Any Fanatec DD owners moved to SC2?

Simucube 2 Simucube 2 Questions
103

I’m sorry but this is a bit of a misunderstanding.
The DD1/2, due to the outrunner design, has static magnets that cause an “abrupt” ramp up of torque even at lower gain settings. This is the physical characteristic that also causes the motor to feel slightly notchy when powered down.

For this reason, when torque signals are sent to the motor at low gain, you have the FFB signal + the static magnets causing motion which can trick you into feeling that the FFB is sharp and more abrupt. But this is actually you getting more information than you’re supposed to get (errors). You see, FFB signals are very dirty.
FFB in Windows has for the most part not really evolved for around 10 years now.
Part of the reason Simucube 1 gained so much popularity is due to how much it was able to smooth out the really primitive and archaic 60 Hz FFB signal that iRacing uses.

Because of the outrunner technology, a Fanatec DD1/2 can beat up your hands more with the same relative “smoothing” and dampening. This tricks you into thinking the FFB is more raw or fast, but really it’s just less filtered and also boosted by the static magnets in the motor housing causing +/- rotational degree errors by rotating or stopping the shaft at the end of every FFB signal.

So basically with a DD1, you’ll need to apply more of their “interpolation filter” in order to smooth those details out.

From what I understand, a Fanatec is great for around 40% max wheel/wheel force in iRacing or lower. Higher proportions than that (i.e. more than 10 Nm of Torque on the SC2 Pro/DD2) and the Simucube 2’s inrunner motor will really show its strength.

Personally, I intend to go the opposite direction. But not because the SC2 is inferior, only because I want console compatibility and I feel that the DD1/2 when the filters are applied will be “smooth enough” for me. But make no mistake, the SC2’s servo motor is the best in the industry. It stands alone.

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104

Thanks for your thoughts, SonnyTron,

I’m curious why you say the fanatec is best at under 10nm and sc2 above?

Thx

105

Both in- and out-runner servos have static magnets, they are both permanent-magnet servo motor types. They both exhibit cogging/ripple torque behaviour, which needs to be compensated for by the electronics.

Due to the design though, out-runners will be more difficult to bring under control, it will have higher torque (generally, if we talk high-quality servos) for the same size servo vs the in-runner, but it will be very difficult to make them as smooth as the in-runner style servos.

Electronics are not infinitely fast, there are limitations to the ripple it can control when considering things such as number of poles and a few other factors. There are a few good reasons to go out-runner servos, or even steppers, but those benefits goes in the form of cost-saving to the manufacturer, giving them better margins et al.

In-runners will mostly always be more expensive, but they are also significantly smoother when compared to out-runners and steppers.

Different horses for different courses though.

Just my 2c.

Cheers,
Beano

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106

It’s not the best, it’s a personal choice, he most likely prefers the excessive noisy/spiky ffb behaviour from the out-runner style servo which might be construed as useful ffb information at lower torque levels.

IMHO, it’s not useful at all and reminds me of the old Argon OSW days when we had a very similar behaviour from the small Mige servos when driving them hard. We have come a long way since then, but you will still find a few individuals that prefer that noisy behaviour.

Good to different solutions to cater for the outliers, but again, IMHO, the SC2 series (almost) covers the complete tactile spectrum other DD wheels offer.

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107

Thank you Phillip,

I think you’re completely right when it comes to the hardware, but the sport and (not so) “pro” have been software crippled, not having the gamma filter, so they cannot be set to behave more exaggerated active at the low end, should you want that. I still don’t buy any of the arguments for that crippling from a marketing or user’s perspective. It’s hugely annoying, since I think some Sims are set up expecting the wheel bases to have this exaggerated characteristic at the low end.

I mention it only again since I know you have the ultimate, in which case I do believe your statement is right on. But on my “pro” I have no way of simulating that low end aspect of some/many wheel bases.

