Gentlemen,

I have a barn with 50 amp 240 service. It now basically has lights and 120
outlets. Is it OK to add a 50 amp receptacle for a welder with the idea that
I won't run the welder at full power?

Thanks in advance for any comments.

RogerB

--
for full context, visit https://www.polytechforum.com/welding/50-amp-receptacle-in-barn-with-50-amp-240-service-54830-.htm

On 3/19/2022 9:18 AM, RogerB wrote:
> Gentlemen,
>
> I have a barn with 50 amp 240 service.  It now basically has lights and 120
> outlets.  Is it OK to add a 50 amp receptacle for  a welder with the
> idea that
> I won't run the welder at full power?
>
> Thanks in advance for any comments.
>
> RogerB
>

I don't know but I run my 65amp welder on a 50 amp circuit all the time.
I do not recall ever tripping a breaker. Most of the time you WON'T
run your welder at its max setting. Maybe never depending on the work
you do. If the breaker trips you stop welding and reset the breaker. I
do not know how your sub panel is setup, but the welder circuit should
be on its own breaker even if its the same size as the incoming circuit.

Its "probably" ok, but I have not seen the barn. However to give you an
idea. Go add up the current limit of all the circuits in a house. Its
almost always much more than the main breaker on the service entrance.
My shop has a 100amp sub panel feeding it, and off that sub panel are
two more sub panels. One is 100 amps, and one is 60 amps. The only
time I recall tripping one of the main breakers was when I accidentally
shorted a transformer while repairing a machine.

MAKE SURE YOUR WIRING IS UP TO THE TASK. DO NOT SKIMP. FOR "NORMAL"
SHOP WELDING IT SHOULD WORK, AND YOU CAN PROBABLY EVEN LEAVE THE LIGHTS
ON.

--
This email has been checked for viruses by AVG.
https://www.avg.com

"Bob La Londe" wrote in message news:t17k6p$1tqu$1@gioia.aioe.org...

On 3/19/2022 9:18 AM, RogerB wrote:
> Gentlemen,
>
> I have a barn with 50 amp 240 service. It now basically has lights and
> 120
> outlets. Is it OK to add a 50 amp receptacle for a welder with the idea
> that
> I won't run the welder at full power?
>
> Thanks in advance for any comments.
>
> RogerB
>

I don't know but I run my 65amp welder on a 50 amp circuit all the time.
I do not recall ever tripping a breaker. Most of the time you WON'T
run your welder at its max setting. Maybe never depending on the work
you do. If the breaker trips you stop welding and reset the breaker. I
do not know how your sub panel is setup, but the welder circuit should
be on its own breaker even if its the same size as the incoming circuit.

Its "probably" ok, but I have not seen the barn. However to give you an
idea. Go add up the current limit of all the circuits in a house. Its
almost always much more than the main breaker on the service entrance.
My shop has a 100amp sub panel feeding it, and off that sub panel are
two more sub panels. One is 100 amps, and one is 60 amps. The only
time I recall tripping one of the main breakers was when I accidentally
shorted a transformer while repairing a machine.

MAKE SURE YOUR WIRING IS UP TO THE TASK. DO NOT SKIMP. FOR "NORMAL"
SHOP WELDING IT SHOULD WORK, AND YOU CAN PROBABLY EVEN LEAVE THE LIGHTS
ON.

----------------------

I run a Lincoln Square Wave 175 welder at about 120A through a 50A breaker
(240V) in a 200A panel (electric heat). The breaker hasn't tripped yet, even
when rods stick. 120A has been good for up to 1/2" plate with 1/8" 7018
rods.

My 50A AC arc welder draws less than 20A at 120V. I've measured it carefully
because I converted it into a variable voltage battery charger, and operate
it short-circuited to test circuit breakers. Some from Amazon degraded after
the first trip. For power calculations the expected arc voltage is 20~25V
and the efficiency is around 60~70% at line voltage, due to the
transformer's simple lossy current limiting design. The efficiency is much
higher at lower input voltages where the core doesn't saturate.

"Jim Wilkins" wrote in message news:t18aoj$pv4$1@dont-email.me...

I run a Lincoln Square Wave 175 welder at about 120A through a 50A breaker
(240V) in a 200A panel (electric heat). The breaker hasn't tripped yet, even
when rods stick. 120A has been good for up to 1/2" plate with 1/8" 7018
rods.

---------------------------

At 100% efficiency 120A at 25 arc volts would equal only 12.5A through the
breaker at 240V. The Lincoln has active SCR control and I haven't measured
its efficiency because welding projects don't appear to affect my home
electric bill.

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Jim Wilkins" wrote in message news:t18aoj$pv4$1@dont-email.me...
>
> I run a Lincoln Square Wave 175 welder at about 120A through a 50A breaker
> (240V) in a 200A panel (electric heat). The breaker hasn't tripped yet, even
> when rods stick. 120A has been good for up to 1/2" plate with 1/8" 7018
> rods.
>
> ---------------------------
>
> At 100% efficiency 120A at 25 arc volts would equal only 12.5A through
> the breaker at 240V. The Lincoln has active SCR control and I haven't
> measured its efficiency because welding projects don't appear to
> affect my home electric bill.

