Sunday, March 29, 2015

Playing with FPV stuff.

The other day I was cruising reddit, and I found this guy had designed, and printed a backplate that would let him combine the RC-305 reciever, and the display in the Quanam FPV goggle.  

http://www.thingiverse.com/thing:692199

So... I did some digging around, and found a guy who'd do a good job printing it out for me.  



And after some serious surgery, the backplate is installed on the monitor, and it works!  Now there's just one wire to hook up my goggles.  


I ordered a new camera to play with.  I kinda expected it would be the size of the one I showed off on the Maltese.  Turns out.. it's less than 1/8th the volume of that camera.  That's a dime sitting next to it.  

 

Oh, I glued the whole shebang together.  That's now an install-able unit.  I should really hunt down some dip switches so I can vary channels.  


Oh yeah, I was also quite suprised by how small the 808 cameras are.  That will eventually live hanging under the QFO, with a couple servos to keep it steady.




Monday, March 23, 2015

The Maltese - A testflight.




Generally speaking, flying a 250 quad in a 10x10 room is not considered a smart move. Yet.. that's what I did tonight.

I wanted to know how the Maltese would fly with a 2200mah pack strapped to it.  As it turns out, it flys ~very~ well.  I suppose when your airframe is not much more than some 3mm fiberglass, things move quickly.



That platform on top is just asking for something isn't it.  Wait.. I know!



9 grams of FPV gear!

Sunday, March 15, 2015

The QFO gets lit, and space becomes an issue.

 Today was an excellent day to go flying a quadcopter.  The weather broke, the skys were clear.  And I had a beautiful park to fly in.  ....  But you see the following component?  This stopped me from flying.
You can't fly if your batteries won't connect to your quadcopter.  Roadblock me during the day, I'm going to make it up at night.

I know what it looks like.  I swear, the problem is resin, not coke.  And really, I'm a pepsi guy.
The LED boards I built, were all a little to tall to fit in the arms.  Most LEDs have a lot of plastic over the die, so I did a bit of sanding.  Did you know ice was clear?  Snow is just ice...  Snow is white becuause of random refraction.  When you sand clear LEDs, you get white powder.  

Now.. I need an envelope...    Moving on...
After finding two of my SMPS just couldn't adjust, I found one that worked.  I got that wired up, and tested.  
I got a new toy in the mail, and I wanted to hook that up too.  The display says "Number 2" and it's about to say the voltage of cell 2.

The suspense has gone on long enough, here's the result.


It looks wonderfully otherworldly.
 And now for the bad news.  Once I had my lighting boards installed, I couldn't fit a 1500mah pack into the airframe anymore.  I won't give up mAh, so it's back to the drawing board on the lighting.  I think I can trim off 3/8" on all of them, and that might make the difference.









Tuesday, March 3, 2015

Can a decent surface grinder be made at home? We're gonna find out.

<NegativeK> I wanna make some decent parallels. =|
<`Nerobro_> NegativeK, I wonder if a homemade grinder would do it..
<NegativeK> Keeping a tenth on a surface grinder is supposed to be not easy; I can't imagine it'd be easier on a homemade grinder. =p
<`Nerobro_> I bet we could...
<NegativeK> We have a hand scraper.
<NegativeK> Someone could three-plate lap a large enough surface plate, make a straight edge, and make some ways.
<NegativeK> s/lap/scrape/
* `Nerobro_ nods.
<`Nerobro_> NegativeK, talking to you always ends up finding some way of absorbing 20-60 Nero-hours
<NegativeK> I bet you a dollar you can't make a 6x12 surface grinder that can hold a tenth within the next six months. ;D
<t_j> NegativeK: what are the restrictions on 'make'?
<NegativeK> I'll even give you a pass on the magnetic chuck.
<NegativeK> t_j: No parts designed for a surface grinder except the abrasive wheel.
<t_j> fuck its 2pm already
<NegativeK> Also you have to stick to the spirit of that rule, not the letter, Hacker McHacky Pants.

Sunday, March 1, 2015

Bit Char-G - Do you like my body?

The battery goes on top.  If I could get my hands on a "fat" 30ma cell, I could probally put it in the bed.  I wonder if I can get my hands on a Estes or Cheeson micro battery...

