Category Archives: Radio Control

Radio Control

GT Power Supply – 600W 17V 36A

To supply power to my power hungry iCharger 3010b, I decided to invest in a power supply box which is able to handle the demands of the iCharger as well as be easy on my pocket. As such, I decided on the G.T. Power power supply box. It is able to deliver 17V, 36A and up to 600W! Heck.. my previous power supply was only able to handle 100W

Needless to say, I am happy with the performance of this box. It is able to provide constant power supply to my iCharger when charging at 5A on my 5000mAh 6S packs. Previously I was only able to push my iMax66 to only 2.2 to 2.5A (maximum of 50W). Of course if I wanted to go above 1C, I am theoretically able to push the icharger up to 23.8A which would mean I am charging at approx 4.7C. I wouldn’t want to try that although the thought of shortening down my charging time to effectively 12.7 minutes (from the original 2hrs) is indeed a nice thought. Of course figures will differ in real life situations.

The only drawback about this power supply is the fan noise. It’s quite noisy but then again it doesn’t really bother me that much and I have peace of mind knowing that the power supply is running cool at all times because of it. I would recommend this power supply to anyone who wishes to have a little bit more power to supply to their chargers.

G.T. Power 600W power supply, 17V, maximum 36 amp DC output, a simple Plug and Play power source. This power supply has an AC power input cable and two Pomona type DC output connectors. All the iChargers and GT Power B620 400W charger can be directly connected to the unit.

Parameters:
Input voltage : 100–240V AC (selected by switch)
Output power : 600W
Output ampage: 0-36 A
Output voltage : 17V DC
Dimensions (LxWxD) : 22.5 x 8.6 x 4.5 cm
Net Weight : 1.97 kg/ 4.4 lbs

 

iCharger 3010b – 1000W 30A charger

Have you ever stayed up waiting for your batteries to be fully charged? Or have you fallen asleep only to be awaken by the beeing of your charger informing you of a completed charge? After having waited many times for my batteries to charge… Up to 2 hours to balance charge my 5000 mAH 6S packs… I decided I needed more charging power since my iMax charger could only charge at a maximum of 2.2 amps or so for my larger packs. Although my power supply could pump out 100 odd watts or so, my iMax charger could only handle 50 watts hence the limiting factor. I wanted a charger which could charge my larger 5000 mAH packs at up to 5A at least (1 hr charge time)… Or better still allow me to parallel charge my 3 packs at 15A (also 1 hr).

Hence my purchase of the iCharger 3010b. This baby can charge up to 30A! What that means is that I can theoretically charge 6 x 5000 mAH packs in 1hr… Or charge my 3 packs at 30A in only 30 minutes! Now that’s what I call power.

After having used the charger for a few weeks now, I am glad I made the purchase. I like the usability of the unit, quietness (fan is quite quiet and only comes on when required), speediness and the features. One feature which I like is the ability to check the Internal Resistence of each individual cell in a pack. With that I am able to monitor and judge when the cell is degrading or requires replacement. Through some formulas and smart calculations, you can tell how much voltage the pack is able to generate and how much of the power is lost through heat generation (Resistence). The build of the charger is also very solid and I am sure it will last me quite a while… which is good thing since the charger ain’t exactly cheap…

Align Trex 550E 3G

Dec 2010, that’s when it was decided that I reward myself with a Trex 550E and boy has it been the best decision ever! Not only and I totally enjoying this chopper, it’s the best chopper I’ve flown in ages, not that I have that many choppers to boast about and not that I have choppers of this class or even bigger. My closest chopper to this size is my trusty Mini Titan 325 from Thunder Tiger.

So why do I enjoy this chopper like countless others who are also doing so? Basically it flies like a big bird (very stable), and it has tonnes of power available at your finger tips. When first building the heli, I opted for the advanced settings, i.e. Full 14/15 degrees pitch and 14 degrees cyclic. However after test flying the bird, I decided to tuned down the cyclic to 11/12 degrees coz it was simple too responsive for my liking. The FBL system also made the chopper really sensitive to cyclic inputs. Even so, I only fly in idle up 1 80% midpoint throttle coz I also fine the 90% midpoint throttle a little too sensitive with the increased headspeed.

Since mid January, I’ve had approximately close to 30 flights and each one with growing confidence. I’m not sure what it is but with the increased size, power, stability, precision and perhaps ease of flight with the 3G FBL system, I have bend able to learn maneuvers faster and try them out in real life instead of just trying them out on the simulator. It is no wonder why they say a well tuned helicopter is so important in speeding up the learning curve. I found that after flying the 550E, I have also increased my handling capability of my Trex 250 (which is inherently unstable esp due to lack of tail authority).

