JR FORZA 450

I’ve never had a 450. I’ve been flying for more than 4 years now, but without a 450. Apparently I kinda skipped that size. Or went around it. Or both. You always hear statements like “A 450 is the perfect heli to always have with you!” or “Try new stuff on your 450, it’ll forgive you!”  or..

“Everyone should have a 450.”

Well I never really believed those people. My usual companion-heli was the Blade 130 and I simply did new stuff on my LOGO, just 2 crashes high. Maybe I didn’t even want a 450. More batteries to look for, more stuff to carry around, one more heli to maintain.

Well, as you already might have guessed from the title of this article, this circumstance changed. And I’m happy it did. I got myself a 450.

The JR FORZA 450

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What’s in the box?

Opening the box reveals three boxes, containing the kit plus one foam-cutout-block with holes for the beautifully packaged, pre-assembled components such as the rotorhead  with swash, tail gearbox and the motor. You’ll also find various manuals which will guide you through the build, setup of the TAGS Flybarless system (I’ll be using a Mini VBar though) and the ESC programming. These boxes contain well sorted bags with parts for 6 clear and easy building steps.

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Step 1: Servos

The best comes for last. Wait no, on the FORZA the best kinda drags on throughout the whole build, starting off with the servo arms. These actually consist of a metal ring that bolts to the output gear of the servo. On that ring the actual arm is clamped then. Yepp, clamped, which means no angle increments and therefore precise centering and symmetric travel through the whole control way.

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!!! Don’t use loctite on the clamping screws yet, you’ll need them later.

The servos are then screwed to two plastic pieces, which also act as main shaft bearing blocks at the same time. The tail servo mounts straight to the frame.

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Step 2: Main frame assembly

Now the frame is put together. The servo unit we just built bolts to the frame, held by 5 screws on each side. Together with a few other parts, the first half of the frame is assembled quickly.

I recommend wiring your servos to your Flybarless right now. Now you have the chance to make the wiring virtually invisible!

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Shortly after that, the second Frame half is mounted, giving you a very rigid yet light frameset.

!!! Don’t use loctite on one side of the tail boom clamp screws yet, you need them later to clamp the boom into place 😉

 

Step 3: More parts for the frame!

The third step deals with main gear, battery tray and skids.

Mounting the main gear is pretty simple. Screw the belt pulley in, slide it into the frame, stick the main shaft through the bearings into the gear, put a bolt through, done. Then add a clamp on top to lock the main shaft into position. Make sure to leave no vertical play here.

Interesting: There is no one way bearing in the main gear. So how does this thing autorotate then? We’ll find out pretty soon 😉

The battery mount slides right into position and is locked in place with ten self-tapping screws. The skids are mounted to the bottom plate with only two self tapping screws, making them easily removable if an auto goes bad 😉

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Step 4: Rotor head

This is the point to level out your swash, using the supplied swash leveling gauge. Make your three linkages, snap them on, snap the gauge onto the main shaft, push the swash down, power up your FBL and center your servos, tighten the servo arm screws, done. Perfectly level 90° arm setup in basically no time.

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!!! Remember to use loctite on the clamping screws for the servos!

The rotor head is then clamped onto the main shaft. The head was pre-assembled and the spindle shaft didn’t unscrew under gentle application of torque, so I guess it’s perfectly secured and fine to install as it comes. Interestingly, the head utilizes plastic DFC arms, so not much mechanical stuff up there.

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Step 5: Tail installation

Even though the tail takes up four pages in the manual, the assembly “happened” so quickly I didn’t even snap a photo of everything. The whole thing is pretty much plug and play, the pre-mounted tail unit was, once again, perfectly loctited from the factory, so everything came together quickly.

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Once you’re holding the boom in your hands, slide it into the main frame and put the belt on the pulley. Check for correct rotation of the tail rotor, tension the belt and clamp it in.

!!! Use loctite on the clamping screws you didn’t secure before!

