Wednesday, July 22, 2015

Bringing an Airhogs Aero-Ace back to life

When I was in junior high one of my favorite things was my Airhogs Aero-Ace bi-plane. The aeroace was a highly regarded RC airplane. It was simple to fly out of the box, could take a beating, and would keep going after many many hard "landings".

I had two or three of these after all was said and done, While they were extremely durable, there is only so much they could take. If I remember correctly the adhesive holding one of my motors on my first unit eventually gave out mid flight and caused some pretty bad damage. I tried to fix it but it never flew the same.

My second unit never had such a catastrophic failure, but eventually the LiPo battery gave out and I could only get a few minutes flight before it fell back to the ground. This plane was lost/ destroyed several years ago. This leads me to my current project. Given my recent resurgence into the RC aircraft area I wanted to try to find and fly one of these planes again. So, over the last few months I have been periodically searching ebay for a decent deal. Luckily, I found one, not a bi-plane but their single winged version which I have read was an even better model.

The item was listed as "opened" but looks brand new, possibly never flown. I doubted it, but the pictures and general description looked OK, so I took the chance.

 It showed up in 4 days wrapped in Christmas wrapping paper. The box had a slightly musty basement smell, not surprising since these things were at least 6-7 years old and was probably stored in a basement somewhere.

Inside the box all seemed well, from the top at least. One of the first things I noticed after pulling the plane out was the worn paint directly under the cockpit from being launched many times. Obviously not new, also not surprising, but otherwise everything looked in good order. Awesome!

The controller however, while fine on the front, had indeed been stored for several years...full of AA batteries. Every single one had corroded and leaked. I didn't take pictures, but it took about half an hour with rubbing alcohol, paper towels, and various scraping tools to being it back to something that might work. Fortunately the transmitter was sitting face up the entire time, so none of the battery acid leaked inside to the electronics.

So! a fresh set of batteries later and the transmitter lives again! With the aero-ace, the plane is charged by the transmitter. So, I plugged in the plane, the green LED lit, and 20 minutes later the LED was out and it was time to test.

I turned everything on, and pushed the throttle full forward, and the results were!...extremely underwhelming. Both motors did turn, but with very little power. Pushing the steering control did reduce the speed of one one motor respectively. Everything worked, but as I expected the battery appeared to be shot.

Replacing these is neither new, or difficult, which is great. Thanks to the recent explosion in popularity of mini multi-copters single cell 100-250+ mAh LiPo batteries are pretty easy to come by. First, however, I need to get inside the plane and take out the old battery and its protection circuit.

Unlike the bi-plane version, as I remember at least, this plane has a little cutout where the battery was inserted to begin with, convenient.

Inside is a little 3.7V 150mAh LiPo battery with a protection circuit soldered directly to the tabs of the battery.

In general, the batteries that are easily available are larger in capacity, size, and weight than this one. Which isn't exactly a bad thing, most of the time, these planes needed a little bit of nose weight added for stable flight anyway.

I found this battery on Amazon that is a little bigger than the stock battery, but had a pretty good price. The hope was that the slight weight difference would work in my favor.

In the mean time, while I waited for the battery to arrive, I wanted to see if a significantly larger battery would work. So, I pulled out one of the 250mAh batteries for my 1SQ mini quadcopter. Long story short, it was too heavy for the plane. While it would mostly glide, gaining altitude and turning wasn't going to happen.

I guess I need to wait for my new batteries to show up.