48V gas powered charger

[mobile_bob]

Bent  (and anyone else that is interested)

having given this issue more thought, it occurred to me that maybe a bit more explanation is in order.

you seem to have an issue with me or think i am only concerned with my method of charging batteries, using only this method, to the exclusion of anything you might have to say or do on the subject.

let me tell you straight up front,

the white paper was not only the result of a lot of work, but perhaps more so a vindication of my dogheaded belief in some ways.

you think you are the first one to run into opposition, (not saying you have, but only acknowledging you feelings) i can tell you that i ran into serious opposition not only from the diy'er community but also more than a few ME and EE! 

rather than getting all wadded up about their being less than supportive (to put it mildly) i used their critiques as motivation and took what i could from that exchange.

rather than getting pissed off, i did my best to understand their concerns, did more research to see if their positions had validity and why.  i always made note of what the oppositions concerns were so that i could revisit them later.

sometimes later i would be confronted with an "aha" moment, and realize then what the critique was all about, learned from it and integrated it into my research and learning. sometimes i would also have a similar "aha" moment and learn that what i was being led to believe was not based on fact but rather on popular belief.

it might have been easier to just gotten pissed off and refused to at least listen to what the nay sayers had to say, however i would have shorted myself a lot of good information that led me to a more successful outcome.

reinventing the wheel really is a lot of work, and i got better things to do.

sometimes the nay sayers know what they are talking about, often times even when they are wrong it isn't because of a fault of theirs but more likely i didn't phrase my question properly or misunderstood what they had to say, particularly when those nay sayers were ME and EE.

bottom line is this, if you feel strongly about something, by all means proceed with all earnest, don't let me or anyone else dissuade you in any way.  take all critiques for what they can do to help you with your goals, and realize that you might have to thicken your skin a bit in the process.

remember anything of value does not come easy, if it did it would already have been done!

bottom line, get out in the shop (if you are at that stage yet) build your project, document it, do the testing, report the results and make alterations until you get the result you are after.  learn what you can from the process, from every other possible source, and from those that support and those that would be less than supportive. 

in the end that is all that is really important, that being learning something you didn't know before you started.

anyway that is the way i see it.

ymmv

bob g 

[Tom Reed]

Bob, your such a rabble rouser, face it the world is flat.  Actually you are a gentleman and a scholar!

I think one of the high points in my software developer carrier was when I delivered a complicated piece of software to client, we went through the testing and after proving that it worked the client remarked that they were told by a major player in the industry that what I just delivered could not be done.

Any comments on my Miller 1e update post?

[Mad_Labs]

Hi All,

Just back form my 48 hour shift.

So Steve, how about a 3.55" pully on the alt and a 4.95" on the motor? That gives me 5kRPM and is much larger.

And Bob, I did mean AX belts, not just A belts.

Bent, I do wish I could remain beltless, I love my current direct drive. Simple and nice looking and I didn't have to build a cage around the belts for safety and it keeps the foot print as small as possible. However in this case belts are going to be easier (I think) than rewinding an alt. I might still buy a 555 core from you to experiment with.

Thanks folks!

Jonathan

[SteveU.]

Sounds good Jonathan
Advantage of going smaller pulley is certainly the price. I have purchased larger up to 12" triples for long service life applications transferring 3X your power. Spendy.
Expanded metal makes a nice ventilated guard material. Realize you this alternator needs to suck cool air in the backside and expel it out the front at the fan edge.
I know you want to stay compact and will using as short of belts as possible. Too short of V bets shortens life. Micro tearing of the cords from the shock absorption and I think not enough cool down off of the pulley time. Too long of belts shortens life. They bounce and flap again micro tearing the cords. Ha! Ha! Best compromise I've found is to use an in local supplier stocked matched belt pair. Not something that has to be special ordered in.

Another basic factor in generating is the rotating feild/armature to stationary poles passing speeds. For truely optimized engineereing this is optimized by going larger with larger diameters to increase this this speed at the determined operating RPM. This is how many of the good DIY wind people do this with their PM hand mades. Same with the larger diameter pancake multi-pole PM direct bolt on units been pictured being used here by others. Very spaecial units. This is how the big boy Inverter unit manufacturers do this.
The low RPM direct drive transit bus units were the Delco type 50 DN's alternators and theirs and others earlier big generator units. You CAN acquire these.
Then have to step up to 3-4X in weight, size and base pricing. Even some specialty high efficiency alternator manufacturers catering to the Emergency vehicle market in Electrodyne, Niehoff and a third I cannot now recall that would down speed direct drive put out better to these expectations. Now into $$$$ new. OK used, but hard to find and high repair costs.
Price, availabilty and operating costs are ALWAYS factors we are all juggling.
With the 555 Motorola/Prestolite/Leece-Neville units you are as inexpensive into it as you will get with a readliavaible buy off the shelf new as a base to work with.

Regards
Steve Unruh

[Mad_Labs]

Steve,

What is a reccomended length or rule of thumb for determining it? While foot print is important to me, belt life is more important.

Jonathan

[SteveU.]

Hey.
Mr Lloyd was going to put up a link to the Gates belt engineering guide on another thread. Best answer would be in there or the Dayco equivalent.
From field service work I'd say minimum of 4 times average pulley diameter spacing shaft center to center. Very much longer is where you then benefit from the expensive top banded belts. Not recommending this as you must then for sure be using the proper depth of pulley V's. DIY you want to be able to substitute as needed.

Regards
Steve Unruh

[Mad_Labs]

Thanks Steve! Out of curiosity, what is the gen beaing run in the second picture above? Looks like a beast.

Jonathan

[Diesel_Mike]

Why not use two, 24 V alternators and split charge the batteries?  This would use off the shelf equipment.  I did this years ago on a boat with 12 V alternators to get 24 V.  Back then it met isolating the second alternator above ground.  Mike