Try in a few modern Sextant they spirit level (they spirit fluid so does not freeze) No a modern nuke Aircraft carry is using a water for navigation. Aircraft use spirit level or mercury (no horizon )
Dave
GPS COMPUTER VS SEXTANT/ASTROLABE/Old ways/manual
- Thread starter SmithDoor
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Dave
Maybe most do not know what radio compass or E6B
I think there would be more respons
E6B is a aircraft Dead Reckoning computer. It would with ground speed direction to point the aircraft with cross wind and more
The radio compass was for per-runner to GPS . Basically it points to radio station on a given frequency. Now few did talk the one for ships by different name.
OR I could toldly wrong again
What do you think ?
Dave
Although they're often referred to as a flight computer, in fact, the E6B is nothing more than a fancy circular slide rule typically made of sheet aluminum; photo below.
Your description of the radio compass is fairly accurate, I will only add that the radio stations (way points) the radio compass points to are ground based and are scattered across the US. Sometime back in the 70's (I think) avionics companies developed the R-Nav which would pick up multiple way point stations and tell the radio compass to display a heading to your destination instead of to the way point. R-Navs were the forerunner to GPS. Those of us who got our US pilot licensee back in the 80's were still required to learn how to navigate using way points and radio compass,...no R-Nav and no GPS allowed.
E6B did a lot with this side rull. Back 1960's every pilot had one or more. It is still amazing they designed the E6B with only a slide rule , paper and drafting board in 1930s
The radio compass dates back to 1920s ith Morse code radio station.
In 1930s and 1940's the used AM radio stations sometimes had to wait for call sign to see if had correcte station.
I still like radio compass
Some aircraft owners had two for triangulation.
Most just did with on radio compass still could do triangulation by switching back and forth.
My first generator I rebuilt was Kholer 5kw 4 cylinder water.
It was 7½ kw under the name plate. It was 240 volt 2 wire.
Hard to use but when built it they just did not add the center Tap but rebuilding found the center Tap. I use for over 30 years till walk a way. It was hard to move about 1,200 pounds was my guess.
Dave
The radio compass dates back to 1920s ith Morse code radio station.
In 1930s and 1940's the used AM radio stations sometimes had to wait for call sign to see if had correcte station.
I still like radio compass
Some aircraft owners had two for triangulation.
Most just did with on radio compass still could do triangulation by switching back and forth.
My first generator I rebuilt was Kholer 5kw 4 cylinder water.
It was 7½ kw under the name plate. It was 240 volt 2 wire.
Hard to use but when built it they just did not add the center Tap but rebuilding found the center Tap. I use for over 30 years till walk a way. It was hard to move about 1,200 pounds was my guess.
Dave
The GPS is great tool
Like saw in pass posts about sun spots. The worst time time for sun spots around 1840's set telegraph stations on fire and wire cattle finding on fire.
Think of that happen what would do world today.
Convertering the lathe to petal power or putting a engine to run thf lathe like good old days.
So away look thing I can build .
I can check off the engines no need for a horse
. Just install one on dishwasher good to go. Today everyone has a GPS. But hod many can navigate on airplane , drive car or sail a ship with out a GPS.
I bet most here can do navigation with out a GPS and build a Sextant.
Dave
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re: "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." - I instructed the inspectors at work to do this when setting measuring equipment truly level along a test track for testing cars.... (Typically a 30m set-up). They were amazed it worked so well, except the guy who got soaked emptying the pipe for storage! They later bought a laser level (because they could) and found it was OK in gloomy weather, great at night, but difficult over long distances in sunshine.. or when the Engineer stood in the line of the beam.
As I had them mark the positions, record the height of the kit above the road, they used that in future as the repeatable set-up was adequately level. No significant difference between either method in practice, but at night the laser was easier to use as a checking tool. And the laser was quicker than the guy getting soaked!
K2
Looking Building a pocket Sextant.
3 to 4" size
Using aluminum, UHMW & brass.
