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solar cell mount math fail

GH
gene heskett
Tue, May 23, 2023 8:22 AM

Greetings all;

Math failure is 100% me. I got some algebra in the 7th and 8th graes,
but the male teacher was far more interested in getting into the girls
panties than he was in teaching algebra. Invited to leave town by an
irate father with a 12 gauge before the 8th grade was done.

I've made a panel and printed it to hold an aliexpress 6 volt solar
cell. This after a mailbox remote alarm dissolved a couple of AA
Durocells in 2 months. Messy cleanup.

Its a hair short of the cell length but that is the max of my printer
bed diagonally. This holder is 71.5mm wide. And it should tilt the cell
so its roughly broadside to the sun at local noon, when glued to the
back of a plastic picket fence rail. I want it inside the yard, semi out
of site as I'll bury the cable to power the gizmo on the inside of the
mailbox door.

A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then
hollow it for 1mm walls and maybe 10% infill with another cylinder
inside it but 2mm shorter and 2mm smaller d.

what is my cylinders d= to get 72mm wide outer walls?

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.

Greetings all; Math failure is 100% me. I got some algebra in the 7th and 8th graes, but the male teacher was far more interested in getting into the girls panties than he was in teaching algebra. Invited to leave town by an irate father with a 12 gauge before the 8th grade was done. I've made a panel and printed it to hold an aliexpress 6 volt solar cell. This after a mailbox remote alarm dissolved a couple of AA Durocells in 2 months. Messy cleanup. Its a hair short of the cell length but that is the max of my printer bed diagonally. This holder is 71.5mm wide. And it should tilt the cell so its roughly broadside to the sun at local noon, when glued to the back of a plastic picket fence rail. I want it inside the yard, semi out of site as I'll bury the cable to power the gizmo on the inside of the mailbox door. A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then hollow it for 1mm walls and maybe 10% infill with another cylinder inside it but 2mm shorter and 2mm smaller d. what is my cylinders d= to get 72mm wide outer walls? Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/>
RW
Rob Ward
Tue, May 23, 2023 8:33 AM

Most frustration with junior high school algebra is the confusion of solving equations with equivalence. The equals signs is used both situations but mean quite different strategies.
To be able to see equivalence is to transform the meaning of an equation, whereas to solve an equation is to manipulate the algebra such that a final result is revealed. Few high school teachers really make this distinction. I wish I had made of it when I was teaching
Cheers, RobW

On 23 May 2023 6:22:00 pm AEST, gene heskett gheskett@shentel.net wrote:

Greetings all;

Math failure is 100% me. I got some algebra in the 7th and 8th graes, but the male teacher was far more interested in getting into the girls panties than he was in teaching algebra. Invited to leave town by an irate father with a 12 gauge before the 8th grade was done.

I've made a panel and printed it to hold an aliexpress 6 volt solar cell. This after a mailbox remote alarm dissolved a couple of AA Durocells in 2 months. Messy cleanup.

Its a hair short of the cell length but that is the max of my printer bed diagonally. This holder is 71.5mm wide. And it should tilt the cell so its roughly broadside to the sun at local noon, when glued to the back of a plastic picket fence rail. I want it inside the yard, semi out of site as I'll bury the cable to power the gizmo on the inside of the mailbox door.

A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then hollow it for 1mm walls and maybe 10% infill with another cylinder inside it but 2mm shorter and 2mm smaller d.

what is my cylinders d= to get 72mm wide outer walls?

