215oz-in CLS

Mfn. No: PDRS215CLHV

Please call for availability


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DISCONTINUED and replaced by DS305CLHV (same price). Visit www.promodeler.com for purchase.

This amazingly quick standard-size high voltage, water-resistant servo with coreless digital motor is for 50-90 size flybarless helis (600 to 700-class), as well as fixed-wing models ranging from 40-size through giant scale, 1/8th scale race cars, and robots.



Nominal Voltage*: 6.0 - 7.4VDC
Operating Voltage: 5.5 - 8.4VDC
Torque: 165 - 215 oz-in
Speed: 0.11 - 0.09 sec/60°
Frequency: 1520µs/330Hz
Dead band: 2µs
Weight: 63.6g
Wire: JR/265mm



  • High voltage
  • Coreless digital motor
  • Titanium output gear
  • Water-resistance o-ring seals**
  • Dual ball-bearing support
  • Durable hybrid polymer/aluminum center case


Product description

Voltage - the only reason to buy HV (high voltage) servos is to use them with an unregulated 2S LiPo battery pack. Otherwise, you may as well opt for servos designed for old fashioned nickel-chemistry packs. Moreover, eliminating the failure point (and expense) of a separate voltage regulator is a plus because your avionics system becomes more reliable. High performance and reduced complexity . . . this is what being a pro is about.


Geartrain - all metal gears makes this servo strong. Material selection makes it tough. Featuring exotic titanium-ceramic (TiCN) armoring of the output gear, which is the same 7075-T6 aluminum-alloy used in components of the upper receiver of an M-16 rifle, this massive gear must be as light as possible to accelerate and decelerate quickly - while being strong enough to absorb the immense cyclical loads . . . and tough to withstanding crashes. These materials were selected because they're strong as steel and lighter than non-ceramic titanium-alloys. The TiCN is actually better because the 800% increase in wearing surface hardness makes it more durable. The balance of the geartrain is made up of combination-gears - gears made with two materials. Each material has been expressly selected for optimum strength, mass, and wear characteristics - based on the load and tooth profile. For example, two intermediate spur gears use C86300 manganese-bronze and one spur gear uses 7075-T6 aircraft aluminum. All three are mated to tough 4140-steel pinions. In short, if there were better materials for the geartrain we'd use them . . . but there isn't, so we don't. Moreover, we went with straight-cut vs. helical-cut teeth because this makes them stronger - end of story. Basically, this no-compromise geartrain is the best available at any price, which is something to remember when you encounter the marketing hype surrounding fake-titanium helical-cut gears. 


TiCN 7075-T6 output gear with brass/4140-steel and 7075-T6 aluminum/4140-steel combination-gears

- TiCN 7075-T6 output gear with brass/4140-steel and 7074-aluminum/4140-steel combination-gears



Hybrid Case - the servo case is water-resistant because o-ring seals are used where the case sections meet the center case. Some pilots only fly electric models and thus, believe fuel and exhaust-resistant servos are overkill, but what about water? Since electronics don't especially care for liquid contaminants, this can suddenly be real important on high humidity days, or when a rain shower pops up. This is why knowing where a manufacturer chooses to cut corners is important - it's because it gives you an insight into their thinking. What if, for example, the manufacturer leaves out some vitally important, and in-plain-sight features, like o-rings? Since there's really no conceivable reason for them to do this beyond their pocketing a few pennies, doesn't it beg the question; have they opted for other savings, perhaps on hidden components, as well? It's hard to know which short cuts were taken, but if they do it on things, which are visible, you can bet they did it on things you can't see too - and it's your model on the line.


Naturally, we all like to save money . . . but only if we can do it intelligently. For example, we believe one smart place to save money is through our decision to use engineering-polymer sections for parts of the case of this servo because the fiber-filled nylon 6,6 (like that used in Glock handguns) means the components are extremely tough, impact resistant, and dimensionally stable over a wide range of temperatures. Then, through savvy engineering, we ensure the polymer gear-case section doesn't deflect under load because we used six screws instead of the normal four to secure it to the CNC-machined 6061-T6 aluminum center-section (four screws from the bottom plus two more from the top). Clever engineering thereby ensures rigidity under load while you save money - and all without sacrificing performance! Meanwhile, machined from a solid billet of aircraft aluminum, the center section does more than provide a rigid foundation, it's the heat sink for the high output digital motor because aluminum absorbs and radiates heat better. In short, shrewd engineering, top notch materials, plus attention to details like o-rings for sealing means intelligently saving you some money . . . without compromising strength or durability. In a world where top pilots use their name to market rebranded servos, engineering separates the pros from the quick buck artists.


Water resistant case features o-ring seals

- Water and fuel resistant case features o-ring seals - this is an extremely important detail



Accessories - standard include an assortment of three Futaba-compatible servo arms (cross, star, and round) however, they're made of tough fiber-filled engineering polymer,which are are better than ordinary ones because they're super strong and won't deflect under flight loads as easily but will protect the servo too because they'll still break during a crash. Along with rubber grommets, brass eyelets, four truss-head screws, and one M3x6mm long machine screw, they complete the hardware package. These servoarms are just about perfect for the cyclic/collective pitch of model helicopters, the flight controls of model airplanes, as well as steering of an 1/8th scale race car, e.g. places where very high loads are routine. Of course, if you prefer further rigidity, optional heavy duty fiber-filled engineering-polymer as well as 6061-T6 aluminum servo-arms are available as well.


