This is the DS1155BLHV servo. In size and shape it's similar to our other standard-size servos. Basic specs are 1155oz-in and 0.10sec/60° but take note; stall current at 7A means you must use a healthy BEC, or a separate 2S LiPo for the control electronics. Consider yourself advised regarding using some weak ass source of power because P=IV is straight physics and physics don't care about brands, OK? The point is, P(W) = I(A) × V(V) means watts are equal to amps times volts.
Anyway, this servo is our best idea for getting more gear area withing a standard size case. An inherent problem with servos for giant scale model airplanes and trucks are twofold; first, the enormous gasoline engines vibrating the Hell out of the control surfaces (feeding straight back into the gear train result in premature gear wear and leading to excess play). And second, especially with fast heavy rigs like an X-MAXX (where some enjoy jumping them an astonishing 100' through the air), the issue is shock damage destroying the gears - they just break on impact! It's not that the gears are bad, just that the forces are huge!
Larger gears (and larger bearings) address both issues for the same reason a larger wing area results in a reduce wing-loading. Since 1155 gears are bigger, they have more surface area, which means a lower working pressure. This is better because the ultimate strength of a material like steel doesn't care if it's within a Savox or ProModeler servo - it's all about withstanding the impact!
So how do our gear train and bearings compare? Let's eyeball the popular Savox 2290SG. Widely available through Amazon for about $140, it makes almost 700oz-in, transits in 0.135sec/60° and is a great example of our competition. And note, we're not saying the Savox is a bad servo. Our whole point is . . . we feel ours is better. Let's look!
- Our bearing is much bigger (+20%) and shielded, plus it's an ABEC-9 quality
The foundation of a load is the bearing because it shoulders the loads. Quite honestly, there's really no substitute for size, where bigger is better. But take note of two things; our bearings isn't just significantly larger but sealed. Plus we're using the highest available quality, which is ABEC-9,
while theirs? They don't say, but it's not even
shielded! So if you ever wondered why our servos cost more? Start right here.
Now let's turn our attention to the gears because smaller gears will either wear more quickly due to vibration, or break like they're made of hard candy on impact! Heck, even our huge gears may break because we're not telling you they're unbreakable . . . we honestly dunno, but without question, they'll hold up better just because they're so much bigger, capice?
So how much bigger are the gears in the ProModeler DS1155BLHV compared to the Savox SB-2290SG? Look below and note the relative difference in size is enormous; Anyway, I believe we're ahead of everybody else (most especially those selling relabeled oriental servos to the gullible).
- Our secondary output is as beefy as their primary - our primary is huge!
Meanwhile, if you're wondering if we've resorted to 15V to achieve this much torque and speed? Nope, it's been designed for maximum compatibility. This means a bog standard 2S LiPo (or healthy BECs). Yes, I grok those who want to connect a steering servo to their 4S propulsion pack for convenience, but not only is this at odds with the needs of our other customers, but honestly, we're already making so much torque the issue isn't tricks due to an inability of making enough power, but ensuring durability! Add in the factor of variable servo performance as the voltage of the propulsion pack varies with motor load and the whole idea is dumb.
Add to it, this class of servo will consume an
appreciable fraction of your propulsion pack's capacity. This means shorter runs (duh). However, our real point is, we're engineers not marketing types. Instead of hype, we work within the constraint of practicality and compatibility. Larger servos, with much larger motors? Well, that's another story but using 15V is best through a regulated supply, e.g. a BEC instead of a propulsion pack that has variable voltage depending on how hard your running the rig's motor. Please believe us; we're capable of making enough power and speed now without resorting to tricks. The DS1155BLHV is the proof.
Bottom line? Is it worth 50 bucks more than theirs? That's for you to decide.
Now for some Q&A.
Q. Asaf Karas wrote; will the servo work with the Traxxas VXL-8s ESC/BEC?
A. The important figure when reviewing their unit is the claim of BEC Continuous Current of 10A. That's plenty - but - the fly in the ointment is this is at 6V while the servo is rated at full power at 8.4V.
Thus, our advice is seek a better BEC to power the servo, or run it off a 2S LiPo (as if it were a nitro powered truck). Honestly, if you have room for a BEC you also have room to install a small battery. After all, these are big ass trucks! Anyway, if you prefer a BEC, then the Castle Creations CC BEC Pro is rated at 20A and is, in our view, a better and less costly option.