Isn't a "rule of thumb"
50% efficiency for copper-and-iron transformer machines
90%+ efficiency for inverter welding machines
? So start with your calculation
(/
(* 120 25) ;; 3000 ;; W
240.0) ;; 12.5 ;; Amps
then double the Amps assumed at the wall-socket ie. 25A
if is a transformer machine.

That inverters are so efficient is rather obvious from the welds you
can run without ever tripping the breaker.

"Richard Smith" wrote in message news:lyk0clxcl8.fsf@void.com...

Isn't a "rule of thumb"
50% efficiency for copper-and-iron transformer machines
90%+ efficiency for inverter welding machines
? So start with your calculation
(/
(* 120 25) ;; 3000 ;; W
240.0) ;; 12.5 ;; Amps
then double the Amps assumed at the wall-socket ie. 25A
if is a transformer machine.

That inverters are so efficient is rather obvious from the welds you
can run without ever tripping the breaker.

--------------------

My largely home schooling in electrical engineering missed that part.
https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703

The idling power loss in the 50A buzz box transformer measured 1/4KW at 120V
in and 1/2KW at 130V in. The no-load magnetizing current is proportional to
input voltage up to 90VAC, then rises rapidly as the core goes into
saturation. They are made that way to limit the welding current, as when an
electrode sticks. I needed to know because a Powerstat variable
autotransformer sets the output voltage and excessive current will burn out
its contact brush.

This is the tool that measures AC current without having to disconnect the
wire.
https://www.amazon.com/Clamp-Meters/b?ie=UTF8&node=5011680011

I have the UT210E because it also measures DC current and reads low enough
to check the power-off drain from a car battery.
https://www.autotrader.co.uk/content/advice/why-is-my-car-battery-draining-ways-to-prevent-it?refresh=true

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:lyk0clxcl8.fsf@void.com...
>...
>
> My largely home schooling in electrical engineering missed that part.
> https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703
>
> The idling power loss in the 50A buzz box transformer measured 1/4KW
> at 120V in and 1/2KW at 130V in. The no-load magnetizing current is
> proportional to input voltage up to 90VAC, then rises rapidly as the
> core goes into saturation. They are made that way to limit the welding
> current, as when an electrode sticks. I needed to know because a
> Powerstat variable autotransformer sets the output voltage and
> excessive current will burn out its contact brush.
>
> This is the tool that measures AC current without having to disconnect
> the wire.
> https://www.amazon.com/Clamp-Meters/b?ie=UTF8&node=5011680011
>
> I have the UT210E because it also measures DC current and reads low
> enough to check the power-off drain from a car battery.
> https://www.autotrader.co.uk/content/advice/why-is-my-car-battery-draining-ways-to-prevent-it?refresh=true

I helped you on something?
I am pleased with myself!

The info you cite
https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703
is great.
So I'd got the numbers about right just by hearsay judged plausible by
observation...

Best wishes
Rich Smith

"Richard Smith" wrote in message news:lyfsn7bny3.fsf@void.com...

"Jim Wilkins" <muratlanne@gmail.com> writes:

> "Richard Smith" wrote in message news:lyk0clxcl8.fsf@void.com...
>...
>
> My largely home schooling in electrical engineering missed that part.
> https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703
>
> The idling power loss in the 50A buzz box transformer measured 1/4KW
> at 120V in and 1/2KW at 130V in. The no-load magnetizing current is
> proportional to input voltage up to 90VAC, then rises rapidly as the
> core goes into saturation. They are made that way to limit the welding
> current, as when an electrode sticks. I needed to know because a
> Powerstat variable autotransformer sets the output voltage and
> excessive current will burn out its contact brush.
>
> This is the tool that measures AC current without having to disconnect
> the wire.
> https://www.amazon.com/Clamp-Meters/b?ie=UTF8&node=5011680011
>
> I have the UT210E because it also measures DC current and reads low
> enough to check the power-off drain from a car battery.
> https://www.autotrader.co.uk/content/advice/why-is-my-car-battery-draining-ways-to-prevent-it?refresh=true

I helped you on something?
I am pleased with myself!

The info you cite
https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703
is great.
So I'd got the numbers about right just by hearsay judged plausible by
observation...

Best wishes
Rich Smith

-------------

I appreciate help on the things I don't know. That's why I ask questions and
post links to the references I find. My scientific education was more
concerned with the means of uncovering new information, by literature search
or experiment, than over-filling my head with details of accepted knowledge.
R&D is all about what you don't know yet.

Apparently that's a fundamental difference between science and liberal arts.

