There is no reason why you can't have a turbo-molecular pump on the SEM.? They are
just more expensive.? The pumps on a Auger-Sims were a roughing pump, turbo-pump and
an ION pump.? Imaging was really bad.? It's job was analysis.

The ISI had a really tiny diffusion pump essentially mounted under the chamber.? It's
no more than a foot tall.? It has No LN2 trap, nor requires LN2, but it is water
cooled.? We had water running continuously and bought he rough and diffusion pumps
running continously and vented.? Some Oil mist goes out the vent from the roughing pump.

Pumping involves closing the foreline valve and rough out the chamber and not letting
the foreline pressure get above around 75 um (memory).? Water vapor takes a while to
pump out.? One way to deal with that is to back fill the chamber with a dry gas and
cycle it multiple times.??

To prevent backstreaming with the rough pump, you can use a bleed valve, but there
are backstream preventors.? Some need to be baked out once and a while.

There is no reason why you can't have a turbo-molecular pump on the SEM.? They are
just more expensive.? The pumps on a Auger-Sims were a roughing pump, turbo-pump and
an ION pump.? Imaging was really bad.? It's job was analysis.

15-20 minutes is a good number, but humidity matters.

if your vacuum meter hovers around 100 uM, you have a water vapor problem.? Usually
in the roughing pump oil.

What you really don't want is to open the chamber to atmosphere with it roughing the
chamber and you also don't want the oils condensing on the column.

The EDS/EDAX unit has a beryllium window which passes low energy x-rays to the EDS
detector (An option).? EDAX - Energy Dispersive Analysis of X-rays.

Pump-down was only manual.?? valves were manual.

Power failures are problematic with larger vacuum systems that have a closed loop
refrigerent? LN2 replacement and electric valves.?


On Wednesday, September 9, 2020, 2:25:03 PM EDT, Dave McGuire <mcguire@...>
wrote:


On 9/9/20 2:21 PM, Mike Vande Voort wrote:

how long to pump down the chamber after loading a sample, and you
backfill with Nitrogen prior to opening ?

? On my very old ETEC Autoscan, chamber pump-down usually takes about
three minutes.? I do not use N2 back-fill.

? ? ? ? ? ? -Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

I went through the Eagle nightmare and all I can say is this: use KiCad. No reason not to. It’s a very reasonable product, resembling old Protel in some ways. It’s easy to use, state-of-the-art interactive PCB routing, and is easy to hack on. CERN is a major contributor to it, I think. There are very few bugs I ran into when using the most recent version - a good sign. I can go a whole day without crashing it and without fighting with it. Eagle’s underlying UX principles were idiotic I from the get go - I can’t understand how could anyone stand that nonsense. It was like a thin graphical shim for directly modifying some rigid data structure. Totally bonkers. I know that Autodesk improved things a bit once they took over, but CadSoft’s “vision” for it was utter garbage. No wonder they had to sell it - it was an insult to the customers.

Cheers, Kuba

8 sep. 2020 kl. 1:57 em skrev Harvey White <madyn@...>:

?The EAGLE version only does 3 by 4 inch boards, single sheet, double sided at most.

For my own purposes, too limited.

EAGLE used to be a separate product, but IIRC, is *only* available as an addon to Fusion 360. More robust versions of Fusion 360/EAGLE are available by subscription only.

Harvey

On 9/8/2020 10:01 AM, Sandra Carroll wrote:
I’m surprised no one has mention fusion360. Full CAD/CAM with Eagle now as well.
3D parametric, direct manufacture to 3D printers. I send to both simplify3D and chitubox all the time.

Easy to use. Still no cost to makers.

On open source
Some comments. I’ve run into countless projects that die or are abandoned in the opensource community. Yeh some of the big stay around but far greater go nowhere.

Opensource is not this great pancea of perfection. If your not a developer yourself you can only hope they’ll accept your proposal for a change. Personal experience is they don’t always do this. In fact in my experience they rarely do. It does not fit the authors vision of how it should work.

I love Perl. But the community refused for the longest time to accept ebcdic(mainframe) into the their world. And only did by making it ascii internally which has its own problems for those of us in the mainframe.

I’m not against opensource, I use it all the time. Like anything it has it’s upside and downside.

Sandra

Sent from my iPhone 7 Plus

On Sep 8, 2020, at 9:29 AM, Chuck Harris <cfharris@...> wrote:

?Bear in mind that one of the features of open source projects
is they really never go away. Commercial projects come and vanish,
and change their licensing terms with great regularity.

OpenSCAD is used by dozens of other projects, and is a very solid
package. The source is available on github, and if you don't like
the direction the authors are going, you can take it and make it
your way. Sure, if you aren't talented that way, you will have to
hire it done, but that is what you are already doing with the outright
commercial packages... without any hope of customization.

If OpenSCAD is too hard to learn (it isn't), you can use one of the
many packages, like FreeCAD, that have incorporated it into their
graphic interfaces.

We greybeards remember the PC so well, that we wrote GNU and linux
for it, and emancipated ourselves from Microsoft.

