Servo, DS845BLHV

This is the ProModeler DS845BLHV servo. It's one of a series of three servos, this one, plus the DS635 and DS1155 where the basic differences are the motors and gear ratios - otherwise they're like three peas in a pod!

It's of a size and shape similar to other standard-size servos meaning it features conventional beam mounts so it's designed to be installed with vibration isolating rubber. Note how it sports a beefy 15T spline (versus the smaller conventional 25T spline output shaft). Why? Simple, the original 25T batch weren't holding up as we'd like so now we make it with the same gnarly spline as our Quarter-size servos (ones outputting +1505-2685oz-in). This puts and end to the problem of twisting 25T splines.

- DS635BLHV with 15T output juxtaposed with 25T original (DS845 and DS1155 look similar)

So the BL in the product name means it relies on a brushless motor - and - is equipped with stainless steel gears, as well as dual bearings, and is built within an bronze-reinforced all-alloy case. What's more, it meets three MIL-STDS . . . servos just don't get any better.

Basic specifications

• 845oz-in of torque
• 0.06sec/60°

There's nothing else as strong and fast the DS845 (not at any price). How's it match up to a well-regarded competitor like the Savox SB2290SG Monster? Theirs goes about 700oz-in and 0.13sec/60° . . . so theirs is not as strong and it's waaaaay the heck slower.

And with regard to how the build quality compare? Well, you decide!

Gears

Bearings

The DS845 bearing on the left as compared to those in Savox SB-2290SG is 25% larger, rated ABEC-9, and shielded. Theirs? Sorry, they don't say.

X-MAXX/XRT

With regard to mounting the 2290SG within an X-MAXX or XRT, you'll need to resort to the plastic Traxxas #7749 adapter vs ours where we make available one CNC-machined from a billet of 6061-T6 aircraft aluminum figuring the 10 bucks difference makes it a no-brainer, but whatever, the customer is always right.

Anti-vibration

Part of what makes the ProModeler DS845BLHV better than competitors is that unlike hobby-grade servos, it's built to meet military standards (and subjected to these tests).

MIL-STD-810G-Part 16

• Shock - Test Method 516.6
• Vibration - Test Method 514.6
• Rain - Test Method 514.5

ProModeler servos are expressly designed to survive the abuse of the real world outside of modeling  . . . and it's another ownership consideration.

Servo arms

In a world where 99% are only familiar with a ø6-25 spline (an ISO), the ø8-15 is new. Most are surprised how gnarly it is compared to the smaller ISO standard spline. Making it easy to use is on us. So we produce (mill, broach, polish, laser, and package servo arms broached for the ø8-15 ( means 8mm diameter, a nominal value as actual parts vary due to tolerance and required clearances for fit and function).

Bigger

Please take note; using a standard size servo in an X-Maxx is Traxxas' idea, our best idea for an X-Maxx servo is our most massive that can be readily fitted, the DS1885BLDP, instead. It's bigger like an Ford F-750 pickup is bigger than an F-250. Costs more, too. Can't be helped. Anyway, use your judgement when selecting a servo for an X-Maxx, a rig that easily goes 15-20lbs, and runs 40-80mph because when you crash it, things are going to break. Can't be helped, maybe call it the nature of the beast. Only solution we've found is a physically larger servo, the DS1885BLDP, and even then we never say it's unbreakable, either. Why not? Simple, because we're not stupid.

Power

Last thing is this, if you're wanting this for a rig instead of an airplane, heads up, servos like these are unlikely to make rated power on the typical BECs they give away for free on some el cheapo ESC. Kindly trust we know more about powering servos than someone going by Rocknutz on a Facebook group or forum, please.

Anyway, while packs aren't really our line of business, we offer several dedicated 2S packs ranging from 650-6000mAh - plus - an excellent standalone BEC. Only downside of the latter is it requires a little soldering. Pay someone, or learn - BUT - our best advice is use a little dedicated pack. Why? Because then you get the cleanest analog current on the planet versus the 0s and 1s of a digital source!

This is NOT about voltage. It's about current. Let's say you have a fire, who puts it out better? You with a 3/4" garden hose or the fireman with a 4" attack hose? No brainer, right? Well, in this analogy, the battery is the attack hose! And please note; the only rationale behind our saying anything about this is we want you to run your servo and be happy. So just refer to the electrical pull-down menu above and add to cart.

Wait, you still want to use the BEC supplied with your ESC? OK, whatever . . . the customer is always right - just please don't make like nobody warned you, eh?

Magic

So where's the magic in this servo? it's in the design of the gear train that allows us to stuff much larger gears into a standard size footprint . . . and it's patent pending!