On 3/20/2022 9:19 AM, Bob La Londe wrote:
> On 3/19/2022 9:18 AM, RogerB wrote:
>> Gentlemen,
>>
>> I have a barn with 50 amp 240 service.  It now basically has lights
>> and 120
>> outlets.  Is it OK to add a 50 amp receptacle for  a welder with the
>> idea that
>> I won't run the welder at full power?
>>
>> Thanks in advance for any comments.
>>
>> RogerB
>>
>
>
> I don't know but I run my 65amp welder on a 50 amp circuit all the time.
>  I do not recall ever tripping a breaker.  Most of the time you WON'T
> run your welder at its max setting.  Maybe never depending on the work
> you do.  If the breaker trips you stop welding and reset the breaker.  I
> do not know how your sub panel is setup, but the welder circuit should
> be on its own breaker even if its the same size as the incoming circuit.
>
> Its "probably" ok, but I have not seen the barn.  However to give you an
> idea.  Go add up the current limit of all the circuits in a house.  Its
> almost always much more than the main breaker on the service entrance.
> My shop has a 100amp sub panel feeding it, and off that sub panel are
> two more sub panels.  One is 100 amps, and one is 60 amps.  The only
> time I recall tripping one of the main breakers was when I accidentally
> shorted a transformer while repairing a machine.
>
> MAKE SURE YOUR WIRING IS UP TO THE TASK.  DO NOT SKIMP.  FOR "NORMAL"
> SHOP WELDING IT SHOULD WORK, AND YOU CAN PROBABLY EVEN LEAVE THE LIGHTS ON.
>

Sorry. Its actually 200amp output. Reccomended breaker is 65 amp.
Never made any sense to me since it came with a 50 amp plug on it brand
new from Miller.

--
This email has been checked for viruses by AVG.
https://www.avg.com

On 23/03/2022 11:33, Jim Wilkins wrote:
> "Richard Smith"  wrote in message news:lyk0clxcl8.fsf@void.com...
>
> Isn't a "rule of thumb"
> 50% efficiency for copper-and-iron transformer machines
> 90%+ efficiency for inverter welding machines
> ?
> So start with your calculation
> (/
>  (* 120 25) ;; 3000 ;; W
>  240.0) ;; 12.5 ;; Amps
> then double the Amps assumed at the wall-socket ie. 25A
> if is a transformer machine.
>
> That inverters are so efficient is rather obvious from the welds you
> can run without ever tripping the breaker.
>
> --------------------
>
> My largely home schooling in electrical engineering missed that part.
> https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703
>
>
> The idling power loss in the 50A buzz box transformer measured 1/4KW
> at 120V in and 1/2KW at 130V in. The no-load magnetizing current is
> proportional to input voltage up to 90VAC, then rises rapidly as the
> core goes into saturation. They are made that way to limit the welding
> current, as when an electrode sticks. I needed to know because a
> Powerstat variable autotransformer sets the output voltage and
> excessive current will burn out its contact brush.
>
> This is the tool that measures AC current without having to disconnect
> the wire.
> https://www.amazon.com/Clamp-Meters/b?ie=UTF8&node=5011680011
>
> I have the UT210E because it also measures DC current and reads low
> enough to check the power-off drain from a car battery.
> https://www.autotrader.co.uk/content/advice/why-is-my-car-battery-draining-ways-to-prevent-it?refresh=true
>
>
I bought a UT210E after your recommendation and it was useful but I now
find it doesn't work any more. It turns on and responds to the selection
switch and buttons and on resistance or voltage it shows its working
when you connect an item to test and then just displays 0.000 which is
all it does in any mode now. I can't see anything wrong internally and
new batteries had no effect so it looks like its dead or at least of no
use whatsoever.

"David Billington" wrote in message news:t1ijcu$25h$1@dont-email.me...

I bought a UT210E after your recommendation and it was useful but I now
find it doesn't work any more. It turns on and responds to the selection
switch and buttons and on resistance or voltage it shows its working
when you connect an item to test and then just displays 0.000 which is
all it does in any mode now. I can't see anything wrong internally and
new batteries had no effect so it looks like its dead or at least of no
use whatsoever.

-------------------

Sorry.
There is a lot of info on line about them, including calibration and hacking
the code. I haven't tried any of it.

On 24/03/2022 21:26, Jim Wilkins wrote:
> "David Billington"  wrote in message news:t1ijcu$25h$1@dont-email.me...
>
> I bought a UT210E after your recommendation and it was useful but I now
> find it doesn't work any more. It turns on and responds to the selection
> switch and buttons and on resistance or voltage it shows its working
> when you connect an item to test and then just displays 0.000 which is
> all it does in any mode now. I can't see anything wrong internally and
> new batteries had no effect so it looks like its dead or at least of no
> use whatsoever.
>
> -------------------
>
> Sorry.
> There is a lot of info on line about them, including calibration and
> hacking the code. I haven't tried any of it.
>
>
I've just started to look at it but haven't found any useful stuff yet.
I wonder as it has firmware if it's trashed its calibration settings,
I've seen that sort of behaviour on a number of occasions where the
device would occasionally write to places it shouldn't do to ill effect.

"Bob La Londe" wrote in message news:t1icr1$1bjd$2@gioia.aioe.org...

Sorry. Its actually 200amp output. Reccomended breaker is 65 amp.
Never made any sense to me since it came with a 50 amp plug on it brand
new from Miller.