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

Most frustration with junior high school algebra is the confusion of solving equations with equivalence. The equals signs is used both situations but mean quite different strategies. To be able to see equivalence is to transform the meaning of an equation, whereas to solve an equation is to manipulate the algebra such that a final result is revealed. Few high school teachers really make this distinction. I wish I had made of it when I was teaching Cheers, RobW On 23 May 2023 6:22:00 pm AEST, gene heskett <gheskett@shentel.net> wrote: >Greetings all; > >Math failure is 100% me. I got some algebra in the 7th and 8th graes, but the male teacher was far more interested in getting into the girls panties than he was in teaching algebra. Invited to leave town by an irate father with a 12 gauge before the 8th grade was done. > >I've made a panel and printed it to hold an aliexpress 6 volt solar cell. This after a mailbox remote alarm dissolved a couple of AA Durocells in 2 months. Messy cleanup. > >Its a hair short of the cell length but that is the max of my printer bed diagonally. This holder is 71.5mm wide. And it should tilt the cell so its roughly broadside to the sun at local noon, when glued to the back of a plastic picket fence rail. I want it inside the yard, semi out of site as I'll bury the cable to power the gizmo on the inside of the mailbox door. > >A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then hollow it for 1mm walls and maybe 10% infill with another cylinder inside it but 2mm shorter and 2mm smaller d. > >what is my cylinders d= to get 72mm wide outer walls? > >Cheers, Gene Heskett. >-- >"There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." >-Ed Howdershelt (Author, 1940) >If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis >Genes Web page <http://geneslinuxbox.net:6309/> >_______________________________________________ >OpenSCAD mailing list >To unsubscribe send an email to discuss-leave@lists.openscad.org
MA
Mike Aubury
Tue, May 23, 2023 8:40 AM

I asked chatgpt

c = (2**72*) / sqrt(3);

cylinder(d=c,h=20, $fn=3);

On Tue, 23 May 2023 at 09:22, gene heskett gheskett@shentel.net wrote:

Greetings all;

Math failure is 100% me. I got some algebra in the 7th and 8th graes,
but the male teacher was far more interested in getting into the girls
panties than he was in teaching algebra. Invited to leave town by an
irate father with a 12 gauge before the 8th grade was done.

I've made a panel and printed it to hold an aliexpress 6 volt solar
cell. This after a mailbox remote alarm dissolved a couple of AA
Durocells in 2 months. Messy cleanup.

Its a hair short of the cell length but that is the max of my printer
bed diagonally. This holder is 71.5mm wide. And it should tilt the cell
so its roughly broadside to the sun at local noon, when glued to the
back of a plastic picket fence rail. I want it inside the yard, semi out
of site as I'll bury the cable to power the gizmo on the inside of the
mailbox door.

A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then
hollow it for 1mm walls and maybe 10% infill with another cylinder
inside it but 2mm shorter and 2mm smaller d.

what is my cylinders d= to get 72mm wide outer walls?

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

I asked chatgpt c = (2**72*) / sqrt(3); cylinder(d=c,h=20, $fn=3); On Tue, 23 May 2023 at 09:22, gene heskett <gheskett@shentel.net> wrote: > Greetings all; > > Math failure is 100% me. I got some algebra in the 7th and 8th graes, > but the male teacher was far more interested in getting into the girls > panties than he was in teaching algebra. Invited to leave town by an > irate father with a 12 gauge before the 8th grade was done. > > I've made a panel and printed it to hold an aliexpress 6 volt solar > cell. This after a mailbox remote alarm dissolved a couple of AA > Durocells in 2 months. Messy cleanup. > > Its a hair short of the cell length but that is the max of my printer > bed diagonally. This holder is 71.5mm wide. And it should tilt the cell > so its roughly broadside to the sun at local noon, when glued to the > back of a plastic picket fence rail. I want it inside the yard, semi out > of site as I'll bury the cable to power the gizmo on the inside of the > mailbox door. > > A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then > hollow it for 1mm walls and maybe 10% infill with another cylinder > inside it but 2mm shorter and 2mm smaller d. > > what is my cylinders d= to get 72mm wide outer walls? > > Cheers, Gene Heskett. > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author, 1940) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/> > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >
RW
Rob Ward
Tue, May 23, 2023 8:43 AM

In other words Gene, don't feel to bad, if you have mastered even the basics of openSCAD you have achieved more than your junior high school would have even be able to imagine. I congratulate you  !!!!!
Cheers, RobW

On 23 May 2023 6:22:00 pm AEST, gene heskett gheskett@shentel.net wrote:

Greetings all;

Math failure is 100% me. I got some algebra in the 7th and 8th graes, but the male teacher was far more interested in getting into the girls panties than he was in teaching algebra. Invited to leave town by an irate father with a 12 gauge before the 8th grade was done.

I've made a panel and printed it to hold an aliexpress 6 volt solar cell. This after a mailbox remote alarm dissolved a couple of AA Durocells in 2 months. Messy cleanup.

