3-D printing Combat parts
by Don Grissom
dongrissom@hilltopflyers.com
We are again approaching the end of the year and it’s time to start building airplanes for next season. It is amazing how fast time goes. One great part of living in the South is that we can continue to fly all year without getting too cold. I hope to have a lot of airplanes ready for next year so that I can visit some more places.
In my last column, I discussed using a 3-D printer to print Combat airplane parts. I was able to get some flights on
the “printed” airplanes this past summer. They did well, except for one problem that came up during my first attempts to fly.
I was using new engines, which sometimes run hot when they’re being broken in. When I went to launch one, it must have been a little too hot and it began to melt the motor mount. I ended up unable to fly because I only had that one type of mount. I had used PLA to print the motor mount, which is a type of plastic that has a lower melting point. It is easier to work with because I do not have sufficient ventilation for ABS plastic.
When I went to the Nats, I took some cutting board motor mounts so that I would not have a problem. All of the other printed airplane parts, such as the control horns and servo mounts, worked great.
After returning home, I gave printing a motor mount another try, but this time with ABS plastic. ABS plastic requires higher heat to melt it, which helps it hold up against the engine’s heat.
After testing the airplane with the new mount, I found that it worked well. Because the engines are now broken in, there still could be a chance that a new engine might heat up too much and I could have an issue, but so far it is looking good.
If you plan to get into 3-D printing, it is a good idea to purchase a unit that can use both ABS and PLA material, giving you more options. Such a unit will have a heated bed, which is required for ABS to print correctly.
RC Combat Nats
I was glad I was able to attend the RC Combat Nats this past summer in Muncie, Indiana, at the International Aeromodeling Center. This is one of the best events to go to every year and it was nice to see some of the other pilots.
Instead of staying in a hotel this year, I decided to camp at the field. Many of the other pilots did the same. When we were done flying for the day, it was nice to sit back and talk about Combat and other things that people are doing. It was also nice to hear the stories that some people tell! It seems that Bill Geipel and Andy Runte have had many things happen to them.
We again had the Indiana Civil Air Patrol (CAP) cadets assist with judging.
Many thanks go to the CAP cadets for their assistance, and to all of the pilots who attended the 2016 Nats.
They also provided lunch for the pilots every day. These young men and women are a great help and we hope to have them help again in 2017.
This year there were five events flown at the Nats. We started the week with Slow Survivable Combat (SSC) and Open B, which are the official events.
SSC was dominated by Andy, who had some very high scores. Andy finished with a score of 4,188; second place went to Bill with a score of 2,436.
In Open B we had a new pilot, Heath Bartel, who flew with electric power in all of the Combat classes. His airplanes were dominating, and he is a very good pilot. Heath ended up in first place with a score of 2,156. George Pritchett placed second with a score of 1,580.
Then it was time for Gnat Combat, 2948 Scale, and Limited B Combat. Eric Gilkey was unable to make it for the first two days, but he made up for it the last two days. We started 2948 Scale on the second day and were able to make it through five rounds of flying before we completed the event the next day.
Eric was not there for the first five rounds, but even with no points he was able to dominate the last five rounds to finish with a score of 2,572 and place first. George was second in Scale with a score of 1,288.
One of the newest events at the RC Combat Nats is Gnat Combat, which is nice to fly, although the wind can sometimes become a problem. Eric finished in first place with a score of 6,144 and Bill (last year’s Gnat champion) finished with a score of 2,696.
We ended the week flying Limited B, which has become a good replacement for Open B. The airplanes are slower, creating less damage, but they still perform well. Eric also won this event with a score of 4,048, although Andy came in a closer second in this contest with a score of 3,452.
We had people from across the country at this year’s event, which made for a great week. I hope to see many of them next year and would love to see more pilots attend.
If you have never been to the Nats, it is a great event to attend, plus it’s held at one of the best flying sites around. To see more about the Nats, visit the AMA website and the NatsNews newsletter for pictures and daily reports.
I hope everyone has a great year, and I hope to see more Combat this season.
SOURCES:
NatsNews
nats.modelaircraft.org
Radio Control Combat Association (RCCA)
www.rccombat.com