----------------

https://www.fs.fed.us/database/acad/elec/greenbook/3_basicdesigns.pdf

Don't ask me to make sense of it.

"David Billington" wrote in message news:t1io3n$7ca$1@dont-email.me...

On 24/03/2022 21:26, Jim Wilkins wrote:
> "David Billington" wrote in message news:t1ijcu$25h$1@dont-email.me...
>
> I bought a UT210E after your recommendation and it was useful but I now
> find it doesn't work any more. It turns on and responds to the selection
> switch and buttons and on resistance or voltage it shows its working
> when you connect an item to test and then just displays 0.000 which is
> all it does in any mode now. I can't see anything wrong internally and
> new batteries had no effect so it looks like its dead or at least of no
> use whatsoever.
>
> -------------------
>
> Sorry.
> There is a lot of info on line about them, including calibration and
> hacking the code. I haven't tried any of it.
>
>
I've just started to look at it but haven't found any useful stuff yet.
I wonder as it has firmware if it's trashed its calibration settings,
I've seen that sort of behaviour on a number of occasions where the
device would occasionally write to places it shouldn't do to ill effect.

--------------------

I have several of Uni-T's products. My impression is that they are bright
young guys with lots of good ideas but are a little short of practical
experience on implementing them reliably. Several times I've noticed that
new electrical engineers don't always know how real-life components deviate
from the theoretical ideal.
https://en.wikipedia.org/wiki/Dielectric_absorption
https://www.murata.com/~/media/webrenewal/products/emc/emifil/knowhow/12to14.ashx
https://electrical-engineering-portal.com/time-current-curves

I learned when I was in the testing business, measuring those things. Many
of the parts I've bought on line don't quite meet their specs. That was true
of Radio Shack too, but surprisingly some were much better than specified,
like a "50V" rectifier bridge that tested OK to >500V.

I have another brand of Chinese DC voltage/current/power meter that goes
haywire if connected to solar panels, apparently from the marginal operating
voltage at dawn and dusk.

Then again I found a bug in an Intel IC's reset circuit and a Texas
Instruments computer's microcode. The latter got me promoted to Engineering.

On 24/03/2022 22:35, Jim Wilkins wrote:
> "David Billington"  wrote in message news:t1io3n$7ca$1@dont-email.me...
>
> On 24/03/2022 21:26, Jim Wilkins wrote:
>> "David Billington"  wrote in message news:t1ijcu$25h$1@dont-email.me...
>>
>> I bought a UT210E after your recommendation and it was useful but I now
>> find it doesn't work any more. It turns on and responds to the selection
>> switch and buttons and on resistance or voltage it shows its working
>> when you connect an item to test and then just displays 0.000 which is
>> all it does in any mode now. I can't see anything wrong internally and
>> new batteries had no effect so it looks like its dead or at least of no
>> use whatsoever.
>>
>> -------------------
>>
>> Sorry.
>> There is a lot of info on line about them, including calibration and
>> hacking the code. I haven't tried any of it.
>>
>>
> I've just started to look at it but haven't found any useful stuff yet.
> I wonder as it has firmware if it's trashed its calibration settings,
> I've seen that sort of behaviour on a number of occasions where the
> device would occasionally write to places it shouldn't do to ill effect.
>
> --------------------
>
> I have several of Uni-T's products. My impression is that they are
> bright young guys with lots of good ideas but are a little short of
> practical experience on implementing them reliably. Several times I've
> noticed that new electrical engineers don't always know how real-life
> components deviate from the theoretical ideal.
> https://en.wikipedia.org/wiki/Dielectric_absorption
> https://www.murata.com/~/media/webrenewal/products/emc/emifil/knowhow/12to14.ashx
>
> https://electrical-engineering-portal.com/time-current-curves
>
> I learned when I was in the testing business, measuring those things.
> Many of the parts I've bought on line don't quite meet their specs.
> That was true of Radio Shack too, but surprisingly some were much
> better than specified, like a "50V" rectifier bridge that tested OK to
> >500V.
>
> I have another brand of Chinese DC voltage/current/power meter that
> goes haywire if connected to solar panels, apparently from the
> marginal operating voltage at dawn and dusk.
>
> Then again I found a bug in an Intel IC's reset circuit and a Texas
> Instruments computer's microcode. The latter got me promoted to
> Engineering.
>
I've got a UT70B IIRC DVM as a back-up to my Beckman DVM, the UT70B has
the RS232 which is handy for data logging from time to time. Can't fault
the UT70B no problem so far and I've had it for a number of years.

I've turned up the odd bug in a MS 16bit Windows time function where it
would report a day earlier at the roll over of midnight from time to
time, easy to write code to test it, other Windows time functions had
the bug reported but not the one I was using.

I know a guy that turn up a serious bug in an Arizona Microchip
processor and he reported it and as a thank you they gave him the
development tools he was using.

I have a Newall DRO on my lathe and from time to time it trashes some
settings, normally but not always the X axis linear error compensation,
thankfully the trashed value is so large that if you move the carriage
1mm it says 10mm so it's obvious. A worse one was a Ubinetics GSM modem
which would occasionally trash its radio calibration data and as the
company was no more due to the poor product it bricked the modem. Turned
out from some testing it was one AT command used to gracefully close the
transmission which was at fault so we removed its use as we had that
option others that used commercial comms software weren't so lucky.

