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Apprentice Design Modifications Thread

Posted: Fri Sep 09, 2016 12:51 pm
by Dennis
UPDATE 1.

I recently acquired a new E-flite Apprentice S fuselage (EFL310002) and am in the process of making various design modifications. I have attach a photo that shows the current state of the project. So far I have completed the following: (1) permanently removed the decals, (2) removed the firewall, and (3) smoothed out the two holes connecting the firewall/motor to the cabin.

The decals were removed and the airplane will eventually be painted, attention being paid to weight and adherence to the Z-foam. The plastic firewall was pulled off by hand, and all of the rubbery glue also peeled off by hand. The remaining plastic components were not removed from the fuselage. The interface between the firewall and fuselage comes poorly bonded and should not be removable by hand! Finally, the holes were poorly cut by the manufacturer and required some carving out with a sharp knife.

The masses of the fuselage and firewall were 189 and 32 grams, respectively. The centre of gravity C.G. for the fuselage without the firewall is just aft of the cabin's centre.

Re: Apprentice Design Modifications Thread

Posted: Mon Sep 12, 2016 12:57 am
by Dennis
Today I discovered how to use the Apprentice as a long-duration, stable, low self-noise, power-assisted glider. Perfect for my surveillance application on the Bay of Fundy. This week I will shop around for a camera to mount on the Apprentice and make the necessary modifications.

Re: Apprentice Design Modifications Thread

Posted: Mon Sep 12, 2016 1:37 am
by Dennis
Found a copy of my 1987 physics paper on air-launched parachutes and payloads. Will rework the mathematics for the equations of motion as applicable to the Apprentice aircraft.

American Journal of Physics - http://scitation.aip.org/content/aapt/j ... 19/1.15111

Re: Apprentice Design Modifications Thread

Posted: Mon Sep 12, 2016 3:44 pm
by Dennis
Found the camera I will use on my Apprentice at Henry's this morning. It is the new Olympus Tracker. It is saltwaterproof, lightweight, and capable of storing several hours of video and lots of photos. It has wi-fi so I can turn it on when the plane is airborne (30 m range). The camera can also be used underwater for other applications that interest me without any protective casing.

Re: Apprentice Design Modifications Thread

Posted: Mon Sep 12, 2016 6:31 pm
by bdg
I feel like an old mother hen.... Trying to offer suggestions and keeping up with your enthusiasm is tough!

Be aware that a 2.4GHz Wi-Fi signal operates in the same band as your Dx6 and there are documented cases of interference. Take it from me - leave the Wi-Fi disabled!!!

Brian

Re: Apprentice Design Modifications Thread

Posted: Mon Sep 12, 2016 8:19 pm
by Dennis
Excellent advice! Thanks Brian

Re: Apprentice Design Modifications Thread

Posted: Mon Sep 12, 2016 9:48 pm
by Dennis
bdg wrote:I feel like an old mother hen.... Trying to offer suggestions and keeping up with your enthusiasm is tough!

Brian
I am 62. In February I suffered a heart attack and survived. Heart disease runs in my family, so, every minute of every day matters to me. This is also one of the reasons we'll be leaving the city for a simpler country life as soon as we can after my wife retires at the end of this school year. I plan to build a small physics lab, a solar energy farm, and a model aircraft airstrip. My wife wants to have chickens, goats, and grow lots of vegetables. Yes indeed, I am one of the most enthusiastic people you will ever meet. :) :)

Re: Apprentice Design Modifications Thread

Posted: Tue Sep 13, 2016 8:41 pm
by Dennis
Working on a technical drawing of the Apprentice S cabin this evening. This drawing will be needed as I make design modifications. The first enhancement will be to eliminate the need for glueing down receiver, servos etc. All these components will be mounted on a removable, modular cradle made of lightweight polymer components. Disconnect a few wires and pushrods and the cradle with all components pops out of the plane. When installed, the cradle will not move. The pushrods will also be modified so they easily unfasten at the cradle.

Re: Apprentice Design Modifications Thread

Posted: Wed Sep 14, 2016 11:22 am
by Dennis
Technical drawing for the cabin is complete. This afternoon I begin cutting some Z-foam.

Re: Apprentice Design Modifications Thread

Posted: Wed Sep 14, 2016 1:47 pm
by Dennis
The cabin floor has now been flattened by removing foam sections G, H, I, O, P, Q, R, ans S. Sounds like a lot but it only adds up to 1 gram removed. The larger two sections G and R will be used to test paint adherence. The next step will be the addition of an ABS cabin floor cut to fit.