SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
navigator2011's blog
Posted by navigator2011 | Dec 01, 2014 @ 12:45 PM | 1,627 Views
In my previous write-up, I discussed some ways to modify a Soko Gauge so that it can be used without removing the main blades of a helicopter. Although I didn't mention it at the time, I find it much easier to use my Soko Gauge together with an adjustable balance table. So, I thought I'd just give a short description of my balance table.

I honestly don't know why I waited so long to build a balance table--it can be used with any helicopter and any pitch gauge. It's actually fairly easy to build a balance table, too. I started out with a pre-cut round board that I purchased at The Home Depot. The round board is nice because it eliminates the hassle of cutting a circular piece of wood, or alternatively having to contend with a square or rectangular piece. Also, the round board features nicely rounded edges, eliminating any need for using sandpaper to smooth the edges. Although my round board remains bare wood, as shown in Figs. 1-2, I think it would be a nice touch to add a varnish finish or a couple coats of Varathane® to give the round board a finished appearance.

As shown in Figs. 1-2, I used three 1/4" diameter brass bolts for legs of the balance table. Although I used 2-1/2" long bolts, it might be a little better to use 3" bolts to give a bit more clearance under the balance table. I positioned my bolts holes 120-degrees apart, as measured at the center of the table, so as to match the position of the balls on the helicopter's swash plate....Continue Reading
Posted by navigator2011 | Nov 07, 2014 @ 02:15 PM | 1,892 Views
For a long time, I have relied upon a regular, manual pitch gauge to set up my helicopters, such as a CopterX Pitch Gauge shown in Figure 1. Besides being rather inexpensive, the regular pitch gauge is convenient because it can be mounted directly onto the main blades of helicopters and then measurements can be immediately performed. Also, typically one gauge can be used with various sizes of helicopters, ranging in size from 250 all the way up to 800-sized helicopters. A drawback, however, is that the gauge must be eyeballed relative to a rod fastened to the rotor head of the helicopter. Certainly, the eyeballing part is where most of the measurement errors generally arise.

As many members of RCG will attest, the Soko Gauge does a great job of minimizing errors when leveling the swash plate and adjusting the blade pitch of collective pitch helicopters. I love my Soko Gauge because it eliminates any need for eyeballing the gauge relative to a rod fastened to the rotor head of the helicopter. One thing I didn't like about the Soko Gauge, however, is that a main blade must be removed from the helicopter and then a platform, included in the Soko Kit, must be installed into the blade grip in order to use the gauge. There are times when I want to do a quick check without having to mess around with removing and installing the blades. There must be a way, I thought, to combine the convenience of the regular pitch gauge with the accuracy of the Soko Gauge. While I did...Continue Reading
Posted by navigator2011 | Oct 03, 2013 @ 01:58 PM | 3,725 Views
If you've read my blog, you'll already know that I love to tinker and try unusual things with my helicopters. My latest project has been installing a brushless motor onto a variable-pitch tail of my 450 Pro. This particular tail configuration, known in the forums as a direct drive variable pitch (DDVP), differs from most motorized tail systems that incoroporate fixed pitch tail rotors, or even use an airplane propeller. In the case of the DDVP tail, the tail blade pitch is controled by way of a tail servo, as usual, while the motor turns the rotor, either at a governed speed or in combination with the main motor speed. Based on some of the information available on the forums, the DDVP has the potential to reduce vibrations and noise often associated with torque tube tail (TT) systems, as well as eliminating belt tensioning issues often encountered with belted tails. However, the weight of the motor also has the potential to affect tail performance due adding inertia to very end of the tail. Even so, I wanted to give building the DDVP tail a try.

For my tail, I chose a Tarot 450 Pro TT tail section because they are less expensive than Align parts and they are readily available. The motor I picked for this project is a Turnigy Park 300 1380KV brushless outrunner because it should produce a tail RPM similar to the TT tail, and because this motor has a 3.0mm shaft diameter, just like the stock tail shaft of the 450 Pro.

