Disto for cave survey work

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Re: Disto for cave survey work

Postby trogman » Oct 3, 2018 3:45 pm

bobby49 wrote:I believe that there was a spelling error in John's name about the DistoX2.


Yep. My bad, should've been "Harman" instead of "Harmon."

bobby49 wrote:That was interesting. I did my own E7400X modification for 3-D and Bluetooth.

A few words of warning. The assembly guide is OK, but it sure isn't perfect. Lots of stuff made perfect sense to the author, but it wasn't good for the reader/user. Some of the photos leave a lot to be desired in terms of clarity. Now that I have it working and charging, I need to do the calibration routine.


So you did your own Disto X upgrade? Cool, way to go, man. I am not that talented, at least not when it comes to electronics.

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Re: Disto for cave survey work

Postby bobby49 » Oct 4, 2018 1:37 am

Technically speaking, I think this upgrade is called the DistoX2.

At least I saved a few bucks over Harman's price.
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Re: Disto for cave survey work

Postby bobby49 » Oct 11, 2018 10:49 pm

Doing the calibration was "an experience." The goal was getting the azimuth error to 0.5 degrees or less. The calibration told me that this error was running at 1.3 degrees, so I may need to try again. Meanwhile, I compared it to my Suunto, and they agreed to 0.5 degrees.

A suitable survey target is normally a rock with a piece of survey tape tied around it with the station number marked on the tape, and the fine detail of the station is actually the knot of the tape. Is there anything better? What if there is no rock to tie on? Somebody suggested using a nail with the tape tied on. But the nail would be steel, and that might throw off the azimuth sensitivity of the DistoX2. I suppose that I could look for an aluminum nail.
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Re: Disto for cave survey work

Postby bobby49 » Oct 12, 2018 12:47 am

Somebody suggested that a good temporary survey target is a wooden popsicle stick. It can be stuck in dirt or mud, and it is easy to write the station number on it. Of course, if the cave floods, then your survey target disappears downstream.
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Re: Disto for cave survey work

Postby bobby49 » Oct 12, 2018 5:10 pm

Hmmm. The calibration error is now 0.75 degrees. That's improving, but it isn't the 0.5 degrees that I was expecting. I compared it to my Suunto, and they were dead on at 360.0 degrees.
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Re: Disto for cave survey work

Postby trogman » Oct 16, 2018 4:58 am

bobby49 wrote:Hmmm. The calibration error is now 0.75 degrees. That's improving, but it isn't the 0.5 degrees that I was expecting. I compared it to my Suunto, and they were dead on at 360.0 degrees.


Are you using any kind of calibration fixture? I built one and obtained average error of .16 deg. There are several designs out there, or you can come up with your own. I did the latter, using wood pieces held together by glue and brass screws.

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Re: Disto for cave survey work

Postby bobby49 » Oct 16, 2018 3:50 pm

I'm using a 45 degree carpenter's angle on a marked flat surface.
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Re: Disto for cave survey work

Postby bobby49 » Oct 25, 2018 10:05 pm

So far I can't get my calibration error to be less than 0.6 degrees, even after three runs on a wooden calibration stand. Granted, that is not a lot of error in the broad scheme of things, but it is slightly more than I was expecting. Part of my problem is human. I have to remember which of the 54 shots is next. Still, comparison to the Suunto tells me that it is right on.

I guess if the job was easy they could have hired just anybody.
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