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Old 07-25-2009, 12:29 AM   #69 (permalink)
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Exclamation Phase 4 Build Log...... finally!

Okay…. Many, many apologies for the long wait. Sometimes helis actually have to take a back seat to life’s little variations!

But anyway, here goes. I by no means feel that my “definitive” build is the only way or that everything I’ve done is necessary to get the appropriate behavior from a Blade, but it is the culmination of a lot of trial and error and expense that isn’t necessary if you make the right choices. Hopefully, this may assist someone in making those choices.

If you have chosen a BladeCP(X) you’re going to face your first decision very soon; all are very sensitive and fragile. After a few crashes, you’re going need to determine if and how far you want to upgrade it. You can spend enough money to buy something considerably better before too long. Just make sure it’s worth it to you to get extreme on a Blade.

The Phase 4 BladeCP build details will pretty much cover frame up assembly, but I’m using a collection of pix to cover the history….. some, not so great; some promised a long time ago.

Phase 4
The Ultimate Goal: Optimize the performance, reliability and durability of an E-flite BladeCP.
The Actuality: Make the Blade survive me learning to fly it.
The Journey: Everything I replaced or upgraded was selected from personal experience, research and/or advise in regard to each event, failure or damage incurred as an end result.
The Quandary: After you replace this many parts, it’s arguably no longer an E-flite Blade. It’s more accurately a micro-heli using some E-flite parts. I guess this is another one of those decisions.

Early in, I started with a FlightTech aluminum frame. I had broken the stock frame in a mild crash and didn’t want to have to replace a frame again. The bonus here was the elimination of the stock landing gear. (Somebody wanted to see a pic of these…… they can be fabricated easily and fitted to the stock frame too)

After a few consults with FlightTech several other upgrades we’re added. The FlightTech Aluminum Head which I’ll talk about a bit later and the Century Hummingbird Autorotation Main Gear. (Century P/N: CNE-250) The base frame and the main gear can be seen in the first pic. You may notice that the main gear is fitted with a Freestyle Hobby pulley for the belted tail conversion…. But that’s a different project!!! The Auto-rotation gear does more for eliminating motor glitches affecting the mains than for auto-rotation landings, but it helps. It’s tough to set it down with no tail.

Almost immediately I found two flaws in the frame design. The servos mounted with Scotch Outdoor Double-sided Tape, provided in the frame kit….. this stuff is great! Holds like it's welded and comes off cleanly when necessary. I highly recommend it. The problem was that they were mounted to thin polycarbonate; even when tie-wrapped the servos moved significantly with control input. The other problem was the actual servo placement. Because of the main shaft mast design, the aileron servos were moved further outboard and slightly aft. The flexing caused control input to be even more sporadic and threw the geometry of the aileron control links way out.

The flexing problem seemed to be limited to the rear servos. I made a couple of 1/16” Carbon Fiber (CF) servo plates, which you can see in the picture. The plates are mounted to the frame at the mast and under the tail boom using four 1/8” I.D. CF tubes held by 1/8” x 1/8” Counter Sunk Pop Rivets expoxied into countersunk holes in the plates. This reduced the flexing and added strength to the mast. The CF strap was added to completely eliminate the remaining flexing and also shored up the CF anti-rotation rods for the swashplate. The flexing was gone, but the plates moved the servos out another 1/16 of an inch. This was a real problem with the stock radio….. enter the Futaba 7CHP and I could dial the geometry problem out with end points.

Also in the pictures, you’ll notice the E-flite S75 servos have been replaced with Hitec HS-55’s. Usually a bit cheaper, the HS-55’s seem to be much more durable. The Z-bend control links have been replaced by Align Trex450 linkage. The Align balls and links eliminate any slop between the servo and the swashplate. The servo arms still flex, but I’m working on that. After changing over to the new links, I was able to shift the balls to the flip side of the servo arms and move all three servos forward enough to make CG improvements too.
I also added some stock ball ends on spacers extending from the starboard side of the frame. The wiring for the Dean's antenna goes through an antenna tube, through the ends... removed from the frame and the servo wiring which is spiral wrapped and attached to the spacers.

