Cave Survey Protractors from Inner Mountain...........junk??

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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Martin Sluka » Apr 8, 2009 10:27 am

Scott McCrea wrote:I like the idea of the Cave Compass. Sort of like this:
Image
Works the same way. It takes a lot of thought out of sketching. Just turn the dial and line it up. Pretty simple.


But no cosine function. Protractor I linked allows graphical reduction of shot according its clino.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Scott McCrea » Apr 8, 2009 10:51 am

sluka wrote:But no cosine function. Protractor I linked allows graphical reduction of shot according its clino.

I do the profile first and get the adjusted distance from the profile.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Martin Sluka » Apr 8, 2009 11:11 am

Scott McCrea wrote:I do the profile first and get the adjusted distance from the profile.


Clever solution. :clap:
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Jeff Bartlett » Apr 8, 2009 2:53 pm

Scott McCrea wrote:
batrotter wrote:I don't normally use a protractor while keeping book...

How do you manage that?


I'm presuming he uses the not-to-scale technique popular up until the 1980s (and really, really frustrating to draw a detailed map from). You know, the one where you pull all the dimensions out of your ass, the angles and distances are all wrong, and you let your cartographer have a breakdown trying to convert your sketch into something that matches the line plot.
"Although it pains me to say it, in this case Jeff is right. Plan accordingly." --Andy Armstrong
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Martin Sluka » Apr 8, 2009 3:01 pm

xcathodex wrote: and you let your cartographer have a breakdown trying to convert your sketch into something that matches the line plot.


Just as curious example: http://therion.speleo.sk/samples.doc/10.html :grin:
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Aaron Addison » Apr 8, 2009 4:37 pm

The CaveCompass looks interesting, but it is not 1:10 (or maybe it is!). Really depends on your terminology I guess. In cartography, "1:10" is a RF or Representative Fraction. It simply means that 1 of something on the map is the same as 10 in the real world. The ratio is unitless. To that end, you could use the scale to sketch in metric. You would simply resize the sketch after scanning.

I think what they mean to say is that 1" = 10' which in this case each foot is represented by on-tenth of an inch on the scale bar.

A good example of RF is on USGS topographic maps, which are mostly 1:24,000. That translates to 1" = 2,000'.

Cheers,

Aaron

BTW: If you don't like the scale on the plastic, just tape a piece of survey paper over it marked off with the scale you do like.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Chads93GT » Apr 8, 2009 9:17 pm

xcathodex wrote:
Scott McCrea wrote:
batrotter wrote:I don't normally use a protractor while keeping book...

How do you manage that?


I'm presuming he uses the not-to-scale technique popular up until the 1980s (and really, really frustrating to draw a detailed map from). You know, the one where you pull all the dimensions out of your ass, the angles and distances are all wrong, and you let your cartographer have a breakdown trying to convert your sketch into something that matches the line plot.



Lol that made me laugh, really hard.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby batrotter » Apr 9, 2009 6:21 am

xcathodex wrote:I'm presuming he uses the not-to-scale technique popular up until the 1980s (and really, really frustrating to draw a detailed map from). You know, the one where you pull all the dimensions out of your ass, the angles and distances are all wrong, and you let your cartographer have a breakdown trying to convert your sketch into something that matches the line plot.


It's amazing how much you think you know about me. What a fricking jerk.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby MUD » Apr 9, 2009 9:46 am

batrotter wrote:
xcathodex wrote:I'm presuming he uses the not-to-scale technique popular up until the 1980s (and really, really frustrating to draw a detailed map from). You know, the one where you pull all the dimensions out of your ass, the angles and distances are all wrong, and you let your cartographer have a breakdown trying to convert your sketch into something that matches the line plot.


It's amazing how much you think you know about me. What a fricking jerk.


:boxing: :clap:

He simply has no respect for his elders! :down:
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby NZcaver » Apr 9, 2009 12:10 pm

batrotter wrote:It's amazing how much you think you know about me. What a fricking jerk.

Please avoid personally attacking other forum members. Let's everybody move on. Thank you.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby hunter » Apr 9, 2009 1:16 pm

I won't quote anyone to avoid reproducing offensive remarks but I do want to add my .02 to this. I use a compass/ruler and most people I know do as well. I have drafted a number of maps from various peoples sketches and the best match I have ever gotten are the sketches from an experienced caver who doesn't use a compass or ruler. I wouldn't try it myself but for some people this is a valid and accurate technique.

Oh, more on topic, I have used the IMO rulers in pretty wet and nasty conditions and never had a problem. Mine are a few years old so maybe the ink changed or something.

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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Chads93GT » Apr 9, 2009 3:57 pm

If someone isnt drawing a plot line on the sketch with a compass/ruler, then how do you know their map sketches line up perfectly? that is something I really don't understand.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Squirrel Girl » Apr 9, 2009 9:06 pm

Chads93GT wrote:If someone isnt drawing a plot line on the sketch with a compass/ruler, then how do you know their map sketches line up perfectly? that is something I really don't understand.

I assume they're drawing the line plot as a sketch where they count squares on the graph paper for distance and they approximate the angles. Most people (I think), but a little compass drawing on their paper. 0-45-90-135-180-225-270-315-0. It's not too hard to interpolate the angles between. I'm not good enough to do it well without a compass and ruler, but I imagine some people are.
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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Spike » Apr 10, 2009 10:44 am

Chad,

I would recommend finding a local university bookstore or similar supply store and getting the Engineers Protractor/Scale. They are the only protracotrs I've used for 5 years here in sloppy Missouri caves and I was surprised to see they were the protractors used 95% of the time at Mammoth in KY.

They are 6 inches long and about 2 inches wide. Printed on clear flexible plastic. Water proof inkwise. If you commonly sketch at 20 feet to the inch you can get them already scaled that way. If you are using them in stream caves you can either punch a hole in them and put them on a lanyard, or I put a piece of reflective tape on the corner. Clear plastic will vanish in a stream. It's amazing. I though the tape had fallen off in the stream once and was floating along but was surprised to pull the whole protractor out. Good Luck!

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Re: Cave Survey Protractors from Inner Mountain...........junk??

Postby Chads93GT » Apr 10, 2009 10:59 am

Thanks spike. The ones i use from hobby lobby are more stiff and break when cold. Ill have to goto the union book store when i head back home this summer to western ill univ ;)
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