Its a hair short of the cell length but that is the max of my printer bed diagonally. This holder is 71.5mm wide. And it should tilt the cell so its roughly broadside to the sun at local noon, when glued to the back of a plastic picket fence rail. I want it inside the yard, semi out of site as I'll bury the cable to power the gizmo on the inside of the mailbox door.

A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then hollow it for 1mm walls and maybe 10% infill with another cylinder inside it but 2mm shorter and 2mm smaller d.

what is my cylinders d= to get 72mm wide outer walls?

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

In other words Gene, don't feel to bad, if you have mastered even the basics of openSCAD you have achieved more than your junior high school would have even be able to imagine. I congratulate you !!!!! Cheers, RobW On 23 May 2023 6:22:00 pm AEST, gene heskett <gheskett@shentel.net> wrote: >Greetings all; > >Math failure is 100% me. I got some algebra in the 7th and 8th graes, but the male teacher was far more interested in getting into the girls panties than he was in teaching algebra. Invited to leave town by an irate father with a 12 gauge before the 8th grade was done. > >I've made a panel and printed it to hold an aliexpress 6 volt solar cell. This after a mailbox remote alarm dissolved a couple of AA Durocells in 2 months. Messy cleanup. > >Its a hair short of the cell length but that is the max of my printer bed diagonally. This holder is 71.5mm wide. And it should tilt the cell so its roughly broadside to the sun at local noon, when glued to the back of a plastic picket fence rail. I want it inside the yard, semi out of site as I'll bury the cable to power the gizmo on the inside of the mailbox door. > >A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then hollow it for 1mm walls and maybe 10% infill with another cylinder inside it but 2mm shorter and 2mm smaller d. > >what is my cylinders d= to get 72mm wide outer walls? > >Cheers, Gene Heskett. >-- >"There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." >-Ed Howdershelt (Author, 1940) >If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis >Genes Web page <http://geneslinuxbox.net:6309/> >_______________________________________________ >OpenSCAD mailing list >To unsubscribe send an email to discuss-leave@lists.openscad.org
GH
gene heskett
Tue, May 23, 2023 9:26 AM

On 5/23/23 04:41, Mike Aubury wrote:

I asked chatgpt

c = (2**72*) / sqrt(3);

chatgpt is doing  something the latest OpenSCAD can't do...
Give it an F. ;o)>

cylinder(d=c,h=20, $fn=3);

On Tue, 23 May 2023 at 09:22, gene heskett gheskett@shentel.net wrote:

Greetings all;

Math failure is 100% me. I got some algebra in the 7th and 8th graes,
but the male teacher was far more interested in getting into the girls
panties than he was in teaching algebra. Invited to leave town by an
irate father with a 12 gauge before the 8th grade was done.

I've made a panel and printed it to hold an aliexpress 6 volt solar
cell. This after a mailbox remote alarm dissolved a couple of AA
Durocells in 2 months. Messy cleanup.

Its a hair short of the cell length but that is the max of my printer
bed diagonally. This holder is 71.5mm wide. And it should tilt the cell
so its roughly broadside to the sun at local noon, when glued to the
back of a plastic picket fence rail. I want it inside the yard, semi out
of site as I'll bury the cable to power the gizmo on the inside of the
mailbox door.

A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then
hollow it for 1mm walls and maybe 10% infill with another cylinder
inside it but 2mm shorter and 2mm smaller d.

what is my cylinders d= to get 72mm wide outer walls?

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page http://geneslinuxbox.net:6309/


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.

