GPS COMPUTER VS SEXTANT/ASTROLABE/Old ways/manual

[ShopShoe]

So......

Further Down the Rabbit Hole....

Amelia Earhart's navigator was using a "Bubble Octant," according to several histories and films made about her disappearance.

Does anyone know anything about that instrument?

--ShopShoe

 

[SmithDoor]

So......

Further Down the Rabbit Hole....

Amelia Earhart's navigator was using a "Bubble Octant," according to several histories and films made about her disappearance.

Does anyone know anything about that instrument?

--ShopShoe

NO
It reason I am here finding out data.

I have used Surveying equipment.

Only reading the internet.

Yes know Amelia Earhart use Bubble Octant and radio for navigation.

Dave

 

[SmithDoor]

So......

Further Down the Rabbit Hole....

Amelia Earhart's navigator was using a "Bubble Octant," according to several histories and films made about her disappearance.

Does anyone know anything about that instrument?

--ShopShoe

Back in 1960's at a EAA meeting the gust speaker selling a high price compass. Use a slide on if down in the middle of ocean. Using a compass and a watch you find location.

This basically what look like.
For longitude
1) If did not know true north find by locating north star and the difference of magnic.
2) At high noon by sun ☀ notd time on your watch using Greenwich Time.
3) Look chart on back side of compass and difference is your longitude

Ladadtue
1) Find the angle of sun at high noon use the compass by pointing it sun and lining un scale on compass.
2) Use chart on backside compass and Time year will give your Ladadtue.

Today look back and think you could hundreds of miles off using this compass.
But when 10 or 12 you think that is fantastic.

Thd speaker did talk how to make sail boat out life raff too. At less no one had to use the magic compass design Hollywood.

Today we have YouTube
I am trying the real way.

Dave

 

[SmithDoor]

Here some data on milling in a lathe making gears on a lathe.
Piston Rings too.


Dave

 

[SmithDoor]

So......

Further Down the Rabbit Hole....

Amelia Earhart's navigator was using a "Bubble Octant," according to several histories and films made about her disappearance.

Does anyone know anything about that instrument?

--ShopShoe

This is better one for Rabbit Hole for bad Aircraft. Works everytime A machine design in France.
It is also a Landlord best day ever

The aircraft cost over Hight lite between brackets for answer {- $400,000 -}

Dave

 

[Daryl_bee]

Back in 1960's at a EAA meeting the gust speaker selling a high price compass. Use a slide on if down in the middle of ocean. Using a compass and a watch you find location.
View attachment 164848
This basically what look like.
For longitude
1) If did not know true north find by locating north star and the difference of magnic.
2) At high noon by sun ☀ notd time on your watch using Greenwich Time.
3) Look chart on back side of compass and difference is your longitude

Ladadtue
1) Find the angle of sun at high noon use the compass by pointing it sun and lining un scale on compass.
2) Use chart on backside compass and Time year will give your Ladadtue.

Today look back and think you could hundreds of miles off using this compass.
But when 10 or 12 you think that is fantastic.

Thd speaker did talk how to make sail boat out life raff too. At less no one had to use the magic compass design Hollywood.

Today we have YouTube
I am trying the real way.

Dave

Interesting reading these posts.

Only partially related, I designed an Astrolabe back in 1993 (on Generic CADD) but it only got to the paper model stage (looks terribly beat up now). It was a PITA because I could not place text on a curve so had to do it letter by letter (or number) and in addition anticipate a vertical offset when the letter was printed. Like I said on my web page at the time I tested it in Canada with one plate and another in St. Lucia (I had plates for every 5deg) and in all cases it was bang-on accurate. What fantastic night skies in St Lucia! I even predicted a solar eclipse and that it would be a grazing partial. I was never able to get photogrametric plates made and lost the source design went I moved on to another job - it was on a work computer back in 1993.
http://surfin_dude.tripod.com/creative/astronomy/astronomy.html#Astrolabe

Previous to that, what got me interested in such things, was a 18” brass sundial design I did which, amongst a host of other things, tracked the sun’s progress across a map on it’s face thought each day and the course of the year. Tricky to etch an 18" dia - 3/8" thick plate or the 1/2" thick gnomen.
http://surfin_dude.tripod.com/creative/astronomy/astronomy.html#Sundial

Now, I keep it simple and use my “Yes V7” watch. Similar but better than the Prague astronomical clock. Used by NASA astronauts & Hollywood movie producers wanting to keep track of daylight. They have a successor to the V7 coming out soon. It will tell you sunrise/set, twilight, moon rise etc a whole host of other things after you program in your city (or manually if your city isn't on the infinitely long list).