From the simple maneuvers of front and back flips, tictocs, loops, tail slides, rolls, stall turns, funnels and etc, I am currently able to have flight times of up to 8 minutes on a 5000 mAH 30C Turnigy pack. More conservatively I think I should dial down to 7.5 minutes to stay within and clear of the 80% battery consumption rule.

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Monster Beetle – 1/16 Brushless 4WD w/ 25Amp System

Monster Beetle 1/16

Just a few weeks back, I decided to order a Monster Beetle – 1/16 Brushless 4WD from HobbyKing coz it was relatively cheap and also coz it came with a 25Amp ESC (Electronic Speed Controller) with breaking and reversing function as well as a brushless motor. Since I already had an old and unused Futaba gun controller, I decided that for USD69.50, it would have been one of my cheaper RC purchases in a while. Heck it was even cheaper than the cost of 1 of my battery packs for my Trex 550E Chopper!

The kit arrived promptly after about 9 days or so in good condition. They basically turned over the box (inside out) and packed it with proper cushioning. Customs did not halt the package so I was really glad. Over the next day or so I fixed up the car by putting in my Receiver and Controller and immediately ran into my first problem… the ESC wouldn’t arm and the Steering was locked to one side whenever I plugged in the LiPo battery. The problem was however soon rectified as I found the problem to be with the transmitter. I had to reverse the servos (or reverse it back) and also perhaps switch the channels (from 1 to 2). I guess it’s been a while since I touched that radio. In anycase after doing all that, the ESC armed perfectly and full speed, breaking as well as reverse was achieved. Even the steering responded well and properly.

To fit in the Lipos which I had, I had to remove one side of the battery guide. That was easily done by removing the screws for the holder from the bottom of the car. After that, the packs went in easily and fit nice and snug.

When using the car with my old (>3-4 yrs old!) 3S 1500mah Flightpower pack, the ESC didn’t seem to hold up even though it was rated for 2-3S lipos which fit in perfectly. The ESC went into overheat protection only after 2-3 of running. However when running with the 2S Zippy Flightmax 2S1P 20C, the car ran fine without any problems. This pack was purchased from HobbyKing at ???http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6541&aff-56685 

The performance of this car is amazing. Though it is only 1/16 scale, it is pretty zippy for its size. Stock on 2S, it runs approx 40km/h. On 3S, it runs perhaps 60km/h? Whatever it is, its pretty zippy for such a small thing. You can use the car indoors as well as outdoors and with its adjustable camber, shocks, ride height, you can fine tune the car to your liking. I kept my ride height on the high side and shocks hard so a few tumbles happened during tight high speed turns. No damage though and the car body held up very well!

For those of you who has a spare controller and receiver, this is a recommended buy. At only USD69.50 (shipping not included), you get a lot of car for your money (ESC, Brushless Motor & etc). PICK UP your Monster Beetle today at http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=13449&aff=56685. Best purchase I’ve made in a while.

Have fun and drive safe! 😉

TRANSMITTER OPTIONS:

If you don’t have a spare transmitter, you can pick up a 2.4Ghz 3 Channel Radio cheaply at Hobby King at http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10608 for only USD15.99

If you prefer to have a slightly more powerful radio with more setting options, you can go for their HK-310 2.4Ghz radio from http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=12181&aff=56685 at only USD31.29

Trex-250 Tail Issue

There has been many posts and articles on the internet about the dreaded Tail Wag on the Trex-250 and even though I thought I had it fixed as stated in my old post, I was wrong as I recently found out when I finally had the time to try to trim & tune up the heli. On higher headspeed, the tail would “blow out” as soon as I pumped (increased or decrease) the pitch/throttle. Why was this happening? I guess firstly I am partly to blame for improper setup and Align is also to blame for their release of a less than troublefree helicopter. As mine was the first original super combos around and not the later SE versions, problems on the tail was bound to occur.

This time round I tried and rectified a few things. Here’s a note to myself and to you who might be interested as to what steps I have taken so far:

1) Decided to move back to the smaller DS420 servo since it was lighter and tried to eliminate the source of the tail issue rather than to over power it with a larger 520(?) servo.

2) Ensured that the servo was properly mounted on the right side of the boom clips to ensure that the “Pushrod” was straight from the servo horn to the guide to the tail control arm. My old servo location had a bend in the push rod. By having the pushrod bent and not straight, it led to an induced “flex” in the system whenever the servo tried to push the pushrod to the tail control arm. A stiffer pushrod will help even more here. Some people have switched to higher gauge wires or carbon fibre rods.

