96in P-51 Miss America

The genesis of this caseSTUDY article began with a phone call, which in an of itself is not unusual in the least. That it ended up with me buying a new model airplane, however, was unexpected. Or put another way, not on my bingo-card when I awoke that morning!

Note; links open in a tab so as not to lose your place here.

Intro

So when the phone rings and the guy on the other end asks for a servo recommendation for a P-51 Mustang, my ears perk up. Always. I may as well be one of Pavlov’s dogs because the conditioning is strong within me with regard to this aircraft.

But it’s when he says it spans 96in and my mind flashes to my 98 in Nick Ziroli P-51 (which no longer is), and I reflect how ‘little’ my Top Flight P-51 seems. that I realize this call has all the hallmarks of the making of trouble. Why is this? Simple because the last thing I need is another Mustang!

So I am determined to hold out. But when he mentions it’s in the red, white, and blue of arguably the most famous P-51 to ever grace the skies of Reno – the Miss America color scheme – that I come to the realization it’s game, set, match.

And just like that, I feel myself giving in. Why?

The answer requires a bit of background about me. You see, as a little boy, when I heard two neighbors fire up a Cox .049 model of the PT-19 trainer in yellow and blue I went running to see. When I caught the whiff of castor-based fuel, the modeling hook was set. Yes, that’s all it took.

Also helped that my Dad and I were building a Guillow’s balsa model of his Piper Cub at the time (but for rubber power). Anyway, the sound and the smell did it for me in terms of starting me down the path of model aviation and the rest is history. So why the Miss America?

The Miss America enters the story because that’s the exact model and color scheme of my first very own Cox control line model. This would be ca. 1965 when I was seven years old and like my neighbor’s PT-19. mine was also equipped with an .049 engine. I’m telling you, sitting here writing this and the memories of my first smell of model airplane fuel continue to reinforce the unexpectedly strong emotional response.

So basically, I was helpless and once I asked for photos of his model, which he obligingly shared, it was game, set, match! Anyway, what’s great about that very first photo is it gives a good sense of scale. This, because he’d laid the fuselage out on top of the bed in their guest bedroom.

And note how nicely the hatch allows ready access to the inside!

Next, he shared a photo of the fuselage interior sans hatch. This showing off how well the interior’s laid out for servos and fuel tank.

At this point I’m especially eyeballing how there are plenty of opportunity to use straps for securing things like the fuel tank, or possibly even a pair of 6S batteries (for if the electric urge should set in).

And because of my experience with the Ziroli Mustang, I knew exactly what I’d be letting myself in for if I got one.

Anyway, once I found the vendor (Chris Hogg at RC Warbird Models), and placed an order, I was set. Honestly? Twas but the work of a few minutes (Cindy responds promptly) and the deed was done. Later that day I let him know what I’d done and just like that, we began scheming much like two little boys planning how to build a treehouse!

So first we began by sussing out the equipment list. He had a head start on this, which helped. This resulting guide may help you. First up, and arguably the most important thing being . . . how to power one of these things?

Propulsion alternatives

His plan was for a DLE85, an extremely powerful single cylinder gasser. This east Asian import is a big ass single-cylinder engine widely considered a thumper (for context, my first motorcycle had a 50cc engine). Simply put, it’s a beast making stump-pulling torque. And while I have experience with both their 35cc and 55cc engines, I had none with the DLE85 (the 85 means it displaces 85cc).

However, while that may well be the perfect engine choice for him, problem for me is, unlike my DA-85, the folks at DLE do two things I’m rather less than sanguine about. First, a reliance on a Walbro-clone instead of the real thing. Second, while my DA is solid mounted, they use soft mounts.

Honestly? While I’m rather less than sanguine about this concept of soft mounting such a big engine, because my customer has one and is set on giving the engine a try (not least because he had one in hand), then I’m not about to discourage him, take my meaning? Added to which, I’m not discouraging him if for no other reason than I’m curious how this will play out.

As for myself? I’m undecided what to use. This, because I have within my inventory a couple of Desert Aircraft DA-85 engines. One is presently on the front of my Top Flight Corsair, where it goes like stink and performs stellar duty (it’s a real powerhouse).

The other, sitting within a box, and equipped with a Keleo exhaust simulating a V-12, may be the ideal engine for this model. Like it would certainly look right. And FYI, the guy behind this is no longer making them but CH Ignitions has the rights and offer systems for the gorgeous Saito 3-cylinder radials but to the best of my knowledge, this V-12 set up is not in production. So I bring this up before you think to reach out to me about it because this is all I know.

Anyway, whether the DA-85 is right for me is an open question. Reason is I have other alternatives. Let’s see what else might work.

Thing is, I also have a ROTOmotor FSI85, an 85cc inline twin four-stroke gasser. So this company, based out of the Czech Republic, make a really nice series of engines. And this one? It will have plenty of power . . . I have no doubts.

Anyway, I think it would be an especially sweet candidate for this aircraft expressly because of the slim profile presented by the inline configuration of the cylinders. This, principally, because it means cutting very little, to none, of the cowl. Win-win.

