated surface area and higher fluid temperatures which may translate into better operating efficiency per square foot.
ELECTRIFIED BICYCLE 1mtnbike1.jpg
Mounting a motor from an electric scooter to a mountain bike this way did not provide enough torque to drive the bike...will need to change the gearing dramatically to make this little motor do the job...
ELECTRIFIED BICYCLE 2: Lessons Learned
linear.jpg

Here are lessons learned through this experience:
Note the springer fork with the Sparrow hub motor mounted in 20inch wheel on Linear recumbent. Acceleration was slow and top speed was not all that great, mainly because of the 60 pounds of lead acid battery weight. But, as always, it was a smooth comfortable ride.
ELECTRIFIED BICYCLE 3 Mockup
This is my second attempt a motorizing a mountain bike. This time I used a hub motor with lots of torque - the Sparrow hub motor from electric rider. In the picture below you can see that I used foam to mockup battery placement. The only reason I was using such heavy and large batteries is because they were free and sitting around in my workshop doing nothing. mockup.jpg
ELECTRIFIED BICYCLE 3 Side Views
This bike setup worked good although it was very heavy. The batteries were 12volt, 20amp hour and weighed 20 pounds each. The motor weighed 12 pounds and the the misc. brackets about 12 pounds.

The setup was direct drive to my front chain ring meaning if the motor was running the pedals were turning. This limits the max speed of the bike to the the max geared speed of about 25mph. The motor had plenty of power left and could spin the pedals faster than I could keep up. So, I'd either need taller gearing on the bike or need to setup the motor to drive the rear wheel directly - at this point the hub motor needs to go back into the wheel.

At 20-21mph the motor was drawing 18 amps x 48 volts = 864 watts.
At 25mph the motor was drawing 27-30 amps x 48 volts = 1440 watts. side1.jpg

side2.jpg

side4.jpg
ELECTRIFIED BICYCLE 3 Lessons Learned
side3.jpg

Here are lessons learned through this experience:
  • I tested this hub motor when it was in a 20inch wheel on my LWB Linear recumbent. Acceleration was slow and top speed was not all that great.
  • This test was to see if this hub motor would work better when driving through a transmission. And the answer is yes. Acceleration and hill climbing are greatly improved. However, it's max speed is still limited by the gearing on the bike (because if the motor is running the pedals must turn). And this makes it not work for what I want to accomplish. I want higher speeds (25-30mph) to reduce my commute time with no sweat on the trip to work.
  • I like the cruise control feature, but it should not be used with a direct drive system. It's too easy to forget to disengage the cruise when you want to stop pedaling.
  • The direct drive forced pedaling was good for exercising, but resulted in me being sweaty when getting to work which is what I'm trying to avoid.
  • The direct drive worked nice and was easy to control and made my average speed increase from 15mph without motor to 22mph+ with the motor
  • At 25mph motor was pulling 30AMPs! Way more than my electric moped at this speed. So, the upright riding position and poor aerodynamics of this setup are apparently killing me for power consumption
  • Need full suspension when riding with +80 pounds of stuff mounted on the bike
  • Weight was fine and although I could feel it when taking off or trying to lift the rear end of the bike when moving it around, when pedalling without the motor running, my average speed was about the same. So, I can carry a lot of cargo on my bike on flat roads at a steady speed without much penalty. However, if I was doing a lot of starts and stops and hills the extra weight would be quite a drag.
  • Chain tensioner as part of system would be nice. I had some problems with chain jumping off. A nice spring tensioner would allow chain to be snug but not tight
  • Observation: When pushing full power on this setup I noticed a lot of chainring deflection. Bicycle chain and chainrings are not built for 2HP+ forces. Should use heavier components when using over 2HP motors.
  • It makes sense to pay attention to 100+ years of bicycle, moped and motorcycle development. Mopeds and motorcycles are equiped with heavier duty wheels, suspension and drive chains to match power and velocity.
  • Hub motor should be in wheel to give simple, quiet operation. I should just purchase a BRUTE hub motor and install it in place of the rear wheel of a fully suspended mountain bike. This would give me high speed commutes (30mph+), allow for pedalling and exercise on the way home. I would still need to install larger chainrings on the bike to allow pedalling in the 25-30mph range.
TREBUCHET RELEASE MECHANISMS atrest.jpg
For Cubscouts, I had our pack at the shop so each boy could build a desktop-size-trebuchet using strips of aluminum for the frame. It was an engineering project teaching the kids about bridge truss design and about various metal working processes (we made parts on the lathe, mill, cut-off saw, and even had the CNC engrave their names on the side of the trebuchet...).



release.jpg
The secret to a trebuchet is an adjustable release mechanism. A rubber coated automobile key blank works great. Drill a hole in the key to hold one end of the sling and attach it to the trebuchet with an 8-32 screw and wing nut.

Adjusting the angle of the key drastically affects the trajectory of the object being tossed. A different angle is required for projectiles of different masses. This makes a great platform for teaching kids how to conduct an experiment. It's fun, and it is easy to change the variables affecting flight distance.

cocked.jpg
For a school science project, one of my boys did experiments with various mass counterweights, projectiles and release mechanism angles.

Using a 4lb 2oz counterweight, 7/16-14 steel hex nuts were easily thrown over 10 meters (10 meters to touch down, they rolled a lot farther than that!).

We found another important variable when conducting the experiment. The release height of the projectile. For some reason, if the projectile is held up away from the ground when released, the distance of the toss is greatly improved.

Notice that a heavy piece of steel was wired tied to the trebuchet to hold it in place while doing the experiments...