"David Billington" wrote in message news:t1iu96$ooo$1@dont-email.me...

....A worse one was a Ubinetics GSM modem
which would occasionally trash its radio calibration data and as the
company was no more due to the poor product it bricked the modem. Turned
out from some testing it was one AT command used to gracefully close the
transmission which was at fault so we removed its use as we had that
option others that used commercial comms software weren't so lucky.

---------------------

Back when I had dialup with a low monthly data allowance I wrote a program
that extracted new connection data from the modem log and reported current
total usage. It had to parse for several AT commands because the protocol
didn't seem to be strictly defined or implemented.

Jim - I did research which earned me a Doctorate (PhD).
It didn't get me a career because
* the project organisation collapsed and mine turned into a solo
effort with no-one there for the outcome
* my scientific endeavours have been "pilot studies" making a lot of
pragmatic progress in the first early stages of the subject timeline,
lacking the highfallutin' theory squeezing the n-th nuance out far
towards to the highly-developed near-horizontal "right-hand-side" of
the subject's progress vs. timeline graph
So some similarities - apart from you had career success in an
entrepreneurial culture :-)

"Richard Smith" wrote in message news:lytubi31cf.fsf@void.com...

Jim - I did research which earned me a Doctorate (PhD).
It didn't get me a career because
* the project organisation collapsed and mine turned into a solo
effort with no-one there for the outcome
* my scientific endeavours have been "pilot studies" making a lot of
pragmatic progress in the first early stages of the subject timeline,
lacking the highfallutin' theory squeezing the n-th nuance out far
towards to the highly-developed near-horizontal "right-hand-side" of
the subject's progress vs. timeline graph
So some similarities - apart from you had career success in an
entrepreneurial culture :-)

-----------------------

The only Space project I was privileged to work on shut down after the lead
scientist/promoter found a better opportunity elsewhere. It was one of many
that was born in a home workshop. They brought me in as electronic tech and
I had to prove I could handle optics and machining as well. The Ph.Ds
designed with what they could buy off the shelf while I made or
custom-ordered whatever I wanted, including a connector for 25um x 125um
gold IC bonding ribbon.
https://www.inseto.co.uk/consumables/bonding-wire-ribbon-precision-metal-stampings-solder-preforms-by-coining/bonding-wire-and-ribbons-by-coining/

Many of the Ph.D theses I've read tend to demonstrate that the author has
the potential to do serious research, but they and their advisors lack
practical experience.

I think I was most useful when I brought my wide but not that deep
multi-disciplinary knowledge to a researcher whose education had
concentrated in one field.

A good example, though not a thesis, is Rossi's E-Cat. It was made from
brazed copper pipe fittings and he either didn't know or hoped others
wouldn't that hot hydrogen reduces copper oxide to copper atoms and carries
them downstream. The copper found in the nickel wasn't proof of nuclear
transformation.
https://en.wikipedia.org/wiki/Energy_Catalyzer
"Given numerous other scientific inconsistencies – such as the ratio of
isotopes in the supposed copper "fusion product" being identical to that in
natural copper..."

Iron, nickel and copper are in the region of greatest nuclear stability.
Lighter elements can release energy by fusion and heavier ones by fission.
They are the end products, the burnt-out ashes of stellar fusion. Imagine
what wondrous civilizations might have lived in the light released from what
ended as a chunk of iron.
https://www.miniphysics.com/binding-energy-per-nucleon-and-nuclear.html
Invert the graph to show energy that fusion or fission can release.

The Cruise Missile/Drone/UAV began as a private project that eventually
collapsed.
https://historycollection.com/the-story-of-the-kettering-bug-the-worlds-first-aerial-drone/6/
The story shows how small details like who happens to be involved can make
or break a project.
If it worked they could get funding, and if they had funding they could make
it work.

The effort wasn't wasted, Sperry and Doolittle gave us IFR flight.
Hap Arnold wrote that by the time it was ready the exhausted Germans had no
worthwhile targets left within its range.

Re the parachute, they had existed since 1797 but wouldn't (yet) reliably
open in free fall. Their container was attached to the fuselage or
observation balloon basket and the falling pilot's weight pulled them out
evenly. That was no good if the plane was burning or tumbling, and if it
wasn't they might glide down.
jsw

> Many of the Ph.D theses I've read tend to demonstrate that the author
> has the potential to do serious research, but they and their advisors
> lack practical experience.

The comment I can make is from other "interactions" with people in
academia. I saw ways of getting at profound scientific issues through
"windows" which practical workshop techniques made available.
Shuffling scientific ideas - what would be valuable to know - against
what was possible to do, in the end I saw very specific "alignments"
where what would be useful was possible.

Basically though, I scared people finding totally unfamiliar
techniques which looked demented to onlookers.

Okay - something like three decades have passed, so - here goes...