3) Reduced the Swash Mix from 60% for Aileron/Elevator/Pitch to approximately 50%. Will lower it to 45% if the problem persists. This is actually stated in the manual which I over looked. I guess too much pitch will definately overpower the gyro.

4) Bought & changed to new carbon fibre tail blades and installed them (No this didn’t seem to make a difference to the wag but then again it seems to create less “drag” as compared to the stock curved blades which I used.

5) Bought and changed to the new METAL Tail Control Arm which is much stiffer than the stock PLASTIC control arm which flexes under heavy load which again contributes to the delay and whipping action & tail wag.

6) I already have the new weighted tail blade holders & tail blade holder hub (which still led to the tail wag issue) and I also added additional weights (nut) to the tail blade screws. It helps with lessening the load but this is still not the only source of the problem.

With the above settings, I seem to have been able to increase the GYRO travel rate from +36 to about +50 (Head Holding Mode). This was with me holding the heli and reving up the motor (without the main blades of course). With the increase, I am sure the tail would have a little improvement. Will try to fly her this weekend and see if this is what’s needed to keep her steady as I do some pitch pumps. It’s a little unnerving when the tail is so soft and doesn’t hold well. That doesn’t allow you to do much on it apart from normal forward flights. Doesn’t help when I’m trying to get comfortable with backward flips.

Yak-55 with 3 Bladed 15×8 Prop

3 Blade EP Propeller 15×8 / 381x204mm

Just received my 3 bladed prop shipment today and I immediately tried it out on my Yak-55. I spent approx. 20-30 mins shaving 2 of the 3 blades to obtain a balanced blade since it ain’t perfect out of the factory.

I hooked up the WATTS UP meter and recorded the following readings. Specs as per below:

  1. SWANG 480Kv Brushless Motor + 80A 5A BEC ESC 158U
  2. RHINO Battery 3700mAH 5S1P 20C
  3. 3 Blade EP Propeller 15×8

Max Amp: 57.74
Wp: 1110.9
Wh: 1.5
Vm: 19.13

Specs look ok for the system so will test out the flying performance soon!

Align T-Rex 250 Tail Issue Fixed

I’ve managed to fix my tail wag issue on my T-Rex 250. Thought I’d share it with those of you who are looking for a solution.

I basically did the following:
1) I made my own “chinese weights” for the tail by using the nut ends of EZ Connectors and putting them through longer screws used to secure the tail blades. With the Nuts as added weight, it perfectly balanced the tennis raquet effect of the unweighted tail grips. After making adjustment, I was able to move the tail pitch slider (with or without the tail blades) easily without much force and when I let go of the pushrod, it would stay in place instead of move back to the center. The basically cures the high-torque needed to move the original tail slider due to design flaws.

2) I substituted the Align DS420 with a DS520 servo. I’m not sure if the 520 is needed after my fix above since I made the changes at the same time but the 520 definitely packs a bigger punch in terms of torque delivered to the tail slider.

As a result of the above changes, My GYRO Sensitivity which was previously at 60% is now up to 70%. I am probably also able to move it up to 75% without getting much wag but since I have changed my pinion from 15T to 16T now, I had to dial it back a little to prevent tail wag.

The Heli now feels locked in. I have yet to test full collective climb outs but I have a feeling the tail will hold this time round. Here’s to having more enjoyable flights rather than an expensive paper weight 🙂

I’ve also ordered a set of new tail grips from Align which comes with the counter weights. I’ll put them on to see if they perform as well as my mod but I doubt it since I’ve seen a video on YouTube which shows that the weights on the new tail grips are still not heavy enough to counter the tennis raquet effect. We shall see…

UPDATE – 4 July 2009 : I’ve installed the new tail grips from Align (which comes with the larger screw heads – thus new allen screwdriver is needed), and true enough, the weights on them does not make a big enough difference. As such I decided to put on my mod onto the tail which seems to even improve it more. Pls refer to the pictures below to see how I’ve done it.

