Posted by RicksterRC |
Nov 10, 2012 @ 03:32 PM | 2,229 Views
First - don't be trying to solder any of the wires on your heli with a big Weller 100 watt gun style. You won't be able to do it.
Get a small pencil iron. No more than 60 watts - max.
Radio Shack has a "starter kit" for $12.00 http://www.radioshack.com/product/in...ductId=2062758
Second - get "rosin core solder". The smallest diameter they sell. Not the huge stuff from Home Depot for plumbing.
Rosin is flux inside the solder. It helps deoxidize the copper as you solder.
Get leaded solder if you can find it. It's much easier to work with than the lead-free: http://www.radioshack.com/product/in...ductId=2062719
(you probably won't be able to find leaded solder in Europe).
Let's assume you're soldering two wires together.
"Tinning" means getting some molten solder on to something - either the soldering iron tip, or the wire.
You want the solder to "plate out" (coat the surface like paint and fill in between the strands).
You don't just little balls clinging to your work. That won't work.
1. Get the iron hot (should only take 2-3 minutes).
Make sure there is some solder on the tip.
Clean it with a damp sponge (while hot).
"Tin" the tip. Which means adding enough solder to coat it and make it shiny.
Wipe it again on the sponge.
Repeat until it stays shiny.
If it's really tarnished (it's probably copper). You may need to clean the tarnish off the iron before it's usable.
You can use sandpaper or a...Continue Reading
Posted by RicksterRC |
Oct 03, 2012 @ 01:28 PM | 1,866 Views
I did some motor testing.
I did static testing. I weighed the helie's All Up Weight.
I then held them down to the scale with a wrench jammed through the skids and zeroed (tare-d) the scale.
I then recorded the "negative weight" at various times. Initial, 1,2,3 and 4 minutes and the time when the motor was no longer generating enough lift that it would be able to carry the heli. I compared stock V911 motor, stock Y911 (yellow) and V911 with SP720 replacement.
Unfortunately, I don't currently have any working Bravo SX motors to test.
I used a 130mAH fully charged battery for all the tests.
I ran full throttle the entire test.
(would be interesting to do a test where the throttle was set to the weight of the heli and time it - but that would require a lot of effort).
All three helis have Extreme Delrin main gears. The SP70 is by far the quietest.
It spins by hand silently and many more turns than either of the others.
Note these tests were performed on a kitchen counter, so the heicopters were in ground effect.
I did try to record the Blue/White with SP270 motor's lift out of ground effect by tying a 3 foot string between the wrench and the heli. This proved extremely difficult as the string's pull made the heli terribly negatively stable. I had to hold the heli gently above the scale.
For the record, it created about 5g of lift or about 20% of the helis mass. Shows why a gram gained or lost makes a big difference in real life performance!
I had an idea that reducing the effectiveness of the self stabilizing/self righting might accomplish the same thing without adding extra rotating mass and air drag.
So I set out to limit the range of the flybar's action.
I used a piece of plastic drinking straw (exactly 0.250" worked great) and a twist tie to hold things in place.
It worked remarkably well.
Because I'm limiting the throw of the flybar (not increasing it like I think the paddles do), I think it acts kind of like it has expo. Stability in hover is maintained, but the response to stick input is dramatically increased - and does not get reduced by the self righting response.
As shown in the pics below, the flight characteristics before the mod are such that after a second with full forward stick, the copter seems to level off and slow down. When the stick is released, the copter tips back by itself and comes to a stop.
After the mod, the angle of attack stays constant and the copter continues to increases speed considerably. I had to ease back on the stick! When the stick is released, the copter didn't do it's rock back thing. I had to actually stop it...Continue Reading
Posted by RicksterRC |
Aug 20, 2012 @ 11:08 PM | 2,656 Views
I found some more cool LEDs.
These are 10mm (fairly big). They are RGB (red/green/blue) all inside one lens with a chip that fades from color to color.
First it does the primaries, then it fades the rainbow, then repeats.
Put it inside one of the white canopies (red/white or blue/white) and the effect is mesmerizing.
I scraped some of the solder mask off the ground plane just to the left of the red battery lead. On my board, it was where the date is silkscreened.
Use a meter to make sure you have 4.2V across the red wire to the scraped spot.
Remove the battery.
Tin the bare copper. Bend the LED leads at right angles close to the LED.
Cut the longer one a little longer so you can keep track of it.
The longer lead goes to the red wire pad, the shorter to the scraped spot.
Tin the leads, then solder to the pads.
I couldn't get a good video of it (for some reason the cameras didn't like the brightness of the led and washed it out to white).