What else may work? I’m also casting side-eyes at the huge hatch. If you know me, then it’s easy enough to see the gears turning in my head. This, because I’m thinking about how easy it would be to exchange a pair of 6S packs configured in series to make the +50V output of a 12S propulsion system through that lovely opening.

Reason is, for an electric, access isn’t just an option but ‘required’ for the purpose of exchanging batteries. Anyway, this model has a very nice access hatch so I’ve ‘also’ got in mind one of these electric set up as an alternative propulsion source for the model.

Anyway, I have lots of choices ranging from direct drive Neu, to gear reduction Kontroniks, to a belt drive setup of which there are several alternatives available.

Anyway, because the propulsion decision can wait, our next step was to begin chatting servos and setup. First up, before the servos, the most important are the setup considerations.

Setup

Focusing on a concept, OK? In the right hands, with proper servos and setup, a big Mustang like this is actually a supremely capable sport model. One ideal for letting out your inner Walter Mitty by performing warbird type combat maneuvers such as the famous split-S, victory roll, and Immelmann.

Interested in learning more? Follow this link;

• Basic Fighter Maneuvers

Changing gears, did you know the moments of the Mustang are ideal for competitive aerobatic flight? Saying it also makes perfect sense that this warbird is capable of flying the old FAI schedule.

And as usual the secret sauce lies all within the setup.

However, in the hands of a hooligan, and equipped with powerful servos and using a setup with reasonable (but not excessive) throws, the aircraft is fully capable of competing in model air races. Talking 200mph, capisci?

So have you heard of Unlimited Scale Racing Association? These guys do exactly this kind of stuff, they race giant scale warbirds! Click the link, learn about this aspect of the sport, and maybe even consider joining just to help support them. Honestly? I’ve been to Madera to see the model air racers. Anyway, believe me, the guys racing giant scale models are having a blast!

Yet here’s the thing, when set up with the right servo arms, regardless of which servos you select, a Mustang – and belying it reputation – is the kind of aircraft, which can be tame and well behaved. Enough so a novice pilot comfortable with his second model, can readily take off, fly, and land it without overly stressing!

Point being, while servos are important, when optimizing this model to be different things for different people, the key is the setup.

So did you count how many times I mentioned setup? 5X – more later.

Background

Fast forward a week, or so later, and the box with my Mustang arrives. No surprise, it’s large. and while it looked a bit worse for wear, all was fine inside. Whew!

However, and unfortunately for me, what happens often enough to be something of a habit is the press of work meant after inspection, I sadly shook my head, and put it on the rack using a forklift.

Means it’ll just have to wait (and there it remains on the rack – to this day – sigh). End of the story? Nope!

Build Saga

It’s not the end of the saga because in the meantime, my customer is plugging away at his build. And he’s sharing photos of his progress with me. This lets me experience it vicariously (and learn from him because I’m taking note as he shares what he’s doing). As I’m about to share with you!

Perhaps most important, he’s taking into account the huge power of the big DLE85 engine. Toward that aim, he’s firm in the need to reinforcing certain areas of the structure. His plan of attack is to begin with reinforcing in the first four phases, then two more, the engine install and avionics . . .

• I. Motor box
• II. Firewall
• III. Fuselage sides
• IV. Main landing gear mounts
• V. Engine install
• VI. Avionics – selecting servos

. . . and if you have no interest in this and just want to skip to sussing out the servos for a big warbird, then the Page-Down key is your friend!

Otherwise, here we go!

I. Motor Box

Convinced the model will never survive the first flight with a DLE85 engine, first up, he hit on the idea of using 1/16″ thick 1″ aluminum angle stock to reinforce the motor box attachment to the firewall. Many sources include Ace Hardware, Home Depot, Lowe’s, etc. Easy to find.

Step 1 – alloy angle

A big plus is it cuts easily with a hacksaw. Then it’s easily sanded to shape with an 80-grit block. Honestly? This is not a bad idea. Reason is the alloy weighs almost nothing. Makes the joint a lot stronger!

And I’ll quite likely steal the idea for my own build when the time comes and won’t even remember whom to credit. So I’m giving credit and writing it down right here, right now – this was his idea, not mine.

Step 2 – test fit

Meanwhile, the photos are motivating, but we’re so slammed with work there’s no way I am more than a spectator in this. And in truth, I am enjoying watching what he’s doing because it’s obvious he’s a skilled craftsman who takes pride in his work.

Next was this shot of the mount and standoffs test fit to the box. Take special note of the offset. This, to allow for right thrust.

And your eyes don’t deceive you, the stand offs are rubber mounted. each corner gets two cup-like pieces of black neoprene, durometer rating unknown.

Since my DA85 is solid mounted I find this especially interesting.

Step 3 – triangle stock

Not content to just add alloy braces, my customer added triangle stock, also. These bits are epoxied on the inside of the motor box where the sides meet the firewall doubler.

This whole thing gets epoxied to another firewall mounted to the fuselage. Even after this, he has some doubts as he knows the big singles are paint shakers – and – the model is lightly built.

But I’m getting ahead of myself.

After agonizing about the strength of the nose (not that I blame him, I took my model down after conversing with him and it ‘is’ lightly built), he takes the step of making another plywood doubler for the firewall.

