Category Archives: Radio Control

Helicopters, Radio Control

Sometimes it seems you can’t catch up. More Madhawk300 frustration.

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So, the replacement blades are just about here for the MadHawk300 FP heli. Awesome. Except, yesterday the dang thing flipped out, suddenly went to full throttle while I was getting ready to swap out the batteries.

It did the ‘Chicken Dance’ on the park bench, snapping off parts the tail rotor. Radio throttle response did not help, it idled down and was just sitting there vibrating wildly (due to broken tail rotor). Carefully reaching under I unplugged the battery.

Swapped the new battery in, got the TX and RX talking to each other… but what now? No throttle!

So, I now have two shattered main blades (replacements arriving today), broken tail rotor ($4.00 which I’d have to mail-order) and now.. neither motor is spooling up!

On the workbench this morning I checked the motors and radio. Seems the RX is no longer sending voltage signals to the motors. Great… why did it do that? Well, a good 6 channel DSM2 receives is about $35 so I checked on the price to replace this thing.

WTH?? Really? $50?!?!

ExceedRC RX2423 replacement cost.

Oh come on now! Worth $15, maybe. Ugh.. more parts. At this point I’m chasing my tail on this thing. It was only $100 new, and 1/2 of the price for the receiver? Might as well just buy a new one and use this for parts! Honestly, I liked the way it few, it was fun, docile and a good trainer, even if the range was HORRIBLE, which I thought maybe I’d fixed by moving the receiver further from motor.. but.. it freaked out and crashed before I could range test.

I’ve read many people doing upgrades to make the thing really reliable. Sounds interesting for certain! But.. then, why toss more good money after bad? Shouldn’t I just chalk this up to some good training and park the thing?

I mean.. for the price of the MadHawk300 I could have bought a EXI-450 AND TX/RX for about the same price!

Then I could get replacement parts locally. Now.. the above also needs:
– motor
– rotor blades
– ESC (electronic speed control)
– Li-Po battery

But it’s also easily upgradable.. with stuff like this, a full CNC rotor head and tail, plus some spare blades:

Or, as my final plan for the EXI-450 I’m waiting for, a scale rotor head:

Sweet 4-blade flybarless scale rotor head.

Update: 9-June-2010 — EXI-450 is here!

And of course you can get really nice scale bodies very inexpensively for the 450’s, especially when compared to the proprietary bodies for other cheaper birds. Here is a short like from just one online retailer:

Factor in cheap proprietary electronics, motors that notoriously fail (tail motors) parts that are not available in any local store, batteries that are a strange size… and you have an exercise in frustration as soon as you run into a snag. And even if you are an expert flyer, you’ll run into a mechanical failure, or electronic failure and voila.. the questions about WTF have you done begin.

So, I’m really REALLY looking foward to the arrival of the EXI-450 kit this week. I’m really bummed that I have nothing to fly right now. 🙁 But at least with the 450 if I break something I *can* get a local replacement part!

Conclusion:
Would I buy a MadHawk300 or Walkera 180x bird again. NO!. I was warned about quality early on, and I chose to ignore that advice of one vocal expert, compared to the many voices singing it’s praises. Well, guess who was right?

Will I fix it at some point? Maybe. But certainly NOT with factory parts. I might turn it into a learning experiment to see what I *can* do with it. But… to what end? I don’t know. The $$$ is better spent on a 450 or 600 class bird instead of patching together what is not basically an expensive paper weight.

Upside, if there is one, is that the radio that came with it might be able to be used as a simulator controller with a $10 cable. 🙂 Maybe I’ll pick one up on the way to work and see what happens.

Helicopters, Radio Control

Documenting research on 450 vs. 500 vs. 600 heli costs

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I clearly need to get starting on the construction of my first collective pitch RC heli. The only question is, WHAT size to buy? I’ve done a lot of reading, talking to people who fly them a lot.. and I’m leaning very heavily to going with a 500 instead of the typical 450. Or, I might just bite the bullet and go with a big 600 electric.

