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EXI-450 Helicopter — Build Day 5

Setting Re-duex.

When I thought I had it all figured out, I learned (in a rather painful way) that I in fact did not. At least no blood was spilled.

OUCH. A 450 blade at full throttle can hurt.

So, after a lot of testing with the heli double duct taped to the floor, I have some new settings that visually agree with my very limited understanding of how these things really work. One mental hurdle was figuring how how the Swash mixing really worked. A simplistic view of individual servos on the swash was getting me into a major logic box. It was when I looked at it from a conceptual standpoint, instead of the discrete mechanics, that it made sense. Confused? Join the club!

DX6i EXI-450 Programming Ver. 2
Dual Rate & Expo
  Aileron Elevator Rudder
  100% INHibited 100% INHibited 100% INHibited
Travel Adjust
  Throttle Elevator Gyroscope Aileron Rudder Pitch
  ↓100% ↑125% ↑100% ←125% →100% ↓125%
Sub Trims
  Throttle Elevator Gyroscope Aileron Rudder Pitch
  0 ↓10 0 →38 0 ↓16
Gyro
  INHibited
Throttle Curve
  Low 1/4 1/2 3/4 Full  
Normal 0 % 25% 50% 85% 95%  
Stunt* 0 % 20% 40% 40% 40%  
Pitch Curve
  Low 1/4 1/2 3/4 Full  
Normal 50 % 50% 67% 82% 100%  
Stunt* 15 % 27% 62% 80% 100%  
Swash Mixing
Swash Aileron Elevator Pitch
  – 60% – 60% + 60%
Channel Mixing
  Master Slave Rate D U Sitch Trim
Mix 1 Throttle Throttle 0% 0% ON INHibited
Aileron Aileron 0% 0% ON INHibited
Elevator Elevator 0% 0% ON INHibited
Rudder Rudder 0% 0% ON INHibited
Gyro Gyro 0% 0% ON INHibited
Pitch Pitch 0% 0% ON INHibited
Mix 2 Throttle Throttle 0% 0% ON INHibited
Aileron Aileron 0% 0% ON INHibited
Elevator Elevator 0% 0% ON INHibited
Rudder Rudder 0% 0% ON INHibited
Gyro Gyro 0% 0% ON INHibited
Pitch Pitch 0% 0% ON INHibited
Revo Mix
  UP DOWN  
Normal 0 % 0 %  
Stunt 0 % 0 %  
DX6i EXI-450 Setup Ver. 2
Reverse
  Throttle Elevator Gyroscope Aileron Rudder Pitch
  Normal Reverse Normal Reverse Normal Normal
Swash Type
  CCPM 120°
Throttle Cut
  POSITION – ACTIVE
Dual Rate Combination Assignment
  Dual Rate Switch: – INHibited
Power Setting
  B-US 247
* NOTE: I have set the Stunt settings for my own safety, not for actual stunt flying. If you use those settings you’ll end up with a bird in the ground, but at least it’s less likely to go full-throttle without you expecting if, if you do something really stupid (like me) and flip the mode from NORMAL to STUNT without thinking.

Not many photos were taken today since this was mostly transmitter programming, a little out of control flying and working on dialing in the Gyro. Still spent more than a couple of hours hacking away at understanding all there is to creating a BASIC setup for a good hobby helicopter. Now I have a better understanding of why RTF helis like the MadHawk typically don’t ship with an BNF (Bind-and-Fly) version. The amount of customer support they would have to deal with would quickly consume the fairly narrow profit margin.

Perhaps I’ll have the bird in the air this next week. For now I need to call it a night and get ready for another exciting week of computer programming, project management and cat wrangling.

Radio Control Flying – Documenting my 450’s part specs

One thing you learn in the tech industry is, Document your specs!. And just don’t link to some manufactures web site and call that documenting your specs. You need to do a little better job of that. I prefer to get the specs and record them in my own documentation. If you do that, you don’t have to worry about the manufacture changing specs (but not PN#), or them deleting the specs from their websites completely (e.g. Loctite deleted the specs on the 224 purple thread locker… yet I can still buy it all over town).

