Power and Weight

[Frank Lee]

Plug your vehicle of choice's stats into the EM performance calculator, then play with added weight to see the predicted effect on rolling resistance. The calculator is pretty good.

Of course if you are in urban/mountainous terrain weight is a bigger factor; for me out on the semi-rural flatlands, not so much especially after the design/construction phase.

[byte312]

Originally Posted by Frank Lee

Plug your vehicle of choice's stats into the EM performance calculator, then play with added weight to see the predicted effect on rolling resistance. The calculator is pretty good.

Of course if you are in urban/mountainous terrain weight is a bigger factor; for me out on the semi-rural flatlands, not so much especially after the design/construction phase.

Wow, I like it. where do I find the calculator. This would end the debate in a hurry.

[Frank Lee]

Top 'O' the page, select "tools" under "Garage & Tools".

[byte312]

Originally Posted by Frank Lee

Top 'O' the page, select "tools" under "Garage & Tools".

Many thanks, I am using the tool to see the calculated results.
Cheers to everyone who are working on these projects. I am watching and learning.

To everyone, sorry if I have sounded too critical lately. I have high expectations for myself.
I have schematics that I offer free to everyone in PDF format. The contents is a few years of my own experimental work. This almost always draws a negative coment and sarcasm but it is OK, a little sand in the oyster might make a pearl. It makes me more determined. I am cool with it.
I will try to post a video link soon. You might see me slip and fall but I can take it. I am looking for your advise when ever you can give it. I think everyone has done something fantastic that they can share and many have done so already. I am in your debt.

[NHRABill]

Originally Posted by byte312

Some good examples are: (and yes I am saying it again) the Tesla cars, or the British Mini with a range of 280 miles. The Leaf is not bad with a range of 100 miles. That would make me happy. There are different and better ways to build a car. Pick the best example and work from there.

Just like all auto companies they Fudge the numbers so much in the beginning by the time the real #'s come out people ignore them

According to the U.S. EPA,

The Tesla gets 244 miles (393 km) on a single charge

Tesla Roadster - Wikipedia, the free encyclopedia

The Leaf is 27% Less than it originally advertised they only get 73mpg as per EPA

Tesla Roadster - Wikipedia, the free encyclopedia

Mini Electric well I couldn't find a EPA sticker rating oddly enough but from the 3 mins of research I keep hearing it only gets 70mpg - a Best of 100 miles per charge

2009 MINI MINI E Review - All Cars Electric

[byte312]

Yes, the advertised numbers are sometimes different than the real world numbers. Sometimes the first numbers are too conservative and sometimes too high. My car was rated at 35 mpg but I average 42. My 1994 Saturn still runs great and I can't find a new car that matches the mileage.
Still, I love working with electronics so much that I am willing to convert it to electric. It is great fun!

[DJBecker]

Originally Posted by byte312

Ok I think that you are correct. But is it fair to say that drag will increase with added weight? The kenetic energy is x2 for twice the weight but now add the increased drag from the tires being pressed into the pavement and the bearing friction then figure in the reduced effeciency of the motor as it passes more current almost like a straight piece of wire under heavy load. This is what will rapidly discharge your batteries.

The aerodynamic drag will be mostly unchanged with higher weight. The rolling resistance and drivetrain losses increase, but not 2x. The impact on range will be very, very dependent on the drive cycle. Driving on a level highway is dominated by aerodynamic drag and speed-dependent drivetrain losses, with almost no dependence on weight. Driving in stop-and-go traffic or on hills is dominated by the vehicle weight.

Originally Posted by byte312

regeneration of 25% to 30% is fantastic. If you can get that much energy back, your range will be 25 to 30% better.

No. No it won't. That's energy recovery, not the increase in range. Especially if you use the optimistic definition of range "how fan could I possibly get at constant speed on a level highway". Regeneration adds 0 to that 'range'.

On a realistic drive cycle, regeneration will improve the efficiency 5-15%. Again, heavily dependent on the details of the drive cycle. Yes, it's free energy. But it's grossly oversold as a benefit.

Originally Posted by byte312

The most practical cars do not have a full transmission, CV joints, and differential.

Practical cars have all of those. Tesla only skipped the transmission because they couldn't get their initial design to work. (Pretty much they ended up with a one speed transmission as an interim substitute.) You can only omit the differential with multiple motors, which is uncommon. And to get rid of the CV joints you need hub motors, with an unworkable increase in unsprung weight.

[byte312]

I have been working on the regenerative aspects of my project for a long time now. When I talk about it people assume that I mean regenerative brakeing, or an off the shelf device. I came up with a way to reclaim the reverse electromagnetic field in the motor also some noise from the brushes and excess forward current when under load or stalled and inbetween pulses. The collected energy is stored in capacitors and consumed by the battery or motor again.

I think I might have posted some of this before but, this has been my baby. I am not as good with the mechanical side of it all and I would appreciate some advise with reguard to mounting the flywheel to the motor shaft. I have found some hardware to fit the keyed 7/8 shaft with a flange but should this be a pressed fitting that grips the shaft tight?

I started with small toy motors to see if I was sane. I got 26% more run time matching the same speed. When the motor finally quit after 26 hours running as fast as it could go, it would slow way down and then suddenly start up again at full speed for a few seconds. It would do this 3 times and then stop as if a switch had been turned off. I allowed the small AA battery to rest assuming that it would run the toy motor again after an hour or so. It did not. The circuit had emptied the battery totally. Chargeing capacitors can do that I discovered.
Then I used an Etek motor and got better results. I won't say how much better until the next motor and all is in the car and I can say, OK here it is good or bad.
I just discovered the benefits of using IGBT modules for power output stages which should make it smaller in the end. The 2nd prototype is in a box that measures approx 14 x 19 inches by 6 inches high.
I do share. If any one understands electronics and pulse width modulated motor speed controls you can ask me for the schematic. Its is crazy different but it works at least as much as it runs my big motor for 52.5 hours on a small car battery. I now have a provisonal patent so I am free to let you all have a look. I am extremly determined to find new and better ways to do things. Please do not hate me for my passion.