II. Firewall doubler

So I’m going to show you in three photos what he did to further reinforce the firewall. And note, if the plan were to use a DA60, or similar, or an electric motor, this likely isn’t needed, but the DLE85 he’s installing is reputed to be something of a shaker.

Enough so DLE invested in a rubber isolation mount system. Me? As a DA85 owner, I fully concur with what he’s doing because I know how much that thing shakes the airframe. Anything that alleviates this will prolong the life of the airframe because with my Corsair, I resorted to beefin’ the crap out of it everywhere!

Note; if you think I’m being a hater for showing this, remember this isn’t a magazine article where an advertiser holds sway. You’re getting the good, the bad, and the ugly because life’s not all unicorn farts and sparkles.

Make no mistake, nice model, but it has warts. Sharing how to fix.

Step 1 – cutting plywood

In this shot, one of what will be three added layers of 1/8″ aircraft ply.

Simply tracing and fitting one before cutting two more thus creating an additional doubler for the firewall of the CY Models P-51 Mustang.

Step 2 – Adding the doubler

So in this close up, we see the inside of the firewall after adding the additional three pieces of 1/8″ aircraft plywood. The two faint marks on the inside are from the C-clamps. These were used to squeeze the new doubler to the original firewall tightly together while the epoxy cured.

Note; he favors Hysol while I’m perfectly happy using 2-hour epoxy with microballoons mixed into the epoxy. However, by any measure, especially when working with the confines of the fuselage, he’s done a nice job.

Step 3 – anchoring to the structure

The final step is to tie in, or anchor, the new to the old. This close up photo details the final step in reinforcing the original firewall of the CY Models 96″ P-51 Mustang. He’s adding a piece of carbon fiber cloth, thus sandwiching the new thicker firewall and tie it into the fuselage. Note the 1″ strips of carbon fiber cloth, which further reinforce where the main weave joins the sides of the fuselage.

III. Reinforcing Fuse Sides

Next he turns his attention to reinforcing the fuselage sides with 1/8″ light ply. Using 2″ wide strips he relies on Hysol once again. This time to stiffen the structure without adding too much weight.

Reason is, when picking the model up, it creaks ominously casting serious doubt on the strength of the sides to withstand even moderate use, much less abuse. Bear in mind, this isn’t some rookie, the guy’s a serious modeler and highly experienced to boot.

Saying he knows what he’s doing and from eyeballing my own model, reason I’m sharing these details is I fully concur with what he’s done.

Step 1 – equipment tray

Gaining access to do a good job of reinforcing the fuselage sides requires removing the equipment tray. Since it’s just 1/8″ light ply, it comes out distressingly easy. In retrospect, no way the tray is to be trusted with the weight of a 32oz fuel tank undergoing high G-loads. And much less the mass of a pair of 6S 7000mAh packs!

Step 2 – forward strips

So cutting strips of 1/8″ light ply and using Hysol to laminate them to stiffen the fuselage sides on the inside is easy enough. This is the forward fuselage immediately aft of the reinforced firewall. Note the inner gear wells.

So rinse repeat, now for the sides over the wing, the mid-fuselage. Once again using 2″ wide strips of 1/8″ light ply. Easy job, not even tedious. not adding much weight.

Step 3 – mid-fuselage strips

So now we get a better sense of the job. These added strips extend the entire length of the fuselage. In this shot we’re getting a better sense of how much area they cover – this being over the wing area.

Step 4 – aft reinforcements

So the aft part of the fuselage gets the same treatment. This aft view of the fuselage further showcases the added reinforcement using strips of 1/8″ thick light ply along with Hysol.

How thin is the fuselage? Note how easy it is the see the N-numbers!

Step 5 – Equipment trays – updated

Note how the original 1/8″ light ply aft equipment mount have been updated with a replacement tray fabricated of carbon fiber board.

The ProModeler DS270DLHV rudder servo is fixed in place, as is the CY Models retract controller, and a Spektrum AR12310T PowerSafe receiver. Also take note how the avionics power switch is also mounted in place.

This is a sanitary installation if I’ve ever seen one.

Also getting the carbon fiber treatment is the forward half of the equipment tray, the one to which the fuel tank is fixed. In this close up the fuel tank is strapped into place using good old Velcro.

Note; nice location for the ignition switch and charge jack mounted immediately aft of the tank. This, so in the event the tank shifts forward, it doesn’t affect the switch (there are no real forces leading a tank to shift aft). Plus there’s a fuel dot on its own bracket, also!

IV. Retractable gear

So the other area to get a bit of attention are the main gear inner wheel wells plus the retract mounts.

Step 1 – Reinforcing

For this, strips of glass cloth and resin everywhere you can reach. Necessary? Yeah, probably so because the build could be fairly described as economical in the application of adhesive – in an experienced builder’s opinion.

Step 2 – main gear

So the über experienced builder shares a tip with us, which I’m passing on when he confided, ‘I’m fed up with using blind nuts and machine thread bolts for installing retract units. These are big heavy models and even a slightly bad landing means I’ve got three days work to make the repair. So I’ve switched to using wood screws, instead. Now a bad landing rips the gear unit out of the wing but leaves the structure largely intact. Means I can come back and drill out the wood and insert a hardwood dowel where the screws ripped out the wood, redrill, and I’m ready to go again. Believe me when I say, *this* is the way!’