So, for my own edification really, I’m going to list the parts specs, original configuration vs. upgrades in those parts that have been upgraded, or changed. YMMV. CYA, BYOB.. you get the idea I’m sure.

 

ORIGINAL BUILD

UPDATED PARTS

Motor Exceed RC Alpha 400 (63M18)  
 
Kv: 3500Kv
Input Watts: 225W
Resistance: .06 ohms
Idle Current: 1.60A
Continuous Current: 19A
Max Burst Current: 23A
Cells Ni-Cd/Ni-MH: 6-10
Cells Li-Po: 3
Weight: 2.1 oz (60g)
Overall Diameter: 28.4mm
Shaft Diameter: 3mm
Overall Length: 31.6mm
 
Electronic Speed Controller ESC Hobbywing Pentium 30A ALIGN RCE-BL35X

Just another morning ‘Air Show’

I see the Airlift Northwest birds all the time. This morning I just happened to have my little Canon S110 camera nearby. The video is pretty horrid, hand-holding a ‘camera’ the size of a pack of cards set to 9x zoom will net just this sort of result.

The point? The noise. And the fact it’s a helicopter, something I’ve been fascinated by since my grandfather first took me to the Heliport (JEM) in Emeryville, CA. I think I was maybe 5 years old. I’m 99.99% certain the place is LONG gone. I can’t find any visual evidence of it anywhere, and the Lon/Lat data I get puts it out in the water. Oh well.

Here is that video anyway.

Radio Control Transmitter Research

Following several days of research into radios, price checking, etc. etc., I’ve decided to go with the Spektrum DX6i to get my feet wet with this hobby.

Spektrum DX6i Radio Control System

It meets the minimum requirements for Helis, and it’s available locally for the exact same price as it is online. Which I found really interesting, no ‘better deal’ to be had. I could go into the used market but, I don’t want to purchase anyone’s previous issues. I’d rather know it’s all new and working to maximum possible performance.

Some time around June they plan to announce US distribution of an 8 and 10 channel model. With a clear upgrade path, which I’m sure means I can use the newer radio with an older receiver and, if I decided to get further into the hobby, my old Heli can still be flown with a newer radio, as well as an older one.

Another neat aspect of the 2.4 GHz Spread Spectrum designs are that multiple radios can run in the same area and not cause problems, no cross-channel issues since the radios can bind to specific receivers and visa-versa, removing the need to fly ‘channel flags’ and have crystals on hand so you do not interfere with other people that might be flying nearby. Plus the Spektrum radios are the only ones that work with the Bind-and-Fly RTF (ready to fly) fixed-pitch trainers also locally available.

Pages I’ve read to learn about the differences in transmitters, pros and cons.


Spektrum DX7 vs. DX6i

Here is a good bit of data, detailing the difference between the Spektrum DX6i (the most common recommendation I’ve heard so far) and their updated DX7. The additional features of the 7 over the 6 for Heli pilots is relevant, mainly in the CCPM mixing realm. It’s also a lot more expensive.

Heli Mixes

The Spektrum DX7 offers more cyclic/collective pitch mixing (CCPM) capabilities than the DX6i. The DX6i will operate 1 servo/90 and 2 servo/120 type swash plates. The DX7 will operate 2 servo/180, 3 servo/120, and 3 servo/90 type swash pates.

The DX7 allows you to program 3 throttle curves and 3 collective pitch curves, where as the DX6i has only 2 throttle curves and 3 collective pitch curves. Each throttle and pitch curves for both transmitters have 5 programmable points.

The heli version of the DX7 allows for up to 3 programmable mixes and the DX6i only gives you 2 programmable mixes. If you’re new to helis and need some more explanation of these features, I strongly suggest checking out this excellent RC helicopter website!


