Genexis's eRaptor custom frame build

[genexis]

Original source: http://simplewords.genexis.net/?page_id=636
I'll try to update this thread as soon as I add more entries into the above site. For faster updates, do visit the site above.


Introduction

This write up is going to be the build log of my second eRaptor, which is build from spare parts that i bought during my stay in Hong Kong. A little story of how i got these spare parts. I was in Hong Kong for an exchange program by my University for about 5 months, and being a RC hobbyist, it is natural that I explore the different RC shops and flying fields in Hong Kong. Prior to flying into Hong Kong, i was already a fan of Thundertiger Raptor RC Helicopter series. I had previously owned a Raptor 50 nitro, but sold it away as i didn’t have that much time to spend at the flying field due to my studies. Hence, i bought my first eRaptor, which was actually a E550 stretched to spin 600mm blades. Anyway, when I was in Hong Kong, i realized that Thundertiger raptor helicopters are not popular there. In fact, they are almost phased out as majority of the people there flies Align Trex helicopters. Thus, through the Hong Kong RC forums and by visiting the flying sites, I was able to get hold of a few remaining people with raptor spare parts. I manage to purchase a few hundred dollars with of spare parts from them, for a fraction of the price. With that, together with my trip to Taiwan (another RC shopping spree), i had enough parts (including blades!) to last me six to seven crashes.

Also, i had previously designed and CNC fabricated my own A123 compatible eRaptor frames, which looked pretty queer. Thus, during my 5 months in Hong Kong, I redesigned the frames and needed to try it out. Thus, this eRaptor build will be from scratch, and will only focus on the uniqueness of it compared to the standard TT E550/E620 stock kit.

First of all, here is the listing of the electronics and parts for this build.

eRaptor #2 Setup:

* Thundertiger E550 (stretched to 600mm)
* Custom designed and CNC’d lower G10 A123 compatible frames
* Metal head upgrades from www.xoluxionhobby.com (http://www.xoluxionhobby.com)
* Spartan 760 + Futaba BLS-251 tail servo
* Futaba S9255 on cyclics and pitch
* Castle creations HV85 on v3.10 firmware
* Turnigy BEC from www.hobbycity.com (http://www.hobbycity.com)
* Scorpion HK4035-500 Motor
* 15S1P A123 LiFe batteries
* 11T pinion (geared for a headspeed of around 2100)
* DSX9 as transmitter, just so that you will know :)

Spare parts I bought from Hong Kong and Taiwan

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0009.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0010_0.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0013_0.jpg

[genexis]

Lets start, CNC Frames

My frames were designed in Solidworks. After which, they are CAM'd in mastercamx and then the G-code is processed by MACH3. My CNC mill is a Sherline 5410 with lots of A2ZCNC upgrades. Basically, the only Sherline part left of it is just the motor, the spindle and the Z-axis column.

This is a picture of the prototype frames. Because the cost of G10 is pretty high in Singapore, i always do my test cuts using acrylic. I am able to increase the feedrate of the cutting as much as 100% when cutting acrylic. For this prototype, i used a feedrate of 200mm/min. The purpose of this prototype is to test fit the design to ensure that everything is what i designed to be.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0006.jpg

This is the final product. It is made with 2 mm G10 fibreglass sheet, CNC milled at a feedrate of 150, using a 2mm carbide endmill. The G10 sheet i bought is actually translucent green, as seen in the picture below.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0010.jpg

I sprayed the back of it with black spray to give it a darker color. Looks a little better, almost the color of the original E550 aluminum frames. Here are some views of it at different angles, and also a view of my work space :)

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0001.jpg

One new feature as compared to my previous frames is the inclusion of the new back plate. This is intended for mounting of the ESC at the back, to balance out the weight.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0002.jpg

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0003.jpg

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0004.jpg

[genexis]

Main rotor head

Once the frames are done, the next thing on the list is the main rotor head. I got my upgrades from www.xoluxionhobby.com (http://www.xoluxionhobby.com), which I have also been using them in my previous eRaptor. Despite being thunder tiger original upgrade clones, they performed flawlessly and were resistive to many crashes - all these at a fraction of the price. Thus for this build, I have decided to use them again, minus the main rotor grips which is really only a novelty.