No end of fun in this field!

 

[SmithDoor]

Interesting reading these posts.

Only partially related, I designed an Astrolabe back in 1993 (on Generic CADD) but it only got to the paper model stage (looks terribly beat up now). It was a PITA because I could not place text on a curve so had to do it letter by letter (or number) and in addition anticipate a vertical offset when the letter was printed. Like I said on my web page at the time I tested it in Canada with one plate and another in St. Lucia (I had plates for every 5deg) and in all cases it was bang-on accurate. What fantastic night skies in St Lucia! I even predicted a solar eclipse and that it would be a grazing partial. I was never able to get photogrametric plates made and lost the source design went I moved on to another job - it was on a work computer back in 1993.
http://surfin_dude.tripod.com/creative/astronomy/astronomy.html#Astrolabe

Previous to that, what got me interested in such things, was a 18” brass sundial design I did which, amongst a host of other things, tracked the sun’s progress across a map on it’s face thought each day and the course of the year. Tricky to etch an 18" dia - 3/8" thick plate or the 1/2" thick gnomen.
http://surfin_dude.tripod.com/creative/astronomy/astronomy.html#Sundial

Now, I keep it simple and use my “Yes V7” watch. Similar but better than the Prague astronomical clock. Used by NASA astronauts & Hollywood movie producers wanting to keep track of daylight. They have a successor to the V7 coming out soon. It will tell you sunrise/set, twilight, moon rise etc a whole host of other things after you program in your city (or manually if your city isn't on the infinitely long list).


No end of fun in this field!

I was paper from 1960's to 1995
First started with Tubocad then switch to Autocad 95. If you have copy of Autocad 95 it works great on Windows 11 64 bit.

I can see itching could problem
I had foundry patterns zinc itching for name plates. That you get at less 24x24. The SMITH logo is a zinc itching.

Like you plates looks like a lot of fun.
Just thing of making back 1500's

Dave

 

[SmithDoor]

Here few more zinc itchings I still have.

I also of the life boat compass my father purchased back in the 1960's it was draw with zinc itchings

With sight open

This had a 3x6 plastic card too. My brothers lost the card back 1960's on a hunting trip.

Dave

 

[SmithDoor]

Any one noticed the 64 division on compass.

Why ? ​

Dave. .

Engineer Directional Compass​

 

[SmithDoor]

Engineer Directional Compass​

In the Philippines we use that technique, but we put food coloring in it to see the level easier

Here in Thailand, building construction guys use a length of clear plastic tube filled with water to insure their construction is level from point-to-point; no fancy lasers needed.

Here thinking about is pocket size Sextant. Most are 3" [75mm] to 4" [100mm] . My plan is 5" [125mm] a little larger making build easier.
The materials are UHMW, PLEXIGLAS, ALUMINUM & BRASS.
The arm fine adjustment and break is not on this drawing. Note the mirror for bull eye level can move (flip up) for use on the horizon level

What do you think?
Note pdf file has better detail.

Dave

 

[Toymaker]

What do you think?
Dave

I'm an old retired electronics engineer, so I think there's plenty of room in your design to install one of those super tiny GPS tracking devices that send their GPS coordinates to your smart phone Do this and you'll never need to take your pocket size Sextant out of your pocket

 

[SmithDoor]

I'm an old retired electronics engineer, so I think there's plenty of room in your design to install one of those super tiny GPS tracking devices that send their GPS coordinates to your smart phone Do this and you'll never need to take your pocket size Sextant out of your pocket

My phone has a real good GPS.
It good to a few feet.

