Want the latest in anti-drift MEMS sensor technology without breaking the bank? The ProModeler G720HV delivers Heading Lock (AVCS) sensor technology in a bullet-proof case . . . yeah, the case has been CNC-machined from a solid billet of 6061-T6 aircraft aluminum. Think of it as the ultimate in crash protection!
- Ultra compact design means the G74720MHV is suitable for helicopters ranging in size from 250 to 800-class
Another thing, while it works with old fashioned low voltage servos, the crew at ProModeler designed this gyro expressly for unregulated 2S LiPo battery packs. This makes it unique - you get a twofer - the lightning fast performance of HV servos and saving money because you won't need a separate voltage regulator. Moreover, while it accepts ordinary 1520µs digital tail rotor servos (and even old fashioned 70µs analog servos - yuk), to really get your money's worth, match it up with high frame rate (760µs/560Hz) super servo and experience the ultimate in high performance. Batches best with our ProModeler brushless motor S74120BLHV tail rotor super servo.
- Survival of the fittest - CNC machined 6061-T6 aluminum case for ultimate protection during a crash
Now you can learn to hover faster because heading lock mode keeps the tail of your helicopter from swinging wildly due to wind gusts, or sudden changes in throttle/collective. Later, when you take your model into forward flight, the remote gain function smoothly transitions the gyro for permitting you to perform blindingly quick flips as well as constant rate pirouettes.
- Dual modes, three types of servos . . . all from one gyro, and it's HV as well
In short, being great for learning doesn't mean the G74720MHV is going to hold you back when you're ready to learn 3D tricks because of the MEMS technology ensures both agility and stability in one. This means you can have your cake and eat it too, and with the greater survivability offered by the aluminum case during sometimes brutal crashes, there's one less thing to worry about. Plus, the highly polished aluminum case simply looks great, which as we all know is important when your friends crowd around casting an eyeball on your model.
- Nicely packaged too as the protective jewel case doubles as a product display
Measuring a bit less than one inch by one inch, and a mere half-inch thick, all while weighing about 1/2 an ounce, this superb MEMS gyroscope works with old fashioned NiCd battery packs as well as the latest in 2S lithium-chemistry receiver battery packs - without a voltage regulator - for the ultimate in high performance! Best of all, whether your budget forces you to repurpose an old fashioned analog tail rotor servo (1520µs/70Hz), or 1st-generation digital tail rotor servo (1520µs/330Hz), for the extracting all the G74720MHV can offer, pair it up with the latest in high speed super servos (760µs/560Hz). Versatile and with super high performance, the G74720MHV makes it easier to hover and learn to fly . . . without busting your budget.
- Dimensions and specifications of the G74720MHV Heading Hold gyroscope
Frequently Ask Questions
Q. Why are there 2 male plugs ends and 1 female plug end on the gyro? I know the female accepts the male plug lead from the tail servo, but what's with having two male plugs ends for the receiver?
A. Yes, the male plug on the servo lead plugs into the female plug end on the gyro. Next, the 3-wire male plug end from the gyro plugs in where the servo would ordinarily go to control rudder (tail rotor) at the receiver. The other male plug end (note, it only has 1-wire instead of 3 and it's red in color) is for the remote gain. This is also plugged into the receiver, but its purpose is to allow you to change gain between normal, and idle up 1 and 2 (perhaps called stunt mode depending on what brand of radio you fly) and usually plugs into channel 5. While the analogy ultimately breaks down, for now think of gyro gain as volume on your TV, so here goes . . .
Just as the television may be louder (more gain) while watching a football game with friends and quieter (less gain) when you're alone watching the news, the purpose of the remote gain is to let you switch between say, 65% gain in normal mode, to 40% in idle up 1 mode, down to perhaps 35% in idle up 2 mode. This is because there is less need for gyro gain when the model is in forward flight (using idle up 1) as compared to when you're hovering (using normal mode), and there's even less need for gain (holding power) while performing 3D-type aerobatics (typically using idle up 2).
Anyway, you'll fiddle with these values (the % gain) based on what the model does in flight . . . just as you raise or lower the volume on your television using the remote control. In this case, to change the volume (or gain) in flight, you raise or lower the % for each of the flight modes using your transmitter's programming section. Please refer to your specific radio system manual for details on how to do this with your particular radio system - but note, all brands and all models within brands work this exact way but the specifics of what they call the functions may vary, e.g. idle up 1 may be referred to as stunt mode 1, etc.
How does it work in practice? Well, if the tail twitches back and forth (characterized by a zoom-zoom-zoom sound, which is due to the tail blades fanning air as the system hunt) you reduce the gain a little bit and go fly the maneuver again. Repeat until it stops. If it's not hunting, raise the gain %. While the hunting is easy to see up close, if it's happening too far away to see in flight, then your ears are your partner for identifying what's going on (hence listening for the zoom-zoom-zoom sound). Anyway, if the tail is hunting, then simply reduce the gain until it stops however, just like you want the televison loud enough to hear clearly, the basic idea with gyro gain is to run as much of it as you can (louder) until the tail begins to hunts left-right, then lower it a little bit (quieter).
Q. What do you recommend for extending the gyro leads if they won't reach the receiver?
A. We advise using the shortest possible servo extensions, e.g. 4-6 inch (10-15cm) long for the P6. However, we urge you to be extremely careful about cheapo extension because what you want are really good quality gold-plated connectors. Unfortunately, cheapo extensions frequently are either not gold-plated, or use really, really thin plating (gold is expensive so you get what you pay for with low bidder extension, e.g. the gold plating is thinner). Since you cannot tell the difference by looking, we suggest buying from a reputable vendor. The point is; thin plating more readily wears off, which leads to corrosion, and possible subsequent loss of control - you've been warned! As an alternative to cheapo extensions from eBay or Amazon we advise visiting the hobby shop and paying for high quality extensions (however, because even hobby shops are prone to buying cheapo units to relabel with their store brand, be careful and stick to name-brand extensions only).