I have intentions of carrying out the mixing levers modification on this build, but i had a design flaw in my previous attempt. I’ve currently decided to put that project on hold while i carry on with this one. But i’ll be back to finish it soon. As for the time being, i’ll just use the normal metal mixing levers, which works well also!

* Swash is the 140 degree eccpm from thunder tiger.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0007.jpg

A new tool which I purchase from HK. Gives me pretty precise duplications and adjustments of the linkages.
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0008.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0012.jpg

I’ve decided to omit the metal main rotor grips upgrade for this helicopter for the time being. I’ve already have one on stand by, but it will not be fitted on unless i feel that there is a safety reason due to the high headspeed. Other than that, the main rotor grips are probably just for show, and it is darn heavy.
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0047.jpg

[genexis]

Custom CNC Fins

One of my first few projects with my CNC mill was to make the vertical and horizontal fins for the Raptor. They are also made with 2mm G10, which has a natural translucent green. Here are some pictures of the fins and tail servo mount i made previously. I intend to spray them luminous orange or yellow over the weekend to fit the color theme of my canopy.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0024.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0023.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0021.jpg

[genexis]

Motor Setup

One of the reasons that motivated me to fix up another eRaptor was because I was keen in trying the up and coming HK4035 Scorpion motor. Prior to the release of this motor, there has been many threads and posts that exclaims the success of this brand. According to the feedback from users who posted their experience on RCgroups, the power of this motor is as good as the NEUMOTORs (www.neumotors (http://www.neumotors)) but at a fraction of the price (I am currently a owner of a Neumotor 1912/1.5Y which is running on my other eRaptor, and there is no lack in power. However, the biggest issue is heat). On top of that, the support of this brand has been excellent on RCGroups, thus i am convinced that i’ll be a satisfied owner of a Scorpion motor.

When the 4035 was designed, it was meant for the 700 class electric helicopters such as the IonX2,eStratus and Joker2 in which 690mm or longer blades are used. However, for my setup, my HK4035 is only required to spin 600mm blades, which in a way seems to be an overkill. I had a few concerns with regards to the usage of the motor for 600 size helicopters, of which one of them is the flight time. I was under the impression a 3500W motor would be drawing tons of power, hence my flight time on a 15S A123 setup will be greatly affected (Currently, i am able to get around 7 mins of sports flying on the NEU 1912). However, when i asked Georges (owner of Scorpion systems, whom i happen to meet when i was in HK), he explained that by spinning the 600mm blades instead of the 690mm ones, the flight time would probably be the same as the load on the motor would be much lesser than expected.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/2008_05240060.jpg

Another concern of mine is the availability of 6mm inner diameter pinions. For my setup, I needed a 11T mod 1 pinion to achieve a headspeed of 2000-2200 at 70-80% throttle, and up till now, I am still not able to find one. However, I was told that www.arkinnovations.com (http://www.arkinnovations.com) (direct link) carries replacement shafts for the 4035 series, that will change the 6mm shaft to a 5mm one, which will solve the problem of pinions. However, there has been reports by early users of this motor that the 5mm shaft breaks easily in flight! This is a real concern, but I am willing to take a gamble since the motor will be used on a 600 size helicopter instead of the 700 size helicopters, which supposedly means less load on the motor. On the side note, Scorpion motors is suppose to manufacture some 6mm inner diameter pinions for the market, but it has yet to be announced and released.

Replacement of the shaft requires a few simple steps:
1) Remove the C-clip which is found at the front of the shaft, remember not to misplace the golden ring
2) Remove the two grub screws at the back of the shaft. You need a long allen key for it
3) Lightly tap the shaft out from the motor case (left of picture)
4) Replace the shaft and put everything back in reverse order.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0013.jpg

HK4035 with 5mm replacement shaft
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0016.jpg

The next thing was to enlarge the holes of the mounting plate that is used in the E620/E550 raptor kit. The mounting holes are meant for 3mm cap screws, but the HK4035 being a 700 size motor uses 4mm screws. Nothing too difficult, just redrill the holes with a 4mm drill bit and a bench press (i used my mill).

