My MOT spotwelder is in the DropBox
 

I did it as a pdf, using CutePDF to convert the html that I wrote in it.
Thanks again, George, for the tip. I pdf'ed it as a single page to
avoid all the white space that gets in when images occur at page breaks.
I wish that CutePDF had an easy way to do it. A "Fit on one page"
option. What's the big deal with "pages", anyhow. The concept is only
relevant to hard copy, mostly.

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

Bob

My MOT spotwelder is in the DropBox
 

Bob Engelhardt wrote:
... I've done a copy of sheet
metal projects with it ...

make that "... a couple of ... projects". But you knew what I meant. Bob

My MOT spotwelder is in the DropBox
 

On Thu, 20 Sep 2007 23:31:31 -0400, Bob Engelhardt
wrote:

I did it as a pdf, using CutePDF to convert the html that I wrote in it.
Thanks again, George, for the tip. I pdf'ed it as a single page to
avoid all the white space that gets in when images occur at page breaks.
I wish that CutePDF had an easy way to do it. A "Fit on one page"
option. What's the big deal with "pages", anyhow. The concept is only
relevant to hard copy, mostly.

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

Bob
========
Good job!

A pleasure to see this type of documentation.


Unka' George [George McDuffee]
============
Merchants have no country.
The mere spot they stand on
does not constitute so strong an attachment
as that from which they draw their gains.

Thomas Jefferson (1743-1826),
U.S. president. Letter, 17 March 1814.

My MOT spotwelder is in the DropBox
 

Bob Engelhardt wrote:

Anyhow, take at look. Â*It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

Thanks for your effort to summarize it. Looks great!


Nick
--
The lowcost-DRO:
http://www.yadro.de

My MOT spotwelder is in the DropBox
 

On Thu, 20 Sep 2007 23:31:31 -0400, Bob Engelhardt
wrote:

I did it as a pdf, using CutePDF to convert the html that I wrote in it.
Thanks again, George, for the tip. I pdf'ed it as a single page to
avoid all the white space that gets in when images occur at page breaks.
I wish that CutePDF had an easy way to do it. A "Fit on one page"
option. What's the big deal with "pages", anyhow. The concept is only
relevant to hard copy, mostly.

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

Bob


Top Notch, Bob. This is exactly the sort of thing that even I should
be able to reproduce. And I know where there are a bunch of junked
microwave ovens to pick thru!

Thank you kindly,

Jim

My MOT spotwelder is in the DropBox
 

Bob Engelhardt wrote:
I did it as a pdf, using CutePDF to convert the html that I wrote in it.
Thanks again, George, for the tip. I pdf'ed it as a single page to
avoid all the white space that gets in when images occur at page breaks.
I wish that CutePDF had an easy way to do it. A "Fit on one page"
option. What's the big deal with "pages", anyhow. The concept is only
relevant to hard copy, mostly.

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

Love that busbar-style secondary winding.
Nicely done.

My MOT spotwelder is in the DropBox
 

Bob Engelhardt wrote:

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf


I showed that to my coworker last night. Boy was he bummed, he just tossed
a microwave.

Kudo's for documenting your project.

BTW, what generally fails in a microwave?

Wes

My MOT spotwelder is in the DropBox
 

Wes wrote:
Bob Engelhardt wrote:

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf


I showed that to my coworker last night. Boy was he bummed, he just tossed
a microwave.

Kudo's for documenting your project.

BTW, what generally fails in a microwave?

Wes

BTW, what generally fails in a microwave?
My wifes cooking.

My MOT spotwelder is in the DropBox
 

Wes wrote:

Bob Engelhardt wrote:

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

I showed that to my coworker last night. Boy was he bummed, he just tossed
a microwave.

Kudo's for documenting your project.

BTW, what generally fails in a microwave?


The fuse, the door switches, the controller board, the magnetron, the
thermal cutouts, and once in a while, the transformer.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

My MOT spotwelder is in the DropBox
 

Very nice, I really like that plate aluminum secondary.

John

My MOT spotwelder is in the DropBox
 

Michael A. Terrell wrote:
Wes wrote:
....
BTW, what generally fails in a microwave?

The fuse, the door switches, the controller board, the magnetron, the
thermal cutouts, and once in a while, the transformer.

In that order. And if the transformer fails, it will mostly likely be
the secondary, which is 22 or 24 ga wire. Which is the part that is
removed. IOW, even a broken microwave oven can be counted on to have a
usable transformer.

Bob

My MOT spotwelder is in the DropBox
 

Thanks for the kind words - I love it.