I wasn't supposed to hear this very experienced industrial
metallurgist say to my supervisor "So now then who's insane?! :-)"
after a technique I proposed worked
(using a "shaper" to machine steel in a bath of liquid nitrogen, to
keep the weld hydrogen immobile until ready to get it to reveal its
location / distribution in the resulting sample).

That experienced metallurgist had faltered to a stop with his jaw
dropped coming into the machine shop, with cold steam pouring off the
table of the shaper.
Explaining I was machine steel in liquid nitrogen, he responded

"I can see what it is that you are doing! What I cannot believe is
that someone would actually *do it*!!!"
(I wish I could convey the intonation)
He knew what I was researching, and had lent me the "Welding steels
without hydrogen cracking" publication. So seeing the shaper with
cold steam pouring everywhere, he could see in a glance exactly what
leap of logic I had made in trying to get in at the issue.

> I think I was most useful when I brought my wide but not that deep
> multi-disciplinary knowledge to a researcher whose education had
> concentrated in one field.

Yes.
A team comprising only one type of person has no significance.

"Richard Smith" wrote in message news:lyfsn11b9d.fsf@void.com...

> Many of the Ph.D theses I've read tend to demonstrate that the author
> has the potential to do serious research, but they and their advisors
> lack practical experience.

The comment I can make is from other "interactions" with people in
academia. I saw ways of getting at profound scientific issues through
"windows" which practical workshop techniques made available.
Shuffling scientific ideas - what would be valuable to know - against
what was possible to do, in the end I saw very specific "alignments"
where what would be useful was possible.

Basically though, I scared people finding totally unfamiliar
techniques which looked demented to onlookers.

Okay - something like three decades have passed, so - here goes...

I wasn't supposed to hear this very experienced industrial
metallurgist say to my supervisor "So now then who's insane?! :-)"
after a technique I proposed worked
(using a "shaper" to machine steel in a bath of liquid nitrogen, to
keep the weld hydrogen immobile until ready to get it to reveal its
location / distribution in the resulting sample).

That experienced metallurgist had faltered to a stop with his jaw
dropped coming into the machine shop, with cold steam pouring off the
table of the shaper.
Explaining I was machine steel in liquid nitrogen, he responded

"I can see what it is that you are doing! What I cannot believe is
that someone would actually *do it*!!!"
(I wish I could convey the intonation)
He knew what I was researching, and had lent me the "Welding steels
without hydrogen cracking" publication. So seeing the shaper with
cold steam pouring everywhere, he could see in a glance exactly what
leap of logic I had made in trying to get in at the issue.

> I think I was most useful when I brought my wide but not that deep
> multi-disciplinary knowledge to a researcher whose education had
> concentrated in one field.

Yes.
A team comprising only one type of person has no significance.

--------------------------

Love it!!

I had the less spectacular equipment to operate electronics in liquid
nitrogen.

Chemists and physicists are encouraged but not required to learn hands-on
experimental technique. In industry they may have to be a team of one.

I've seen evidence that mechanical engineers gravitate toward racing and
electrical engineers toward amateur radio if they are inclined to build
things. Otherwise the EEs I worked for depended heavily on techs to create
what they wanted and fix their personal devices, and to clean up after they
did try to do something themselves.

At Segway the mechanical engineers all knew how to operate the CNC machine
tools, usually crowding me onto the manual ones. Doing weird things was
formalized into Frog Days.
https://news.yale.edu/2008/12/05/students-learn-how-kiss-frogs-and-take-risks-morrell-s-class

As brilliant and well educated as he is, John didn't know how to fabricate
and join sheet metal until I showed him press-in PEM nuts.

> ...
> As brilliant and well educated as he is, John didn't know how to
> fabricate and join sheet metal until I showed him press-in PEM nuts.

I did this and kept my job
"Tensile-test rig for beam-configuration fillet-weld samples"
Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/ua4ke9y4w3bcp6d/210122_fwtr.mp4?dl=0
Sound is like firing a NATO 7.62 round inside the building.
I think they politely pretended they didn't know because they had a
feeling I could be a useful "card up their sleeve" if the customer was
disputing their weld quality and properties.

In a "fabrication skill practice" exercise with ulterior motives,
http://www.weldsmith.co.uk/tech/struct/201113_u_rhs/pics_urhs_test/201118_085226_ut.jpg
[http://www.weldsmith.co.uk/tech/struct/201113_u_rhs/201120_U_RHS_make_analyse_test.html
"U-weldment in R.H.S. - fabricate, analyse, test"]
the hydraulic cylinder blew its seal... You can see the oil leak.
No-one "grassed me up", but I was definitely persona-non-grata.
I snuck around the hydraulics shop and paid for a new seal
out of my pocket. Wasn't that much, though. Restored to persona grata.
Especially as had learned how to dismantle cylinders and renovate them
:-)
That ulterior motive was:
Finite Element Analysis <=?=> real world structural performance
Answer; they matched more exactly...

"Richard Smith" wrote in message news:lypmm4v7yj.fsf@richards-air-2.home...