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0033.jpg

For the pinion, i had a 11T thunder tiger stock pinion lying around, hence i decided to use it. However, despite pushing the pinion all the way till the end, I was not able to get it to get it to align perfectly with the main gear. The difference is about 1mm, as seen in the picture below. I guess a new pinion will solve this problem, but I think it is not too critical for the time being.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0041.jpg

I’ve also decided to mount my motor on the reverse side of the mounting plate. I am doing this as i hope to improve air flow as the reverse side of the mounting plate is hollow, hence more air will be flow through the motor when it spins. I’m not sure if this is going to help, but according to a post in RCgroups, there was supposedly some changes made to the newer versions of HK4035 that enlarges the air intake holes (or output holes) to improve air flow. More information about the change in design can be found on this thread.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0035.jpg

Thats about all the modifications I made before mounting the motor onto the helicopter. There isn’t a need to enlarge the frames of the eRaptor as it fits fine. Although it is a little difficult to see in the two pictures below, but there is actually a gap of about 1mm between the motor and the sides of the frame. Hence, the Scorpion HK4035 fits the E620/E550 raptor frames well.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0042.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0044.jpg

[genexis]

Electronics Setup

This section will cover the choice of Servos, ESC, BEC and Gyro.

Servos

For the selection of servos, I zoomed down my choices to the following three servos: Futaba BLS-451, Futaba 9255 or the JR 8717. I'll personally think that the BLS-451 and the JR 8717 would be a higher end, mainly because of pricing. I did quite a bit of reading up from RR and RCG and i'll summarize them as follows:

BLS-451:
http://static.rcgroups.com/forums/attachments/2/7/4/6/t1533657-202-thumb-futm0552.jpg
* Coreless motors
* Impressive specifications (4.8V: 118 oz./in., 0.13 sec; 6V: 147 oz./in., 0.10 sec)
* NOT made specifically for helicopter
* Expensive replacement gears
* Relatively higher AMPS draw, hence need a more expensive BEC
* Expensive

JR 8717:
http://www.jrradios.com/ProdInfo/JRP/100/JRPS8717-100.jpg
* Supposedly top of the range helicopter servo as of then
* Super impressive specifications that can take up to 8V INPUT!
* Very high AMPS draw reported by users of it, so bad that CC has to make an announcement that their BEC may not be suitable for it
* Relative affordable replacement gears
* Expensive

Futaba 9255:
http://www.futaba-rc.com/servos/futm0225.jpg

* Much more affordable compared to the rest
* Specifications though not as impressive as the newer range of servos, but they sufficient for almost any 50 to 90 size helicopters
* Tested and proven servos that has awesome reviews and feedback from users of it. Tested to be able to center after long usage of it.
* Very affordable servo replacement gears and case
* Again … it is a proven solution, a higher end version of the well known Futaba 9252 servos.

Eventually, I decided to go for the Futaba S9255 for my cyclics because of the price. I do not need that high performance servos for my type of flying. Compared to Hitec 6985 servos which I am currently using on my other eRaptor, these 9255s has a much better feel and response.

Picture of the wiring of the servos after they are mounted.
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0071.jpg

ESC - Electronic Speed Controller

For the selection of ESCs, I zoomed down my selection to: Castle creations HV85, Kontronik JIVE HV and the Scorpion 12S ESC. There really isn’t much of a choice for ESCs because there aren’t a lot of manufactures that produce ESC which can take an input up to 15S A123 or 12S Lipo. I have been a fan of castle creations ESC since the day I started with E-helis. Despite the numerous complains and *****ing about their firmware and product, I personally didn’t have much major issues with them. Although the firmware 1.55 aand 1.56beta gave me serious issues with the governor mode, but i was able to get a good governor called the eMultigov. But for users who are thinking if they should purchase the CC ESC, my answer is YES. This is because the I have tested the newest firmware version 2.0 that was recently released by the castle creations development team and the results have been very good so far. I’ll post more about this, with an included video at the end of this build log. Stay tuned :)