A primary part of this project is mounting the...Continue Reading
Posted by navigator2011 | Aug 26, 2013 @ 03:19 PM | 4,249 Views
It seems to me that there is a schism growing within the rc helicopter community. On one hand, there is the well-known group of pilots whom enjoy flying 3D stunts--flips, rolls, inverted, tic tocs, rainbows, piro-flips, and the like. On the other hand, there are the scale pilots whom aspire to make their aircraft and flights look as much as possible like real, fullsize helicopters. Obviously, performing stunts has a certain potential for causing injury to the pilot and anyone nearby, and there can be no doubt that this is fueling the debates in a few recent, popular threads:

Guy hit by 700-size heli at IRCHA 2013

Tragic accident in switzerland

3D is NOT for everyone

It is not difficult to see in these threads that the discussion of scale versus 3D is becoming, somehow, more angry, with lines being drawn. Does flying scale and 3D have to be mutually exclusive? I don't think so. As I posted in the latter thread, scale flying, 3D smack flying, random flying, why not learn and appreciate it all?

Personally, I am a scale pilot; at least, for now. I haven't the skills for stunts, and I am unwilling to crash heli after heli just to learn a particular stunt--that's what the simulator is for. But it was the allure of flying 3D that motivated me to buy my first collective pitch helicopter . . . boy, was I in for a surprise! Consequently, today I am a very good helicopter mechanic and a decent scale pilot. Most of all, I enjoy my flights now that I have stopped...Continue Reading
Posted by navigator2011 | Jun 02, 2013 @ 09:39 PM | 4,727 Views
The other day it suddenly occurred to me that, after over a year of ownership, I had not yet gone through and tuned up my little Walkera V120D02S. It had been flying fine for my purposes, but I did notice from day one that while the swash plate looked level, the servo arms weren't very well centered and I'm sure there was some binding at the pitch extremes. Certainly, the swash plate was not remaining level throughout the pitch range.

In a previous write-up, I discussed creating a plumb line pitch gauge, and I touted it’s usefulness across a wide variety of helicopter size classes. I thought, what better time is there than now to demonstrate the usefulness of this pitch gauge on a helicopter as small as the V120D02S. Figures 1 and 2 show the plumb line pitch gauge taped onto one of the main blades of the V120D02S. As is standard operating procedure, the receiver was bound to the transmitter with the motor leads disconnected for safety's sake.

The blade pitch-angle is clearly shown in Figure 1 to be 0-degrees with the throttle stick positioned at mid-stick, but things didn't start out this way. On one hand, the blade tracking appeared to be set up very well at the factory, and the swash plate appeared to be vertically centered along the main shaft when the blade pitch-angle was 0-degrees. On the other hand, however, the swash plate obviously had been leveled with the servo arms positioned at different angles. Thus, there was no way the swash plate was actually...Continue Reading
Posted by navigator2011 | Apr 02, 2013 @ 01:08 PM | 5,902 Views
In my previous blog, I discussed a few simple techniques for setting up a collective pitch helicopter, which focused on leveling the swash plate and setting the blades to 0-degrees pitch-angle when the throttle is set to 50%. Once those tasks are finished, the next step is to set up the helicopter's pitch curve. For those new to collective pitch helicopters, the term "pitch curve" merely refers to a sequence of settings in the transmitter that governs how much the main blades tilt, or pitch, as the throttle stick is moved from 0% to 100% throttle. If the main blades have too little pitch, the helicopter will have very little lift and may not get off the ground even when the motor is at full throttle. Too much pitch can lead to motor bogging and overheating. Or, if your motor is reasonably powerful, too much pitch can make the helicopter jumpy and difficult to hover. Either extreme can lead to hours, if not days of frustration for those just starting out with a collective pitch helicopter. Clearly, measuring the pitch-angle of the main blades at various throttle values is an essential part of setting up any collective pitch helicopter.

