Matt Walker's Tech and Hobby Blog » Hobbies

Building a LiPo Charging Station

Matt — Fri, 03 Aug 2007 18:25:53 +0000

If you haven’t seen/heard about it yet. LiPo batteries can be dangerous, check it out. It is very rare that a lipo would ignite under normal use. It would take charging it at a higher rate than recommended (typically 1C) or a internal short. People have had serious property damage, here is a list of what causes the fire and what is damaged. They make commercial battery bunkers, some people use cinder blocks and bags of sand. I have also seen ammo cans used, but I could not find them locally and I didn’t want to pay for shipping. I found a honeywell steel lockbox at WalMart for $10, that is pretty stout. I don’t have the desire to test it (yet), but I think is should hold just fine. Also to help suppress any fire that could arise, I put a Pyrex pan over the battery. I did buy one of those LiPo charging bags, but it is a pain to open and close every time I want to charge a battery. I have it lining the bottom of the box. it is definitely not necessary, but since I have it, why not. The way I see it, all this effort is the cheapest fire insurance available.

Terminal Velocity Pentax Optio S6

Matt — Fri, 20 Jul 2007 23:24:20 +0000

I learned two very valuable lesson today…

1.) Don’t rush sending electronics airborne
2.) When attaching anything to a RC Plane, make sure it’s on there good.

I had so much fun the other day taking the video with my soarstar, I rushed out there today and look what I did…

The last time, I attached the camera on top of the wing, in the center facing forward. It worked well, but I noticed after the flight, I was blocking the air flow to the motor and it got pretty hot. So… I figured I would try attaching it under the wing, facing down to hopefully get better footage and not overheat the motor. Everything worked great. I took it waaayyy up there almost so I could tell the orientation of the plane. As I was descending I got impatient and did a dive. I have done this before, but not with a camera strapped to the plane. When I pulled back, it took longer than usual to level out. As it leveled out I noticed a little black dot falling from the plane… crap, it was the camera. I followed it to the ground and watched it bounce about 20 feet back into the air. It ran to were it fell, about 50 yards for some reason hoping it would be ok, lol. It was destroyed, and I didn’t even capture the fall, because it shorted out and didn’t save anything to the memory card. I guess that is the end of the my aerial video for awhile. So if you ever find the urge to strap a camera to an airplane, take your time and make sure it on there good.

Soarstar RC Video (First Attempt)

Matt — Tue, 17 Jul 2007 17:14:41 +0000

I had been flying my Soarstar for a couple of months and finally decided to attach my Pentax Optio S6 camera too it. The easiest setup what to just strap it down and record video. Eventually I would like to setup a servo to take pictures. These cameras are not great a shooting video, but here it is:

AirHogs Just Not Enough Anymore

Matt — Sat, 30 Jun 2007 04:34:37 +0000

I have had alot of fun with them, but I’m just itching for more. My biggest desire is to for control surfaces. You can move the rudder and elevators on the AirHogs, but not in-flight. I have been doing quite a bit of research online and finally committed to the next step. In reading most of the “Beginners Guides” they recommend joining a local flying club and learning with a buddy box (were you can tether your transmitter to an instructors). I am sure this is great way to learn, but this is the digital age right? Yup, they have several RC flight simulators that are very realistic. The most popular is Great Planes Realflight. However, there is a new kid on the block. Horizon Hobbies has built FSOne. Apparently their physics engine is unmatched. You can get the software with a USB transmitter or with a USB adapter for a real transmitter. I decided, why not get a real transmitter and learn on that. So, I went to the LHS (Local Hobby Shop) and picked up a Spektrum DX6 Transmitter and order the flight-sim online. They had a Real-Flight kiosk, but something about all the “add-ons” really didn’t appeal to me.

When I bought the Transmitter, the guy at the hobby shop talked me into buying a plane to “actually fly”. I wan’t planning on getting a plane until I tried several models in the simulator. I am glad I did though, I didn’t even think about the building part of the hobby. He recommended a SoarStar, it is a simble 3 channel plane that is easy to build. It was a great exercise to get familiar with servos, linkage, expoxy, esc (electronic speed controllers), recievers and working with foam. I really learned a lot.I found out really quick that the batteries that the transmitter came with wasn’t going to work. It had a trickle charger without peak sensing and it was only 600mh. I found some rechargeable AA NiMh’s on eBay for really cheap and found a battery tray from RadioShack that fits in the transmitter. 8 AA’s work out to the same voltage and have 2400mah of juice.

Before I figured the Transmitter batteries out I thought oh no… I should have got the Simulator that came with the transmitter. There would be nothing worse that having the transmitter die in the middle of a flying session. The point of the simulator is to learn and spend more time flying that building, fixing, charging, etc. Turns out it didn’t matter anyway. When the transmitter is plugged in to the USB converter, it draws a small amount of current. Not enough to charge the battery, but enough to keep it at the same voltage (or so it seems).I haven’t flown the SoarStar yet, I am still logging some time on the simulator. It is not easy, but it’s a lot of fun. I have saved at least a thousand dollars in all the planes I would have wrecked.

AirHogs are a blast!

Matt — Thu, 28 Jun 2007 03:11:17 +0000

I have been researching the different models of AirHogs and it is quite difficult to see what they actually offer. The AirHogs site is horrible. All I have to say is infomercials and the web don’t mix. They just don’t have any information on the different models. It appears that all of the ones setup with the two props are the AeroAce model. They have a BiPlane, Jet and Diamond Aircraft look alike. I have found that the other models are no good. I tried the F-22 “Park” jet and it was not much fun. It used a weird pulse for throttle control/roll and the aerodynamics/glide were really non-existent. Estes makes a few nice models, but steer clear of the larger “Park” fliers. Stick with the ones labeled “Backyard”.

Getting Started With RC Airplanes

Matt — Fri, 15 Jun 2007 22:30:53 +0000

I have always been a fan of radio control; cars, robots, computers now planes. As a child I had several RC Cars that were a bunch of fun. At the time airplanes were too expensive and the technology was not all that great. I had left RC altogether for the past 10 years or so.

Recently my Dad sent me an AirHogs Aero Ace and boy I am glad he did. They are a ton of fun. You can get them at WalMart or Target for $30. Without a doubt the best toy for the price. They have a 2-axis controler for throttle and lef-right. There are two small motors setup in a push configuration. The throttle controls the prop speed and the left-right governs the speed to allow it to pitch side to side. They fly great and take a lot of abuse. Here are some pictures:

As you can see it can take some abuse. The plane itself charges from the 4 AA batteries in the transmitter. It is an amazing use of technology. More to follow.