Insanity? -- 3 phase battery powered MOTORCYCLE!

Hm, he could just buy 8 garden tractor batteries. Not exactly cheap, but not that expensive.

Agreed.

Well, that's a part of fun of life. After all, it is much easier to buy a working gasoline motorcycle than it is to dick around with strange motors.

Sometimes using scrounged parts helps. For example, I built a 10 HP phase converter for $45 worth os used components. A commercial one would cost me $600 plus freight shipping. Mine works just fine.

This may be the case with a 3 phase battery, inverter, phease converter and 3 phase motor powered "motorcycle", but not in general.

It's a matter of common sense related to the individual project in question.

Should I hire a licensed electrician to replace an electrical outlet? DIY is a better option for most.

Should I build a $10 digital clock myself? Not really.

Should I build a $45 phase converter instead of $600+shipping phase converter? Sure.

Should I buy a cheap 3 phase compressor and repower it for single phase, inctead of buying a more expensive single phase compressor? Why not.

Should I build a homemade lathe using hand files and home castings? That would be stupid.

Should I build a homemade water slide? Why not.

It's all about specific details of specific projects.

That statement is too broad. The guys who made compressed homemade air dryers are way ahead, money wise and likely functionality wise.

That would be my approach if I was tasked with "making an electric motorcycle". All it needs is batteries and motor and speed control.

That would also involve an incredible amount of time needed to make sensible operator controls. (start, stop, accelerate, etc)

It is not the kind of project that I would undertake.

i

They are polyphase AC motors, but they're not induction motors.

There's really no such thing as a "DC motor". In motors that run on DC, commutation is accomplished either with brushes on a commutator, or with electronics. In either case, the windings are driven with AC. That's why even DC motors are made with steel laminations, not just big chunks of cast or forged iron or steel.

If you'll excuse my pedantics, I believe a homopolar motor could be called a true "DC motor".

Based on my limited experience, it's easier to buy a *broke* gasoline motocycle and fix it than to dick around with strange motors.

But not really suited to the job, becasue they are not deep cycle batteries.

You are correct.

But I still think making a motorcycle with a large heavy 3phase motor is the wrong approach. chuck

It's hard to get cheaper than mass production, particularly offshore mass production, with a one-off. However....

take a look at electric drives for boat lifts.

Not counting enjoyable shop time, I'm quite sure you or I could design and build something like that for a whole lot less than what they're asking.

Motor & gear train: Harbor Freight, item # 92860, $49.99. Drive wheel: haven't figured that out yet. Maybe Tim Williams would pour me one out of aluminum if I sent him a pattern......???

Having a son that is a silicon peddler works too!

Ah, I see. Makes sense.

i

Yep.

i

That could get him running.

Oh, I also think that it is a very bad project to undertake.

i

I was thinking of this ,too bad you don't know if this going to be a trike or a 2 wheeled motorcycle ,or if he is going to be running a motorcycle transmission or not ,if he built a trike then he can easily get a generator head from harbour freight for like a couple hundred bucks and you can buy small engines of different sizes all over the place to power it for little bit of money and put it in a small trailer with a small battery bank in it you could actually have almost limitless range with it (when the power gets down just hit a switch to start the generator run off it while the residual power is recharging the batteries then when charged up switch off the generator and run off batteries) if i remember right the new electric conversion kits run a 3 phase motor hooked to the stock transmission ,because they go better in traffic and since they do have an electric motor you can't stall it and it don't really have a torque range so you get plenty of power to the wheels i wont be surprised if he is building a trike like that ,but if it is a 2 wheeled bike you can still hook it up to the tranny using a 3" belt to the tranny and adjust the sprockets for best speed and would be a great little runabout for the local area he wouldn't have to use gas for little runs which could save him hundreds of dollars in gas (this would be my second guess ) since a car uses more gas on short runs just my 2 cents

A friend of mine built an electric motorcycle from scratch. He used 2 12v deep cycle marine batteries, but was unhappy with the performance. He opted for nickel metal hydride cells. About 210 of them, IIRC It did work to his satisfaction.

He got bored with it, though, removed the battery pack, and installed a Wren brand model turboprop engine unit. Also a success, and turn way more heads in traffic. If you follow behind him, you can read peoples' lips... "what the ..."

I'd like to know what his range was. Steam power consumes an awful lot of water.

I just saw a car today, when I went out running, that reminisced of what you are describing. All wheels were probably from different vehicles, very little "body" to speak of, and salvaged parts everywhere.

i

According to the OP, the boiler exploded not too far from home.

i

I like the Sidewinder Remote control Direct "Dive" motor myself. :-)

I think the wheel needs to be rubber coated. Say a good heavy duty rubber tired caster wheel.

Wayne Cook Shamrock, TX

"Ignoramus32687" wrote in message news:%EiOe.1769$ snipped-for-privacy@fe16.usenetserver.com... | I had a visitor yesterday who responded to my craigslist ad about a | free 200V 7.5 HP 3 phase motor. A pleasant, intelligent young man. I | asked him what he was doing with the motor, and he replied that he was | going to build an electric motorcycle. His plan is, apparently, to | have a motorcycle based on batteries, inverter, phase converter, and a | 3 phase motor drive. I just could not believe what I heard. (and still | have doubts about his veracity) Am I going crazy or does this sound | like a completely insane idea to you? | | i

Not insane. Just ignorant. Not his fault. I bet that he's got just enough knowledge under his belt to be dangerous, so if I were you, I'd let him have it. He can't kill himself (I doubt it, anyway!) with it but I'm sure he'll learn a whole lot about efficiency in the process, which coupled with his real understanding of how things work, will undoubtedly be useful some day. Let him know that you'd like to be there if he has any issues, which will for sure be the case. You never know, he just might come up with something useful, although not what he started out to do! I've done far worse than that when I was a kid. My dad really got fed up with all the fuses I was blowing in the house from junk I was whipping up and plugging into the wall! I'd say I've done a bit better as I got older and just slightly wiser.

I already gave the motor to him.

I agree here. I did tell him that he was welcome with questions.

i