It is difficult to measure the pitch-angle of the main blades just by eyeballing the blades. Thus, it is essential to actually measure the pitch-angle with a suitable tool, and there are a variety of tools available for just this purpose. Probably the most common and cheapest tool for measuring blade pitch is a simple...Continue Reading
Posted by navigator2011 | Mar 13, 2013 @ 01:06 PM | 10,006 Views
In a previous write-up, entitled "Properly setting up a V400D02," I gave several steps on the proper way to set up the swash plate and blade pitch of a collective pitch helicopter. Although the discussion focused on the Walkera V400D02, the principles are applicable to virtually all collective pitch helicopters. Certainly, that previous write-up targeted those readers just starting out with flybarless collective helicopters; and to quite a large degree, this write-up is directed to such readers, as well.

When setting up the swash plate of a collective pitch helicopter there are a couple of areas to be concerned with: 1) we want the swash plate to be level, or more precisely we want the horizontal plane of the swash plate to be perpendicular to the main shaft, and 2) we want the blades to have zero pitch when the swash plate is positioned in the middle of its vertical path along the main shaft. While it is critical that the swash plate remains level throughout the entire throttle range, we want the blade pitch to be zero when the throttle is set to 50%. The vertically centered swash plate and zero blade pitch configuration provides a critical reference which facilitates setting up throttle and pitch curves later on. There are a variety of tools that can be purchased to level the swash plate and measure the blade pitch, but I rather like to come up with cheap household solutions that are easy to build. Following is a discussion of a couple of simple...Continue Reading
Posted by navigator2011 | Feb 26, 2013 @ 02:55 PM | 5,659 Views
Blade balancing certainly is a fundamental part of flying helicopters, but it can also be one of the more frustrating and tedious tasks involved in setting up a helicopter. A typical instrument for balancing blades is a simple seesaw type of device, where the helicopter blades are fastened onto opposite ends of the seesaw and then the angle of the seesaw and blades can be directly observed. The seesaw portion of the blade balancer typically rides on bearings so as to minimize errors due to friction. Blades that are very well balanced should sit nearly horizontal, perpendicular to the direction of gravity. When the angle of the blades and seesaw is not horizontal, the blades are out of balance and will cause vibrations during flight. Typically, an appropriately sized piece of clear tape is applied to the center of gravity of the lighter blade to bring the two blades into balance.

Ideally, the base of the blade balancer should be placed on a flat, horizontal surface so that the angle of the blades and seesaw can be compared to that of the surface. One difficulty that I continually encounter is that there is not even one truly horizontal surface in my home. This causes blades to appear unbalanced even when they are actually balanced. Of course, this can be overcome by taking careful note of the angle of the surface, but it is not the easiest approach. Another difficulty is that it can be difficult to discern small angles. For example, a difference in 0.05g on 450-...Continue Reading
Posted by navigator2011 | Jan 30, 2013 @ 01:19 PM | 5,895 Views
What had originally started out as a simple main bearing replacement turned into a full-blown rebuild of my 450 Pro. I can never resist the argument that while the heli is already apart, I might as well do things right, not over. As a consequence, this formerly clone 450 Pro is now almost entirely an Align Trex--I think the carbon fiber frame, main gear, and skids are the only remaining clone parts. Oh, yeah, the motor is not Align, either. I used a Turbo Ace 804 Brushless Supremo Motor, which seems to have plenty of power for this helicopter.

All along my intention has been to turn this heli into a proper Align Trex 450 Pro, but there are a few noteworthy areas where I have deviated away from Align. One thing I decided to do was install turnbuckles for the servo links. Turnbuckles are offered at quite a few places online, but it seemed that everyone is constantly out of stock. I did finally manage to find Tarot TL45116-02 Servo Linkage Rods 1.5mm x 19mm. These turnbuckles make leveling the swash incredibly easy without destroying the links by popping them on and off the swash balls repeatedly. Every kit should include a set of turnbuckles!