Step 3 – tail gear

The tail gear unit bolts into the bulkhead with four bolts, easy peasy!

And once installed, adding a ProModeler DS75CLHV submicro servo completes the installation as this close up of the electric retracting tail gear assembly – now installed on the aft bulkhead – demonstrates. Note the very nice scale wheel with rubber tire.

V. Engine installation

With the model finally setting on its feet, it’s time to install the engine. A few bolts and the job’s done. Side exhaust engine means carving out the side of the cowl. Ugly but can’t be helped.

Note how the DLE85 engine is mounted on rubber isolated standoffs.

So who is the fellow who has graciously shared his experience with the CY Models 96in P-51 Mustang for the rest of us to follow? Here he is, Phil Formento a denizen of south Texas in Tomball, which is in the near vicinity of Houston.

What’s more, along with the other photos, he kindly attached a photo of himself alongside his model along with a few thoughts about our servos, which I immediately sought and received permission to share.

After receiving all the photos, especially this last one after the test flight of him and his model, this is also when I decided to pen this white paper regarding his experience. This is offered in hopes you find a kernel of useful information for your build. Maybe think of this as passing along tribal knowledge!

Also, if you haven’t figured it out, ProModeler’s about shaking things up. Our whole approach is different. Shaking up the market means paying attention to the detail like bushings, o-rings, MIL-STDS, and better cooling – and slipping the shiv between the ribs of our competitors, offering same at a fair price. If you’re up to challenging the status quo, then we’re of a similar mind . . . and very well met.

Next, and at last, our interest in all this, let’s finally delve into servo selection.

VI. On selecting servos

So the 93″-class of models are actually bound more by powerplants than wingspan. These encompass 85″ wingspan aircraft at the lower end of the range, and 94″ wingspan models on the upper end.

Typically, they’re powered by twins like a DA70 in models with radial cowls. Also, depending on size, smaller thumpers like DA60 or more powerful variants like a DA85. The well heeled amongst us love small radials like the Saito FG-60R3 through FG-90R3 four-stroke gassers. And there’s also those who prefer 12S electric propulsion systems.

Propulsion wise, we’re spoiled for choice! But what about servos?

As it turns out, warbirds of this size are a great size model to own because they fly big, without actually ‘being’ too big, if you catch my drift.

Elevator servo installation within the CY Models Mustang relies on the now classic hatch system with hardwood beams.

Servo-wise the right answer is largely determined by three things. These being pilot, budget, and goals – no surprise there.

And by pilot, I mean a specific type.

Pilots

In our experience, there are three basic types of pilots. Of course there’s an infinite number, but if we slice and dice to put them in three buckets, they’re the club pilot, hotshot, and hooligan.

And look, guiding you would be much easier if we were mates. Like if I knew how you fly ‘because’ we flew together instead of what you say to me, because then I could maybe say, bluntly, ‘I’ve seen you fly inverted on purpose once, and I could hear your knees knocking, so those $45 servos are plenty good enough for what you do.’

But since we’re not mates, meaning I don’t actually know how you fly, then we have to trust ‘you’ to be true to yourself in making the determination.

Best I can do is try and help you see yourself more clearly.

Club pilot

The club pilot is what’s often referred to as a gentleman flier. Pilots fitting the description of ‘club pilot’ encompass a wide range of skills.

For example, on one end of the scale are pilots who fly a lot. They go to the field two maybe three times a week and as you’d expect, burn lots of fuel. They know everybody, everybody knows them, and they’re totally solid pilots who appreciate good centering and saving money.

Then there are those who don’t fly as often. They fly fairly high and rarely fly inverted. They’re perfectly happy flying circuits and making the occasional low pass and on their way home at the end of the day, quietly utter a sigh of relief and reflect on the successful landings.

Another fellow flies once or thrice on any given weekend, 2X a month, and enjoys visiting most of all because for him flying is about the fellowship and a break from the M-F grind. It’s about the fun.

Then there’s an in-between type of club-pilot. Talking about pilots with solid technical skills. The über competent sticks who attend a lot of events, fly a lot, and for whom centering is supremely important.

Hotshot pilots

Then there are folks who can competently perform 3-rolls down low (low being 10 feet). They are hotshots and like to show off. And they’re such good sticks they’re often called upon to do the majority of test flights for other club members.

These are the guys at the very top end of the club pilot skill set. They’re totally into performing maneuvers smoothly. Think IMAC types who love scale warbirds and they also pretty much comprise the best pilots in the club.

These are pilots whose repertoire of maneuvers includes credibly performing many from the old FAI schedule.

Hooligan pilots

These pilots are gifted natural sticks. We’re talking about guys blessed by God himself with a talent that brings the show to a stop when they take to the sky. Didn’t get there without practice, of course, but they make it look effortless.

You know what I mean, the ones for whom folks stop flying just to watch as they fly their models.