Educator licenses are available to universities to allow them to
train their kiddies on the package at no cost to the university.

The university professor gives a 1 year copy to each student, and
they use it for their course work. At the end of the year, it is
inactivated.

The companies do that because it is free advertising, and a free
beta testing of their product. They also know that once trained on
a product, students will ask for it where they work.

That is the sole and only reason Apple and Microsoft have such nice
licensing terms for K-12 schools.

Also, to use a student license, usually you are required to show
registration at a university. The rules on student licenses are
highly restrictive relative to commercial intention. A product
designed on a student license cannot ever be commercialized without
transferring it to a full on commercial seat... at typically $50K a
seat... and once there, it can never be brought back to a student
seat.

-Chuck Harris

Tom Gardner wrote:

Overall I doubt that members of this group will want to make anything really complex,
but they might like it to be available to other members in a decade or so. So have a
quick look and choose any tool that feels comfortable without a large learning curve.

After a///very//quick look/, it appears that OnShape is....

Free for "educators", with a 1 year time limit on the licence - whatever that means.

Online only, running in a browser like OpenJSCAD. The standard questions with any
"cloud service" are whether:

* it will be there in 5 years time; see Microsoft PlaysForSure(TM), and giggle
* the licence conditions can be changed, e.g. is the company/product changes ownership

Greybeards will remember the sighs of relief when PCs became available, because it
meant that users' data was not "held hostage" inside silos owned by other companies.

On 08/09/20 02:54, Kuba Ober wrote:
OnShape - as long as it’s not for commercial purposes - all your projects are
publicly viewable then. A joy to use. All it needs is an OK internet connection and
a supported web browser.

FreeCAD is another option.

7 sep. 2020 kl. 10:17 fm skrev victor.silva via groups.io
<daejon1@...>:

?This is off topic but the end result will be for HP products so please bear with me.

I am looking for recommendation on 3D modeling software (preferably freeware) and
a company that I can then send the 3D model to
make a battery holder clamshells. I propose to make half clamshell pieces that
would then make a complete
battery holder by using 2 pieces that would fit together.

Thank you,
Victor

OpenSCAD may be popular but it’s crickets in the repository, and that’s what I judge it by in terms of long-term viability. It takes an actual dedicated human being, with relevant knowledge - or willing to learn a lot fast - to keep it moving. There’s nobody deeply invested in it enough to put in serious engineering time it needs - at the moment. This may change overnight of course, and the source will be there forever as well. It doesn’t change whether it’s fit for the job, and for the most part it actually does do what I want it to. But - again, at the moment - it’s abandonware, and dead. Notice that it has not all that much impact on its utility!
Cheers, Kuba

8 sep. 2020 kl. 10:57 fm skrev Dave McGuire <mcguire@...>:

?On 9/8/20 9:29 AM, Chuck Harris wrote:

Bear in mind that one of the features of open source projects
is they really never go away. Commercial projects come and vanish,
and change their licensing terms with great regularity.
OpenSCAD is used by dozens of other projects, and is a very solid
package. The source is available on github, and if you don't like
the direction the authors are going, you can take it and make it
your way. Sure, if you aren't talented that way, you will have to
hire it done, but that is what you are already doing with the outright
commercial packages... without any hope of customization.
If OpenSCAD is too hard to learn (it isn't), you can use one of the
many packages, like FreeCAD, that have incorporated it into their
graphic interfaces.
We greybeards remember the PC so well, that we wrote GNU and linux
for it, and emancipated ourselves from Microsoft.

Not exactly...GNU software was initially developed to emancipate us from Sun, AT&T, and related companies in the UNIX world, and not generally for PCs. In recent years it has become a way for PC users to get away from the childish mess that is Microsoft, but let's not forget that they (GNU and Linux, separately) were envisioned and implemented as an alternative to commercial UNIX on far higher-end hardware than PCs. And I'm not just talking about in the beginning.

But otherwise you hit the nail very much on the head. OpenSCAD is exploding in popularity, politics and release schedules notwithstanding. The notion of it being "dead" is pretty silly.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

8 sep. 2020 kl. 1:57 em skrev Harvey White <madyn@...>:

?The EAGLE version only does 3 by 4 inch boards, single sheet, double sided at most.

For my own purposes, too limited.

EAGLE used to be a separate product, but IIRC, is *only* available as an addon to Fusion 360. More robust versions of Fusion 360/EAGLE are available by subscription only.

Harvey

On 9/8/2020 10:01 AM, Sandra Carroll wrote:
I’m surprised no one has mention fusion360. Full CAD/CAM with Eagle now as well.
3D parametric, direct manufacture to 3D printers. I send to both simplify3D and chitubox all the time.

Easy to use. Still no cost to makers.

On open source
Some comments. I’ve run into countless projects that die or are abandoned in the opensource community. Yeh some of the big stay around but far greater go nowhere.

Opensource is not this great pancea of perfection. If your not a developer yourself you can only hope they’ll accept your proposal for a change. Personal experience is they don’t always do this. In fact in my experience they rarely do. It does not fit the authors vision of how it should work.

