Remember my daughter (and designated hi-start retriever) Laurel from that picture in Los Alamos in Part I of this series? They grow up so fast!

How Many Degrees in a (GPS) Triangle?

Part II: Well, you know, life.

For those who have not yet done so, you may want to read the first article in this series before proceeding with Raymond’s next instalment. — Ed.

When I last actually got an article out to the ever patient editor there was great hope that I would be flying my GPS Triangle Racing† Sport Class plane at the Fall Soar for Fun at HighPoint Aviation Airfield in beautiful Cumberland, Maryland (see Resources for links). Not so much. Life is funny, so I barely got to fly this summer. But, things are much more stable, and I am pretty sure the light at the end of the tunnel is not a train.

So, I am sure you have thought of nothing else besides “what plane did he get?” I did a lot of research and ended up with a Valenta Model Thermik XXXL 5m. She is an older model, around 2009, but seems to be an economical yet effective entry point to GPSTR. Older or not, she is a beautiful, well-made ship. It is my first time rigging up an eight servo wing and also a 5m ship is just big. How big? I either needed a new car or a full size roof top box. I tried to reason with my wife that a new car/SUV is absolutely required to carry my new plane, but she did not buy it and so roof top box it is — for now at least.

†Okay, side note: can we just agree to call it GPSTR or GPS-TR? I don’t type that fast!

Left: This is my VW Golf with a 3.5 meter. When I try to put the 5m Thermik in there, I have no room to do important things like shift (yes, it’s a manual!) | Right: No pictures of the roof top box, but here is a picture of the boxes box. Grandson #2 not included.

I mentioned that I am a JETI guy and the YouTube videos by Harry Curzon (link in Resources) have been a life saver to figure get the most out of the these radios. On one of his videos he had his plane ‘bread boarded’ on cardboard — yes I know he is not the first — so he could see how things were going with his programming. I did the same for my initial set-up, but unfortunately that is where that part of the project sits.

The avionics on the cardboard ‘bread board’.

I have been a HAM radio operator (N1LUL) for many years and would say I have better than average soldering skills, but the thought of making the harness for the wing made me nervous so I contacted soarerf3j who I saw on RCgroups sailplane classified and we started communicating about what I needed. Super nice guy and made sure that everything was in order before he started the harness. I quickly received the harness and it is a work of art, so much nicer that I could have produced and at a reasonable price.

However…

His harness is a DB9 connector for each half of the wing, but the kit was molded for a single db15 connector. I once again contacted soarerf3j about redoing the harness with a single connector, but his logic for using a connector for each wing half is strong. So my challenge is to figure out a way to securely mount two DB9 connectors in the wing and fuselage. The easy way would be to hard mount one half and have the other half free floating. The harder, but in the end better, way will be to just suck it up and engineer the mounts so as I put the wing on the connectors mate. I did ask for a 3D printer for Christmas which could help me out in this endeavor. Any ideas?

I need to put two of these in the wing mount area.

As I write this it is Thanksgiving and I really want to have her flying in the Spring, again over in Cumberland. I have 90% of the stuff I need to complete her, so it is up to me. I did get all of the juicy electronics I need to make her a GPSTR plane, but I have not even opened the box. If you all will stick with me, I’ll update you on the progress through the winter. Knowing that my dedicated fans are waiting on a update will help me keep the momentum up.

Wish me luck, thanks for reading and see you next time!

©2022 Raymond Wright

Resources

• HighPoint Aviation Airfield — “The general area along the road going up Knobley Mountain to the airfield is known as High Point Acres…it naturally followed that the airfield could be called High Point Acres Airfield…”
• Thermik XXXL from Valenta Model. — “The experience with handling this model is very similar to flying a real glider. The model is suitable for flying in big slopes…”
• soarerf3j on RCGroups. — “F3X/F5X/scale sailplanes custom made wiring harnesses…”
• Sailplane Classified on RCGroups.
• Harry Curzon on YouTube.

All images by the author. Read the next article in this issue, return to the previous article in this issue or go to the table of contents. A PDF version of this article, or the entire issue, is available upon request.