Another important factor concerns the Align DFC rotor head. When I first began assembling the DFC head, I was a bit shocked to find that the DFC head dampers are so rigid, as though they were just solid plastic. On my other, conventional Align rotor head, the dampers are rubber. The rubber dampers have worked out very...Continue Reading
Posted by navigator2011 | Dec 03, 2012 @ 03:14 PM | 8,457 Views
After having put the Hybrid 450 Pro into the air without any problems, and having sold all of my V400D02-related equipment, it is time to return my attention to my other 450 Pro. In the course of building the Hybrid 450 Pro, I found that the clone rotor head was irreparably warped, and so I substituted the Align rotor head from my regular 450 Pro. The Hybrid 450 Pro is flying very smoothly with the Align rotor head, but this left my regular 450 Pro without a decent rotor head. This seemed like a good time to spring for an Align Trex 450 DFC Main Rotor Head Upgrade Set, Part Number AGNH45162.

I suppose I didn't research this purchase quite well enough because only after receiving the DFC rotor head did I start encountering postings about the DFC grip links snapping. It appears that the tiny threaded grip links do not extend deep enough into the plastic ball links to provide adequate support, possibly during flight and certainly not during a crash. While there are many people flying just fine with the DFC links, there seems to be a growing number of people who've crashed and cannot determine whether the links simply snapped on impact or actually broke first and caused the crash. In either case, the threaded links that come with the 450 DFC kit look very small and fragile by any standard. There is no way I will put a heli into the air when I have foreknowledge of a weak link that I fear could cause a crash, so my 450 Pro has been grounded for a while as I work to...Continue Reading
Posted by navigator2011 | Nov 16, 2012 @ 01:34 PM | 6,227 Views
After having stripped off all of the dual brushless electronics from the V400D02 for installation on the Hybrid 450 Pro, I discovered that I had enough leftover spare parts to completely rebuild the V400D02 all over again. Well, I had everything except the Rx2614V receiver, anyways. The V400D02 now has a COCO Superframe, Hitec HS-5055mg servos, a brushless Esky main motor, an RTF-Heli style signal converter, and the stock brushed tail motor. All of these parts are used, but are still working just fine. Although a brushless tail motor is preferred, my original reason for changing to the brushless tail was reliability, not performance. The stock tail always handled well enough for this heli, but the stock motors are frequently reported to quit working quite suddenly. At any rate, the objective of this build was to use up a lot of the spare parts I had on hand, and I didn't want to spend any extra money on this heli.

It is no secret that installing the brushless system on the V400D02 can require a lot of wiring. Another objective of this build was to minimize the amount of wiring needed, especially inside of the lower frame area, which houses the battery. Minimal wiring makes the heli lighter, looks better, and allows for the use of bigger batteries. The lower frame area is now largely void of wiring--at least as compared to previous builds. The wires from the battery to the stock ESC and the connectors to the brushless ESC are soldered together into one assembly. The brushless ESC still can be unplugged, which simplifies putting the ESC into programming mode and setting the throttle range. Additionally, rather than using zip-ties to consolidate excess wiring, I have used heat shrink to organize all of the wires that plug into the receiver. With the heli set up this way, I should be able to attach an Rx2614V, plug in all the wires, set the throttle range, and then go fly with minimal fussing around.
Posted by navigator2011 | Oct 29, 2012 @ 02:10 PM | 8,500 Views
If you visit the Walkera V400D02 thread, you will find that it's no secret that the V400D02 frame is very lightweight and flimsy. Many RCG members have reported that the upper portion of the frame just below the main motor is prone to cracking; and once that happens, strange wobbles begin to present during spooling. The lower portion of the frame is easy to bend, as well, thereby changing the shape of the battery cage and giving the heli a noticeable lean when sitting on flat ground. Moreover, the plastic boom mount is easy to snap in a moderate to hard landing. Aftermarket parts must be purchased in order to reinforce the boom.

I have never been a fan of the V400D02 frame. One problem I found is that the battery must be loaded into the frame, thus limiting the size and dimensions of the batteries that may be used. Another problem I encountered is that it is difficult to secure the battery inside the frame. Walkera supplies stiff rubber bands with the V400D02, but I didn't like forcing rubber bands onto the frame every time I loaded a battery. Velcro seemed to work pretty well, but then I needed a spatula to insert and remove the battery.

