XCVG
ModRetro Legend
Maybe two weeks ago a guy brought an interesting toy to class. It was a small toy truck with a small wing and propellers duct-taped on. It was unable to fly but went pretty good. I said I'd one-up him and make a flying RC version. Well, I haven't accomplished the flying part, but it is RC.
Most of this happened yesterday.
This is the victim. I've had this thing for years. I've disassembled it three times, kicked it down the stairs, dropped it, and crashed it into things. It's survived it all, and now it's being abused in a different way.
And this is the insides. The battery holder is part of the chassis and is located directly below the board. It runs on 4 AA batteries, alkaline or rechargable, so the voltage range is probably between 4.5-6 volts or so. I don't want to overvolt it as it will probably go up in smoke.
Since the original intent was to make the thing fly, the drive motor would have to be removed to save weight. The motor box contains gears and the shaft. On the far left is another shaft from a smaller RC vehicle; I don't know what it's doing there.
Inside the motor box. Some small, cheap, and weak plastic gears, a motor, and the driveshaft. I removed the motor and gears and put it back together.
The fan motor being tested. As it turns out it had almost no thrust. The fan is actually spinning in this picture, apparently the camera is faster than I thought it was.
This is what I ended up using. It's a Speed 400 type motor from a Wing Dragon RC aircraft. This sucker is intended to run at 8.4V and around eight amps I think. At this point I thought about bringing out the real RC gear, but I wanted to keep this project more... ghetto. Anyway, this motor is way overkill and the prop WAY too big, but I don't have anything suitable.
The original motor mount plate was balsa, but it broke during drilling so I got out something a little stronger. I think this is steel, but it might be aluminum. Either way, I needed a safe way to drill it so I build this ghetto rig. The metal is clamped to the wood with vice-grips (I later moved one to the opposite side for balance). The wood is clamped to the table and weighted down with a heavy transformer.
Two long brass screws (it's what I had sitting around) go up from underneath and through some balsa spacers before the motor mount plate goes on and is bolted down. The brass screws turned out to be a good thing- the motor is very magnetic! The motor mount is a bit wobbly but mostly okay. I later added more spacers to raise the prop higher, as it kept hitting the ground. The motor itself is zip-tied down and is pretty secure. Right now it's connected with alligator leads.
I have a video but no pictures of the test. With standard alkalines, the machine could go down our slightly sloped garage floor but would not go up or even traverse level ground. With rechargable NiMh batteries it was a lot more powerful, despite the lower voltage (4.8V vs. 6V). It would go across level ground and even up the floor. The motor even SOUNDED more powerful. If I find my single AA holder I'm going to try five rechargable AAs. Also, if I can get a 5V relay I'm hooking up the big RC airplane battery and powering the RC circuit with a 7805.
Most of this happened yesterday.
This is the victim. I've had this thing for years. I've disassembled it three times, kicked it down the stairs, dropped it, and crashed it into things. It's survived it all, and now it's being abused in a different way.
And this is the insides. The battery holder is part of the chassis and is located directly below the board. It runs on 4 AA batteries, alkaline or rechargable, so the voltage range is probably between 4.5-6 volts or so. I don't want to overvolt it as it will probably go up in smoke.
Since the original intent was to make the thing fly, the drive motor would have to be removed to save weight. The motor box contains gears and the shaft. On the far left is another shaft from a smaller RC vehicle; I don't know what it's doing there.
Inside the motor box. Some small, cheap, and weak plastic gears, a motor, and the driveshaft. I removed the motor and gears and put it back together.
The fan motor being tested. As it turns out it had almost no thrust. The fan is actually spinning in this picture, apparently the camera is faster than I thought it was.
This is what I ended up using. It's a Speed 400 type motor from a Wing Dragon RC aircraft. This sucker is intended to run at 8.4V and around eight amps I think. At this point I thought about bringing out the real RC gear, but I wanted to keep this project more... ghetto. Anyway, this motor is way overkill and the prop WAY too big, but I don't have anything suitable.
The original motor mount plate was balsa, but it broke during drilling so I got out something a little stronger. I think this is steel, but it might be aluminum. Either way, I needed a safe way to drill it so I build this ghetto rig. The metal is clamped to the wood with vice-grips (I later moved one to the opposite side for balance). The wood is clamped to the table and weighted down with a heavy transformer.
Two long brass screws (it's what I had sitting around) go up from underneath and through some balsa spacers before the motor mount plate goes on and is bolted down. The brass screws turned out to be a good thing- the motor is very magnetic! The motor mount is a bit wobbly but mostly okay. I later added more spacers to raise the prop higher, as it kept hitting the ground. The motor itself is zip-tied down and is pretty secure. Right now it's connected with alligator leads.
I have a video but no pictures of the test. With standard alkalines, the machine could go down our slightly sloped garage floor but would not go up or even traverse level ground. With rechargable NiMh batteries it was a lot more powerful, despite the lower voltage (4.8V vs. 6V). It would go across level ground and even up the floor. The motor even SOUNDED more powerful. If I find my single AA holder I'm going to try five rechargable AAs. Also, if I can get a 5V relay I'm hooking up the big RC airplane battery and powering the RC circuit with a 7805.
