The new camera gimbal

The Cave quad is designed as a payload carrier, strength, reliability and durability trump weight and performance.

The old camera gimbal was a cheap hobyking thing, and while it worked, it was never straightforward, and it didn't take a big impact to break it or make it fall apart. It also suffered from a limited range of motion in both directions.

The new one is direct drive, using much larger servos. The yaw servo has been modified to be continuous drive, so we should be able to look around 360 degrees, and the device is designed to be self contained, so it can rotate continuously in one direction for as long as desired.

The parts:

• Yaw servo (modified for continuous drive)
• Tilt servo
• Receiver
• Flip 32 flight controller
• Video Camera (Mobius Action Cam clone)
• Video transmitter
• OSD for Video
• 350mAh 3S battery
• 4 LED spotlights
• 2 voltage regulators

Using the FC to pass through the servos also has the advantage that the gimbal will be self stabilising to some degree, although the use, and effectiveness of that remains to be seen. 

Big Quad

This quad is a payload carrier, designed purely to fold up small, and lift a potentially heavy load.

It runs on a folding 60cm X platform with 10mm square cross section aluminum arms - it's a cheap and versatile platform from hobbyking, and spares are available.

This is lifted by 12 or 14" props, spun on 750kV motors.

The whole thing packs down into a length of 8" ID PVC plumbing pipe, making a waterpfoof and almost indestructible case that can fit throw confined spaces and be abused without damaging the quad itself.

A 5Ah 3S battery powers the motors and flight controller, with seperate small batteries for lights, cameras and 2 penlight lasers that assist in range-finding.




At the moment it runs twin recievers and video transmitters - one controlling the craft, and another controlling a gimball camera with live video transmission

The idea is to have modular plates that can be attatched or removed to alter the functionality, these will include:

• A secondary video layer
• Additional lighting for night work
• Additional sensors
• A parachute
• Bumpers and landing gear as required

Cave Quad - Finally we can record data

Finally we have the data logger functioning, apparently the original flight controller I was testing on is buggy on the UART 1 lines.

Solder the OpenLog datalogger direct to the flight controller, or via wires if that suits your layout better.

The settings required in Cleanflight are as follows:
 - Enable Blackbox on UART 1, set baudrate
 - Enable blackbox

Data is recorded whenever the craft is armed, and you can verify that it is recording by the flashing LED.

The data that is sent from Cleanflight is in binary format, and is not immediately human readable. The Cleanflight blackbox flight recorder viewer allows you to get a visualisation of some of the data, but it seems to be limited in what it can display.

Instead we are just converting the file into a .csv viewable in excel, as the main thing that we are interested in is the barometer value at the peak of the flight. This is accomplished using Blackbox Tools, and dragging and dropping complete and non-corrupted files onto the blacbox_decode.exe executable. This will give a csv file that includes all of the data embedded in the blackbox log, which includes barometer altitude as well as stick positions, motors etc.

Bike Tool Roll

I've suffered from back pain for a few months, and there's a suggestion that it may stem from my use of a messenger bag continuously for the last 8 years or so. Hence I've decided to replace it.

Of the options available, I found only a couple that I liked. Simple stying for day to day use, and durable materials for the same reasons. A decent harness, and somewhat waterproof were the other requirements.

It also needed to be large enough to to swallow shoes, and a change of clothing in a main compartment, not bulked out with dividers and mesh that will get caught on everything.

In the end I went with a Mammut Courier 25L  - It's only drawback is that it has only a small front pouch, 2 small zip pockets - both inside other pockets, the main compartment, and a laptop sleeve.

None of these will easily hold my bike tool kit as they are too deep, or too hard to get into easily. I saw a Silca tool wrap a few months ago, so I figured that would be a solid solution, keeping things together, and making it easier to find what I wanted if needed.


The design work started with a bunch of googling existing products. At some point I saw a design which had sealed pockets on both sides, while keeping the tool roll closure. This seemed likely to be more secure - I've had some issues in the past when I've made tool rolls for other things.

I made one roughly, shown here, and then made a few tweaks to even it up and make a nicer looking one.













I decreased the overall width a little, so one side rolls over again - this should allow me to tuck a $20 note inside, as well as other very small things.

The final product. It rolls up to be just larger than the tube, and holds a small multitool, a few levers and a tube. 

Disc Dying - Confetti

I've recently taken up disc golf, and most of my discs now get some form of custom dye to make them easier to identify, plus it's fun to make them. 

Confetti Dye

There have been a few of these showing up on Reddit /r/discdying and for sale in various places. They look a bit like the stock Vibram discs, flecks of colour on a plainish disc.

The basic process is a shaving cream dye, but the dye powder is sprinkled on top and left for a few hours. I recently made an order from Dynamic Discs, mostly for some extra putters, towels, minis, shirts and a Birdie Bag for wet rounds, but the shipping was going to be much the same so I added a mixed 10 pack of misprint discs. There are a few nice light coloured discs in there, that while I may not add them to my bag, they'll make for some interesting dyes.

Shaving cream bed

Among these was a pink Lucid Defender - an even more overstable Enforcer, and one I will probably need on windy days if I throw much faster than I currently do, so it's going in my bag. Which means it needs to be dyed. I had seen a few confetti dyes, and wanted to try it out, but most of my dye has been mixed so I had to go with purple iDye Poly.

Sprinkle dye on top. Use a spoon, there is too much on this one

The hope was for a dark nebula kind of pattern on the translucent pink disc.

I started with 90 minutes, but it only left a light dye on the disc.

Just after placing the disc on the dye bed. 

I started again, and left it for 4 hours, and while better it's still not as dark as I'd like.
A few ways to make a more obvious dye would be to:

• use black dye
• spraying acetone on the dye before placing the disc
• increase the time to 12 hours/overnight
• add hot water to the base of the disc. 

There is a light nebula pattern