On 5/23/23 04:41, Mike Aubury wrote: > I asked chatgpt > > c = (2**72*) / sqrt(3); > chatgpt is doing something the latest OpenSCAD can't do... Give it an F. ;o)> > cylinder(d=c,h=20, $fn=3); > > On Tue, 23 May 2023 at 09:22, gene heskett <gheskett@shentel.net> wrote: > >> Greetings all; >> >> Math failure is 100% me. I got some algebra in the 7th and 8th graes, >> but the male teacher was far more interested in getting into the girls >> panties than he was in teaching algebra. Invited to leave town by an >> irate father with a 12 gauge before the 8th grade was done. >> >> I've made a panel and printed it to hold an aliexpress 6 volt solar >> cell. This after a mailbox remote alarm dissolved a couple of AA >> Durocells in 2 months. Messy cleanup. >> >> Its a hair short of the cell length but that is the max of my printer >> bed diagonally. This holder is 71.5mm wide. And it should tilt the cell >> so its roughly broadside to the sun at local noon, when glued to the >> back of a plastic picket fence rail. I want it inside the yard, semi out >> of site as I'll bury the cable to power the gizmo on the inside of the >> mailbox door. >> >> A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then >> hollow it for 1mm walls and maybe 10% infill with another cylinder >> inside it but 2mm shorter and 2mm smaller d. >> >> what is my cylinders d= to get 72mm wide outer walls? >> >> Cheers, Gene Heskett. >> -- >> "There are four boxes to be used in defense of liberty: >> soap, ballot, jury, and ammo. Please use in that order." >> -Ed Howdershelt (Author, 1940) >> If we desire respect for the law, we must first make the law respectable. >> - Louis D. Brandeis >> Genes Web page <http://geneslinuxbox.net:6309/> >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to discuss-leave@lists.openscad.org >> > > > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/>
MA
Mike Aubury
Tue, May 23, 2023 9:37 AM

I added the *  * around the 72 for bold to show where you'd put in your
variable.
(It works - I tested it..)

On Tue, 23 May 2023 at 10:26, gene heskett gheskett@shentel.net wrote:

On 5/23/23 04:41, Mike Aubury wrote:

I asked chatgpt

c = (2**72*) / sqrt(3);

chatgpt is doing  something the latest OpenSCAD can't do...
Give it an F. ;o)>

cylinder(d=c,h=20, $fn=3);

On Tue, 23 May 2023 at 09:22, gene heskett gheskett@shentel.net wrote:

Greetings all;

Math failure is 100% me. I got some algebra in the 7th and 8th graes,
but the male teacher was far more interested in getting into the girls
panties than he was in teaching algebra. Invited to leave town by an
irate father with a 12 gauge before the 8th grade was done.

I've made a panel and printed it to hold an aliexpress 6 volt solar
cell. This after a mailbox remote alarm dissolved a couple of AA
Durocells in 2 months. Messy cleanup.

Its a hair short of the cell length but that is the max of my printer
bed diagonally. This holder is 71.5mm wide. And it should tilt the cell
so its roughly broadside to the sun at local noon, when glued to the
back of a plastic picket fence rail. I want it inside the yard, semi out
of site as I'll bury the cable to power the gizmo on the inside of the
mailbox door.

A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then
hollow it for 1mm walls and maybe 10% infill with another cylinder
inside it but 2mm shorter and 2mm smaller d.

what is my cylinders d= to get 72mm wide outer walls?

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law

respectable.

- Louis D. Brandeis

Genes Web page http://geneslinuxbox.net:6309/


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

I added the * * around the 72 for bold to show where you'd put in your variable. (It works - I tested it..) On Tue, 23 May 2023 at 10:26, gene heskett <gheskett@shentel.net> wrote: > On 5/23/23 04:41, Mike Aubury wrote: > > I asked chatgpt > > > > c = (2**72*) / sqrt(3); > > > chatgpt is doing something the latest OpenSCAD can't do... > Give it an F. ;o)> > > > cylinder(d=c,h=20, $fn=3); > > > > On Tue, 23 May 2023 at 09:22, gene heskett <gheskett@shentel.net> wrote: > > > >> Greetings all; > >> > >> Math failure is 100% me. I got some algebra in the 7th and 8th graes, > >> but the male teacher was far more interested in getting into the girls > >> panties than he was in teaching algebra. Invited to leave town by an > >> irate father with a 12 gauge before the 8th grade was done. > >> > >> I've made a panel and printed it to hold an aliexpress 6 volt solar > >> cell. This after a mailbox remote alarm dissolved a couple of AA > >> Durocells in 2 months. Messy cleanup. > >> > >> Its a hair short of the cell length but that is the max of my printer > >> bed diagonally. This holder is 71.5mm wide. And it should tilt the cell > >> so its roughly broadside to the sun at local noon, when glued to the > >> back of a plastic picket fence rail. I want it inside the yard, semi out > >> of site as I'll bury the cable to power the gizmo on the inside of the > >> mailbox door. > >> > >> A cylinder with an $fn=3; is the nominal tilt, giving a triangle. then > >> hollow it for 1mm walls and maybe 10% infill with another cylinder > >> inside it but 2mm shorter and 2mm smaller d. > >> > >> what is my cylinders d= to get 72mm wide outer walls? > >> > >> Cheers, Gene Heskett. > >> -- > >> "There are four boxes to be used in defense of liberty: > >> soap, ballot, jury, and ammo. Please use in that order." > >> -Ed Howdershelt (Author, 1940) > >> If we desire respect for the law, we must first make the law > respectable. > >> - Louis D. Brandeis > >> Genes Web page <http://geneslinuxbox.net:6309/> > >> _______________________________________________ > >> OpenSCAD mailing list > >> To unsubscribe send an email to discuss-leave@lists.openscad.org > >> > > > > > > _______________________________________________ > > OpenSCAD mailing list > > To unsubscribe send an email to discuss-leave@lists.openscad.org > > Cheers, Gene Heskett. > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author, 1940) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/> > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >
GH
gene heskett
Tue, May 23, 2023 10:00 AM