Standard assortment of Futaba-compatible arms

- Standard assortment of Futaba-compatible arms



Beyond basics like strength and speed, plus voltage, and how a servo is physically constructed, e.g. materials used for case and gears and whether o-rings are used for water resistance, other design considerations include the type of motor and electrical issues like frequency, frame rate, and dead band. While the latter three are detailed in the specifications section above, this brings us to motors, and more specifically, why do we select certain types of motors, or what's enough servo?


Coreless Motor - to begin, selecting a digital servo vs. an analog servo is a no brainer because the digital servo will hold position precisely when the analog servo will mush and deflect under the same load. Basically, digital servos have greater holding torque. Delving deeper into motors though, a digital servo with a coreless motor is better than a standard digital servo because it has less mass to accelerate, which means it's a little bit faster. However, while some pilots can tell the difference, others can't so our best advice is . . . don't overpay for what you can't feel. Especially because ProModeler hews to the philosophy of offering good, better, and best servos based on motor types while still including the good stuff like a titanium output-gear, 12-bit processing, plus essentials like o-rings. You'll receive these benefits with all our standard-size servos regardless of price.


Meanwhile, if there's a downside to motors used in both digital and coreless servos it's due to the use of brushes and commutators, which wear over time - this is true for all brands. How much time? Years, typically, before a decent pilot notices. However, the very best digital servos offer a brushless motor, which completely eliminates both brushes and commutator, e.g. the things which wear the fastest. Brushless digital motors are the best because they last much, much longer - think in terms of a few thousand flights. As a practical matter for most modelers, brushless digital motors will last almost indefinitely. Add to it, ProModeler uses million-cycle potentiometers in all our standard-size servos and thus, pilots who fly a few hundred flights per year are very well served regardless of motor type. Of course, competition-level pilots who fly thousands of flights per year should always opt for servos with a brushless motor, but when you don't fly that often, or budget considerations dictate using digital or coreless motors, it's good to know it doesn't mean skimping on construction, o-rings, or a top quality geartrain . . . the really important things.


This brings up the question of how do you keep from spending more for servos than you should? This is trickier to answer because standard-size servos installed in a 40-sized model airplane are the same physical size as those used for a 90" wing span giant scale model, or a 700-class helicopter. Thus, you'd be wise to mind how your interests may change when selecting servos because you may want to repurpose them to a different model years later. This likely explains why some 600-class helicopter pilots equip their models with servos capable of controlling a 700-class model performing the most abrupt and violent of 3D maneuvers. Basically, they're thinking ahead and trying to future-proof their servo-investment. However, since few of us are made of money, the truly wise pilot will consider both need and budget because the answer to which servos is best is . . . it depends. Here's why.


Heavy duty dual ball bearing supported output gear

- Heavy duty dual ball bearing supported output gear with a CNC machined 6061-T6 center



Pro Tip - Selecting the right servo for your application:

Marketing - many companies market servos specifically to model helicopter pilots, giant scale modelers, robot-builders, or model car drivers - as if servos knew in what they were being installed. This may explain why reducing the servo-lead from 10" to 6" and calling it a car-servo works in the minds of marketing-types. ProModeler doesn't engage in those games because the only thing that really matters is whether the servo is strong and fast enough for the job - either it is, or it isn't - simple as that. The ideal servo is a fiction because it's infinitely strong and takes zero seconds to move from one extreme to the other (and only exists in the imagination of servo designers). Realistically, good pilots begin to notice when 60° speeds are much more than 0.12 seconds. Obviously, faster is better. Sufficient torque is harder to quantify.


Rotary wing - for example, 700-class helicopters being hovered and flown in sport aerobatic maneuvers like loops, rolls, stall turns, plus the occasional flip may be safely controlled with 70 oz-in servos, but a 3D pilot would complain the model didn't feel crisp. Interestingly, if you watch old videos of top helicopter pilots like Curtis Youngblood performing 3D maneuvers a decade ago (predating the revolution in digital servo design) many would be amazed to learn he was using analog servos of about 90 oz-in of torque and .18 sec/60°. Today, the same model flown through sport maneuvers with a flybarless head would need about 120 oz-in to feel right, while a more aggressive pilot flying 3D-maneuvers would be pretty happy with 140 oz-in servos . . . but once again, more is always better, which is why we offer this 215 oz-in coreless digital servo. Beyond the increased power however, what you get is the increased quickness afforded by the coreless motor, which because it accelerates and decelerates ~10% faster than a standard digital motor affords a significant benefit to discerning pilots. 