After firming up the control side of things, I focused on making the whole core of the heli more rigid. I incorporated the Freestyle Hobby lower frame plate to the base frame using lightened aluminum angle. The lower frame is closer to the main frame than the stock battery tray, so I can squeeze the TP2100 in there……. One of those promised pix!! This also moves the vertical CG closer to the center of the whole assembly. Notice the direct access for replacing the main shaft. I’m using E-sky CP main shafts, which are a direct replacement. A stainless alternative is available from Microheli and shows great promise.

In addition to the brackets for the lower frame, I added mounts for the Rx and ESC (shielded from each other by the aluminum) and one for the Logictech 2100T Gyro at the rear of the frame. The Rx /ESC tray can be spaced forward from the frame as necessary to assist in CG adjustments. This is a very solid core for the heli. You’ll notice in the servo layout pix that the Rx tray spacing makes a nice place to run the motor leads. The only sacrifice thus far is weight. It is heavier, but the increase is less than you would think….. so far anyway. You can see the gyro tray and the mounted gyro, tucked in there nicely, in the pics further along.

My attention now went to the tail. I preferred to use a CF boom, because it’s more rigid and allowed no flexing in the boom, but I couldn’t fit the 3 wires for the brushless (BL) motor, so I went back to the aluminum boom. I decided to use TRex boom supports for the strength and looks. Custom brackets were made to handle the front side of the tail boom supports. Once in place, there was absolutely no flex in the frame assembly from front to rear or top to bottom. The other important aspect is that this assembly was completely independent of the landing gear. The only purpose the landing gear had was to hold the heli off of the ground……. no longer part of the battery tray! Dressed the struts with some CF tube for fun, fuel line on the skids and we’re good to go. I used HeliDirect tail fins, like the ones that come with the SuperSkids. 2mm screws and nuts were used to mount the fin and anchor the boom supports firmly on the rear side. A short length of fuel line was used to hold the fin bracket from sliding on the tail boom. You can see this in the pictures of the tail.

Next we’ll address power, since I’m saving the main rotor head for last. I’m using the E-flite Park370 4100Kv BL with a 10T pinion and Castle Creations Phoenix-25 ESC for the mains. The programmability of the Phoenix ESC’s lets you avoid most power issues, just like a programmable Tx can dial out and correct some physical problems….. like my servo placement. On the tail , I’ve got a CC Phoenix-10 driving a Medusa Research 12mm Afterburner 4000Kv BL motor with a GWS 3020 prop and adapter. I’ve got this mounted in the stock tail box bonded with the vertical fin. FYI….. the BL DD tail is the best solution short of installing some kind of variable pitch tail setup, belt driven or otherwise. The drawback is that the tail rotor actually spins the wrong way. Remember to Dremel out the front of the tail box….. you have to relieve it a bit to mount the motor correctly. Just round out the flat.

I’m actually co
nsidering a main motor change. I have a HDX300 sitting here and the NEU (Razor) RZ350 with the finned can is attractive too. Had these motors been available when I upgraded, I would NOT have the Park370!!! I’m going to keep playing with the ESC programming to get this thing to respond yet!!!!! (or I’m getting a NEU motor….snicker). BTW…..I’m using pinions for a HPI RS4 mini-truck. They’re held with setscrews rather than having an interference fit so changing pinions is a breeze.

The main power-battery connections are handled by Dean’s plugs. Tail ESC power with JST connectors. Be aware that in order to program the ESC’s with Castle Link, the power leads have to be disconnected. Also, make sure to remember to disable the BEC on the tail ESC. If you use a servo extension you can cut or pull the pin for the “red/+” wire on the extension rather on the ESC….makes it easier when it comes to programming. I also use a main power switch, despite the numerous opinions against it. On the Blade this isn’t too much of a concern due to the relatively low voltage and current draw. Things are just too tight to fuss with a main power connection and flipping the switch doesn’t mess with the gyro like bouncing the heli around after connecting wires!!