While I research this, I thought it would be wise to document that things I learned, not only for myself, but for anyone else that might be interested.

Electric R/C Helicopter Notes
  450 class 500 class 600 class
Battery Cells / Voltage: 3 cell / 11.1v 6 cell 7 cell
Rate / Capacity:   25C ~2300mAh  
Battery Avg. Cost $30 $120 $180
Speed Control
(ESC)		   70-100 amp  

DECISION! – Buying the 450-EXI.

OK, decided. Finally decided. I certainly could have afforded any of the 500’s (or 600 clones) I’ve seen, but I’ve learned a cruel lesson of late, with the MadHawk300. Having local parts is critical to me having FUN!. Having to search and wait for parts stinks. Luckily the local shop has plenty of 450 parts. But they don’t carry 500 or 600 parts. That alone was the deciding factor.

So.. I ordered the following:

Order Number: 854679
———————
Quantity Item
1 GY48V headklock gyro
2 FRP main blade for electric 450 helicopter(335mm)
1 EXI Leveler 450/400 (Green)
1 30A Electronic Brushless ESC Speed Controller [Volcano Series]
1 Alpha 400 (3500kv) Brushless Motor
1 EXI 450 ARF Radio Remote Controlled Helicopter Kit (Plastic Version 2)
3 9g servo
1 9G EXI Digital Metal Gear Servo D213F
2 main blades (these are replacement blades for MadHawk 300)

So, the clock ticks down on the delivery, scheduled this week of my first ‘Grown-Up’ hobby heli. I debated the $30 more for a metal version (or $70 more for the CF), but I plan to crash this thing, and I suspect that most of the parts on this that I’d upgraded out of the box, I’ll be replacing due to crash damage. Why waste the money? Plus, in the long term I plane to buy a nice scale body for it, with a cool 4 or 5 blade scale head (they can be had for around $150), and if I *plan* to do that, then why burn $75 on a CNC aluminum setup that I plan to replace soon enough?

I hope I don’t chop off a limb learning to fly it! 🙂

Update: 9-June-2010 — EXI-450 is here!

Helicopters, Radio Control, YouTube

MadHawk300 hover practice, however I killed tail drive.

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OK, this is frustrating. 20 some odd flights and the thing’s rear motor is going out. There is a dead spot in it, so, somethings on a hard right yaw, the motor does not start back up and it spins into the ground, breaking… more stuff.

I did manage to get in some good practice on the day before though:
WATCH VIDEO: MadHawk 300 Hover Practice

So I’ve started to research updates to this rear drive issue, and the lack of power in the main motor (seems to be losing power, turning freer than it should.. seems like it cooked too, too much hover practice and not enough cooling airflow?).

At any rate, I found this info on the Walkera 180 (same heli, different brand name) that might get me a really sweet flying ‘learner’ heli for friends and family.

I got this info off the RCGroups forum [LINK]:

CB180Q Conversion to Brushless
8g Outrunner – brushless C10 (2S)- 180 Serie
Tail Gear Holder from Q for Brushless direkt drive
26g Outrunner -brushless C20 around 4000 KV
pinion 16 T(metal) Modul 0,3, hole 2,3mm
20A ESC for Main-Motor
12 A ESC for Tail-Motor
Gyro WK-016 Gyro 8g 4-6V

RX 2801PRO
TX 2801PRO
good Lipo around 1200 to 1500 mAh

Here is another thread [LINK] with similar solution. It might be overkill for what I want to do.

Another idea on 'fixing' the MadHawk300 shortcomings.

Helicopters, Radio Control

Blade CX3 nearly meets it’s demise – out of action

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Yesterday evening, was a great evening to fly. Not much wind, very very light rain and nobody at the ‘fly zone’ to accidentally kill. When you are unleashing an 8 year old piloting a P-51 Mustang model, these are things you need to consider. To be honest, he’s better at flying it than I am.

While the P-51 was zooming around the park, sometimes slamming into the ground nose first at full throttle (foamy planes are really good trainers) I took up the two Helis for some practice.