On 5/23/23 04:44, Rob Ward wrote:

In other words Gene, don't feel to bad, if you have mastered even the basics of openSCAD you have achieved more than your junior high school would have even be able to imagine. I congratulate you  !!!!!
Cheers, RobW

Actually, the main reason I quit school was that I was well ahead of
what they were teaching in the late 1940's. I quit school and went to
work fixing the then newfangled things we call tv's today. I tested at
147 on the Iowa version of the IQ test in '47. I wired the house my
father built us right after WW-II. Tried to join in the middle of korea
by having my number moved up, but got 4F'd by my score of 98 on the
AFQT, next best score of around 135 boys that took it that day was 36,
passed a 1st phone test in '62 w/o cracking a book, and in '72, passed
the CET test at 123 out of 125 w/o cracking a book. Most EE's will fail
that test. Switched to broadcasting after getting the 1st phone, and
spent my last 18 years working as the Chief (& usually only) Engineer at
WDTV-5.  Now 88 & long retired, getting rusty.

I've not had that great a luck with the fairer sex, I've now outlived 3
women, and the 3 children the first one gave me. And the last one died
of COPD 2+ years back.  So I'm alone, my own chief cook and bottle
washer. The place is paid off for 25 years now.

And this stuff keeps me out of the bars. ;o)> << smiley with beard.

Now, if somebody would translate that chatgpt thing into something
OpenSCAD can understand, I'd be obliged.

Take care & stay well everybody.

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.

On 5/23/23 04:44, Rob Ward wrote: > In other words Gene, don't feel to bad, if you have mastered even the basics of openSCAD you have achieved more than your junior high school would have even be able to imagine. I congratulate you !!!!! > Cheers, RobW > Actually, the main reason I quit school was that I was well ahead of what they were teaching in the late 1940's. I quit school and went to work fixing the then newfangled things we call tv's today. I tested at 147 on the Iowa version of the IQ test in '47. I wired the house my father built us right after WW-II. Tried to join in the middle of korea by having my number moved up, but got 4F'd by my score of 98 on the AFQT, next best score of around 135 boys that took it that day was 36, passed a 1st phone test in '62 w/o cracking a book, and in '72, passed the CET test at 123 out of 125 w/o cracking a book. Most EE's will fail that test. Switched to broadcasting after getting the 1st phone, and spent my last 18 years working as the Chief (& usually only) Engineer at WDTV-5. Now 88 & long retired, getting rusty. I've not had that great a luck with the fairer sex, I've now outlived 3 women, and the 3 children the first one gave me. And the last one died of COPD 2+ years back. So I'm alone, my own chief cook and bottle washer. The place is paid off for 25 years now. And this stuff keeps me out of the bars. ;o)> << smiley with beard. Now, if somebody would translate that chatgpt thing into something OpenSCAD can understand, I'd be obliged. Take care & stay well everybody. Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/>
MA
Mike Aubury
Tue, May 23, 2023 11:04 AM

Final time.. Then I give up.

c = (2*72) / sqrt(3);
cylinder(d=c,h=20, $fn=3);

Replace the 72 with whatever you want for the length.
I'm not going to highlight it in bold because that adds extra stars.

