The DS505BLHV servo is the latest iteration of our most popular servo ever!
This all-alloy standard-size servo is equipped with a brushless motor and has an all-steel gear train. It's not only strong, but fast and we've made thousands upon thousands of them. This is a superb all around servo. Maybe the best bang for your buck in the whole world . . . at any price. Yes, those are big words, but here's why.
Initially introduced in 2012 as the S74420BLHV, before the year was out we figure how to improve. How? By changing from all-metal gears to all-steel. Rechristened the S420BLHV, two years go by and we refined the design by reinforcing the alloy case with bronze inserts (where the steel gear shafts fit) leading another name change, the DS420BLHV.
Do you know how a Porsche 911 from 2009 and 2019 are recognizably the same car? This, despite a decade between them! Yet if you park them side by side they are 'totally' different cars, right? This is because Porsche engineering evolves their designs (little known fact, the first one hit the market in 1963).
So basically, ProModeler have the same engineering philosophy as Porsche because we're doing the same thing. We introduce iterative improvements to our original 420oz-in servo. And just as Porsche 911 had a 2.7L engine, then a 3.3L, then back down to 3.2L displacement, we also use different servo motors. And always with the same goal, to make a better servo!
This brings us to the next step in the DS420BLHV evolution, the availability of a more powerful motor, leading to our introducing the DS470BLHV. Basically the same servo, ever evolving like Porsche does their 911 supercar, (even the same price, $100, which Porsche doesn't do).
Then our motor vendor approaches us about another motor. This leads to a further evolution as the servo becomes the DS555BLHV. So now we have a further advancement as this servo has become the DS505BLHV? Less torque? Yes, but a better motor meant the tradeoff was worth it in the eyes of engineering. What makes it better is about math, and beyond the scope of this description but just as Porsche engine displacement has varied up and down, torque output for this servo has now also gone up, up, up and now down. Bottom line? better servo. Best it's ever been.
Where can you use it? A lot of places. Pretty much any 3D airplane to mid-size, call it 96" with a DA100. IMAC models to 104" with a DA120. Obviously, even a 40-size trainer since the physical dimensions are standard size even though the price of a single servo approaches the price of the whole airplane, but who knows, maybe the fellow has plans to build a big ass gasser once he learns to fly. Not our business.
Where else? Pretty much any helicopter in existence that uses a standard size servo - 600-class, larger 700-class, and even 800-class are going to be perfectly served by this servo.
Surface use, both land and sea. On the water, this is an outstanding servo for big hydro models for steering at 80mph. Surface use includes any 1/8-scale racing buggy, crawlers like a TRX4, etc.
There are several servos on the market in a similar performance range. Popular ones include;
- Futaba S9177SV and BLS177SV
- Hitec HSB-9381TH
- MKS 777+
- Savox SW2210SG
Futaba S9177SV is a generally very well made, high quality servo featuring a hybrid case (polymer/aluminum) and a coreless motor. Equipped with steel gears like the DS505, it's priced in the range of $180. If you want a Futaba servo, but with an all-alloy case and brushless motor like ours, then you'll have to pony up more money (to the tune of $240) for the BLS177SV, instead. Theirs both makes 65oz-in more torque than a DS505 - but - are a tick slower. If the torque is critical, eyeball our DS630BLHV. Honestly? It's hard to go wrong with either Futaba product - but - we feel ours give them a good run if you're interested in a solid alternative.
Hitec HSB-9381TH is a very nicely made, high quality servo featuring an all-alloy case and brushless motor. At $190 it's very similar to the DS505BLHV in terms of torque (a tad less powerful at 472oz-in v. 505oz-in), but while this is a difference we can measure in the lab, in the real world, it's insignificant (in our opinion). However, at 0.14sec/60° it is considerably slower than the DS505 (which is a 40% faster at 0.094sec/60°). While the speed difference is of no consequence in a scale or sport model, its a definite disadvantage for the pilot of a 3D model of any kind (or on the race track). A further disadvantage - in our view - are the titanium gears. In general, titanium is a wonderful metal for an SR-71 Blackbird flying +2000mph, but it's much softer (and more brittle) compared to steel gears, which wears faster. In demanding applications, what you're going to find transmitting the power (like a money-is-no-object Ferrari F1 race car or on the track at a NASCAR event), the material of choice is steel for the gears, never titanium. While titanium 'is' better in the eyes of marketing (vs. engineering), it's because like carbon fiber, the word titanium gets rubes reflexively reaching for their wallets!
MKS 777+ is a very nicely made high quality servo featuring a hybrid case (aluminum upper, polymer lower, with an extruded aluminum center). It lacks cooling fins and when compared to our case, which is CNC-machined from a solid billet of 6061-T6 aircraft aluminum, it's no contest in the ability to shed heat when the servo is working hard. Simply put, ours is better. Priced in the range of $130, it also has a coreless motor (like the Futaba S9177SV) instead of the superior brushless motor like we use in the DS505 (as so Hitec for their 9381TH and Futaba in the BLS177SV). Like the Futaba, this one is a bit more powerful than ours (by 55oz-in) and we have the same advice, if that's enough to move your needle, consider the DS630BLHV, instead. But like we said with the Hitec, these are differences you can measure with an instrument, but in a model? Not so much. Note; if you're not familiar with what's in it for you when selecting the motor that powers your servos (like coreless vs. brushless), then review this article titled; About RC Servo Motors because we actually cut motors open with a lathe and show you! Facts are, it's what's inside that makes them different, and this determines what's better for you (but in general, any brushless beats any coreless). Speed-wise this servo is a close match - ours is a tick faster at 0.094sec/60° versus 0.10sec/60°, and this is a slight advantage for 3D-maneuvers and racing, but of no consequence for scale and sport flying, otherwise. However, a serious downside in our opinion is the 777+ is equipped with titanium gears instead of steel.
Savox SW2210SG is a finely crafted servo featuring a brushless motor but, perhaps to hold down the price ($108), they opt for a hybrid case (polymer upper and extruded aluminum center). This means no cooling fins and significantly weaker in terms of resisting abuse (all-alloy case is where our DS505 as well as the Hitec 9381TH and Futaba BLS177SV spank the Savox). Performance-wise, it's a fair match at 500oz-in versus 505oz-in for ours (indiscernible in any model), but at 10% slower ( 0.11 sec/° vs. 0.094sec/60°) - nothing important in a scale model or monster truck, in any kind of high performance application like 3D-flight or on the race track . . . faster is always important. This servo is equipped with good quality steel gears, so it's macht nichts when choosing between theirs and ours if you're only looking at the gears since they're both essentially in the same league in this regard. Bottom line? This Savox servo is quite decent and definitely worthy of being on this list of servos compared to our DS505BLHV but it's absolutely not better.
We hope this honest take on how some top competitors stack up is of some use. Click the links and you'll see a new tab open so you can look them over and not loose your place here. Anyway, if you feel you know a servo worthy of being on this list, tell us and we'll take a look. reach out to us at: info@promodeler.com or via; 407-302-3361 because we're all ears!