It looks good to me.

Friday, February 27, 2015

Bit Char-G - Doing research long after it matters. And making a 1/64 scale proportional car.



I want some r/c cars to drive around my computer room.  The room is about 10x10, and has a bunch of furniture and other stuff in it.  That means even 1/32 scale cars are a bit big, if I want to set up a course and do laps.

Several years ago, I was into these cars called Bit Char-G.  They were made by Tomy, and sometimes were sold on the MicroSizers name by Hobbico in the US.  I got most of mine from a little Japanese mall, and mail order.

Here's a Bit Char-G next to a AAA battery...


Their turning radius is about a foot, so they're great for rolling around on linoleum floors.

So lets talk about the cool stuff on these cars.  First, they have replaceable final drive gears.  They come in three color coded sets.

Now, this seems great, excepting they're not proportional.  They use a magnet and field coils to steer, and have what amounts to a pager motor to make them go.  Admittedly, they have enough power to really go, and be challenging to drive... so that's not the problem.

Now.. how do you give proportional steering to a car that's 55mm between body mounts.

Happily, there are servos that are "about the right size".  The one thing that's missing, is a decent micro speed controller.  "micro" speed controllers seem to start in the "few amp" range, and go up from there.  The smallest brushed one I can find, is a 3amp one for airplanes.

What we need here, is a 1 amp speed controller, with coast, brake, and reverse.



But.. do we really need 1 amp?  I pulled 1 amp out of the air, based on the run time of the car.  Which is "a few minutes" on 50ma.  I think we need to do some testing....


So testing we shall do.  From a fully charged 50ma NiCd cell...

No load: 33ma
Some load: 55ma (finger dragging on the wheels making them slow down)
Full stall: 99ma

I was expecting "amps" not under a tenth.  But.. I'll take that.

The usual answer for "I need a really tiny ESC" is to gut a larger r/c servo, glue the pot  on center, and call it a day.  I want a really good tiny ESC.  If this project pans out... I'll need to do some research to find that sort of thing.


I started digging through my gear to see what I have that might suit this build.  

How are we going to squeeze a battery, ESC, Servo, and RX into that?  Specifically this gear:


It looks like the receiver would fit upside down, without interfereing with most bodies.



And the servo looks like it will fit flat  if I carve out the bottom



But.. in the end, those weren't going to work tonight.  If i want a chassis like that, I'm going to need to build this up as a pan car.  (a completely sane, if time consuming option..)  That, was not in the cards tonight.

Speaking of tonight, I needed an ESC.. now.  Thankfully, a servo was willing to spill it's guts for me.



I'm decent at soldering, but lets say this was a challenge.  Much to my joy, it worked.

Thursday, February 19, 2015

A practical airframe. The QFO could fly.

Finding time to work on hobbies is.. a challenge.  Sometimes, you have a cat sleeping on your work surface.  Everyone, meet Al.  


Building inside a QFO frame is an interesting task.  In order to get all of the power wires going the right way, the speed controls all needed to face the same way.  And to have clearance for the battery, and flight controller, the speed controls needed to be tucked into the sides of the airframe.

To get the motor wires going the right way, I soldered them on backwards.


Trying to take a photograph of the inside of the QFO isn't easy.  Here's where I mounted the speed controls.  


I still dislike PDBs.  So I built another one of the Warpquad style wiring harnesses.


And here's the power harness in place.  Somehow, I didn't get a picture of the cable end I built, that includes a JST lead to power the lighting system.  I still plan on using the balance connector to power the video system on this quad.


With everything on board, excepting an antenna, and a camera, it comes to about 400 grams.  


It's all a really very tight fit.  I need to dig up a receiver with CPPM so I can get rid of most of that wiring harness.  Somewhere, I have a couple of those.  


Someday soon, it will fly.  


Next up, is figuring out the camera situation.  I plan on putting an 808 based camera under the airframe.  And.. so long as I don't try to do any high performance flight, I could use the video feed off of the 808.  I'm also considering cutting a hole in the side of the fuselage to stick a tiny camera through.

I should also finish the lighting rig.