Basically the new tail from Align and the weighted nuts did the job of curing the tail issue. When spooled up, I can move the tail freely with hand and if I leave it at any spot, it does not move or spring back to any position. Having said that, I’ve left the DS520 on the tail because that seems to deliver more power than the DS420 which in my opinion is a little on the weak side. Good Luck Guys

17 X 8 Turnigy Light Electric Propeller Specs

Turnigy Prop

Just managed to get my prop back from my friend today who got the hole enlarged to 8mm?!? Thank god for him coz I wouldn’t know how to get it drilled without having to bring it to a machine shop. Anyway I managed to hook up my WattsUp Meter to my Yak55 and got some readings off it. Specs as per below:

  1. SWANG 480Kv Brushless Motor + 80A 5A BEC ESC 158U
  2. RHINO Battery 3700mAH 5S1P 20C
  3. Turnigy 17×8 Light Electric propeller

Max Amp: 54.46
Wp: 1049

Just as a comparison from my previous post with a 16×10 prop:

  1. SWANG 480Kv Brushless Motor + 80A 5A BEC ESC 158U
  2. RHINO Battery 3700mAH 5S1P 20C
  3. TGS Sport 16×10E Precision propeller

Max Amp: 52.08
Wp: 923.3

From the looks of it… its not overdrawing any Amps for both the motor/esc & battery. The only problem is… there’s actually very little clearance of the prop from the ground. Especially hard not to scrape the tip on fields with loads of pebbles. Probably need to increase the wheel size perhaps 😉 Happy Flights all!

Align Trex 250 – Micro Heli with an attitude!

 

My latest addition to my fleet is Align’s newest micro helicopter, the TREX 250. This little baby captured my interest the first time I laid eyes on it… or rather the first time I laid eyes on the box. My next encounter with it was by reading an article on RC HELI magazine which featured the new comer. What got  me interested was that the combo kit came with almost everything that you would need to get this heli up and flying except for a radio, receiver and battery. Apart from those three items, it came with everything like its very own digital servos, 3 for the cyclics and 1 for the rudder and it also comes with a high quality gyro fit even for larger birds.

The build of this heli was done over a span of 2 weeks although I believe you can actually get it done in 1 night since most of the heli was already pre-built. I took my time because I had to order LIPO batteries for it. For those of you who are short sighted and have fat fingers, do be warned… the screws and parts are really really minute! Don’t drop any screws or you’ll spend the rest of the night looking for them! Having said that… the instructions that came with the kit was pretty well written and laid out. Oh might I also add the quality of this kit is unbelievably good with its machined metal heads, carbon fibre parts and basically smooth operations of the tail drive and all head linkages.

I have just managed to fly this baby last Thursday / Friday but found that the GWS receiver which I used was prone to interference (which almost cost me to lose the chopper a few times). I have since changed it to a ‘spare’ 8CH corona receiver which seems to be doing very well.

I was also hit by the dreaded tail wag issue when gain was only set at 51% (head-holding) or 49% (non-head hold). Needless to say, the tail held terribly. I was so sure that I used the correct ‘+’ (plus) shaped horn measured at 5mm but still I decided to try to change it to the ‘o’ shaped horn which seemed to have the mounting point just slightly closer to the center than the ‘+’ shaped horn. Unbelivably, that cured the problem! So if you guys are having tail wag problems, make sure you use the right horn with the Align DS420 servo and Gyro! 5mm is the magic number. you might even want to try 4mm if there’s such a mount point! My rates are not at 65% there abouts and the tail holds like a dream. I  have also set my gyro to have a delay of close to 100% since a 0% delay seemed to give me a slight wag. I think the servo might be a little too quick for the tail and gyro to keep up!

Alright that’s all I have to report for now. Btw I’m using a Zippy 1000 mAH battery that’s rated at 25C. It was a little tight for the canopy but that was cured by drilling two new holes just about 7 or 8 mm back from the original holes. The power is good but I will need to try some pitch pumps and see how well the power holds now that my tail wag problem is gone and that the tail holds rock steady!

Yak 55 Maiden Flight

After a period of slightly over 1  month, I finally managed to put all the needed parts together for my Yak-55. The maiden flight was successfully flown on 21 Feb 2009 under the watchful eye of my flying buddy who was well versed with the plane (seeing that he was the one who influenced us all and showed us how nice this plane flies). This plane is fully 3D capable and I hope to be able to execute some nice clean maneouvers in time to come.

Here are some pictures of my Yak-55, which is basically a 50 sized plane with the following specs:

  1. Wingspan – 58″
  2. Fuselage Length – 59″
  3. Wing area – 713 sq inches
  4. SWANG 480Kv Brushless Motor + 80A 5A BEC ESC 158U
  5. RHINO Battery 3700mAH 5S1P 20C
  6. TGS Sport 16x10E Precision propeller
  7. 4  x Align Digital Servos

Current Draw:

Amp Hours: 0.152 Ah
Max Amp: 52.08
Wp: 923.3

 

Forum Details at: http://www.rcbuddies.com/forum/index.php/topic,198.0.html