On Tue, 23 May 2023 at 11:00, gene heskett gheskett@shentel.net wrote:

On 5/23/23 04:44, Rob Ward wrote:

In other words Gene, don't feel to bad, if you have mastered even the

basics of openSCAD you have achieved more than your junior high school
would have even be able to imagine. I congratulate you  !!!!!

Cheers, RobW

Actually, the main reason I quit school was that I was well ahead of
what they were teaching in the late 1940's. I quit school and went to
work fixing the then newfangled things we call tv's today. I tested at
147 on the Iowa version of the IQ test in '47. I wired the house my
father built us right after WW-II. Tried to join in the middle of korea
by having my number moved up, but got 4F'd by my score of 98 on the
AFQT, next best score of around 135 boys that took it that day was 36,
passed a 1st phone test in '62 w/o cracking a book, and in '72, passed
the CET test at 123 out of 125 w/o cracking a book. Most EE's will fail
that test. Switched to broadcasting after getting the 1st phone, and
spent my last 18 years working as the Chief (& usually only) Engineer at
WDTV-5.  Now 88 & long retired, getting rusty.

I've not had that great a luck with the fairer sex, I've now outlived 3
women, and the 3 children the first one gave me. And the last one died
of COPD 2+ years back.  So I'm alone, my own chief cook and bottle
washer. The place is paid off for 25 years now.

And this stuff keeps me out of the bars. ;o)> << smiley with beard.

Now, if somebody would translate that chatgpt thing into something
OpenSCAD can understand, I'd be obliged.

Take care & stay well everybody.

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.


OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org

Final time.. Then I give up. c = (2*72) / sqrt(3); cylinder(d=c,h=20, $fn=3); Replace the 72 with whatever you want for the length. I'm not going to highlight it in bold because that adds extra stars. On Tue, 23 May 2023 at 11:00, gene heskett <gheskett@shentel.net> wrote: > On 5/23/23 04:44, Rob Ward wrote: > > In other words Gene, don't feel to bad, if you have mastered even the > basics of openSCAD you have achieved more than your junior high school > would have even be able to imagine. I congratulate you !!!!! > > Cheers, RobW > > > Actually, the main reason I quit school was that I was well ahead of > what they were teaching in the late 1940's. I quit school and went to > work fixing the then newfangled things we call tv's today. I tested at > 147 on the Iowa version of the IQ test in '47. I wired the house my > father built us right after WW-II. Tried to join in the middle of korea > by having my number moved up, but got 4F'd by my score of 98 on the > AFQT, next best score of around 135 boys that took it that day was 36, > passed a 1st phone test in '62 w/o cracking a book, and in '72, passed > the CET test at 123 out of 125 w/o cracking a book. Most EE's will fail > that test. Switched to broadcasting after getting the 1st phone, and > spent my last 18 years working as the Chief (& usually only) Engineer at > WDTV-5. Now 88 & long retired, getting rusty. > > I've not had that great a luck with the fairer sex, I've now outlived 3 > women, and the 3 children the first one gave me. And the last one died > of COPD 2+ years back. So I'm alone, my own chief cook and bottle > washer. The place is paid off for 25 years now. > > And this stuff keeps me out of the bars. ;o)> << smiley with beard. > > Now, if somebody would translate that chatgpt thing into something > OpenSCAD can understand, I'd be obliged. > > Take care & stay well everybody. > > Cheers, Gene Heskett. > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author, 1940) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > Genes Web page <http://geneslinuxbox.net:6309/> > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >
GH
gene heskett
Tue, May 23, 2023 4:43 PM

On 5/23/23 07:05, Mike Aubury wrote:

Final time.. Then I give up.

c = (2*72) / sqrt(3);
cylinder(d=c,h=20, $fn=3);

Works, thank you. But Cura has too #%&$ many knobs and switches. I just
spent 6 hours cuz it wouldn't do any infill, when another file loaded
and got infill like it was instructed. Even tried 2 more Cura updates,
finally discovering that somewhere in the last couple months the "make
overhangs printable" had gotten turned off. My clue was the first one
I built, using the above code, collapsed in on itself as it cooled.
So what s/b a good one is making now. With some infill.

