Project V-Bar 130X

Everyone loves the 130X. It is a small, handy, and yet very powerful helicopter. Everyone loves the V-Bar. It is probably one of the best 3-axis systems on the market.

Wouldn’t it be nice to have both combined?

Voilà project V-Bar 130X.

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Building

The whole story started with an unused V-Bar and my summer holidays. A combination that sometimes leads to crazy ideas.

Stripping the V-Bar out of its housing is easy. Four screws on the bottom of the plastic housing will free the board.

A quick check at the 130X revealed: this is not going to fit instantly. It was more like: it wouldn’t fit at all.

I unscrewed the skids to spread open the fuselage. This gave me the needed space the slide the board right in. Upside-down, servo-connectors to the front seemed to be an actually pretty comfortable position.

The fuselage needed some work with a Dremel to access to the satellite ports and to make it close again, since the USB-port hits the frame on one side (still unsure if this thing was ever going to fly properly). I grabbed my Dremel and started to take some material off the frame. As a result, the V-Bar board fitted in the frame as if it was made for no other purpose.

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Next up: The receiver. It would for sure be a satellite, but a normal DSM2/X would be a little big for this heli. I remembered the Orange Satellite I had laying around for a couple of years. It’s smaller and lighter than an original stellite so it would probably do a great job in this little heli after reliably working in a T-Rex 250 and on the AccuRC simulator for a long time. Bye bye wireless simming, hello cool little heli! 🙂

Next thing between me and a 130X with Vergnugen(stabi) was the servos. Tiny E-Flite Plugs would not fit the 2,54mm (0,1 inch) pins used on the V-Bar for connecting “regular” servos. Pictures tell more than a 1000 words:

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IMG_2545Be careful once you pin the plugs out. I accidentally destroyed two of them by breaking the tiny little plug-holders when lifting them up with a knife..

All servos finally connected, there was still the need to fix the board. Four layers of Tesa Powerstrips (which I generally use for everything) are now holding the V-Bar well in place.

I went for a first setup, which literally took me 5 minutes. I just copied my Logo 600’s model memory and rebound it to the 130X. I love the V-Bar.

Seeing the new brain (nope, not the Brain FBL :P) working in the 130X for the first time was a pleasant feeling. It still needs a strong heart to pump some amps through the motors veins 😉

I had a Turnigy Plush 6A laying around which I accidentally ordered when I actually needed an 8A ESC. Quick test revealed: Nope. That won’t take this heli anywhere, the BEC is too weak (0.8A continous) plus I’m confident that a 6A ESC wouldn’t survive very long with me flying the heli.

Luckily, my friend Philipp borrowed me the Plush 12A ESC from his foam plane. We soldered it into the heli directly at the flying field, with all the long, heavy wires, I wanted to fly! First testrun revealed two things: 1. the rotor actually turned clockwise! Thank you Murphy! 🙂 2. The motor wouldn’t start up on it’s own. No matter how wide you open the throttle, you’d always end up with a hung start, resulting in the ESC getting extremely hot. (Any Bell 206 pilots out there? 😉 )

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Flying

I still fixed the ESC quick-and-dirty to finally get the heli airborne. I placed the heli on the ground, increasing the throttle to ~20% and turned the rotor by hand. This finally did the trick and the blades started turning. The moment of truth, would it fly?

Well, the heli wobbled like crazy and had close to no power but – it flew. What a feeling!

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At home again, i went over the setup. Essentially cranking up all sliders to their limits, reducing the gains. While charging the batteries, I stripped the ESC, took off all unnecessary wiring and fixed it to the frame nice and clean. With two charged batteries, I went into my garden to fly again, the V-Bar felt awesome now. The ESC still had massive problems with the HP08-2S, the heli was totally underpowered and required hand-starting.

I wouldn’t give up. Not now, not here. My clubmate and friend Marcus had a brushless mCPX whose ESC he flashed with the BLHeli firmware. We met up the next day, soldered an extra set of pins to the ESC and flashed BLHeli onto it. First startup test reminded me of a turbine. The rotor started smoothly, slowly ran up to a suitable rpm and then accelerated rather quickly to full headspeed.

That didn’t solve my power-problem though. We went outside and played around with the PWM and timing. After two batteries, in which we essentially doubled the power, it struck me like a lightning. I was so stupid.

This heli had no power because I’m running my Logos throttle curves. 70% flat. Changed it to 100-85-70-85-100, lifted off, smacked around, landed, slapped myself into the face. At least it’s working now. And it’s working good. a little too good if you ask me, my batteries are as good as dead. The following video was then made:

Conclusion

3 minutes of full power with almost dead batteries. Needless to say I already ordered 4 new ones. V-Bar feeling in a 130X. This is incredible. Battery voltage being independent of the mainboard. This opens up endless possibilities.

The final weight of the heli is incredible, without canopy and battery it’s at only 88g which is just 4g heavier than a stock 130X! AUW with custom Logo XXtreme canopy and mylipo 2s 360 batteries is 117g.

In the end, I would NOT say this is a necessary mod. The AS-3X works great and is lighter than V-Bar, ESC and satellite. The conversion is rather for people who want to get the maximum out of their 130X, want to go 3S or just have a V-Bar left. 😉

Maybe I’ll go 3s one day? Who knows. I’m already totally impressed with this little beast.

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