So bearing in mind who ‘you’ are pilot-wise, we’ll make equipment recommendations for your 96 inch CY Models Miss America P-51 Mustang. Just remember what Shakespeare said . . . to thine own self be true.

But first, let’s touch on budget.

Budget

After pilot type, budget is second on the list of considerations. Money lurks in every decision. Be one thing if we were all rich but the facts are money doesn’t grow on trees, so selecting servos involves a keen focus on what’s important.

I’m going to concentrate on three servos, ones ranging in price from $50, another at $70, and a third at $100 (although I’ll mention others worthy of contemplation).

However, beyond servos, I’m also going to present servo arms for which you should budget because they’re not all the same. And the proper ones are crucial in achieving the proper setup. Yes, setup!

And we’ll lightly touch on stuff like getting enough juice to the servos. If you don’t, they just won’t function as designed. This last being true whether you use our servos, or opt for a competitor’s because we’re not dealing with opinion, but with physics, instead.

These things aren’t expensive, but they’re money out of the budget.

Goals

After pilot type and budget, third on the list of considerations are your goals. Every pilot is on an arc of development.

Like there’s the guy getting started with scale models who will put himself out there for two hours every evening on a simulator. Why? Because he’s seen YouTube videos of warbirds being put through their paces and wants to reach for the same skill set.

Then there are guys who have enough stress Monday through Friday and fly a model like this Mustang for the fun of it. They love the look but they have absolutely zero intention of ‘ever’ going inverted down on the deck.

This circles back to budget and what I meant about being true to yourself because you may ‘choose’ to equip your model with our most powerful brushless servos to impress the peanut gallery but if you’re flying high due to concern with taking risks, then you’ll just be pissing away your money. Saying, choose wisely.

Note; I recognize for many of you it’s not so much because you can’t fly like a hooligan if you really set your mind to it (because you’re a decent stick and can learn, especially using a simulator). Suspecting it’s more like you’re not really into stressing over things and want the aircraft to perform realistic flight – more like maneuvers the aircraft would do at an airshow – instead.

Anyway, most serious of all are the IMAC competitors who fly scale warbirds, also. The goal for these guys is to focus on a single maneuver and work, and work, and work until they perfect it. And then go to a scale event and do four-point rolls with a Mustang to prove to their mates they can fly really well regardless of the model. These guys tend to buy our best servos.

Yet all of these guys, each with their own goals, need servos that can take whatever is dished out – and – get in return, equipment they can depend on. This describe you, too?

So next we’re going to sort the servos in terms of three broad categories of good, better, and best, and along with servo arms and extensions make equipment recommendations for your CY Models 96″ in either Miss America scheme or warbird finished P-51. But note, just because it costs $50 doesn’t make it inferior to a $100 servos, makes it a different set of choices in motors and case, but the pot’s the same in both so they both center equally well, capisci?

We’re using good, better, and best to differentiate budget vs quality.

Equipment recommendations

For pilots who want the good stuff, but don’t want to spend stupid amounts of money, allow us to introduce you to the ProModeler DL-series.

These are a family of 5 servos ranging from the DS90DLHV through the DS360DLHV – all hybrid construction standard class servos.

Good

• Qty 7) DS360DLHV – 2X ailerons, flaps, elevators, plus rudder
• Qty 1) DS90DLHV – throttle and possibly a 2nd servo for choke
• Qty 1) DS75CLHV – tailwheel
• Qty 6) PDRS25-25T arms (or PDRS20-25T if you detest touchy)
• Qty 1) PDRS34PP-25T pulley (pull-pull rudder, otherwise, a 7th 25)
• Qty 2) PDRS105 – arm (throttle and tailwheel, possibly a 3rd for choke)

Gear train

At $30 for the DS90DLHV, and $50 a pop for DS360DLHV servos, what you get are servos with the most durable and vibration resistant of all gear trains, stainless steel. And not just any stainless, 330 for the bull gears and hardened 412 pinions.

Spot Welding

But there’s more because if you’ve been flying servos equipped with brass steel gear trains, let me show you what you’re gonna get with these rugged servos, instead.

Part of making us different, the whole reason we give engineering a free hand, and behind ‘why’ for contracting officers and industrial users selecting ProModeler are thoughtful touches. Like spot welding the 6/7 compound bull and pinion gears together to reinforce them.

Or as has been observed, God is in the details

Bronze Bushings

DL-series servos also feature a rugged impact resistant upper case. One that’s injection molded of Nylon 6.6 fiber-reinforced polymer. This is the same kind of stuff used in a Glock handgun frame – and for pretty much the very same reason . . . lightweight and tough!

Moreover, to give you a long service life, one easily rivaling a pricey all-alloy case (whilst keeping weight low), and unlike others their class, you get bronze bushing reinforcing the gear shaft pockets.

13 Seals and O-rings

Another thing you get with DL-series servos, important because they’re mounted external to the aircraft, are 13 seals and o-rings. This matters not just because of the oil in the exhaust due to the premix, but because so many of you love to fly with smoke oil.

Saying this is also a big deal.

Million-cycle Pot

Also worth noting is this; you get the same 1-million cycle Noble 1mc potentiometer in a $30 servo as in our $100 and $140 servos. Means exactly the same great centering performance.