ESC mounted at the back of the custom A123 frames

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0066.jpg

Castle creations HV 85 version 2.0 firmware settings for 15S A123, Scorpion HK4035-500

Will post this in a while…

BEC - Battery Eliminator Circuit

Although there are many choices of BECs in the market, but this is one component I didn’t really want to splurge on. There are many high end BECs such as the Arizona regulator and the SGP Reactor-X that looks really cool and performs well. However, I was looking for something within the US$20 to US$30 range that has a soft switch. This switch is a requirement because I didn’t like the idea of plugging in the receiver pack into the BEC, fit the canopy on and bring the helicopter into the launch pad. I’ll very much prefer to power on the helicopter AT the launch pad with a flick of a switch (and of course connecting the main battery packs). On the whole, it is for convenience. For those who has never tried having a switch that powers the receiver, TRY IT!

For this project, I have decided to give the Turnigy 8-15A UBEC a try. Some features of this BEC:

* External soft switch
* LED Indicators (4 of them) to indicate the Lipo battery capacity
* 2 - 3 Lipo input
* Switching 5V or 5.9V output regulation
* Two output connectors of the same voltage, but there is a 6 to 5 volt step down harness that comes along with the BEC. This way, you can run 6 volts on one of the outputs and 5 on the other.
* NOTE: 5V output actually 5.3 volts. 6V output is 5.9V
* Two ferrite rings to reduce the glitches

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0064.jpg

Gyro

I didn’t even have to think much about this. It is either the GY611 + BLS251, or the Spartan DS760 + BLS251 Combo. I went for the Spartan due to the superb response from the forum thread at HF and RCG. Besides, Finless @ Helifreak has an awesome video on how to set it up and lots of tips regarding it.

Since I’m using the DSX9, also known as the X9309 in the US, the gain channel is set to AUX2. This way, I can control the gain of it from the gyro settings menu. One thing to take note is that in the gyro sensitivity menu, anything below 50% will result the gyro in behaving in rate mode. Anything above 50% will be AVCS (head holding) mode. Thus, for a gain of 37%, my gyro gain in my transmitter needs to be set at 69%.

Calculation: Let X = setting for TX gyro gain

37% gyro gain = (X-50) / (100 - 50) x 100% ; X = 68.5

I’ll be using the Futaba BLS-251 digital servo for my tail. This is the next “legendary” tail servo for helicopters after the futaba 9256.

Picture of the wiring and the tail servo mounted on my custom CNC mount:
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/thumbs/thumbs_dscf0063.jpg

For tail pitch slider setup, it is advised by raptortechnique.com to mechnically adjust the tail servo position such that when the servo horn is 90 degrees to the tail rod, there is a spacing of 4.5mm between the slider to the tail hub. The picture below is taken from www.raptortechnique.com. Visit this site for some detailed information.

http://www.raptortechnique.com/images/tailpitch.jpg

The correct method to adjust your tail slider is to hover the helicopter in RATE mode and mechanically adjust the servo’s position until the helicopter’s tail is stable. Once this is done secure the tail servo in that position and turn on head holding mode. This is VERY important and crucial as it will solve the problem of tail running when punching up the helicopter. This is tested and verified to work by me.

Swash Leveling

Once the servos and linkages are adjusted and work, the next step is to fine tune the swash travel such that the swash is always leveled at the 0%, 50% and 100% pitch position. This can be done by using tools such as the swash leveler which can be purchased from www.readyheli.com. However, most of the swash levelers in the market is for 120 degree eCCPM swashes such as the Align Trex series. Thus, i bought the swash level from Trueblood Engineering and made a additional plate to be attached to the bottom so that it can be used for both the eRaptor’s 90 degrees swash and 140 degree swash. For this setup, it will be used for the 140 degree eCCPM swash.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0080.jpg
What it should be like at 0%,50%,100% pitch. All three points of the swash touches the swash level.
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0075.jpg

In the event that it is not, adjust the end point travel adjustment. The picture below shows that when the swash was at the 100% pitch position, one of the points of the swash was not touching the swash leveler.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0079.jpg

Finless @ Helifreak has an excellent video on how to resolve eCCPM interactions without using a swash level. It can be viewed here (http://video.helifreak.com/?subpath=finless/trex450&filename=CCPM_Part_2.wmv) .