Take care & stay well.

Cheers, Gene Heskett.

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.

On 5/23/23 07:05, Mike Aubury wrote: > Final time.. Then I give up. > > c = (2*72) / sqrt(3); > cylinder(d=c,h=20, $fn=3); > Works, thank you. But Cura has too #%&$ many knobs and switches. I just spent 6 hours cuz it wouldn't do any infill, when another file loaded and got infill like it was instructed. Even tried 2 more Cura updates, finally discovering that somewhere in the last couple months the "make overhangs printable" had gotten turned off. My clue was the first one I built, using the above code, collapsed in on itself as it cooled. So what s/b a good one is making now. With some infill. Take care & stay well. Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/>
JB
Jordan Brown
Tue, May 23, 2023 8:21 PM

If I understand correctly, you are asking for the "diameter" of a
triangle with sides 72 units.  Right?

First, to be clear, the diameter here is the diameter of the circle that
encloses the triangle.

Consider this diagram:

Here's a one-paragraph introduction to trigonometry:

The basic trigonometric functions are defined for a right triangle
(a triangle with one angle 90°).  (In this diagram, we're going to
work with the triangle ABC.)
They are functions of one of the two other angles. (Either BAC or
ABC in the diagram above, but we're going to concentrate on BAC.)
The hypotenuse is the long side, the one opposite the 90° angle. 
(AB in the diagram.)
The adjacent side is the side that connects to the angle that you're
working with, that isn't the hypotenuse.  (For angle BAC, this is AC.)
The opposite side is the side that *doesn't* connect to the angle
that you're working with.  (For angle BAC, this is BC.)
The sine of an angle is the length of the opposite side divided by
the length of the hypotenuse.  (The sine of BAC is BC/AB.)
The cosine is the adjacent side divided by the hypotenuse. (The
cosine of BAC is AC/AB.)
The tangent is opposite divided by adjacent. (The tangent of BAC is
BC/AC.)
The "arc" functions (arcsine, arccosine, arctangent) take the ratio
as an argument, and return the angle.

Now we can do your math.

(Values below to three significant figures.)
You want the side BD to be 72 units.
BC is half of that, 36 units.
The angle BAD is one third of a circle, 120°.
The angle BAC is one sixth of a circle, 60°.

sin(BAC) = BC/AB
sin(BAC)AB = BC  (multiply both sides by AB)
AB = BC/sin(BAC)  (divide both sides by sin(BAC))
AB = 36 / sin(60)  (substitute in the actual values of BC and BAC)
AB = 36 / 0.866  (value of sin(60) from the sin() function)
AB = 41.6 = radius of the circle
2
41.6 = 83.2 = diameter of the circle

A few more hints that can help to sanity-check your results:

Note that the opposite and adjacent sides are always smaller than
the hypotenuse, so sine and cosine are between zero and one. 
(Actually, between -1 and +1 when you consider triangles in the
other quadrants.)
Also note that when the angle is small, the sine is small, and when
the angle is large the sine is large.
And the other way around for cosine.

So, sanity-checking our result...

We expect the radius AB to be larger than the half-side BC.
We're dividing BC by a cosine, which is a number less than 1, so the
result will be larger than BC.
Check.

That kind of sanity checking won't catch all errors, but it'll catch
cases where you divided instead of multiplying, and things like that.

Note that this basic diagram and set of operations will tell you all
sorts of things about the dimensions of regular polygons.  For a polygon
with n sides, BAD is 360/n, BAC is half of that, and you can use the
same sine and cosine ratios to relate any of the dimensions to each other.

For instance, if you know the distance that you want to the center of a
side, AC in this diagram, and you want the "radius" that you would pass
to OpenSCAD...

BAC = 360/n/2
cos(BAC) = AC/AB
AB * cos(BAC) = AC
AB = AC / cos(BAC)

Thus for a regular polygon with n sides, where you know the length of
AC, the radius AB is AC/cos(360/n/2).

Again, sanity checking...

We expect AB to be larger than AC.
We're dividing AC by a cosine, so the result will be larger than AC.
Check.