First up was the MadHawk300. The CX3 and Foamy P-51 are both bound to the same transmitter, so I could not fly the CX3 while the transmitter was in use. I’d done some tuning on it, adjusting the motor. The last failed flight attempt was dashed when on run-up the main pinion began to slip at 1/2 throttle, keeping the heli from getting off the ground. I’ve since lock-tited those motor motor screws.

It few well. Adjustments I made to the swash gave me some really nice control. At higher speed and throttle, helicopter flight dynamics are not at all intutive to a guy that’s used to fixed-wing models. But it still went well, with a couple of hard landings, no big deal.

Then, it happened. While at the east end of the part, close to one of the Pavilion buildings, the tail suddenly started to swing wildly, it accelerated upward, then nosed rolled right and slamed into the pavement at near full throttle, doing quite a number of the landing gear and main rotor blades.

Madhawk 300 with broken landing skid.

🙁 Nothing that was too tough to repair, but I didn’t have the wrench to replace the rotors on site.
Toasted main rotor blade on the Madhawk 300.

At this point the battery on the P-51 was running low. I recouped the transmitter and started to fly the CX3. It was flying very nicely. Nicer than the Madhawk in fact! Zoomed round the park, turned on and off the model navigation lights, did some high speed passes, landings, just some fun landing.

Then, it happened.

Right in the same place the MadHawk had trouble, the CX3 started to go crazy, and started to go into the TBE death spin. I tried to regain control but no luck. It accellerated upward, then nosed over and went straight down, nose first into the ground at full throttle. 15′ was more than enough room for it to gain some momentum.

CRUNCH. It was not a nice scene. The following photos are after I attempted a field repair on the fusalage to fly again. Unfortunately it would not happen since the radio and transceiver were no longer talking to each other.

Once home, I tore down the heli (I’m getting far too good at this) and discovered that the radio receiver took the full-force of the crash. Part of it’s case was ripped off and one of the dipole antennas was missing. Oh oh!

Helicopter on the operating table. Trying to get TX and RX to talk to each other

Removed the plugs from the Spektrum AR6100e receiver in the heli, plugged in the 3-in-1 mixer, checked response. The mixer would not show it’s green ‘lock’ signal. It was not until later that I noticed that the signal lock LED on the AR6100e’s front was actually missing. But it was at that point I realized, that not only was the body smashed, the lower section of the frame mounts for the battery are broken, but the receiver is, completely, shot. I’ve broken at lot of things crashing R/C aircraft, but never destroyed a receiver. It’s at this point I’m thankful for using Spektrum R/C equipment. Replacements are 1/2 that of Futaba or JR radios. Still, it’s a $55 part. Ugh. 🙁

Close up of AR6100e broken receiver (unmounted) and 3-function mixer (mounted)

I don’t want to order a replacement receiver unless I *know* that’s what is broken. So I dug up the AR56200 full-range receiver I have, wired it in to the heli’s remains, and tested. Viola. 3-in-1 mixer lock and receiver lock. It’s a go. Now I just need to decided where, and when, to buy a new receiver. In the mean time, she’s out of commission.

At least I still have the MadHawk300 to fly. And if I crash that into pieces, well.. I’ll just say I have a contingency plan arriving for that soon as well. ):

What's next!?!

Helicopters, Radio Control

Digging this MD500E Scale Helicopte vid

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Found this on the XHeli.com Facebook page. Love the sound of these things.

I’m anxiously awaiting the arrival of my EXI-450 from XHeli.com, hopefully in the next week! Then I’ll have to build it. Then learn to fly it. Then learn how to repair it after I crash. Eventually I want to add a body kit like this, and replace the stock plastic parts (ordered plastic on purpose, about 1/2 cost and I plan to replace it as noted) with one of these:

HAC 4 blade Rotorhead for 450 class Heli

Radio Control, Technology

R/C micro Li-Po batter charger testing

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It’s come to my attention, that the little battery chargers that came with the various helicopters, might not be working up to par. Taking longer than I want to charge is one thing, but not charging properly is another entirely! A recent visit to the hobby shops indicated that it’s common for them to fail. But, they should be easy enough to test to see if they are applying a full charge by the simple use of a multi-meter.