With research found most was accurate to 30 minutes.
Using a sprint level with horizon
So can be used on seas , land & air.
It only early days of design.
See below of 3" dail
Dave
What do you think
Here main two types of Sextant
VENEER TYPE
Note the it is mark in ½°
Very close
Note the veneer is in 10 parts or 3 minutes marks and has the degree sign not minute
Micrometer type
Very close
The numbers are 25 , 30 , 35 & 40 next with 5 marks between next number looks to be 1 minute, That a guess looking at photo
Dave
VENEER TYPE
Note the it is mark in ½°
Very close
Note the veneer is in 10 parts or 3 minutes marks and has the degree sign not minute
Micrometer type
Very close
The numbers are 25 , 30 , 35 & 40 next with 5 marks between next number looks to be 1 minute, That a guess looking at photo
WHAT DO YOU THINK ?
Dave
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Here chart on figuring out the dial
The was touch and fell 3" vs 4" dial
Looking size and graduation and the ability to read.
If cilpers to see best that works
First was 1/64" or 0.015625 or 0.39mm
Next veneer back to a clipper 0.001 not easy to read. But look around 2x a big improvement or 0.0022 or [0.0558mm]
Now to chart on 3" dial it work out to 10 minutes or 6 marks.
Dave
The was touch and fell 3" vs 4" dial
Looking size and graduation and the ability to read.
If cilpers to see best that works
First was 1/64" or 0.015625 or 0.39mm
Next veneer back to a clipper 0.001 not easy to read. But look around 2x a big improvement or 0.0022 or [0.0558mm]
Now to chart on 3" dial it work out to 10 minutes or 6 marks.
Dave
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Here one on ROTARY TABLES
I just found today.
. I just found today.
The accuracy of TABLE are from 20
seconds to 80 seconds or 1 minute 20 seconds
The digital from LMS is 70 seconds or 1 minute 10 seconds.
This best I Found this one on internet
Maximum individual spacing error 4" table 120"
Dave
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I really have no idea.
K2
K2
If go to calculate and may need error to see how close is good enough.
I am look building a sextant and need to know witch rotary table is the best choice.
Here drawing I been working on today. It rough only and different directions like simple astrolabe.
Drawing are cheap for me.
As see it simple but I have to make my own scale .
If build Astrolabe I use a protractor off shelf.
The Sextant uses ½ because of mirror . The Astrolabe is direct
Dave
FYI The pdf file is same but greater detail
I am look building a sextant and need to know witch rotary table is the best choice.
Here drawing I been working on today. It rough only and different directions like simple astrolabe.
Drawing are cheap for me.
As see it simple but I have to make my own scale .
If build Astrolabe I use a protractor off shelf.
The Sextant uses ½ because of mirror . The Astrolabe is direct
Dave
FYI The pdf file is same but greater detail
Here other use off the shelf protractor. This one I am looking at this one .
A Sextant each mark on the protractor. So veneer would normally need to read 0° to 1°. Using a off shelf protractor would need to read 0° to 2°.
See the second photo
Dave
Veneer for a off shelf protractor.
Close-up of veneer using 2°
Showing full size
Showing 4 different position
Dave
A Sextant each mark on the protractor. So veneer would normally need to read 0° to 1°. Using a off shelf protractor would need to read 0° to 2°.
See the second photo
Dave
Veneer for a off shelf protractor.
Close-up of veneer using 2°
Showing full size
Showing 4 different position
Dave
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Try this for time and earth 360°
Try this for time at different Latitudes
One hour is 1020 miles
how about one minute
At 0° = 17 miles in minute
at 35° = 14 miles in minute
at 65° = 7.2 miles in minute
.
how about one second
At 0° = 0.28 miles in second
at 35° = 0.23 miles in second
at 65° = 0.12 miles in second.