I was looking at some other stuff that I had posted to the DropBox and I
saw where the description was lacking. I think it is a matter of at the
time you're so close to it that you don't realize how someone else will
read it. So, I'm sure that I've done that with the spotwelder post,
too. If there is anything in the post that is confusing, or could be
added, or improved, please let me know.

Thanks,
Bob

My MOT spotwelder is in the DropBox
 

That's a really nice piece of work!

I'd have to dig out my freshman physics book to be sure, but I expect
the reason filling the space in the transformer is good is to have as
much magnetic field as possible in the conductor, giving as much
current (ie efficiency) as possible.

My MOT spotwelder is in the DropBox
 

On Sat, 22 Sep 2007 10:17:21 -0600, Joe Pfeiffer
wrote:

That's a really nice piece of work!

I'd have to dig out my freshman physics book to be sure, but I expect
the reason filling the space in the transformer is good is to have as
much magnetic field as possible in the conductor, giving as much
current (ie efficiency) as possible.


Optimum economic use of the total weight of copper is when
the volume of the copper in the secondary is about equal the
copper volume in the primary because this equalises the primary
and secondary copper losses. It's a very flat optimum and various
second order variables shift it a bit either way.

When you've removed both the high voltage winding and the
magnetic shunt from a microwave oven transformer the winding
space left is a lot more than that occupied by the primary, so
it's possible to install a much larger volume secondary.

If you're using welding cable most of the possible output
is achieved once the copper volume has exceeded the primary
copper volume. If you're using Aluminium aim for more at least
50% more volume because of the higher resistivity.

Jim

My MOT spotwelder is in the DropBox
 

My MOT spotwelder is in the DropBox
 

On Thu, 20 Sep 2007 23:31:31 -0400, Bob Engelhardt
wrote:

I did it as a pdf, using CutePDF to convert the html that I wrote in it.
Thanks again, George, for the tip. I pdf'ed it as a single page to
avoid all the white space that gets in when images occur at page breaks.
I wish that CutePDF had an easy way to do it. A "Fit on one page"
option. What's the big deal with "pages", anyhow. The concept is only
relevant to hard copy, mostly.

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

Bob

Nice job, Bob. Thanks for posting that.

My MOT spotwelder is in the DropBox
 

My MOT spotwelder is in the DropBox
 

My MOT spotwelder is in the DropBox
 

On Sat, 22 Sep 2007 15:10:18 -0600, Joe Pfeiffer
wrote:

writes:

On Sat, 22 Sep 2007 10:17:21 -0600, Joe Pfeiffer
wrote:

That's a really nice piece of work!

I'd have to dig out my freshman physics book to be sure, but I expect
the reason filling the space in the transformer is good is to have as
much magnetic field as possible in the conductor, giving as much
current (ie efficiency) as possible.

Optimum economic use of the total weight of copper is when
the volume of the copper in the secondary is about equal the
copper volume in the primary because this equalises the primary
and secondary copper losses. It's a very flat optimum and various
second order variables shift it a bit either way.

That makes sense -- my intuition is that this implies that if the goal
isn't economic optimum but rather maximum current then filling the
volume accomplishes it...

When you've removed both the high voltage winding and the
magnetic shunt from a microwave oven transformer the winding
space left is a lot more than that occupied by the primary, so
it's possible to install a much larger volume secondary.

If you're using welding cable most of the possible output
is achieved once the copper volume has exceeded the primary
copper volume. If you're using Aluminium aim for more at least
50% more volume because of the higher resistivity.

Volume or area (of course, in this application increasing the volume
does increase the area)?


More secondary conductor always gets a bit more output but
it's a diminishing rate of return.

In trying to keep the explanation simple I was a bit
cavalier in the use of the term "volume". Volume is the correct
yardstick if (as is usually the case) the overall physical shape
and average turn length is pretty similar for both primary and
secondary.

A more accurate yardstick is the comparative fraction of
the window area occupied by the total cross sections of the
primary and secondary conductors.

However even this mouthful gets into trouble if the
primary and secondary average turn lengths are widely different!

Jim

My MOT spotwelder is in the DropBox
 

On Sat, 22 Sep 2007 20:24:05 -0400, Wes wrote:

wrote:

Optimum economic use of the total weight of copper is when
the volume of the copper in the secondary is about equal the
copper volume in the primary because this equalises the primary
and secondary copper losses. It's a very flat optimum and various
second order variables shift it a bit either way.

Hey Jim,

I ordered your motor book. Amazon seems to be having issues getting it.
I've had to confirm once that I'll keep waiting. Any insight into what is
going on?

