New Landrover Fan has arrived

A2 is double A3

A1 is double A2

A0 is double A1

/disclaimer: all afair

High street print/copy shop should be able to make copies and/or reductions.

and range :)

On or around Tue, 19 Dec 2006 00:48:21 -0000, "William Tasso" enlightened us thusly:

they are indeed, I think there's an A0A as well.

Put 2x 210x297 A4 side by side and you get 297x420 which is A3, etc. cut A4 in half on the long side you get erm...148.5x210: A5.

and so on.

On or around Mon, 18 Dec 2006 22:45:41 GMT, "JacobH" enlightened us thusly:

hmmm. this is true. And that's now scheduled for next summer...

Simon Isaacs wrote: Also

If you have a motor on each wheel, you wouldn´t need any transmission at all, in series the motors will self-differential, in parallel they won´t. It would mean you also have to repatch the battery pack, else in parallell mode, the drive would be very seriously interesting, since the motors would be 100% overvoltage.

Can you say "pole position" Baby Isaacs ?

Steve

I think at this rate he's not only going to need a crash helmet, but also a model Sankey trailer to carry all the batteries!

On or around Tue, 19 Dec 2006 08:46:04 +0000, steve Taylor enlightened us thusly:

will they? spose they might at that; each motor will get an equal share of current.

hmmm. not sure about this one. A motor with no grip in a parallel situation can't steal all the torque in the same way as wheel on an open diff.

No, I think my point is that the motors are essentially now in "locked" diff mode - all wheels will turn, if the battery impedance is very low.

Steve

the doubling is along the long side!

On or around Tue, 19 Dec 2006 12:43:07 +0000, steve enlightened us thusly:

well, yeah. but what stops 'em doing that wired in parallel?

They CAN all turn, but the wheels that are spinning freely take naff all current.

Steve

On or around Tue, 19 Dec 2006 22:27:08 +0000, steve enlightened us thusly:

wheels with resistance would draw more, though? It's torque that counts, after all. Provided a free-spinning wheel can't rob power from a not-spinning one.

I'm trying to determine whether it needs complicated driving systems or whether you simply feed all 4 motors in parallel and let the unloaded wheels spin if they want to. They'll soon slow down if/when they get any grip. meanwhile the wheels under load will draw more current and produce more torque. Maybe.

then again, in terms of speed control and efficiency, I reckon a fullsize one running off a generator would do better on AC, but I've not looked into it in detail.

Exactly, hence my comment about the low resistance battery supply.

Yes.

Its generally reckoned that permanent magnet, brushless DC drives are the most efficient motors available, or possibly even possible IYSWIM.

STeve

PS Parcel arrived. Ta.

On or around Wed, 20 Dec 2006 16:02:44 +0000, steve Taylor enlightened us thusly:

hmmm. wonder how the overall efficiency stacks up with variable speed drives... one advantage of DC would be that you could do a hybrid with batteries as well to cover power surge requirements, and a smaller generator a la toyota prius. voltage is another thing - you'd want it to run as high a voltage as reasonably practical to minimise the current required.

ah, good, I was meaning to ask about that.

You want to run at a high voltage, but your control comes from switch mode electronics feeding the thing. You really want > 200 V DC.

Steve

Congratulations to you and Dawn from Neil and Diane (and crazy dog Cody!)

(Reply via NG please)