I have watch never needs batteries winding and keeps time for ever

I have very good hand held calculator never needs batteries or sun light to work . FYI my phone has one too.

Now on lighter side I had a ticket got this flight thank God for dear hunting

My crew wanted the day off for hunting so took different flight 182 vs 172

Dave

 

[SmithDoor]

I'm an old retired electronics engineer, so I think there's plenty of room in your design to install one of those super tiny GPS tracking devices that send their GPS coordinates to your smart phone Do this and you'll never need to take your pocket size Sextant out of your pocket

I like building old things of past . Like engines and anything that is pocket size. Have castings for a single cylinder. Because of health it on hold for better days. So I am keeping to small simple things from pass.

I just pitchers my self on a life boat trying to use my life boat compass after my phone has dies from water or batteries. I just need to know witch way to go with my outboard engine I built
Saying to myself it is a bad day again. Now what

Dave

 

[TonySteamHobby]

I used new technology (home built CNC machine) to engrave this old technology. They look a lot cooler than a GPS chip.

 

[SmithDoor]

Looks great .

Just think doing that work with tools they had 500 years ago

Dave
Any build photos?

Dave

 

[HMEL]

Any one noticed the 64 division on compass.

Why ? ​

Dave. .

Engineer Directional Compass​

View attachment 164910

View attachment 164909

I believe this compass is an artillery compass these units 64 are in mills. There are different mill scales in use dependent on the time in history and the military using the standard. You can with some training estimate range using those numbers. My old military compass has only degrees a radium dial for night work. You cant make them anymore because of the radium dial. Mills are dialed in on the gun sight from the fire direction control. Now they set range and azimuth with electronic stuff. A forward observer might have carried this compass. But usually there is some markings if it is military. Its use is for estimation only. The degree scale is obviously for traditional direction determination.

 

[HMEL]

Engineer Directional Compass​

Here thinking about is pocket size Sextant. Most are 3" [75mm] to 4" [100mm] . My plan is 5" [125mm] a little larger making build easier.
The materials are UHMW, PLEXIGLAS, ALUMINUM & BRASS.
The arm fine adjustment and break is not on this drawing. Note the mirror for bull eye level can move (flip up) for use on the horizon level

What do you think?
Note pdf file has better detail.

Dave
View attachment 164957

Well for the fun of it am giving you my answer. Its a fun project and maybe challenging to build. But for accuracy its not going to tell you where you are. Need the larger arc to reduce error in reading and you can probably tell the accuracy by the separation in degree marks. The old navy sextants were much larger and accuracy was one reason. The distance on the earth varies because its not a perfect circle so standards are established and technically you need a good watch and charts to go with it. Not to valuable to know you are maybe 50 to 500 miles of something. I jest but there is an element of truth here. Now to be honest I have been toying with building one for the last five years just for the fun of it. So I kind of went down the rabbit hole as the old saying goes. But you should build yours anyway just for the fun of it.

 

[SmithDoor]

Well for the fun of it am giving you my answer. Its a fun project and maybe challenging to build. But for accuracy its not going to tell you where you are. Need the larger arc to reduce error in reading and you can probably tell the accuracy by the separation in degree marks. The old navy sextants were much larger and accuracy was one reason. The distance on the earth varies because its not a perfect circle so standards are established and technically you need a good watch and charts to go with it. Not to valuable to know you are maybe 50 to 500 miles of something. I jest but there is an element of truth here. Now to be honest I have been toying with building one for the last five years just for the fun of it. So I kind of went down the rabbit hole as the old saying goes. But you should build yours anyway just for the fun of it.

That alway do here build for fun!!!

I can tell any how build to last a long time but that is a lot more cost and time.

I have a Theodolite I purchased new in the 1970’s.
But this just for fun and will work.

I start this after reading about Navy is going back to training on the Sextant.

I look at could big one but it big or a Astrolabe.
Next look at smaller size. The pocket Sextant look just right for sitting on a shelf and need to really works too. Everything I build needs to work or just a model.

Then I look bubble type because I not near a ocean.
I am still working the design and seeing what everyone thinks and give input?

Dave