Thanks
Wes

Hi
I think it must be an internal Amazon.com problem.We supply to
Amazon.co.uk and their site is offering "Electric Motors"second
edition ex stock delivery. New copies are also available from
various booksellers on Ebay.

It may be an error in ISBN numbers

The old first edition ISBN 1-85242-914-2 This is no longer in
print so delivery would be a problem!.

The second edition is ISBN 13-978-185486-246 published 2006.


The two editions are easily distinguished by their cover pictures
The first edition shows a single dis-assembled motor, the second
edition shows multiple motors plus a central VFD controller.

Jim

My MOT spotwelder is in the DropBox
 

On Thu, 20 Sep 2007 23:31:31 -0400, Bob Engelhardt
wrote:

I did it as a pdf, using CutePDF to convert the html that I wrote in it.
Thanks again, George, for the tip. I pdf'ed it as a single page to
avoid all the white space that gets in when images occur at page breaks.
I wish that CutePDF had an easy way to do it. A "Fit on one page"
option. What's the big deal with "pages", anyhow. The concept is only
relevant to hard copy, mostly.

Anyhow, take at look. It works very nicely - I've done a copy of sheet
metal projects with it & only had a couple of kinks to fix.

http://www.metalworking.com/dropbox/MOTSpotwelder.pdf

Bob


Question (open to everyone)... so what happens when I go to print
this out?
Does it get compressed onto a single page (I'm thinking so...), and
how do I change that?


Cheers,

Al

My MOT spotwelder is in the DropBox
 

Al Porter wrote:
Question (open to everyone)... so what happens when I go to print
this out?
Does it get compressed onto a single page (I'm thinking so...), and
how do I change that?

Oh... good point! I selected "Print" and the preview showed it cut off
at 11". I.e., 1 paper page's worth, not compressed. If nobody has any
better idea, I'll load another version, reformatted for real pages.

Bob

My MOT spotwelder is in the DropBox
 

On Mon, 24 Sep 2007 15:34:36 -0400, Bob Engelhardt
wrote:

Al Porter wrote:
Question (open to everyone)... so what happens when I go to print
this out?
Does it get compressed onto a single page (I'm thinking so...), and
how do I change that?

Oh... good point! I selected "Print" and the preview showed it cut off
at 11". I.e., 1 paper page's worth, not compressed. If nobody has any
better idea, I'll load another version, reformatted for real pages.

Bob

Just a suggestion...

I would do my layout in a word processing type program. Most
likely my old WordPerfect which does really well WYSIWYG.
Set the page size to 8.5 x 11 with margins such that the
printable area is no more than 8 x 10.5 inches. The reason
for this is because most printers can't print on a full 8.5
x 11 inch page. Then choose to print as PDF. That should
make your page breaks exactly where you want them.

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

My MOT spotwelder is in the DropBox
 

Bob Engelhardt wrote:
Al Porter wrote:
... so what happens when I go to print this out? ...

... I'll load another version, reformatted for real pages.

http://www.metalworking.com/dropbox/...rPrintable.pdf

My MOT spotwelder is in the DropBox
 

On Thu, 27 Sep 2007 20:30:03 -0400, Bob Engelhardt
wrote:

Bob Engelhardt wrote:
Al Porter wrote:
... so what happens when I go to print this out? ...

... I'll load another version, reformatted for real pages.

http://www.metalworking.com/dropbox/...rPrintable.pdf


Perfect, Bob. Thank you very much :)

On a sadder note... they cleaned up the electronics pile at the local
dump a couple days before you posted the first copy, so my source of
MOTS has dried up for the time being :(

Cheers,

Al

My MOT spotwelder is in the DropBox
 

My MOT spotwelder is in the DropBox
 

On Fri, 28 Sep 2007 06:05:53 -0600, Al Porter wrote:
On Thu, 27 Sep 2007 20:30:03 -0400, Bob Engelhardt
Bob Engelhardt wrote:
Al Porter wrote:
... so what happens when I go to print this out? ...

... I'll load another version, reformatted for real pages.

http://www.metalworking.com/dropbox/...rPrintable.pdf

Perfect, Bob. Thank you very much :)

On a sadder note... they cleaned up the electronics pile at the local
dump a couple days before you posted the first copy, so my source of
MOTS has dried up for the time being :(


Where are you? I'm in Whittier, CA, and I've got two whole ones
and one with the shunts and secondary gone. Also some little misc.
MO parts, like fans, and those mechanical timers with a physical
bell. (turn the knob, it turns on, motor turns knob back, DING!)

Cheers!
Rich

My MOT spotwelder is in the DropBox