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Step 6: Electronics

Now  we come to installing the motor. And here we also find the solution to our missing one way bearing hub on the main gear: JR put the one way bearing into the pinion to save weight! That’s also where the installation differs a little from other helis. The pinion is simply slid onto the shaft. A pinion stopper clamp is then clamped onto the motor shaft right above it.

For setting your gear mesh you can simply use a strip of copy paper. This was my first time to actually use this method, it worked!

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Important: ESC installation!

This gave me headaches. Make sure to slide the ESC into the frame as far as possible, without hitting the pinion! Keep the battery wires as short as possible. In order to get the canopy on (still requires some persuasion), the whole front of the heli should basically be wire-free. Thank me later.

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A setup with a ~200g battery is slightly nose-heavy though, due to the missing tail boom cover on the 3s version. I assume that the CG will fit on the spot with the 450 EX tail boom cover.

Setting up the Flybarless controller:

When you’re using a VBar, you’ll notice that you’ll get pretty low values when setting your pitch. The reason for that is that JR used pretty slow servos (0.13s/60°) on long servo arms with high leverage ratios on the rotorhead. In fact, you can get 25° cyclic, over the whole collective range (I didn’t even measure that but it’s probably around +-30°). Don’t worry, the servos are extremely precise, you’ll get crisp 3D performance, even though they are slow.

Flying:

If I only had three words to describe flying the FORZA 450, they would be:

-Smooth

-Crisp

-Precise

If I was allowed to add more, they would be: agile, stable, fun! That basically sums it up. This heli flies stable like a way bigger chopper, while being super nimble and never running out of cyclic deflection. The 3s drive train is not exactly overpowered, but sufficient for most of the stuff the heli can do. 14° on the collective is way too much here, I never hit the stop while flying. 12° is what I’m flying now.

The heli was delivered with 325mm blades but can take up to 360mm. I guess I’ll do some experiments with longer blades pretty soon.

The only thing I noticed while flying is that sometimes when you bog the motor down, it wouldn’t recover the full RPM instantly. That’s not such a big deal though since you really have to mess up badly to bog it down to a point where this happens.

Sadly, I ran into some problems with the ESC. Short version is, the ESC could need some active freewheeling. I had it overheat pretty badly after doing some low rpm indoors. It apparently died from the excessive heat produced by freewheeling currents from the motor in partial load (low throttle setting). In that situation, the FETs in the ESC have to do a lot of on/off switching in order to reduce the motor rpm. The currents from the motor run back into the main circuit through a diode, which has a significant voltage-drop which results in generation of heat due to power-dissipation/loss. Active freewheeling would lead these currents back through a FET. They would still be able to flow, but with a minimum of power loss and therefore a minimum of temperature.

An update for pilots who want to fly that heli indoors, with indoor-capable headspeeds on 3s, might be needed here.

Anyway, this is what flying the FORZA looks like:

 

 

Conclusion

All in all, this heli’s price-to-fun ratio is extremely good 😉

Building the FORZA 450 is a dream. I’ve never had a kit that assembled that easily and precisely. Everything basically snapped into place seamlessly.

Setting up the FORZA 450 isn’t a big deal at all, clamped servo arms rock and wonderfully play together with the provided swash leveling gauge.

Flying the FORZA 450 is pure fun. The whole heli is made for taking everything you throw at it with ease, you can suck your batteries empty in a 3 minute smackdown session or just cruise around for 8 minutes on a low headspeed!

The only things I noticed are the tight fit of the standard canopy (keep them wires short!) , the whole heli being a little nose-heavy without the tail boom cover and the ESC which could maybe use an update with active freewheeling. This capability would greatly reduce the temperature generated in the ESC when running low throttle values.

All in all this heli is definitely worth getting it. From what I’ve seen so far, this is one of the highest quality 450 helis on the market and definitely worth a shot if you consider getting a new heli.

Well I guess I have found my new heli for trying new stuff and always having it with me… 😛