Non magnetic tripod systems

[CoryT]

In case anyone uses azimuth and distance for geolocation, I've been successful in converting the Manfrotto 410 Gear Head to a non-magnetic condition. I did a conversion of the larger PL plate system to the RC2 system. Then I replaced all the stainless hardware with brass. The springs all must be replaced as well, for that I used phosphor bronze spring wire to make replacements, I still have some bearings on the Manfrotto mag fiber tripod that should be replaced, as well as the base screw, but given the distance to the parts with the head mounted we seem to be good. I now get coordinates of a target within +/- 10 meters while mounted on the gear head.

I tried the same exercise with the Benro copy of the 410, no joy. There are some strongly magnetic spacers in the knob system and the castings do not seem to be very clean Mg, I get a 20+ degree variation when mounted to the head.

 

[Fred @ Bison Tactical]

Have you checked these out, and would they help with what your doing?

oops forgot to put in the link...

Wind Wheel — The Avid Shooter

The Avid Shooter Wind Wheel is a Tripod Mounted tool to help you correctly judge wind and target angle. Coupled with a Kestrel Weather/Ballistic device and you have the ultimate wind cheater tool.

theavidshooter.com

I have had issues with my Kestrel constantly needing to be compass calibrated causing problems, so have been pretty interested in something that solves the issue of using the Kestrel's electronic compass. These wheels don't give you the actual direction, but allow you use mount the wheel to your tripod and then set and obtain both direction of fire and/or wind on a mechanical system. You still obviously need something to determine North...

 

[CoryT]

The main use here is with the rangefinder tethered to the computer, when I click the button I get the firing solution and the grid coordinates of the target. Having an amagnetic tripod setup makes that very accurate. Vectronix sells tripods for that purpose, and they are military issue (the Viper has fire control software embedded). Those work fine, but are pretty expensive, shorter than I'd like, and don't have the gear head.

I've just about completed work on the tripod, making up some new bonze bearings for the legs today and that should do it. Fortunately Manfrotto supports their products with full parts breakdown and replacements, which makes it easy to tear it apart and swap parts out. All metric of course, but McMasterCarr has brass replacements for everything, including the bearing bronze bushing tubing I needed.

 

[wadebrown]

You can also use 300-series stainless steel when non-magnetic materials are required.

 

[CoryT]

I actually used some 316 SS parts originally, but they have enough ferritic mass to still throw the DMC off, even though they are "non-magnetic" You may not be able to pick them up with a magnet, but they are not totally non-magnetic like brass is.

 

[TonyC]

I've just about completed work on the tripod, making up some new bonze bearings for the legs today and that should do it. Fortunately Manfrotto supports their products with full parts breakdown and replacements, which makes it easy to tear it apart and swap parts out. All metric of course, but McMasterCarr has brass replacements for everything, including the bearing bronze bushing tubing I needed.

Is this for ranging targets in to FFS Cory or are you using other apps ?

How much difference have you seen between magnetic/amagnetic ?

cheers

Tony

 

[CoryT]

Primarily FFS, Vectronix also has its own app that is very nice. I’ve seen 13 to 24 degrees of error, which is hundreds of meters off in the calculated position.

 

[TonyC]

Thanks Cory, that’s a surprising amount of error!

I have FFS on a Trimble which of course works well with the PLRF. I’ve been playing with the Vectronix app and have just worked out how to export from it in to Google Earth. Interesting components but could be so much more.

I’m looking forward to seeing what direction you take with FFS.