I did this and kept my job
"Tensile-test rig for beam-configuration fillet-weld samples"
Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/ua4ke9y4w3bcp6d/210122_fwtr.mp4?dl=0
Sound is like firing a NATO 7.62 round inside the building.
I think they politely pretended they didn't know because they had a
feeling I could be a useful "card up their sleeve" if the customer was
disputing their weld quality and properties.

--------------------

Wow, dramatic, and your test rig works very well.

Is that sudden brittle fracture typical of welds in tension? I thought it
was better to have a joint plastically deform somewhat and distribute any
localized stresses before fracturing.

"Jim Wilkins" <muratlanne@gmail.com> writes:

>> "Richard Smith" wrote in message news:lypmm4v7yj.fsf@richards-air-2.home...
>>
>> I did this and kept my job
>> "Tensile-test rig for beam-configuration fillet-weld samples"
>> Movie of - 10 seconds - shared on "Dropbox"
>> https://www.dropbox.com/s/ua4ke9y4w3bcp6d/210122_fwtr.mp4?dl=0
>> Sound is like firing a NATO 7.62 round inside the building.
>> I think they politely pretended they didn't know because they had a
>> feeling I could be a useful "card up their sleeve" if the customer was
>> disputing their weld quality and properties.
>
> --------------------
>
> Wow, dramatic, and your test rig works very well.
>
> Is that sudden brittle fracture typical of welds in tension? I thought
> it was better to have a joint plastically deform somewhat and
> distribute any localized stresses before fracturing.

It is sudden fracture with no warning.
Reason had to make the rig - sudden elastic energy release at full
load. Unfair to do to a shop press.
But brittle - not really. The fracture surface looks like "microvoid
coalescence". The fracture looks to be a shear in line with the
applied stress, so sudden fracture but ductile fracture mode??

I can see where you are going with your question about the overall
joint, but the good solution has a different logic.
You are thinking that virtue is in the joint be able to and actually
plastically deforming.
The good solution is totally different.
Given the strength you see is way higher than expected. There is no
sign of the yield stress manifesting - neither the plate steel nor the
weld metal has its yield stress show. This makes no literal sense,
but - the sudden fracture is at stress about the same as the rated "Ultimate
Tensile Strength". You see around 560MPa with S355 steel (355MPa
yield) welded with G3Si1 (ER70S-6) GMAW welding wire. Why I can't see
how this makes sense that the strength you see matches the UTS is that
the UTS is obtained in uniaxial tensile test of a long cylindrical
sample and there is plastic necking - with UTS being
breaking-force/*original*-area. The break area is much smaller than
the original cross section in relation to which the yield stress
manifests.
*** If anyone can explain this about seeing break stress same as
uniaxial-test UTS please offer that explanation ***

Anyway, long digression into mechanistic detail.
Seeing a very high stress at the joint before anything happens, it
follows that you can protect the joint(s) by ensuring that the
sections you are joining would have general yielded at a lower stress
than would break the joints :-)

So for many structures you check that distributed general beam bending
- the tabulated or easy-to-calculate "Euler-Bernoulli" plastic yield
load - is less by a satisfactory margin than the sudden break
strength of the fillet welds.

As I said - I think if you do that you fully protect the joints with
their high strength but sudden breaking behaviour.
*** comment requested on this too - if you know the answer please
share ! ***

Richard Smith <null@void.com> writes:

> "Jim Wilkins" <muratlanne@gmail.com> writes:
>
>>> "Richard Smith" wrote in message news:lypmm4v7yj.fsf@richards-air-2.home...
>>>
>>> I did this and kept my job
>>> "Tensile-test rig for beam-configuration fillet-weld samples"
>>> Movie of - 10 seconds - shared on "Dropbox"
>>> https://www.dropbox.com/s/ua4ke9y4w3bcp6d/210122_fwtr.mp4?dl=0
>>> Sound is like firing a NATO 7.62 round inside the building.
>>> I think they politely pretended they didn't know because they had a
>>> feeling I could be a useful "card up their sleeve" if the customer was
>>> disputing their weld quality and properties.
>>
>> --------------------
>>
>> Wow, dramatic, and your test rig works very well.
>>
>> Is that sudden brittle fracture typical of welds in tension? I thought
>> it was better to have a joint plastically deform somewhat and
>> distribute any localized stresses before fracturing.
>
> It is sudden fracture with no warning.
> Reason had to make the rig - sudden elastic energy release at full
> load. Unfair to do to a shop press.
> But brittle - not really. The fracture surface looks like "microvoid
> coalescence". The fracture looks to be a shear in line with the
> applied stress, so sudden fracture but ductile fracture mode??
>
> I can see where you are going with your question about the overall
> joint, but the good solution has a different logic.
> You are thinking that virtue is in the joint be able to and actually
> plastically deforming.
> The good solution is totally different.
> Given the strength you see is way higher than expected. There is no
> sign of the yield stress manifesting - neither the plate steel nor the
> weld metal has its yield stress show. This makes no literal sense,
> but - the sudden fracture is at stress about the same as the rated "Ultimate
> Tensile Strength". You see around 560MPa with S355 steel (355MPa
> yield) welded with G3Si1 (ER70S-6) GMAW welding wire. Why I can't see
> how this makes sense that the strength you see matches the UTS is that
> the UTS is obtained in uniaxial tensile test of a long cylindrical
> sample and there is plastic necking - with UTS being
> breaking-force/*original*-area. The break area is much smaller than
> the original cross section in relation to which the yield stress
> manifests.
> *** If anyone can explain this about seeing break stress same as
> uniaxial-test UTS please offer that explanation ***
>
> Anyway, long digression into mechanistic detail.
> Seeing a very high stress at the joint before anything happens, it
> follows that you can protect the joint(s) by ensuring that the
> sections you are joining would have general yielded at a lower stress
> than would break the joints :-)
>
> So for many structures you check that distributed general beam bending
> - the tabulated or easy-to-calculate "Euler-Bernoulli" plastic yield
> load - is less by a satisfactory margin than the sudden break
> strength of the fillet welds.
>
> As I said - I think if you do that you fully protect the joints with
> their high strength but sudden breaking behaviour.
> *** comment requested on this too - if you know the answer please
> share ! ***

