Tuesday, March 18, 2014

R/C P-38 and another crash

I fixed her up and took her for a spin.
It was relatively calm, just a little gusting.

Well, by the time I got started, the wind picked up.  I should have aborted, but I am stubborn.

As soon as I got it in the air, I lost control.

I thought I managed to get it back, and tried to enter a left-hand pattern.

Suddenly, a huge gust kicked up, and she went down. Hard.


Both tail booms took serious damage.

The battery popped out, I had to hunt for it.

Left aileron is almost disconnected

Left and right props are wonky.  I don't know if I can fix them. Or by a new set... Or

Sunday, March 16, 2014

R/C P-38 and hard landings

so a friend is trying desperately to get me into R/C airplanes. So he surprised me with a Flyzone P-38. It is a micro plane, 4oz tops.

Well I am not a particularly good pilot. Two flights, two crashes.

First flight ended in a nose dive. Broke the nose right off. Fortunately, the nose protected the props. The fix was pretty easy. Good as new.

Second flight. Much better. I even controlled it in heavy winds. Unfortunately, I can't tell whether it is coming or going, and I flew it imto an oak tree. I ripped the tail off trying to get it down.

I am gluing it back now. Maybe a 3rd flight this week. 3rd time's the charm, right?

Friday, July 15, 2011

Turtle Hat

I learned to knit when I was deathly ill on New Year's.
After the perfunctory "hello world" of knitting, a scarf, I tried to do something a little more interesting.
I came across some "hairy" yarn in a mossy green color. I decided to make a "turtle shell" hat.

This was my first real project. I didn't have a pattern; so I made it up on the fly. The first attempt was HUGE. Yeah, round 2.

I shrunk it and did a 2x2 rib. I used 2 continuous strings (green and brown). When I was done, it was gorgeous. Super cute, perfect, and.... SMALL.
It was so tightly knit from carrying the 2 lines the whole time. I gave it to a friend for her doll.

I was so frustrated, that I promised to never do it again. Instead I did a simple grey hat, fast, easy and pretty.

Then I got the itch to try the turtle hat again. This time I ran 12 lines! One for each color and patch. It was a difficult task to keep everything straight, but it worked. This time it was JUST RIGHT.
I gave it to my niece(nicknamed "Princess Turtle"). I would like to thank her for being my model.

Friday, June 17, 2011

Spy Trakr: Headphone Jack

The first hack everyone does to the Spy Trakr is to install a headphone jack. I jumped on the band wagon. My biggest issue was the mic-speaker feedback when I had the Spy Trakr next to the remote; LOUD!

So I opted for headphone jack AND a volume knob.

I carved out a slot in the right grip with a soldering iron (it is a sin, I know) for the jack (ebay 5-pin) and a small wheel potentiometer (Radio Shack 271-001). This 5-pin jacks automatically switch from speaker to headphone when you plug it in.

This is a crude wiring diagram. It is sad how long it took me to figure it out.
This is a shot of the holes and where the stuff fits in the remote.

The components assembled and awaiting final gluing.

The final installed setup.

The speaker shuts off when the headphones are installed.
Speaker: the wheel controls the speaker from NORMAL to mute. Not a lot of fine control.
Headphones: the wheel controls the headphones from REALLY LOUD to NORMAL.

Overall, I am happy with the results.

Spy Trakr: Motors

There are many complaints about the Spy Trakr motor; all of them say it's too weak.

I opened it up to see what we were dealing with.

Four gears in the train from the motor to the wheel
overall 1:40.4

Should be beefy enough, but the motor spins so slowly; the wheel does about 100 RPM.

Three wires to the motor: black, red, orange (the other wheel is green, blue, yellow)
This is a simple brushed DC motor. Orange/black power the motor and red is a ground to motor chassis.

The motor itself is a little larger than the typical guys I see at the hobby shop.
I will revisit this later to get a better idea of the motor, and how to improve the situation.

Spy Trakr: Wide Angle Lens (more)

A little bit more about the lenses and installation.
This is the 1.8mm lens installed on the board.

I had to make a custom lens holder and I made it a little loose. The lens would shift when I installed it in the TRAKR. So I manually focused it and dribbled Elmers glue into the threads overnight. Now it is sturdy enough to install in the 'bot.

These are 3 of the 4lenses I used (excluding the one I installed).

The TRAKR lens is on the right. It has a 9mmx0.5 thread on the lens. This diameter is less common, but not too bad. The screw holes on the lens mount (and the TRAKR CMOS) are 18mm apart. This lens has an IR filter built in. This lets 850nm pass and blocks the other IR frequencies.

The other two lens are from the Surveyor SRV-1 (basic on left, wide angle in the middle). These are both 12mmx0.5 thread lenses. Much more common size. The included lens mount is on the center lens. The screw holes on the lens mount are 22mm too big for the TRAKR.

So I built my own lens holder: 12mmx0.5 thread with a narrow 18mm base. Not hard, but I was sloppy (thus the glue)

Friday, June 10, 2011

Spy Trakr: Wide Angle Lens

I recently purchased a Spy Gear Spy Trakr. $80 R/C Tank with video camera that displays on the remote. It's claim to fame is that it runs Linux and is user programmable. Hackaday.com did a few good write-ups on it //hackaday.com/2010/08/27/spy-video-trakr-first-impressions/

Unfortunately, Spy Gear has stopped supporting it and taking the source code with it. Darn.

In the meantime, it is still a fun little toy. I drove it around the apartment, tough to navigate on the small screen. Just for giggles, I thought I would swap out the lens with a wide angle lens. I had 3 other lenses from work: 3.6mm, 2.2mm, and 1.8mm. (The Spy Trakr lens looks to be 3.6mm).
These lenses are 12mmx0.5 thread, very common; the Spy Trakr lens is 9mmx0.5 thread, less common.

This is an image with the default lens

This is an image with the 1.8mm lens

A top view of the kitchen, er... test arena.
The green line is 1.8mm and red is the 3.6mm.

The wider view and increased "peripheral vision" make the Spy Trakr an order of magnitude easier to drive.

A couple of notes about the 1.8 mm lens. It was labeled as 180-degree field of view. Clearly not 180 degrees. The fine print is that on a 1/3" imager it yields a full 180-degrees, but on the Spy Trakr 1/4" imager, we get 90-degrees. Again, still better than the 45-degree Spy Trakr lens.

A problem though, the wider lens needs A LOT more light. Thus my images are bad outside of natural sunlight. D'oh. External LEDs will fix that.