I love Perl. But the community refused for the longest time to accept ebcdic(mainframe) into the their world. And only did by making it ascii internally which has its own problems for those of us in the mainframe.

I’m not against opensource, I use it all the time. Like anything it has it’s upside and downside.

Sandra

Sent from my iPhone 7 Plus

On Sep 8, 2020, at 9:29 AM, Chuck Harris <cfharris@...> wrote:

?Bear in mind that one of the features of open source projects
is they really never go away. Commercial projects come and vanish,
and change their licensing terms with great regularity.

OpenSCAD is used by dozens of other projects, and is a very solid
package. The source is available on github, and if you don't like
the direction the authors are going, you can take it and make it
your way. Sure, if you aren't talented that way, you will have to
hire it done, but that is what you are already doing with the outright
commercial packages... without any hope of customization.

If OpenSCAD is too hard to learn (it isn't), you can use one of the
many packages, like FreeCAD, that have incorporated it into their
graphic interfaces.

We greybeards remember the PC so well, that we wrote GNU and linux
for it, and emancipated ourselves from Microsoft.

Educator licenses are available to universities to allow them to
train their kiddies on the package at no cost to the university.

The university professor gives a 1 year copy to each student, and
they use it for their course work. At the end of the year, it is
inactivated.

The companies do that because it is free advertising, and a free
beta testing of their product. They also know that once trained on
a product, students will ask for it where they work.

That is the sole and only reason Apple and Microsoft have such nice
licensing terms for K-12 schools.

Also, to use a student license, usually you are required to show
registration at a university. The rules on student licenses are
highly restrictive relative to commercial intention. A product
designed on a student license cannot ever be commercialized without
transferring it to a full on commercial seat... at typically $50K a
seat... and once there, it can never be brought back to a student
seat.

-Chuck Harris

Tom Gardner wrote:

Overall I doubt that members of this group will want to make anything really complex,
but they might like it to be available to other members in a decade or so. So have a
quick look and choose any tool that feels comfortable without a large learning curve.

After a///very//quick look/, it appears that OnShape is....

Free for "educators", with a 1 year time limit on the licence - whatever that means.

Online only, running in a browser like OpenJSCAD. The standard questions with any
"cloud service" are whether:

* it will be there in 5 years time; see Microsoft PlaysForSure(TM), and giggle
* the licence conditions can be changed, e.g. is the company/product changes ownership

Greybeards will remember the sighs of relief when PCs became available, because it
meant that users' data was not "held hostage" inside silos owned by other companies.

On 08/09/20 02:54, Kuba Ober wrote:
OnShape - as long as it’s not for commercial purposes - all your projects are
publicly viewable then. A joy to use. All it needs is an OK internet connection and
a supported web browser.

FreeCAD is another option.

7 sep. 2020 kl. 10:17 fm skrev victor.silva via groups.io
<daejon1@...>:

?This is off topic but the end result will be for HP products so please bear with me.

I am looking for recommendation on 3D modeling software (preferably freeware) and
a company that I can then send the 3D model to
make a battery holder clamshells. I propose to make half clamshell pieces that
would then make a complete
battery holder by using 2 pieces that would fit together.

Thank you,
Victor

8 sep. 2020 kl. 10:57 fm skrev Dave McGuire <mcguire@...>:

?On 9/8/20 9:29 AM, Chuck Harris wrote:

Bear in mind that one of the features of open source projects
is they really never go away. Commercial projects come and vanish,
and change their licensing terms with great regularity.
OpenSCAD is used by dozens of other projects, and is a very solid
package. The source is available on github, and if you don't like
the direction the authors are going, you can take it and make it
your way. Sure, if you aren't talented that way, you will have to
hire it done, but that is what you are already doing with the outright
commercial packages... without any hope of customization.
If OpenSCAD is too hard to learn (it isn't), you can use one of the
many packages, like FreeCAD, that have incorporated it into their
graphic interfaces.
We greybeards remember the PC so well, that we wrote GNU and linux
for it, and emancipated ourselves from Microsoft.

Not exactly...GNU software was initially developed to emancipate us from Sun, AT&T, and related companies in the UNIX world, and not generally for PCs. In recent years it has become a way for PC users to get away from the childish mess that is Microsoft, but let's not forget that they (GNU and Linux, separately) were envisioned and implemented as an alternative to commercial UNIX on far higher-end hardware than PCs. And I'm not just talking about in the beginning.

But otherwise you hit the nail very much on the head. OpenSCAD is exploding in popularity, politics and release schedules notwithstanding. The notion of it being "dead" is pretty silly.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA

?

8 sep. 2020 kl. 12:25 em skrev Roy Thistle <roy.thistle@...>:

?Hi Carl! Is that you from TekScopes?
About InfiniiVision I do!... but if you get a chance, and would like to... can you explain why you are posting open ended questions?
And also, might you comment on why you are sometimes posting links to only superficially topical articles... links to re-posted articles on a Ghanaian political Website... articles that are seemingly taken verbatim from American trade journals, posted without credit to the journal, or the original author... and in fact crediting a different author?