[rotorhead58d]

:shock::shock::shock::shock::shock::shock::shock:: shock::shock::shock::shock::shock::shock::shock::s hock::shock::shock::shock::shock::shock::shock:

are you an engineering major? that is some heli. please post some video of that e monster fying. i would love to see it in action

[genexis]

Hi, thanks for the encouragement. I'm an engineering major, but i'm still in the course of attaining my degree. RC and CNC is my interest.

I'll post the video soon, but i'm not an extreme pilot. But the video will show that the new CC firmware works well on my setup. VERY WELL i mean.

[Gernejr]

Your ERaptor is looking sweet:thumbup: What does A123 15s = in lipos 10s/12s? Sounds like it will have all kinds of power! :wow2: Keep up the post.

[genexis]

Batteries

For this project, i’ll be using 15S1P A123 batteries. This will give me a nominal voltage of 49.5V, which is more than a 12S Lipo setup. However, A123 batteries delivers less punch when compared to Lipo batteries, hence the increase in voltage will help make up for the lack in punch.

I’ve gotten my cells from ebay at around US$9 per cell at that time. They came from the Dewalt DC9360 battery packs where I have to tear it down to retrieve the cells in there. Each DC9360 Dewalt battery pack consists of 10 pieces of A123 cells.

When the cells are separated, I used sand paper to roughen up the surface of the terminals. This will also clean any dirt off the surface, for the solder to stick on it easily.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0107.jpg

Next, I used a cotton bud to spread some Aluminum soldering flux on the surface. I got my ALU Solder flux from a brand called “Solder-it”. It can be found in many online RC Stores.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0108.jpg

Next is to use a 100 watt soldering iron to tin the surface of the terminal. Takes a bit of skills and practice to get it done properly.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0090.jpg

Repeat the above steps for all the other cells. For this battery pack, i have decided to do away with the paper wrapping and replace it with heat shrink. No particular reasons, but i just that it may save some weight and allows the packs to slide into my custom A123 lower frames more easily.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0093.jpg

The next step is to solder the cells together to form a 8S1P and 7S1P pack. Also, I had to solder the balancing tabs for it. Many people have argued that A123s requires no balancing, however i beg to differ as I have seen some of my cells go out of balance after around 30 cycles. Thus, balancing does help.

This is the way I attach the balancing wires onto the molex connector. First i strip the end of the wire and bend it down.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0094.jpg

Next, i’ll crimp the wire to the molex connector. I’ve done it this way because it is gives a much better and firm contact between the molex connector and the bare part of the wire.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0099.jpg

And finally assembly of the pack. The below picture the wiring diagram for a 8S standing pack. It is configured to use for the Hyperion 12S charger and two LBA10 balancers

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/thumbs/thumbs_8sdiagrambalancer.jpg
http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0104.jpg

Lastly, shrink wrap the pack. I used two layers of shrink wrap for extra protection as from my past experience, sliding the pack in and out of the A123 compatible lower frame tends to cause some wear on the outer layer of the heat shrink.

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0114.jpg

And its completed!

[Gernejr]

Man you are doing a he!! of a job . I love to see it fly.:noteworthy:noteworthy

[genexis]

Hi, its actually already posted here:

http://simplewords.genexis.net/?page_id=636

Just yet to update the forums.

[genexis]

Flight test

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0082.jpgWith the kit and electronics installed, its time for a test flight. I was very eager to try out the HV85 ESC new firmware as the features are fantastic. For simplicity, i’ll be using the “Set RPM Governor mode” as I didn’t need to have a friend to tach my headspeed as i set it up.
Castle Creations HV 85 settings for Scorpion HK4035-500 “Set RPM Mode”:


Pole count = 10
Main gear = 111T
Pinion = 11T
Nominal battery voltage = 49.5V (15S A123)
Motor Kv = 500
Governor gain = medium
Headspeed change = medium
spool up rate = medium
PWM = 12Hz
Normal headspeed = 1900
Idle1 = 2100
Idle2 = 2200

DSX9 settings:


Normal: 0 30 30 30 30
Idle1: 70 70 70 70 70
Idle2: 100 100 100 100 100
End points - High: 100%; Low: 115%

Like all other feedback from the users of the new firmware, the new CC firmware delivers an excellent initial spool up. There is significant improvement from the previous 1.56 beta firmware, and simply looking and listening to the smoothness of the spool up puts a smile on my face.