Fixed wing - similarly, there's a dichotomy with model airplanes. Take, for example a 22 pound, 90" wingspan scale-model of a P-51 Mustang equipped with 140 oz-in servos on all the flight controls. The pilot will safely loop, roll, and fly it with joyful abandon - without a care and power to spare. However, by using 215 oz-in servos instead, he has a greater margin of safety coming out of a 400' loop a mere 10' off the deck (because figure 9s into the dirt will ruin your day). Conversely, a 22-pound 90" wingspan Extra powered by a 100c gasser flown through 3D maneuvers by a hot shot pilot presents a case where he shouldn't even think about using 140 oz-in servos. Instead, he'd be wise to use our 245 oz-in servos for the ailerons and elevators and because this same servo would be overpowered by the rudder during aggressive maneuvers, the smart pro will opt for an ultra-torque 420 oz-in servo for the rudder. Complicating things, however, is how the plane is flown because this same Extra flown like the Mustang in the first example, e.g. engaging in sport aerobatics as flown by an average pilot would have a greater safety margin with 215 oz-in servos on the ailerons and elevators (though using a 245 oz-in servo on rudder for better knife edge performance would be prudent) with the added benefit of having the servo quickness to more easily enter and exit snap rolls and some 3D maneuvers like a Harrier descent where the model gets close to the ground.


See what we mean when we say it depends? Thus, while more torque and faster speeds are always mo betta', the reason ProModeler offer standard-size servos ranging from 110-oz-in to 420 oz-in of torque and from 0.03 to 0.12 sec/60° is to help meet the exacting demands of uncompromising pilots who thoughtfully select the right servo for the job.


Advice - if you are unsure about the best servo for your application, don't just take the advice of some anonymous 2-gallon expert on a forum, or buy whatever your buddy thinks is best. Instead, give us a call and ask because we have the experience to help guide you. Best of all, our advice is free (and worth every penny) and because we have a solid reputation for honesty and offering common-sense no-bull answers, we won't sacrifice our reputation just to upsell you on something a little bit more expensive. Especially because we know that when you're happy, you'll tell a friend . . . but when you're unhappy you'll tell everyone! Reputations are earned and we value ours above making an extra buck.


Wind the lead and heat for a few seconds for a clean professional installation

- Winding the lead and heating it for a few seconds gives that clean professional install



Packaging - nestled within a high density foam insert for protection, each servo arrives packed in a jewel case, which many subsequently use to store glow plugs and other small hardware. Moreover, ProModeler servos aren't just functional, they're attractive, too. Just because form follows function doesn't mean we ignore the fact good looks never hurt. Thus, the tasteful crimson polymer components, complemented by the laser-etched polished aluminum center present a nice appearance and offer a substantial feel. Think in terms of the fit and finish of other high quality servos from the likes of Futaba or JR. You'll be proud to install them in your model partly because of their superb performance, but also because of the fine appearance and craftsmanship. These servos are a perfect reflection of modelers with uncompromising standards and a demanding attention to detail.


Classic jewel case packaging with the servo snugly secured in a high density urethane foam insert

- Classic jewel case packaging with the servo snugly secured in a high density urethane foam insert



NOTE: deciphering the parts code - PDRS74215CLHV means:

  • PDR = ProModeler
  • S =Servo
  • 74 = 7.4VDC - nominal voltage*
  • 215 = oz-in - torque
  • CL = coreless digital motor
  • HV = high voltage


*Nominal voltage - for a LiPo cell, it's 3.7V (or 7.4V for a 2S pack). However, a 2S pack fresh off charge reaches 8.4V (4.2V/cell - though it quickly depresses as soon as you load it, e.g. start flying). This means servo performance varies because the input, or pack-voltage varies (the lower the voltage, the slower and less quickly the servo reacts to your input, which is the root cause of why an HV-servo offers superior performance compared to old style SV-servos). bascially, we believe rating servos at 8.4V is pure bull because this isn't what the servos sees - or not for very long - and certainly not once you begin flying. Thus, these specs represent worthless puffery.


While some call this practice smart marketing, we think it's really just a sharp business practice, or deceptive marketing because the pack voltage quickly drops with use . . . so what's the point of offering these specs if not to deceive? Thus, please note, our specs are offered at the nominal LiPo voltage (7.4V for a 2S) despite them being designed to handle the higher voltage. This is expressly because nominal voltage is very close to the average voltage on the discharge curve (4.2V+3.3V)/2=3.75V/cell, or 7.5V (average) for a 2S-pack. Furthermore, be aware nominal voltage is also about the point at which professional pilots recharge the pack (to maintain the high performance they're paying for).


What this means in a practical sense is, yes, you can expect somewhat better than rated performance with a fresh pack. But what we guarantee are the specs in the real world, e.g. at nominal voltage because inflating specs is a fool's game (a matter of questionable ethics too, because what's portrayed is fleeting). Remember, the figures don't lie, but the liars figure!


**O-rings - amazingly, some el cheapo servos leave out the o-rings just to save the manufacturer a few pennies. Since water, fuel, and exhaust residue don't mix well with electronics, it's reasonable to wonder about other short cuts taken. Basically, is their quest to save pennies worth putting your dollars at risk? We offer this observation as food for thought.