Thus, I dug up my trusty Fluke (it must be over 25 years old now), put in a new 9v battery and started some testing.

All batteries here are Lithium-Polymer (Li-Po) 2-cell 7.4v batteries. 2 of the batteries tested are for the Blade CX3, the other for the Madhawk 300. Here is a link to the chart I created to document the batteries I’ve used.

  E-Flite Battery Charger ExceedRD Battery Charger
Exceed-RC 7.4v 1000mAh 8.4v     8.4v    
Tenergy 7.4v 900mAh 8.43v     8.43v 8.43v  
E-Flite 7.4v 800mAh 8.43v 8.38v   8.43v 8.43v  
Hyperian VGX3 #1 8.43v          
Hyperian VGX3 #2       8.43v 8.43v 8.44v

Results

Testing so far indicates that the chargers, although slow, are doing the job. One battery, the E-Flite 800mAh seemed a little down on power during the 2nd cycle of the test. It might already be suffering some degradation of performance. If that’s the case, it’s pretty pathetic. I plan to run each through at least 3 charge cycles to get a decent dataset.

Helicopters, Radio Control

CX3 repaired and flying again!

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The Blade CX3 is repaired and flying again! The $22 aluminum swash plate repair, actually has the thing flying better than it did right out of the box!

E-Flight OEM Plastic Swashplate E-Flight Upgrade Aluminum Swashplate

Here is a 3 min video of first test flights in the studio, and finally my 8 year old attempting to fly it, for the first time, outside! The crosswind was playing havoc but he did a pretty good job of keeping things together. I think he’s going to be a good pilot some day.

Even though it’s a Toy Co-Axial helicopter (a $200 “toy” to be exact), with the upgraded part, it’s a joy to fly. There is something so therapeutic about an activity that puts nice big genuine smile on your face. And in the end, what price is too high a price to pay for some joy? 🙂 Even though I’ve “outgrown” this helicopter in about 1 week of intense practice, I still want to keep it around, and even put some more upgrades on it! Such as this cool LED strobe kit I’ve seen on the web. Here is a video from a guy that I think, sells the best of them:

Here are a few pics flying it outside, just before dark. Shot with an f2.8 200mm lens, 50D camera set at ISO1600 and roughly 1/30th second shutter speed. Despite the slow speed and high ISO, I think the shots are work posting.

Blade CX3 spooled up and ready for takeoff.

Blade CX3 spooled up and moving out. Still in ground effect.
Blade CX3 after battery change, ready to go again.
Blade CX3 in flight.
Blade CX3 flies overhead.
Radio Control

Factory batteries for R/C helis

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This is purely for my own reference, but if others find this useful, then enjoy.

E-Flight Blade CX3

Factory E-Flite Battery
Brand E-Flight
Type Li-Po
Voltage 7.4v
Current 800mAh
Cells 2 cells
C Rating unknown
Model # EFLB0990
Dimensions 70mm x 25mm x 11mm
Suitable Aftermarket Battery
Brand Tenergy
Type Li-Po
Voltage 7.4v
Current 900mAh
Cells 2 cells
C Rating 10C
Model # 31104
Dimensions 73mm x 25mm x 11mm

Exceed-RC MadHawk 300

Factory Battery for Madhawk300
Brand unknown
Type Li-Po
Voltage 7.4v
Current 1000mAh
Cells 2 cells
Model # n/a
C Rating unknown
Dimensions 61mm x 30mm x 15mm
Helicopters, Radio Control

Unpacking the Madhawk 300

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Unpacking the Exceed-RC MadHawk 300 heli was easy enough. It comes in a variety of body styles. If there is one thing I’ve learned int this hobby so far, I’m going to CRASH. So I went for the simple ‘Normal’ canopy style instead of the cooler looking full-bodied birds.