By the way, we’re occasionally asked why we don’t use a Hall Effect potentiometer like some newer brand imports. We don’t for good reason and to keep from going into a dissertation, maybe just review this brief article and learn more:

• About pots vs Hall Effect sensors

Heat Sink Center

So it gets better as you consider using DL-series servos because you also get a center case CNC-machined from a solid billet of 6061-T6 aircraft aluminum. What for? Simple, to give you better cooling.

As for when this is super important, it’s when your servos are working hard because heat is the enemy of electronics. Moreover, I suspect if you look at servos you already own, ones also equipped with alloy centers, what’s often missing are cooling fins.

This is a case where less is more because it’s within what we removed, excess aluminum by machining the fins, that you benefit. Point being, ProModeler servos use the center case as a heat sink!

Potting Compound

Something else you get with DL-series servos are how we coat the PCB with potting compound. This protects them from vibration and shock. It’s an aerospace technique, which flows and surrounds the surface mount components in sticky compound (which stinks to high heavens, and which we call monkey snot).

What costs about doing it is the time to apply – and – because we have to wait for it to cure. So time really is money during assembly. As for what’s in it for you, and why hobby grade servos don’t do it, just follow the Benjamins because unlike our direct business-model, their business sees a lot of folks wetting their beaks in getting servos into stores (e.g. the importer’s 15% cut, distributor’s and their 25% cut, and the hobby dealer’s 40% cut – all for just touching the servo and – for which you pay).

So back to the monkey snot; the end result of using it your servos are more shock and vibration resistance because of it. And what’s the alternative, doing without? This is what the hobby grade servos do.

Why? They’re rely just on the strength of the solder to securely hold delicate surface mount components like microprocessor, diodes, resisters, and FETs to the circuit board. This is a problem awaiting an ass to bite.

Saying there’s a reason the airlines, NASA, and the Air Force insist on potting compound within the avionics. And this is probably why you’d prefer your servos have it, also. Basically, solder easily fractures due to vibration.

Anyway, if you agree vibration is bad juju for your servos, then this matters! And it’s what engineering-driven means, and why modelers are switching to ProModeler.

MIL-STDS

Know what else you get with DL-series servos? Eight MIL-STDS.

Our principal customer insists on them and you benefit, too because we’re not building two grades . . . so you don’t pay a thin dime more!

What do you give up?

It’s reasonable to wonder, ‘What do I give up buying $50 servos?’

Maybe a lot, maybe nothing. And maybe nothing important to you. And probably less than you might imagine. It depends.

For example, while they’re plenty fast enough for any warbird needs at 0.14sec/60°, they’re not great if you like flying with a gyro where faster servos are better. Some care about this, others don’t.

Moreover, while they’re great for any warbird maneuvers due to their good centering, and while the brass bushing reinforced polymer case helps them last a long time, an all-alloy case will last longer than a hybrid case if you fly single cylinder engines. This is a point in favor of forking over for the best servo we will bring to your attention.

Saying unlike a smooth twin, or electric powered model, a big thumper like a DA85 will beat the ever living shit out of all the equipment, to include the servos. What happens is the plastic (where the steel output shaft bearing seats) begins to wear over time (years, though) and eventually needs replacement.

True for any servo with a polymer upper, any brand, not just ours.

Output Shaft Reinforcement

However, knowing this, we ponied up for a new mold and reinforced the DL-series around the output shaft. This, back in 2023.

So eyeball this before-and-after photo to see how this iteration is stronger due to making the ring supporting the bearing a lot larger. And now let’s compare to a popular competitor’s servo.

Better – intro

Nevertheless, there’s a reason why high time pilots, folks who fly precision maneuvers (think IMAC types who practice several times a week and also attend contests) fork over for a more expensive servo. It’s principally, for the brushless motor.

So you have to look to yourself to assess your goals, needs, and budget because to the question; can I really use $50 servos and be happy? The answer is . . . yes, you can!

Like if you’re a sport pilot, or one who doesn’t fly a lot, then it’s crazy spending more money for brushless motor servos. Especially as many warbird models don’t see a lot of flight (and note, this is true for any and every servo, from any manufacturer, which uses an iron-pole motor). They’re great motors, and highly reliable, but not especially fast and nowhere near as durable as a brushless motor.

So whether DL-series are the right servo for you, depends, It’s an open question. For me, it’s an easy question to answer.

My Top Flight Corsair with DA-85 has DL-series servos installed. And because the ailerons are comparatively small I opted for DS180DLHV on them. However, for the big ass flaps, I opted for DS360 (and also the tail feathers). Take note of the PDRS20-25T servo horn.

And although I can – of course – grab anything I want from the warehouse (although, believe it or not, I have to pay for them just like you do), for the vast majority of ‘my’ own personal warbirds, I use DL-series servos.

It is however, important to note, I don’t fly with gyros. If I did then I’d probably select DS415BLHV servos, instead. However, when it comes to ‘you’, then there’s only one answer to which servo is the best . . . it depends.

Now let’s look at what may be a better alternative servo selection for you. Making the better-list are servos with brushless motors. They offer a bit more torque, but a huge boost in speed. This is important for some.