There's two things I see that I didn't explain well

*
"microvoid coalescence" is the classic fracture mode of a *ductile*
material in overload.

*
as the fillet weld strength is very high, it is easy to ensure the
fillet welded joint is significantly stronger than the sections it is
joining.

Iterating again, using more fancy terms : given fillet welds break by
sudden fracture at a very high stress - and you want to avoid any
sudden fracture - it is easy to arrive at a safe structure by ensuring
that the structural loadings which make the sections (I-beams,
Rectangular Hollow Sections, etc.) bend by plastic yielding are
significantly lower than the structural loadings which if passed to
the fillet weld joints would make then break.
The reason this is easy to ensure by design is that the fillet weld
strength you see is so high in relation to the yield stress behaviour
of the sections being joined. So the strength of the fillet welds
easily well-overmatches the section's plastic deformation limited
load-bearing capacity.
Yet another round of explaining - what you'd see with such a "safe
structure" on increasing load beyond anything sustainable is that the
long sections begin to bend while the welded joints seem unchanged and
not involved.

"Richard Smith" wrote in message news:lysfr015j9.fsf@richards-air-2.home...

"Jim Wilkins" <muratlanne@gmail.com> writes:
>..............
It is sudden fracture with no warning.
Reason had to make the rig - sudden elastic energy release at full
load. Unfair to do to a shop press.
But brittle - not really. The fracture surface looks like "microvoid
coalescence". The fracture looks to be a shear in line with the
applied stress, so sudden fracture but ductile fracture mode??

I can see where you are going with your question about the overall
joint, but the good solution has a different logic.
You are thinking that virtue is in the joint be able to and actually
plastically deforming.
The good solution is totally different.
Given the strength you see is way higher than expected. There is no
sign of the yield stress manifesting - neither the plate steel nor the
weld metal has its yield stress show. This makes no literal sense,
but - the sudden fracture is at stress about the same as the rated "Ultimate
Tensile Strength". You see around 560MPa with S355 steel (355MPa
yield) welded with G3Si1 (ER70S-6) GMAW welding wire. Why I can't see
how this makes sense that the strength you see matches the UTS is that
the UTS is obtained in uniaxial tensile test of a long cylindrical
sample and there is plastic necking - with UTS being
breaking-force/*original*-area. The break area is much smaller than
the original cross section in relation to which the yield stress
manifests.
*** If anyone can explain this about seeing break stress same as
uniaxial-test UTS please offer that explanation ***

Anyway, long digression into mechanistic detail.
Seeing a very high stress at the joint before anything happens, it
follows that you can protect the joint(s) by ensuring that the
sections you are joining would have general yielded at a lower stress
than would break the joints :-)

-----------------------

That 16' portable overhead gantry track I built last spring was designed so
the center splice would be somewhat stronger than the 4" channel iron, by
having a higher moment of inertia. As expected the first sign of overload
was the channels twisting, and I added bolts and spacers connecting their
webs until the deflection was satisfactory. It held the 2100 pound log
without the central support legs but as a precaution I left them in and
walked them over the grounded log to move it from the storage to the sawmill
side.

The splice bolts were fitted with only a few thousandths of clearance,
0.370" shanks in nominally 0.375" holes, and some went in with finger
pressure while others needed help. I turned tapers on the ends of some to
aid assembly. That was a tedious task fit for a retiree not working on the
clock. When I took it apart the bolt fit hadn't changed much and there were
no indications of overload.

The project met its design goal of lifting 2000 Lbs and moving it 16', using
components I could carry through the woods to a log or rock and erect on
site by myself. 2000# is the rating of the trolley, I think the track could
hold 3000 with the center supported. I moved the load with a long rope in
case I was wrong.

When I was in school I had a part time factory job at which I operated a
Tinius Olsen tensile strength tester.

I suppose the difference between a UTS test and your rig is that the tester
doesn't have much stored energy so plastic deformation reduces the stress,
while on yours it remains high. Yours represents actual service better.