Madhawk 300 at XHeli.com

Closeup photos of the heli

The box.
Parts as packed. Typical Chinese blister pack maze.
Parts unpacked. Heli, radio, battery, charger, spare blades (yeah!), mini-tool.
Programmable 4-channel 2.5GHz transmitter that comes in kit.
300 class electric heli - Madhawk 300 'Normal Edition'
Extra blades, charger, power supply, LiPo battery, mini-tools.
Metal rotor head and swash plate. Impressive for such little money.
Metal swash plate, and shaft-drive tail motor w/ heat sink.
Gearbox drive 3-blade fixed pitch tail rotor (plastic)
Bottom view with battery bay. Low in body and near rotor shaft CL.
Side view of heli with laptop to show scale.

I dot not yet have any in-flight video of this to upload, but I’ll say this. WOW, it’s fun! Establishing your first full hover with the blades of death whirling violently around, is as cool! The blades also make that trademark ‘whoop whoop whoop’ any proper helicopter should. It just adds to the fun.

There is a lot to learn about handling helicopter physics, but I’m finding that the 300 class with training gear installed is EASIER TO LEARN than the smaller co-axial craft. And the price is just about the same (or about 1/2 that of the CX3 to be honest).

So, the advice I’d received from a few people, and read on a few other sites is RIGHT ON. If you really think you are going to get into this, just buy a decent Fixed-Pitch kit for $120, add the $8 training kit and learn. You’ll be happier in the long run. Less frustration from slow co-axial heli response, heavier so you can fly in our outdoors, and it’s probably going to be fun to fly for quite some time.

So, once I get my head-in hover fully mastered I should have a nice EXI-500 built and ready to go. The EXI-500 will be good for years. I’ve met a number of people who suggested going from the little trainer STRAIGHT to the Collective-Pitch 500 or larger birds. And as crazy as it sounds, right now, I think they are right.

For now though, I’ll keep learning on the Co-Axials and Fixed-Pitch helis littering the house. Weather is pretty nasty outside so having some good indoor fun is a bonus. One of the next ‘upgrades’ to the CX3, after I fix the swash plate issue, is going to be a cargo hook. 🙂

Helicopters, Radio Control

Good times, bad times, upgrading and crashing the CX3…

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Good times. The Blade CX3 is one heck of a fun bird to fly.

The first update today was to add the factory heat sink for the main motors.

E-Flite CX3 heat sink

After removing one of the motors, installing the sink was pretty simple.

Heat sink install 1/2 complete

Motor re-installed and bolted back into position:

Motor re-installed.

The fame looks a little naked without the body installed. But it does not take long to put it back together, and ready for flight.

E-flite CX3 with body removed.

A little time lapse video of re-assembly:

Ready to enjoy some indoor heli flying fun.

Completed bird, and Spektrum DX6i flight controller

Well, it was, until the plastic factory swash plate decided to separate. I’d been fighting with adjusting the swash links most of the evening, after putting the heli back together again. I thought that maybe I’d bent a servo link rod during the heat sink install, so I worked on adjusting the cyclic/swashplate links.

Trying to stop a hard forward and starboard liftoff, and full rear cyclic would barely have any effect. It was not until an hour or so later I noticed that the plate where the servos attach was separating from the bearing and main rotor shaft. Duh. This explains why 2 directions worked great (pushing up on the plate) but the opposites failed (pulling down on the plate, but the upper bearing remained in position, thus no control. No control, but one check of an exciting crash!

The official term for this is TBE (toilet-bowl effect). Not fun. There is quite a discussion of the problem HERE. Once I discovered the problem, it was a matter of deciding how to solve it. There are a couple of solutions.

First of which is a pretty inexpensive factory replacement part.

Stock replacement swash plate.

Second is one of the CNC or cast metal solutions from E-Flite (the original manufacture) or other sources. Research indicates that the E-Flite is the one to buy.

E-Flight aluminum replacement swash plate.

Fortunately, there are plenty of other heils in the shop ready to fly.

Blade CX3 (left), Exceed-RC Madhawk 300 (right)