You’ll also notice we’re guiding you to a stouter rudder servo, too. This because for pilots who fly harder, and more often, servos are getting more specialized.

So with better, we’re getting into more ‘trick’ components.

Better

• Qty 6) DS415BLHV – 2X ailerons, flaps, and elevators
• Qty 1) DS505BLHV – rudder (more powerful for knife edge)
• Qty 1) DS75CLHV – tailwheel
• Qty 1) DS90DLHV – throttle and possibly a 2nd servo for choke
• Qty 6) PDRS25-25T arms (or PDRS20-25T if you detest touchy)
• Qty 1) PDRS34PP-25T pulley (pull-pull rudder, otherwise, a 7th 25)
• Qty 2) PDRS105 – arm (throttle and tailwheel, possibly a 3rd for choke)

Pluses and minuses

So what do you get, what do you give up? To begin, the DS415 and DS505 are BLS0-series and BLS1-series, respectively

No clue what the numbers and letters mean? No need for Cliff Notes:

So while you get all the goodness of a BLS0-series, the price is higher and you get something in exchange. This is what’s better;

• 15% more torque in going from 360oz-in to 415oz-in
• 250% decrease in transit speed from 0.14sec/60° to 0.05sec/60°
• 5X longer motor life and cooler operation with brushless motor

. . . so first up, the torque.

15% torque increase

So the bump in torque in going from 360oz-in to 415oz-in represent a 15% increase. What more can you do because of it? Not much. Honestly? We only mention the torque increase because it’s greater, not because it really matters very much.

However the rudder servo goes from 360oz-in to 505oz-in and that’s a 40% increase, and in going from 0.14sec/60° to 0.10sec/60° you get a 28% faster rudder response. This is nice if you use a gyro for rudder, which is helpful on take offs and landings.

Both servos are useful as hell with big fast and heavy warbirds, the DS505 especially in knife edge because you’re asking a lot out of one servo.

Oh, and the DS505 is an all-alloy case servo, which is nice, especially if you fly hard. These servos are favored for IMAC and 3D, also.

250% quicker transit

However, the big deal is the DS415BLHV are way the hell faster than than DS360DLHV servos. And one thing faster servos open the door to are gyros.

Simply put, gyros LOVE fast servos. And this is the whole reason for the move from DS360 to DS415 servos – not – the slight bump in torque. Faster like from 0.14sec/60° to 0.05sec/60° is a welcome development for pilots who like what these devices bring in terms of flight stability.

So with gyros, the faster the servos, the better the correction for disruptions due to things like turbulent winds. Bottom line? Gyros deliver smother performing models, and faster servos are the key to this.

Brushless motor

Another thing, and one easily justifying the price for the DS415 vs DS360 is the brushless motor. These are the best money can buy. They run cooler and last 5X longer.

Don’t know diddly about the subject? Read up and learn more here:

• About RC servo motors

Bottom line? Facts are the ProModeler DS415BLHV is our top selling brushless servo because it’s so versatile it can serve in many models. Our DS505BLHV is a close second. Both are über popular with 3D pilots, also.

Next, let’s look at our best servos for this Mustang. Servos on the best-list are significantly stronger because the entire case is made of 6061-T6 aluminum alloy. Who buys these? Simple, the guy who opens the conversation with, ‘John, I want the best you have!’

And because the DS505 are $100 a pop, some guys blanche at the thought. Others? Not so much. So here’s the equipment list when you want our best.

Best

• Qty 6) DS505BLHV – 2X ailerons, flaps, and elevators
• Qty 1) DS630BLHV – rudder (even more knife edge authority)
• Qty 1) DS90DLHV – (a second if equipped with choke)
• Qty 6) PDRS25-25T arms (or PDRS20-25T if you detest touchy)
• Qty 1) PDRS34PP-25T pulley (pull-pull rudder, otherwise, a 7th 25)
• Qty 2) PDRS105 – arm (throttle and tailwheel, plus a 3rd for choke)

An all-alloy case

The DS505 case which is CNC-machined of 6061-T6 aircraft. This makes it more durable than the polymer case. If you favor thumpers, then these servos are a no brainer because the steel bearing securing the output shaft can’t deform the alloy like it does a polymer case.

Know what else you get? Now the reinforcing bushings are steel instead of bronze because believe it or not, whilst lots stronger than plastic, aluminum is relatively soft. Especially compared to the steel gear shafts of the transmission. This article may prove interesting:

• On rebuilding damaged DS505s

So if you were to open a competing servo, you may find they took a shortcut. One, which you likely wouldn’t notice until after the warranty expired. Your money, of course but when they only show the outside of the product, you should maybe wonder why this is.

For example, we have matchUP articles on the site. Like this one;

• Hitec D645MW vs DS180DLHV

Both are $40. Think this means it’s a fair comparison? Nope, the DS180DLHV upholds the family honor. Anyway, poke around with EDU on the site – no telling what kind of interesting things you’ll find.

Setup

So we began all this with a discussion about servos and setup. How with one model you could set up for a beginner, a sport pilot, or a hooligan such that the same model can be set up suitable for a novice to enjoy without getting overwhelmed.