Thanks,

-K

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Hi K,
I actually have a very custom setup, based on a SC2 Ultimate controller, married to an AKM65K servo. This servo has a fair bit higher inertia that the SC2 Sport, Pro and Ultimate.

So my settings are actually leaning very much towards a smoother experience, cancelling the noisy spikes from especially iRacing. Seeing the servo has higher inertia, it has more natural damping to start with, on top of that, I still add additional damping, friction and inertia.

Anyway, I personally had never had a need for a variable gamma, I could always use existing settings to get the feel, even very active, what I wanted from the sim.

See attached, the very special test-horse I am using. I have an Ultimate (and OSW, Podium DD2) as well, but my personal preference is my custom setup. The Ultimate though can be made to get very close to the active behaviour of the Podium wheels, but imho, that is not realistic and representative of even remotely close to real-life at all.

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109

Nice :smile:

But having more inherent inertia, do you not feel that it exhibits both the good part of making the ffb feel more real, but also the bad part, that it hinders movement sometimes when it should not?

110

Not at all, this thing has 45NM on tap if required, and the servo has a pretty high rpm level too at 48V.

So response can be very dramatic, enough to rattle the fillings from one’s teeth :rofl:

111

Hehe!

You take FFB commitment to the next level :smile: :+1:

112

It’s good fun, plus wrestling a big servo keeps me fit :rofl:

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113

there is no such thing, all sims are designed first and foremost to run on low/mid level hardware, not dd wheels. we adapt to run dd wheels with sims, not the opposite.

114

“we adapt to run dd wheels with sims, not the opposite.”

Exactly, which is why it’s an annoyance to not be able to exaggerate the low end, when it sometimes feels needed.
I am not sure why you say I stated otherwise.

Best,

-K

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115

The only thing that you have in the post that is incorrect is that with the design you are not getting more information than you are supposed to you are getting the information faster and more abruptly with the DD1/2. None of the wheels can by themselves determine which signal is in error and which is correct so the difference is that some wheels are less likely to reproduce the signal fast enough to be able to give you all of the signal coming through to the wheel…

It sort of depends on which side of the fence you are on as far as which end of the spectrum you want to be on active or not as active…

@kledsen - This activeness is part of the reason why the DD1/2 is a better wheel than the SC2 at lower at the wheel (specific output) power levels because of the higher Magnet count and faster ramp up of torque it is able to give a sharper signal at low power which allows you to better feel the feedback when it is being provided at a lower amplitude… This low power phenomenon is one of the reasons why many always ask where is all of this feeling of understeer, detail, ect… is, but then you find they are running at 20% specific output… it just because they are unable to actually “feel” it at the settings they are running… it is there but not as detectible with a system that provides softer transitions between signals.

116

Hey bsohn,

Thanks again for all your input, really appreciate it!

@phillip.vanrensburg posted yesterday additionally that:

I think you both agree the outrunner is more “active” & Phillip likes a more relaxed wheel base, like his monster motor or a SC2’s motor, since they remove some feelings he would otherwise use filters to fight.
One part of that is def. spikes in the ffb signal from whatever game & also caused by low frequencies being provided.

But he’s also saying the magnets contribute to a great deal of the details feel & that these are inaccurate artifacts that you don’t want. Do you not agree to that part?

Thanks again,

-K

117

Yea I tend to like a more subdued servo as well but not quite to the same degree as Phillip does… I actually have a monster servo that I haven’t yet hooked up to my SC1 (mainly because I don’t have a set-up capable of holding the weight of the thing let alone the power of it) and I believe one of the keys to a well behaved system is actually static inertia… On the SC2 Pro I actually use a decent amount of torque skew to mimic the feel of having a heavier servo without having to slow it through the use of Damping and Friction.

I do agree that there are errors in FFB that can give unwanted feelings / signals but all the wheels have to cope with these same signals. None really have the ability to reject these errors as actual errors, Because the systems just don’t know what is actually an error or a true signal.

