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

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!

MadHawk300 hover practice, however I killed tail drive.

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.

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

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!?!

Digging this MD500E Scale Helicopte vid

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