As I mentioned in the blog post (Progress Update - 2011-10-17), I'm going to be modifying the plane slightly to make more room in the plane for the control electronics. Although when doing flight testing, I may just end up strapping a box to the undercarriage of the aircraft until I can design a custom control board small enough to fit inside the plane. Either way, the modifications are going to be going ahead once I'm certain I won't cause the plane to have structural issues. This is because I plan to remove sections of foam to make more room for the electronics but I will be also reinforcing the sections that have had foam cut with fibreglass and epoxy. The sections to be cut are:
(Please note the below pictures use red dashed lines to show cuts while green marks are used to show additions.)
There is a decent amount of space behind the foam in the rear of the cockpit area to house electronics. The servos directly below this space will also need protection from anything placed into that space, so a removable tray will probably be made for that section also to protect the servos.
The main length of the cockpit area will be widened slightly to increase the width of any electronics board to be put in.
The cockpit lid will have a hole in the back for either a camera or a GPS antenna.
There are also a few other modifications that will be made to the plane, including:
Cutting the control surfaces off and remounting them with hinges to ensure the servo load should be lower during normal flight. While this is being done, the leading edges and control surfaces will also be given a light reinforcement with fibreglass.
Servos as previously mentioned in other posts will be replaced with more reliable ones. I believe the servo shown on the left has been stripped; something that is amazing considering the fact the plane has yet to fly. The other servo shown on the right will randomly sweep from side to side rapidly; it is still unknown why this occurs.
The receiver for this plane is still to be modified to allow for a test fight to be made. For a test flight to occur, it will require at least the servos to be changed and the receiver to be modified as the control surfaces don't require the hinge to be put in yet, although it's a highly recommended upgrade according to several reviews and build tips I've seen on this plane.
I made a test piece of fibreglass with the resin, however the results of that test were unexpected as it was extremely flexible but also very light weight. It is thought that the proportions of the epoxy used were not correct (I was attempting a 1-1 ratio) which resulted in the test piece not being at full strength. Unfortunately during my move, the first test piece I made was lost; however because of the reduced strength of that test piece, another test piece needs to be made to ensure the process to make and apply the epoxy mixture is correct before I attempt to apply fibreglass to the aircraft.
Lastly, I now have a major problem with developing this project (this even affects MEHA, although there is more I can sort of get away with, since a helicopter can work in a more confined space) and even just testing the aircraft. The problem comes with the fact that I have an untested aircraft (not so much an issue), I'm not certified to fly RC aircraft by myself (this requires a MAAA Flight Proficiency) and also the RC transmitter and receiver pair I have is not certified for use at MAAA associated clubs.
The transmitter and receiver pair doesn't have any real failsafe feature either, which isn't as much as an issue for an electric plane as speed controller will stop if no signal is given to them after a timeout period of about 4 seconds. It is a problem for nitro planes which use a servo to control the throttle, as servos will loosely hold their last position instead of causing the engine to go back to idle. The failsafe feature can be implemented by the onboard microcontroller (although that could be enough for the MAAA to classify it as a UAV) since it is possible to detect when the signal has dropped out.
The radio equipment allowed at the above clubs is limited based on equipment that meets frequency standards (this is the standard set by the Australian Communications and Media Authority, ACMA) and as far as I can see, also has a programmable failsafe. While radios not on the list are allowed, the restrictions imposed on the aircraft controlled with those radios, prevent me from flying this aircraft. The list I'm referring to is on Appendix A of this document (MAAA Policy MOP058). Although in the future, this will not be a problem, but for the moment, it's a problem that I will need to find a solution for. I'll cover why this is not a problem in the future in my next blog post.
To do the flight testing, I need a large area to run my tests, collect data and also just generally making sure the aircraft is working. I searched for RC aircraft clubs and there are a couple of ones that are fairly close, but the problem is they have what I would consider hefty fees to join (I am not employed currently, so I have to be strict in my spending), and also the insurance the aircraft clubs use is done through the MAAA, who prohibits the use of UAVs at the airfields.
The problems stated above require that I either fix the issues (which some of them I cannot afford to do right now) or I find another place to fly. Given my current situation, it means finding a remote area/private property that I can get permission to fly at without being at risk to other people. Safety is a large consideration that I must take seriously as it's the reason why UAVs are not allowed at the clubs. I have more reading to do regarding this project, and will be going into it and the laws governing this project more soon.