The magnets, the power of those magnets , how the motor is wound, how much current can flow through the motor, the overall weight of the armature, ect… all contribute to the torque and power profile of the servo… Out-runner Servos don’t carry their winds (electro magnets) on the armature which generally allows them to have less static inertia and as well more magnets for a bigger magnetic field. This is why they tend to be quicker responding than a similarly spec’d in-runner style servo.

Depending upon how the servo is controlled at the Drive level there can be unwanted out of control actions that the servo’s have at the extents of there signal, i.e over or undershooting the intended torque mark… though this can generally be controlled either by the manufacturer of the drive system internally or the user through the use of the filters provided… A more active servo will be more difficult to control in this manner because it will reach the target point Much quicker than that of a less active unit. so when you put more power behind that movement the controllability becomes even more difficult. This is one reason why lighter weight, Higher torque servos tend to get very harsh at high strength levels (i.e why the Fanatec feels better at lower powers than higher powers). though even if that faster servo is controlled properly the speed at which it gets to a point and returns to another can cause the feel to be rougher if not harsh depending on the game signal.

An in runner servo will generally have more static inertia which naturally makes it a little slower to respond though it can ramp up to meet the torque commands properly but if the signal changes during that ramp up it is possible it will never reach the torque level before responding to another signal where the faster unit would… This is where the in-runner can have a softer smoother feel as due to the natural inertia it automatically smooths the signal. it still reacts to everything it just doesn’t react as fast… when using lower power there is not enough grunt to get the servo moving as fast as quickly do the servo smooths even more creating that sense of lost detail the comes back when using higher forces.

Small low torque in runner style servos can be very responsive and feel more abrupt as well but they of course can’t deliver as much torque.

Overall though it is a personal preference as to the feel that you as a driver enjoy… For me in all the race cars I have driven the steering was not harsh per se but was forceful. Generally lively but not super quick, felt rubbery but not lazy… generally provided a little but not in your face feel for road texture, and this is how I set up my wheels. Or at least try to… With the Fanatec DD2 I have I was able to get close but it always felt a little to harsh at the power levels I like… My SC1 Large was about perfect the SC1 Small i used for a while for comparison I got close but to get it right I would have to over filter it which caused it to feel sluggish, I have gotten the SC2 Pro to be just about where I like it…

The one thing that I do belive is that the SC1/2’s have always had software which is good to get a wide range of active to inactivity out of the servo without necessarily going overboard on the filters… though I will say if the Sportor Ultimate are similar in Feel to the pro they are slightly biased toward the less active more natural side of the spectrum… and an SC1 small mine and units like the Fanatec will be better suited for low force users.

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118

Probably quite a few points in Brion’s post above I either misread, or don’t agree with, from a technical perspective.

Both in- and out-Runners have fixed stators, in both cases the rotor has the magnets attached. On an in-runner, the rotor is the central part of the servo, and rotates, whilst the stator is fixed to the outer shell/case.

In an out-runner, it is the exact opposite, the stator is fixed to the inside of the servo, and the outer case/shell houses the magnets, which also rotates…

In-runners are typically smaller in diameter, but are longer, vs out-runners which typically have a larger dia, but are shorter. Wrt speed, please note comparable sized in-runners typically have a higher RPM/V (Kv) value than an out-runner.

Out-runners with their larger dia rotor (outside rotating part) allows more magnets to be placed, which leads to a larger circumference of rotation in one direction, which might also give you a larger arm of momentum, hence more torque vs comparatively sized in-runner.

But, the caveat here is, that was my earlier point, that this higher magnet-count requires significant faster switching electronics due to a much higher pole-count, which leads to much more work to be done by the controller, slowing down the RPM/V capability of the servo. Due to cost, designing fast-enough electronics to control ripple, becomes a limitation.