35° 0.8192
65° 0.4226
If your time is off 5 minute 35° you are 70 miles off
Dave
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To manage Mercator projection, (When at sea in the R.N.) we used the dividers to measure distances, by taking a standard nautical mile from the vertical scale at the side of the chart relevant to our determined position, NOT horizontal scale, and comparing that to the distance we had drawn as a straight line on the chart. For a few tens of Nm (Quarter-Hourly fixes) it was the most accurate we could do. But taking fixes so frequently was to get a lot of practice, and reduce errors (Trainees making errors? HMMM!) so at 13Kn we had not travelled far anyway! When sailing around Scottish islands, we took hourly fixes for positions. managing 60 miles in 24 hours... (Battling a head-wind from a storm for 40 miles. We must have tacked 3 times the distance over the water!). We returned in 8 hours, reaching and running.
K2
K2
It is a good video.
Now have GPS fantasy.
It sounds like Aviation lot great .
Lost great data like where not to fly.
Like that mountain is higher I can fly
In California and Nevada there places you will be shot down . Like Homely field in Nevada it are in Ballon they will shot you down too. FYI I did not know until 1980 Homely field was rename by Hollywood for movies. It field the they test flops .
The other parts before GPS is radio stations that change every few years.
Then magnetic compass every aircraft has one. Most dangerous part of aircraft. It only good as a backup. Pilots will watch the compass and fly into ground. It also shows horizon if clouds. But slow turn it does not work right in a turn.
Then the magnetic compass will false north with iron deposits in earth.
Navy should have similar problems on water.
Since I have only been on a large fairy one time life I can only read hear Navey fun on water.
Dave
Navy.
President’s Day.
Try this from in lines of command.
❋ Aircraft ❋
We all know a pilot does everything on the Aircraft like B29 . The pilot controls four engines, rudder, lookout, evaluator and list goes on . If on a fighter ads navigation, radar , and radioNow the Titania and later ship too.
❋ Below deck. ❋
1. Look out aka Crow nest Titania a bell later a phone had phones 1912
2. A guy on rudder in closed room no windows watching a need to move rudder
3. A team for each enigen of 2 to 4 engines watching a need to change to speed.
❋ On the bridge ❋
4. A guy moving the need for rudder aka Helmsman.5. A guy moving the need for speed control aka I do not know.
6. The Captain giving the order to move the needs and listening for guy with bell. 7. Not listening to Radio operator
8. Not using a carbon light for looking for chunk of ice.
❋ Aircraft engine vs size of small engine on ❋
Engine power: 2,200 hp (1,640 kW) each engine X four engines vs Liberty ships 2,500 horsepower (1,900 kW) one engine
Now fighter pilot engine end of WW2 WAS 2,000 HP doing everything.
Just picture the Navy running a fighter Aircraft. one guy on rudder, one guy on elevator, one guy only Ailerons, guy on flaps , the list goes on . Then captain would sould like a Auctioneer trying fly.
Bottom like never let Navy design Aircraft
Dave
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COLOR="#008000"]
This very interesting because of name I found internet [/COLOR]
Smith's Astroscope
Drawing of Smith's Astroscope or Sea-quadrant
Caleb Smith, an English insurance broker with a strong interest in astronomy, had created an octant in 1734. Called it an Astroscope or Sea-Quadrant.[6] His used a fixed prism in addition to an index mirror to provide reflective elements. Prisms provide advantages over mirrors in an era when polished speculum metal mirrors were inferior and both the silvering of a mirror and the production of glass with flat, parallel surfaces was difficult.
In the drawing to the bottom, the horizon element (B) could be a mirror or a prism. On the index arm, the index mirror (A) rotated with the arm. A sighting telescope was mounted on the frame (C). The index did not use a vernier or other device at the scale (D). Smith called the instrument's index arm a label, in the manner of Elton for his mariner's quadrant.[7]
I included both types .
Note the veneer
❋
This veneer is off different model about same year. Looks like each mark on veneer is 5 minutes
How do you see the veneer ?
Dave
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