View Single Post
  #284   Report Post  
Old June 28th 05, 01:55 AM
Posts: n/a

On Tue, 28 Jun 2005 09:36:36 +1000, George Ghio

wmbjk wrote:
On 26 Jun 2005 19:48:32 -0700, "Too_Many_Tools"

Here's a sample day's work (yesterday's) in an off-grid workshop. The
project was building the last 2 of 5 scissor trusses for a friend's
aircraft hangar. All material was scrap - chords of 2" and 1.5"
schedule 40 pipe. Long braces from T posts, shorter ones from 5/8"
sucker rod. Most of the material was cut a few days ago. I wore out 3
chop saw blades (medium quality ones) which should give you an idea of
run time. The trusses are 40' wide, but built in halves. Each half
took about 30 minutes to lay out and prep, including about 15 minutes
use of a 4" side grinder. Then 26 welds per side, flip, another 26
welds. Layout, prep, and welding - about one hour total per half, with
a long break between each one to cool off. I built 4 halves, about 100
minutes welding for the day. I didn't check the current draw, but the
machine was set at 280 inches per second, 18 Volts, with .035" solid
wire. Perhaps 5kW input. Charging rate was medium, there was good sun,
but almost no wind, which was nice because I could leave the shop
doors open. When I quit for the day, my wife commented that battery
state of charge had dropped 6 Amp hours, and that she'd used the AC in
the office for a couple of hours. On this project, like most others
here, there wasn't any penalty for being off-grid, which is way cool


Ah Wayne, it looks like your saying 5kW for 1.6 hours and claiming that
it equates to 6 amp hours.

Would you like to refrase that amd perhaps look at the maths.

You use of units may be suspect. And your numbers would suggest that you
can only work when the sun is out.

5Kw input for 1.6 hours at 24V looks suspiciously like 333Ah.

I started at about 8AM, and I finished up at about 4PM. During that
time, 2000 Watts of tracked PV was doing its job, along with a tiny
bit of help from 1300 Watts of wind generator in the AM. Duh!

Even after all your pathetic nonsense, I'm still astonished that with
your claimed 20 years of experience, that you need such simple
concepts explained to you. Haven't you learned *anything*? How the
hell can you function? As usual, whatever you do, don't admit that you
just wrote perhaps *the* biggest blunder of your Usenet career, or
apologise for it. But if you had one iota of shame, you'd go stand in
the corner for the next 20 years.

BTW, in your haste to act the fool, you failed to notice an actual
mistake - that I wrote "inches per second" wire speed when I should
have written inches per *minute*. Can't you do *anything* right?