I have done extensive testing on Podium DD2 (Out-runner), Accuforce (Stepper), and a huge range of in-runner servos. I can, at will, induce torque-ripple in both Podium DD2, as well as Accuforce, due to the point mentioned above. You can test yourself if you have those systems, set torque to maybe 8-10NM, run a tight, fast road-course on iRacing, like the Esses at Rd Atlanta, Monza, Donnington, etc…do fast steer and counter-steer moves, see if you can feel the ripple induced onto the ffb signal.

Perhaps best not to do it, because once you have felt it, you can’t ‘unfeel’ it … :frowning:

But please note, the relationship between Torque and Kv is inversely proportional, one increase, the other decreases. My comments above are very generalist, quality of the components, design and a few other factors all play a key role in how well a specific out-runner will perform vs an in-runner.

Generally, another point of consideration is heat, and efficiency. In-runners typically run much cooler, no requirement for large heat sinks or active cooling, as opposed to out-runners, which often requires these measures. In-runners are also much better when considering efficiency.

If I want to drive tricycle in Down Town Hong Kong, or diy a nice powered skate-board, I will opt for an out-runner, but for DD wheels, I will always pick an in-runner.

Not all servos are equal, I am well aware of the servo-selection process GD went through to select these specific 3 servos for their commercial DD wheel series. There are none better, certainly not in the affordable range, if at all. I would very much say it is safe to think that if you have 1000 units of each subjected to testing, a very small percentage would go for the higher ripple-prone behaviour of out-runner or steppers, vs in-runners.

One word of advice I always give to people though, before you make your mind, please try and test (for at least a day each) different technologies before splurging your cash. Please avoid the pit-fall of a more active feeling is a more accurate feeling. But if that’s your thing, there are DD wheels that will cover your needs.

Be aware though, that if you are after that very active feel, go for a small, but high-torque servo, as different weighted /dia wheels will significantly impact your DD wheel’s overall inertia, being counter-productive at some point. Hence my recommendation to go for something like the SC2 Pro, which is the best of all worlds.

Also consider latencies of the equipment under test, I know I am quite sensitive to latencies, and from worse to best, the Bodnar SS2 is the slowest, followed by Podium, next Simucube 1 and the fastest, the SC2 series.

Tommi however knows a lot more about the servo-topic than I do, hopefully he can chime in.

Cheers,
Beano

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119

This is a pretty good summary by Brion though, one I agree with :wink:

Between advanced filters like Skew, Torque Reduction, and Reconstruction Filters, and more basic filters, like Damping, Friction and Inertia, you can basically emulate any other DD wheel on the market. For the record, I hardly ever use Torque Reduction (Kledsen can use this one to almost create the effects he is after), nor Skew.

I do tune Damping, Friction and Inertia based on wheel-rims though. But hardly ever have I found a need for more. I basically set Reconstruction to 3-4 on my large servo, 5-6 on my Ultimate, and never touch them again.

@Kledsen: To maximise the raw ffb feeling from your servo, there are a few things you can do:

Reduce Damping, Friction, Inertia as much as you can tolerate without oscillation.
Reduce Reconstruction Filter to either 0 or 1
Maximise Skew and Torque Bandwidth Limit
Set Torque Reduction Filter to perhaps 25-35%
Increase Servo power to 70-100%

Adjust in-game (iRacing) gain during high-speed turns to be pleasant/manageable.

See how it goes for you wrt feedback effects.

Cheers,
Beano

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120

Would you be willing to share those settings?

121

Thank you @phillip.vanrensburg & @bsohn!

For your long & detailed answers, I finally have my question marks well covered!

Really appreciate it, big time, I learn a little bit more every time you guys spill it & this time, added to the prior times, I finally feel that I have the almost full picture in my head :slightly_smiling_face: :+1:
I might be slow, but I know when to be appreciative :smile:

Thanks again,

Best, -K

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122

You’re welcome, and don’t worry, I have many ‘slow’ days :rofl:

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