Servo arms

In our Good, Better, and Best recommendation, we guide you toward 25mm long servo arms. In common with all three recommendations, the horns are tapped for M3 mounting hardware.

These offer three mounting positions. These go from 15-25mm and from 15mm, step outward in 5mm increments to 25mm. experienced pilots who fly hard will probably use the 25mm position and set up with ATV at about 100-120%

This presents an incredible amount of flexibility as moving the ball inward tames the model further for a tamer set up.

Note the H-beam cross section delivering incredible stiffness. Also, notice they’re thick enough using a backing nut on the bolt securing the ball link becomes a thing of the past.

Note, for pilots who prefer a smoother versus an aggressive set up, we offer a 20mm arm, also. These use M2 mounting balls and instead of three mounting positions, have seven mounts ranging from 20mm down in 2.5mm steps all the way to 7.5mm allowing you to fine tune the set up to your tastes.

Pulley – pull-pull rudder

This is where the magic happens.

And the benefit of the pulley for pull-pull control is unlike a conventional tiller arm where the non-pulling side goes a bit slack, the principle of the pulley keeps both legs taunt. The more perfectly you build your rudder pick up points (the control horns), the better. The goal, just as with a tiller, is for a straight edge between the two pick up points to be perfectly in line with the hinge line.

Since a pulley works rather nicely for cables, as shipwrights discovered centuries ago, why models reach for a tiller for this job is a bit of mystery. And yes, we offer tillers but their principal purpose is linking two mechanisms together, e.g. harnessing two or more servos together into a gang. But for cables? Pulleys are far superior for this job.

Pulleys are available from 34mm, through 50mm, to 100mm;

• PDRS34PP-25T
• PDRS50PP-25T
• PDRS100PP-25T

. . . the 34mm suited for the Mustang, while the 50mm and 100mm are best suited for 3D models spanning 85-95″ and 103-126″ respectively.

Added capacitance

Note; the savvy modeler uses a capacitor at the load end whenever an extension exceeds 30″. The trade name of the capacitors is the stupid sounding Glitch Buster but using them is smart business.

Along with a Y-harness, which is how you physically join the servo, the cap, and the extension, the basic reason for these things is to boost the juice at the servo under load. This is especially important when the servo starts, stops, and changes direction, and especially when struggling with big forces – think elevator coming out of a big ass 800′ loop.

Click on the image of this brief bestPRACTICE: article to learn more.

As for why it’s smart to add them to servos and some receivers, rather than offer you a sip and present you with a firehose, maybe clicking the photo and following the link to read later is more respectful of your time. But I promise you this – this – is the kind of stuff you need to understand.

And just a hint, the reason for needing to understand is you can think of a capacitor – basically a reservoir of current – as serving the same function as a spotter at the gym.

When you’re pressing weights, the spotter is there to help save your ass and the capacitor does the same, it’s the helper of last resort.

Both caps and Y-harnesses are available in hobby shops, or direct from us. They add negligible mass to a model and may help you. Instructions within the article explain what to buy, or how to make your own if you’re so inclined because selling these isn’t a matter of money but of best practices and is more important than anything.

Please take time to read up on this and learn why these benefit you.

Final thoughts

Allow me offer a few final thoughts. The right servo for you is a reflection of yourself, your goals, your dreams, and your budget. We put a better grade of servos in your hands. But nobody can make you buy them. This you decide for yourself.

Any questions? Feel free to reach out, we’re readily available;

• Telephone: 407-302-3361
• Email: info@promodeler.com

. . . maybe together we can suss out what’s best for you!

I’ll close with this, one thing’s certain, best is a race that’s never finished. Best right now? ProModeler, but far from David vs Goliath, we’re more akin to a flea on the elephant’s back in this battle.

Means we need your help. Presuming you like our servos, then do us the favor of taking one to a club meeting. Pass it around. Maybe even pull out a 1.5mm Allen driver and open it up – you’ve seen how they go together, there’s nothing to be afraid of. And please, show them to a pal.

But most of all, kindly grace us with a photo sharing your thoughts. What for? To put on the website, and within articles like this. Basically, for telling the next guy what you like about our servos.

We’re Jones-ing for photos like this one because your favor is priceless and can’t be bought. We know this. So do others.

Last thing

Have you enjoyed this? If you like reading and are interested in learning more, then maybe find time to review more articles like this;

• On the batteries John prefers using
• About pots vs Hall Effect sensors
• On selecting battery packs
• Pro tips for improving your ARF
• Amazon servo vs DS505s
• Why’s my pack got two JR-connectors?
• Rip Van Winkle, on returning to RC
• How to guide a rocket using servos
• Phoenix Models 70in Strega guide
• Advantages of pull-pull via pulley
• Bret Becker: Mr. Top Gun
• Will ProModeler servos work with NiCds?
• How to determine flight time for a 2S850 LiIon
• Hangar 9 60cc Pitts S-2B servos
• Fear of loss, or how to stack the odds in your favor!
• When LiFePO4 is mistakenly charged as LiIon
• Idle thoughts regarding chargers

. . . and hundreds more. Best part? They’re all free!