The more sides we have, the closer AB and AC will be.
The more sides we have, the smaller the angle BAC will be.
Smaller angles yield larger cosines; as the angle approaches zero
the cosine approaches 1.
Thus when the number of sides is large, the cosine approaches 1.
As the cosine approaches 1, AC/cos(BAC) will approach AC.
Check.

UNITS NOTE:  OpenSCAD works in degrees.  Most other programming
languages work in radians, and some calculators default to radians.  If
you're doing this math using some other tool, make sure you convert
appropriately:  360° = 2*PI radians.  Most environments provide
conversion functions.

If I understand correctly, you are asking for the "diameter" of a triangle with sides 72 units.  Right? First, to be clear, the diameter here is the diameter of the circle that encloses the triangle. Consider this diagram: Here's a one-paragraph introduction to trigonometry: The basic trigonometric functions are defined for a right triangle (a triangle with one angle 90°).  (In this diagram, we're going to work with the triangle ABC.) They are functions of one of the two other angles. (Either BAC or ABC in the diagram above, but we're going to concentrate on BAC.) The hypotenuse is the long side, the one opposite the 90° angle.  (AB in the diagram.) The adjacent side is the side that connects to the angle that you're working with, that isn't the hypotenuse.  (For angle BAC, this is AC.) The opposite side is the side that *doesn't* connect to the angle that you're working with.  (For angle BAC, this is BC.) The sine of an angle is the length of the opposite side divided by the length of the hypotenuse.  (The sine of BAC is BC/AB.) The cosine is the adjacent side divided by the hypotenuse. (The cosine of BAC is AC/AB.) The tangent is opposite divided by adjacent. (The tangent of BAC is BC/AC.) The "arc" functions (arcsine, arccosine, arctangent) take the ratio as an argument, and return the angle. Now we can do your math. (Values below to three significant figures.) You want the side BD to be 72 units. BC is half of that, 36 units. The angle BAD is one third of a circle, 120°. The angle BAC is one sixth of a circle, 60°. sin(BAC) = BC/AB sin(BAC)*AB = BC  (multiply both sides by AB) AB = BC/sin(BAC)  (divide both sides by sin(BAC)) AB = 36 / sin(60)  (substitute in the actual values of BC and BAC) AB = 36 / 0.866  (value of sin(60) from the sin() function) AB = 41.6 = radius of the circle 2*41.6 = 83.2 = diameter of the circle A few more hints that can help to sanity-check your results: Note that the opposite and adjacent sides are always smaller than the hypotenuse, so sine and cosine are between zero and one.  (Actually, between -1 and +1 when you consider triangles in the other quadrants.) Also note that when the angle is small, the sine is small, and when the angle is large the sine is large. And the other way around for cosine. So, sanity-checking our result... We expect the radius AB to be larger than the half-side BC. We're dividing BC by a cosine, which is a number less than 1, so the result will be larger than BC. Check. That kind of sanity checking won't catch all errors, but it'll catch cases where you divided instead of multiplying, and things like that. Note that this basic diagram and set of operations will tell you all sorts of things about the dimensions of regular polygons.  For a polygon with n sides, BAD is 360/n, BAC is half of that, and you can use the same sine and cosine ratios to relate any of the dimensions to each other. For instance, if you know the distance that you want to the center of a side, AC in this diagram, and you want the "radius" that you would pass to OpenSCAD... BAC = 360/n/2 cos(BAC) = AC/AB AB * cos(BAC) = AC AB = AC / cos(BAC) Thus for a regular polygon with n sides, where you know the length of AC, the radius AB is AC/cos(360/n/2). Again, sanity checking... We expect AB to be larger than AC. We're dividing AC by a cosine, so the result will be larger than AC. Check. The more sides we have, the closer AB and AC will be. The more sides we have, the smaller the angle BAC will be. Smaller angles yield larger cosines; as the angle approaches zero the cosine approaches 1. Thus when the number of sides is large, the cosine approaches 1. As the cosine approaches 1, AC/cos(BAC) will approach AC. Check. UNITS NOTE:  OpenSCAD works in degrees.  Most other programming languages work in radians, and some calculators default to radians.  If you're doing this math using some other tool, make sure you convert appropriately:  360° = 2*PI radians.  Most environments provide conversion functions.