Normal mode
As the headspeed reaches the targeted RPM (1900 for normal mode), there was a sudden burst of over speeding for a second or two. However, it quickly settled down to around 1880, not too far from the target of 1900, not perfect but acceptable in my opinion. As the helicopter lifts off, I noticed the tail being a little twitchy (high frequency small wags) and tends to sway to the right when i did a punch up. It seemed as though the ESC was not able to keep the headspeed when the load changes.


Idle 1
When I switched to idle1, the headspeed increased to about 2080, again not perfect but acceptable. In idle1, the tail was locked and didn’t show any signs of wagging or occasional kicks (as seen in previous firmware). In that mode, I did multiple punch ups and fast forward flights and tail held very very well. This can be seen from the video at the bottom of this post.


Idle 2
Being happy with the flight characteristics when in idle1, i thought of increasing the headspeed further more. I flicked the idle2 switch and but somehow I did not hear the sound of the increased headspeed from 2100 to 2200. From the tach, the headspeed dropped from 2080 to 2070 (hovering)! Very weird! I landed the helicopter and checked my settings on my transmitter again - no errors! idle2 curve is a flat 100%. I spooled up again and tested with the same results. The next thing that came to me was that my battery pack was weak, and decided to try again with the next pack. However, even after changing to a fresh pack of 15S A123s, the results was the same. idle2 was broken for me. I makes me wondering if the ESC is already running at the maximum headspeed for my gear ratio.


Motor performance
The power delivered by the Scorpion 4035-500 was awesome. Despite being designed for a 700 class helicopter, i feel that it works just as well for a 600 class helicopter. The power was superb. The climbs were explosive, and all these was only at a positive pitch of 11. I am sure that if I was able to increase my pitch to 13 or 14 (via Kasama or mixing lever mod (http://simplewords.genexis.net/?p=628)), the performance would be even better!


Flight time
I was able to get a 7 minutes of sports flying from my setup, almost the same when I used the NEUMOTOR 1912/1.5Y. During charging, I was putting back about 2100+ mah to the packs (A123 is 2300mah). One huge improvement from the NEU motor is the sound generated when it flies. The Scorpion is surprisingly silent compared to the NEU 1912/1.5Y. Power wise, they are about the same for my setup.
Anyway, although the idle2 did not work out as planned, I was pretty satisfied with idle1 and the overall performances of the Scorpion HK4035-500. In the next flights, I’ll try to make some changes to the pinions and settings to see if i can get idle2 working. After which i’ll try a little more on the new auto-rotation function.


Here is the video as promised:

Download link right click save (http://simplewords.genexis.net/wp-content/uploads/cchv84_firmware2-0_test/cchv85_firmware2-0_test.wmv)

[genexis]

Final words and conclusion

This project has been a great success. The design of the frame performed exactly the way i expected it to, and I’ve already started to pen down some minor changes which I can make to it to further enhance its capabilities.


Some final pictures:

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0081.jpg

Side view with my old 15S A123 packs (yellow shrink wrap)

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0085.jpg
Bottom view. The stock TT canopy clips firmly onto the landing skids!

http://simplewords.genexis.net/wp-content/gallery/rc-eraptor-build-log/dscf0086.jpg

On the side note, I think that castle creations have done a fantastic job for this release of the firmware. Despite a lot of flaming and complains from users who are not able to get the ESC to work as they expect it, I was lucky and I didn’t have this problem. Just for information, I bought my ESC from a forum member in RCG, and it has the date “Jan08″ stuck on the back of the ESC.

This has been a very satisfying project and fantastic results. Now that it is over, I’ll be spending more time on flying and not taking pictures and documenting. However, i’ll be happy to share my experience with anybody who is interested. I hope the readers have enjoyed this build as much as I have writing it.