Another annoying aspect of the V400D02 frame is that it limits the types of cyclic servos that may be used. Small brackets are utilized to secure the stock servos to the frame. I had to cut and hack the servo cases to fit them into the brackets, remove a portion of the V400D02 frame for clearance, and drill new holes in the...Continue Reading
Posted by navigator2011 | Oct 25, 2012 @ 12:04 PM | 7,445 Views
When the stock brushed main motor and brushed tail motor in the Walkera V400D02 are replaced with superior brushless main and tail motors, there arises a few other issues that must be worked out. One issue that was discussed previously is the need for creating a power check bridge for the Rx2614V. The power check bridge enables the Rx2614V to power the brushless motors in the absence of the stock brushed ESC. Another issue is setting, or programming, the throttle range in the new, brushless ESC.

A typical approach to programming the throttle range in the brushless ESC is to turn on the transmitter, raise the throttle stick to its highest position (e.g., 100% throttle), connect the battery to the brushless ESC, wait for the brushless ESC to issue 'two beeps,' and then immediately drop the throttle stick to its lowest position, 0% throttle. The brushless ESC then finishes initializing and all is good. Although this sounds simple enough, it doesn't appear simple when the V400D02 is involved. The reason is because Walkera transmitters and receivers often take up to 10 seconds to bind, whereas most brushless ESCs want to initialize immediately. By the time the Walkera system begins sending a high-stick signal, the brushless ESC has already stopped listening.

Of course, there are ways around this problem, depending on the type of receiver you are using. For instance, with the Rx2702V in the V450D01, you can speed up the binding process considerably by setting a fixed...Continue Reading
Posted by navigator2011 | Oct 24, 2012 @ 02:01 PM | 6,703 Views
It is no secret that the stock, brushed main motor and tail motor that come installed on the Walkera V400D02 are woefully underpowered and a chronic source of grief for virtually everyone who has become involved with this helicopter. The only component that ranks worse than the motors is the stock servos--many are stripped right out of the box. Changing the servos to metal gear servos ranks very high on the list of needed improvements to the V400D02. Changing the servos is a topic for another day, however. Here, the topic is generally related to replacing the stock brushed motors on the V400D02 with brushless main and tail motors.

Many members have gone to the trouble of purchasing and installing all of the parts needed to convert the V400D02 to a dual brushless heli, only to find that when the battery is connected, the heli just sits motionless, repeatedly beeping. The reason this happens is because the Rx2614V receiver needs to 'see' some voltage from the ESC before the receiver will power the motors. When you look at the Rx2614V, you will see a Power Check port which receives a plug from the stock ESC. Although the Rx2614V is powered by the ESC through a Main port, the receiver apparently also needs to detect power to the Power Check port. When we convert to a dual brushless system, of course we remove the stock ESC, and with it goes the plug to the Power Check port. Even though the Rx2614V then receives power from the brushless ESC through the Main port, the...Continue Reading
Posted by navigator2011 | Oct 23, 2012 @ 03:25 PM | 8,644 Views
As most RCG members will tell you, a universal rule in this hobby is that RTF helis rarely are ready to fly safely out of the box--and the Walkera V400D02 is no exception to this rule. A misadjusted micro heli can be annoying and tricky to repair, but a maladjusted V400D02 is very dangerous and quite a bit more costly, too. You will be best served to make it a personal requirement to go through any new heli and perform a mechanical set up before even attempting to spool up. So how do we mechanically set up a V400D02?

The picture below shows a V400D02 that is properly set up. When the throttle stick is positioned at 50%, each of the servo arms is at a 90-degree angle to the servo casing, the swash plate is level, and the swash plate is positioned in the middle of its total path of travel along the main shaft. Additionally, the two grip links should be the same length, and adjusted so that both main rotor blades have zero blade pitch. Many beginners are uncertain how to make all of these adjustments. The following steps are intended to provide a formula for setting up the V400D02.

The first thing to do is unplug the main motor and the tail motor--this is the best way to prevent an accidental spool up and injury. With the motors disconnected, put the throttle stick to 50% in stunt mode (ST-1), and switch the receiver from WK mode to ADJ mode to turn off the 3-axis gyro. This will put the servos into their centered positions without the 3-axis gyro interfering....Continue Reading