Lloyd Bosworth : archaeologist | human | beard

Update: This brushless gimbal is completely spanked and in the bin! The problem with the pitch bearing meant that it never fully calibrated as there wasn’t enough free movement. I’ve since used the gimbal as a template to create an improved version, with proper bearings, and had it cut from 3mm G10 fibreglass sheet.

Thoughts on the brushless gimbal

The HobbyKing brushless gimbal is so-so. The parts didn’t fit together too well and I had to hack the camera tray to give it free pitch movement. The bearing on the pitch axis has a lot of resistance and I think it’s a little too stiff. However, the camera is a little top heavy on that axis, which isn’t helping the gimbal level out.

The gimbal controller

The gimbal controller was from ElectriFlite and seems solid enough. This is my second controller, the first being a nasty Chinese fake off eBay that never worked!

The BruGi firmware is a dream. The only change I’ve made to the default settings is to reduce the PWM max by a tad. You can hear the motors humming in the video, so the setup is not perfect, but out of the box this is pretty amazing. Only a few small tweaks to the settings to finish it off.

More information

Gimbal – http://bit.ly/Shock_Absorbing_2_Axis_Brushless_Gimbal

Controller – http://bit.ly/brushless-2-axis-tilt-and-roll-gimbal-controller

BruGi – http://sourceforge.net/projects/brushless-gimbal-brugi/

Ratio Calculator

Reference scale =

Model scale =

Ratio as percentage increase/decrease =

I developed this ratio calculator to re-size illustrations drawn in Adobe Illustrator. It uses a target reference scale and model scale to calculate the percentage increase or decrease. It also works as a simple ratio calculator.

Google Earth Pro now Free!

Google Earth Pro reduced by $400!

Georeferenced LiDAR image of Bigbury Hill Fort, Canterbury, imported directly into Google Earth Pro. On January 30, 2015, Google announced that the Pro version of their Google Earth software would come down in price… to free. Until now, the Pro version would have set you back $400 per year. For those on a tight budget, (or with sense!), this was reason enough to stick with the free version and forgo the extra tools in Google Earth Pro.

I always felt that $400 per year was an almighty rip-off and was happy to integrate the free version within my workflow as far as it could go, and then use other tools where necessary. But what could you do with the $400 Google Earth Pro that you couldn’t do with Google Earth, and why should you now switch? Well, it’s not for higher-resolution imagery, as this is the same across all Google products. But the available toolkit for working with this imagery does increase.

Why a 3D Topographic Model?

dem created in arcgis from contour dataI’ve been asked to produce a walk-through animation of a reconstructed archaeological site that shows the landscape setting of important buildings, and how these buildings constrained the movement of people. Reconstructing the buildings is pretty simple, with lots of reference material available. However, the 3D topographical model of the landscape is much trickier, made worse by not having any digital elevation data, only paper maps with contours.

Drawing contours with height attributes is easy in ArcGIS, but when I was asked to create an animation, I had no idea how to get the GIS shapefile data into my 3d software for animating. I figured there must be a way, and sure enough, ArcGIS has all the tools for converting and exporting a shapefile that can then be opened in pretty much any 3d software package.