Now….. for the rotor head. If you don’t consider my little heli a Frankenstein creation, the head would most definitely qualify!!! The head consists of a FlightTech hub and button with the seesaw; A Microheli Flybar Frame, B&H Aluminum Blade Grips and hardened Feathering Shaft; HDX300 Flybar links; E-flite Swashplate and Dog Bones. If the E-flite Aluminum head would have been available I would have gone that route, but it wasn’t and since FlightTech is no more, would be my recommendation for a full head upgrade, should you desire to do so. Microheli makes a head and swashplate replacement also, but it needs some work to make it right as it tends to be sticky.

Here are the pieces-parts. There are a few hidden mods here…… The O-ring dampers were replaced with bearings. This makes cyclic and collective even more sensitive, but because it allows for more accurate cyclic and collective input this results in a more controllable bird…… IMHO! The head’s reaction to input has become very consistent. With that, exponential settings on the Tx can be easily be used to tame the heli’s behavior. The Flybar links had to be fitted with Blade Ball ends….. not a big deal, trim a screw and adjust overall length to match the stock ones.

The last of these mods is perhaps the most important……. After replacing the O-rings with the bearings, I noticed that the feathering shaft wasn’t quite flushing out with the bearings in the blade grips. Tightening the screw to hold the grip on would cause the grip bearing to bind and the screw would never tighten. To fix this I snagged an old (bent) stock feathering shaft and cut about a 3mm piece from each end with a small pipe cutter. I then threaded the spacer collar onto a sacrificial screw and filed and polished it to the appropriate length…… I’m pointing the collar out in the picture; done this way, it effectively lengthens the feathering shaft. (BTW…. I’ve found that the collar length is specific to the hub, grips and feathering shaft that you’re using) The collar allowed me to be able to place the race washers in the proper locations and tighten the feathering shaft screws properly.

I’ve been flying with ThunderPower 900 & 1320 mAh 12C packs. They are a couple of years old, but just don’t have the necessary punch; I think it’s the 12C part more than the age. The next step is probably a 20-30C 1000-1300 mAh packs. I’ll probably go with Zippy FlightMax, but still hashing it out….nice performance on my Rex with the Zippy’s.

As far as main blades are concerned, I usually fly E-sky CF blades. They’re expensive, but look really cool….. I love Carbon Fiber! If you really want it to scream, use the woodies. The E-flite sym blades are actually very good, but there are others out there cheaper with similar performance. (Check out Dieselracer’s and Buildem336’s Blade vids if you have doubts!!)

Throttle curves, pitch curves and ESC programming are typical. I set everything up mechanically like Finless outlines for the Trex450 build vids. (great stuff!!) I’m constantly working to improve these and I still have to check my head speed. I wanted to get the curves and programming tweaked first. I’ll post that info as soon as I get it!

That’s about it folks. Like I wrote, this may be a BladeCP, but I’m pretty sure it’s not an E-flite BladeCP anymore!!! The end result is a very well behaved, well-balanced, very responsive and very rugged 250 class micro heli, that’s almost like flying a rock on a string! I hope this was worth the wait and that my experiences and findings will help make some of your BladeCP decisions and choices a bit easier. After you work the bugs out, the 250 class helis make nice little flyers and remember, if you can fly a Blade, you can fly just about anything!

I know, the only thing missing is pix of the finished article....... The canopy is in the paint shop and I'm waiting for blades...... Soon as I have 'em I'll post 'em. Once I get it adjusted, I'll post head speeds, weight, etc. too. Have fun and happy flying!

Doug Bonham, WickedDragonRC
Gravity isn't just a good idea, it's the LAW!
TRex450SE DFC; TRex450Pro DFC; TRex500 DFC Pro; TRex600N DFC's; CHP-TRex600eDL DFC; Trex700e DFC Pro

Last edited by WickedDragon; 07-25-2009 at 07:17 PM..
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