Spectrum DX5 vs. DX6 vs. DX7

Read Here


DX7 Heli Prices

RedRocket Hobbies
Spektrum DX7 7Ch Heli w/AR7000 & 4-DS821 MD2
Our Price: $349.99


DX6i Transmitter Prices

RedRocket Hobbies
Spektrum DX6i 6 Channel Full Range w/o Servos MD2
Our Price: $199.99


Weather Station Page v 1.0

OK, finally have something that I like. At least for now:

Personal Local Weather Station

If you’d like to see the actual page, you can find it linked here -> http://www.daviddemartini.com/WX/

In the next day or so, other changes will be made, so I’m saving this for posterity. I often find it interesting to look back at the genesis of a software project.

The creation of this page is documented here, in a 4 part (4th part still underway) set of posts.

Installing libevent on MAC OSX 10.6

So, today I set about installing libevent on my laptop. It’s a required library for system event handling applications. An example of that would be Gearman.

First off, you are going to need to have install MacPorts installed.

Step 1 – install MacPorts:

Now this is where the fun begins. Now, if you followed my other blog page on installing MacPorts, you can move onto Step 3. If you have not, then, proceed at hast to installing it (follow this link too).

Step 2 – install libevent

If you enjoyed installing MacPorts, you are going to LOVE this! 🙂 Now, the step of building libevent from source, probably not *required* but, after three installs that were not picked up by the gearmand, I though I’d just, do this the old fashioned way too.

First off, run the standard install. This did not toss errors for me on the normal install. You can stop with this Step after it installs and move of if you like. I’m going to show the extra couple of steps I took.

#root: port install libevent

Step 3 – locate tarball, extract and build from source

UPDATE: 6-JUN-2013. Get the latest tarball from [HERE].

Now, move the distribution for libevent, and untar the tarball. The path here is from my current build. The one you eventually get will possibly have a higher number (more recent build). Don’t freak out if this exact path is not on your system. If you are building from source, I’m going to assume you also know how to find things on your computer. The reason I built this from source, was to provide the option –prefix=/usr/local to configure. It establishes where it will deploy it’s libraries.

#root: cd local/var/macports/distfiles/libevent
#root: gunzip libevent-1.4.13-stable.tar.gz
#root: cd /opt
#root: tar xvf libevent-1.4.13-stable.tar
#root: cd libevent-1.4.13-stable
#root: make
#root: make install

Now, you should have a nice clean build of libevent on your computer. Having accomplished this, you can install an array of scheduling and system event driven applications.

Enjoy.

Saturday trip around Puget Sound with kids and cameras.

One of the things I did today, was sign up for ‘foursquare‘, an app that lets you ‘check-in’ to places, and those with participating incentives will send coupons to your phone. It’s and interesting experiment. I’ll see how that works out today.

M.V. Kitsap mid-sound, enroute Bremerton
Passengers on stern pickle-forks of ferry M.V. Kitsap
M.V. Kitsap about to make starboard turn into Rich Passage.
M.V. Kitsap foreground, Olympic National Park, background.

$518 later, a new pair of tires for the CLK

OUCH. Pricy tires! But like most things in life, the true cost of owning a vehicle can be a lot more than just the ‘purchase price’. $1100 for a set of tires, $1300 for a set of decent (not great) wheels, $400 for sport shocks… $200 for spark plugs (takes 16 multi-tip Platinum).

In the end, a tire I was not really comfortable driving on with kids in my car, has been replaced and I can move on with life.

Still.. $518 unplanned dollars…. (+ tax) was a bit hard to swallow!

Maybe snow, maybe not.

We were forecasted for snow overnight. Nothing materialized.

Forecast has changed a little bit. Right now it’s raining at just above freezing.

2009-12-14_forecast
Tomorrow, the streets will probably be a ice rink. I’ll have to get my camera ready to train on the highway outside. It’s steep and heavily traveled. Could be some amusing or frightening stuff caught.

I wish the weather would ‘decide’ to do something other than drizzle on the verge of freezing. That’s boring.