Search This Blog

Thursday, December 28, 2017

52" Extra EXP__One Year Endurance Test

A year is a long time in the life of a 3DXA airplane. Even under the best of circumstances it's going to take a solid thrashing, and when it becomes your daily beater then the abuse really gets heaped upon it. My beloved 52" Extra EXP 53A began as an experiment, and has always been flown hard. It's been a little over a year since her first flight and this has been an exceptional plane, which is saying something for a plane that comes from such an exceptional line up.

At the time this project began, money was especially tight, and I did not think this out very well when I ordered the plane. When it came time to order the servos, I had about $50 disposable cash left, so I had to improvise. I took a set of highly abused Hitec HS85MG servos and sent them in to Hitec for service.
These servos had problems that ranged from stripped gears and broken cases, all the way to another that didn't run at all, and one that had it's servo plug ripped off the end! When I got them back they were in brand new-like condition and apparently ready to roll, for $45 including shipping. This certainly beat spending $120 for new ones, and I didn't have that money anyway.

You might notice the absence of decals on this plane. Usually I like to take it out a few times to cycle it in and out of the air conditioning, into the sub light and generally see how the covering is going to hold up. It usually loosens up a little, and it's far easier to tighten it back up if there are no decals on the plane. This time, though, I love the scheme so much I preferred to keep it simple and clean.


While this was not the ideal way to start a project, Hitec service has always done exceptional work for me, and in a lot of ways a rebuilt servo can be even better than a brand new one. When I was in the audio business I learned that electronic equipment usually fails in the first 30 days, or never at all. If you can get past the initial burn-in period, electronics tend to run and run and run. Since these servos had already been through the wringer, it's safe to assume they were past that burn-in point.

So, I fearlessly dropped them in. You can read about it in 52" Extra EXP__What To Do With Your Spare HS85MGs.  Here it is worth pointing out that Extreme Flight recommends Hitec's excellent HS5087MH high voltage servo and the HS85s don't even get a mention. Running these servos is something I took solely upon myself to try. Your results could vary, but all I have to offer you is what's worked for me.


It's no secret that I am an Extra man. I've always loved Extras, from my first SHP through the 48" EXP and 60" EXPs and right into the 52", which might be my favorite of them all. As with the Slick, there is something about the 52" format sets this series apart. In general, they are far superior to the 48" span planes, and fly nearly as well as a 60". The 52s are still a very convenient size, and since they fly so nearly as well as a 60", I predict 52 is where it's going to be at in '18. We've been told some more 52s are in the works, and I am shifting my focus to these planes.

I kind of lost track of how much time I put on this plane, but it was a lot. I was so pleased with it that it became my primary plane, so it was out there three or four times a week grinding out the flights. I flew it hard too, and have become really connected to it. In a lot of ways I equate this plane to my first 48" Extra EXP, which was also blue. Both were beautiful, graceful planes that opened new worlds for me. The 48" Extra redefined what I could do with a 3DXA plane, and the 52" is showing me how to do it all better.

Mostly the Extra does things the way a plane is supposed to do them. You may notice when I do breakdowns of any plane's attributes that I always compare them to the Extra. The Extra does not always do everything better than all other planes, but it still does everything well enough that all the other have to live up to it. The Extra is truly the benchmark all 3DXA planes must be measured against.

Extra EXP__Long Term Abuse Testing 002 from Doc Austin on Vimeo.
Long Term Equipment Evaluation
After a year's worth of abuse, I took the plane completely apart to see how things were holding up. It was all surprisingly good news.

First, let's talk about the power system, because there is the least to say about that. I plugged it in, forgot about it, and flew the crap out of it. That's it. That's all there is to it, and that's exactly what I have come to expect from Xpwr systems. I get explosive power and speed, and such reliability that once I bolt the cowling on that's the last time I think about the power system until I move it into another plane. While all of this might not make for riveting reading, it certainly makes grab and go flying a reality.

Not much to say about the airframe either except it still looks and performs like new. It helps I've become a little more careful with my planes and have stopped bouncing them off the ground as much, but this is a pretty sturdy beast anyway. Since I built the plane I have done very little maintenance, and it only took about a half hour with a sock covered Monokote iron to get the Ultrakote drum tight and flattened down on the wood. Generally I don't like Ultrakote, but I think working with it over the last ten years has taught me a pretty good technique for getting it nailed down. The biggest secret I have found is using a sock on the iron. It puts the heat where you want it and provides enough cushion that you are less likely to dent the wood, and it's soft enough that you don't scratch the covering or dull the shine. My planes look a lot better since I started using this method. This planes has looked great for a year and it did not need a lot of attention. I only worked on the covering because I was going through the entire plane, and I am pretty obsessive about keeping my planes nice. For the airframe, the worst of it is that it simply needed a good cleaning. While I had the servos out of it and the cowling off, I wiped all the covering down with lacquer thinner and that got it spotless.

Focusing on the servos, these HS85MGs have performed admirably, especially considering that they were in such rough shape before I had them serviced. I did not have one instance of stalling or blowback, and these servos are nearly as fast as the high voltage HS5087MH. Of crucial importance to me, these servos also center extremely well, so the plane trims out and stays trimmed out. You can't fly decent precision maneuvers if the trim keeps jumping around, and it takes the fun out of flying when you are constantly trimming the plane. On this plane, I trimmed it once and forgot about it.

After a year's worth of beat down, the servos are still working well. Since they were as good as dead before servicing, this speaks really well of Hitec service. Three of the servos were getting sloppy gears, but this is no surprise because they were starting to get a little of that when I sent them in for service. Remember, these servos were a collection that had been abused, thrashed and crashed. It's not even really fair to the servos to expect anything from them at all. They had already served me well past what you could reasonably expect, but service gave them a new life. That, and as you can se from the video, even after I wore the gears pretty ragged the plane is still really locked in. A full year on worn gears serving in my primary plane was a little too much to ask from them, so I replaced them with four more used HS85MGs that I also had serviced. The servos I just removed will go back in for new gears, and that will give me another set of essentially new servos.

All of the video was shot with the first set of servos, but I have since taken the plane out with a fresh set of rebuilds and she is better than ever, which says a lot considering she has been already  pretty jolly awesome. . She is trimmed and the CG is totally locked in and this is absolutely my #1 Plane,

So, we are set for at least another year of abuse, and probably even more if I can avoid the ground or banging the elevator when loading the plane into the car. This plane has been especially robust and reliable, and it's performed well enough to bring me a lot of joy.

This has been a jolly damm good project.

No comments:

Post a Comment