Before adding this servo to your cart, note it's a tail rotor servo only!
This mini-class 95oz-in servo is suitable for helicopter tail rotor applications only! This means neutral is 760µs instead of the 1520µs like servos, which function when connected directly to a receiver. Basically, a receiver's servo output sensitivity doesn't extend into the range at which this servo operates, so it only responds when connected to a gyro's output. So heads up before you order and later call whinging about it not working because we've warned you, eh? Meanwhile, take note; three things.
First, the label says 85oz-in instead of 95oz-in. This is because we made them based on 7.4V performance not realizing the industry was moving toward using BEC output of 8.4V as the measuring standard. Since we're too cheap to throw away perfectly good artwork and labeling, until we run out this is what you're going to get. But the servo is indeed 95oz-in when measured at 8.4V like our other servo (until we run out of labels).
Second, this is a mini-class, servo, but if your model requires a standard-class servo, then order an M2S adapter plate (https://www.promodeler.com/PDRSM2S), or our DS135BLHV standard-size tail rotor servo, instead.
Third, this servo has a standard size motor, which is why we window the case for it to fit. Point being, don't be fooled into thinking because we built it within a mini-size case it's less capable because you'd be mistaken. This servo is more powerful and as fast as competitor's standard-class offerings only being beaten by our own standard-size tail rotor servo. Seriously, this thing is strong enough for 700-class models!
As you look this servo over, one thing stands out. We've crammed a large BL-frame motor into an M-size case. This is why we machined slots in the case (expressly to let the larger motor hang out in the breeze). It means you can see the actual brushless motor after we slot the case to fit and CNC-machine a solid billet of 6061-T6 aircraft aluminum to include cooling fins. Slotting it is what lets the larger motor fit! Then we use 10 (ten) Allen head machine screws to secure the assembly together (instead of 4 like our competitors). We do this because it's more rigid for handling double the usual torque for a tail rotor servo. And this makes it more rigid than servos with fewer bolts (good because it keeps gear better aligned for longer wear and greater durability).
Hidden within are dual ball bearings. But instead of ABEC-3 bearings, you get ABEC-9
because ultra high precision bearings offer better performance. These cost a little more, and we tell you about this because we're proud of what
goes in your servo. of course, you also get metal gears. While the key to getting a servo's speed up is to use a lightweight hard anodized 7075 aluminum (25T) output gear, the balance of the gear train consists of steel gears for enhanced durability compared to an all-aluminum gear train as used by competitors. Added to which, our gears are wider
(thicker) than usual because increasing the surface area means greatly
reducing gear pressure, for improved wear characteristics.
Better servos. The formula is simple. Decisions regarding what go into
ProModeler servos aren't made in accounting to optimize price
and profit, but in engineering. The reasonable price
comes about because of a better business model that eschews the old way
of doing things (importer + distributor + hobby dealers) because they
all get a cut at your expense. With us you're smartly cutting out the
middlemen by dealing direct.
Note: operating voltage is
4.8-8.4V, but optimal performance is obtained with a 2S LiPo instead of a
BEC. This is because LiPos deliver the required current without
voltage spikes, noise, or otherwise adversely affecting the delicate
avionics (25C or better is recommended). After all, synthetic orange
colored Tang may have gone to the moon, but it doesn't compare to
freshly squeezed orange juice. Same thing when it comes to feeding your
For detailed specifications and dimension drawings, select the Specs tab above. Also, there's an even-handed look at the competition in the Comparison tab. Meanwhile, TL;DR
is chock full of nitty-gritty details so if you love delving deeply
into stuff some find too tedious to read, don't overlook this tab.
Note; if your gyro will function with a 1520μs servo, many pilots find our DS110CLHV
an attractive offering because it outputs 110 oz-in at an über speedy 0.035sec/60° (so it's fast enough for tail rotor use) but so versatile you can re-purpose it by plugging it into a receiver also.
These are mini-size servos with very small gears and operating
them manually via the servo horn may damage them. This damage is not
covered by warranty. Please do not treat these like a standard size
servos. You've been warned. Also, operating voltage is 4.8-8.4V, but
optimal performance is obtained with
a 2S LiPo instead of a BEC. This is because LiPos deliver the required
current without voltage spikes, noise, or otherwise adversely affecting
the delicate avionics (15C or better is recommended). After all,
synthetic orange colored Tang may have gone to the moon, but it doesn't
compare to freshly squeezed orange juice. Same thing when it comes to
feeding your avionics!
To begin, take note of the fact this is a brushless
servo. Lots of coreless servos look similar, but savvy modelers know
how brushless servos are different - and better! What's confusing is
they share nearly identical internal construction. In point of fact,
technically, the both are 'coreless' motors. This, as compared to the
workhorse of the industry - the FE-core 3-pole motor. The reason
coreless motors are preferred for high performance application is the
absence of an iron core, which means they accelerate faster. If you
compete, you know a faster servo is super important.
So what makes
the brushless motor different from the coreless motor if they both have
coreless-construction? One thing, it comes down to commutation, or how
they turn the electromagnets that make them spin, on-and-off. Basically,
a brushless motor has electronic instead of mechanical commutation.
Mechanical commutation depends on brushes. in the case of miniature
servo motors, the brushes are tiny little wires and they make and break
the magnetic fields as they jump the gap between windings as the motor
rotates. This technology is well over 100 years old. It's simple and
reliable - to a point.
Have you ever seen sparks when a motor is
run at night? What you're seeing as sparks are what's created as the
sharp edge of the brushes jump from field to field. They spark brightly
as they jump the gap just like an arc welder sparks when the electrode
makes contact with the surface being welded and current flows fast
enough to melt the wire. And just like an arc welder consumes the
electrode, over time minute bits of metal evaporate from the tips of the
brushes. The higher the current, the greater the wear because each
spark is bigger as the motor is loaded more, and more. Moreover, as the
metal evaporates off the tip of the wire brushes, it doesn't disappear.
Instead, it becomes tiny bits of metallic dust. Since servo motors are
sealed, you can't see the sparks - and this also means the dust stays
within the case. It accumulates, and no surprise to the engineers
amongst you, it acts exactly like an insulator. This leads brushed
motors to run hotter and hotter over time.
motors run cooler - always - because a) there are no sparks creating
heat, and b) because insulating dust doesn't accumulate internally. But
the real benefit to you it this one. Brushless motors last longer
because electrons don't wear out. How much longer? It varies with
current but on average, a brushless servo motor last as much as 5X
longer than a coreless servo-motor. Thus, even if your money grows on
trees, brushless servo motors are what you want so don't be fooled by
look-alike products equipped with coreless-motors!