Rotational inertia problems for small Mige?

Hi guys,

I have a question that feels important to me, but hopefully its not really an issue.
I am going to buy a mige OSW, however I am struggling with the well known “large” or “small” issue.

The point that makes my question specific is that I am going to run it with a 4-5 inches long spacer and a quiet heavy quick release. This adds some extra inertia (I think 400 grams or so).Wheel itself is 335mm diameter.

Can this be an issue to the quality and strength of the FFB with the small mige, due to the extra rotational inertia? Or would it be safer to go with the large?

If you’re worried about inertia, well, the small Mige has less than the large and will thus be more responsive for the same external weight added.


Thanks for your response!
That seems as a fair point. But does the small mige produce enough peak force to get it moving quickly enough to avoid loss of detail?

Furthermore I have read quite a lot of your posts Beano
But do you have a specific recommendation for going either with a small or a large Mige (both with a sincos encoder) in order to most exactly replicate the handling of a race car as correct as possible?

Remember that sim is sending torque commands only and reads back position. It’s not sending position. So loss of detail is a mute point here. But you can decrease wheel weight to reduce inertia since that is by far outweighs everything else. Unless you need to have more torque - smaller motor is better by all means.

Small mige is plenty of strong more than you will ever need imo. And i would always advice it because it responds faster because of having less inertia.

Most of the mass in such cases is generally near the center so it’s not likely to be an issue at all with this type of steering system. The 20Nm system far exceeds what I can use anyway and in many cases, I actually need to tune in some dampening to slow down the response a bit. Adding some mass might actually have a positive effect in improving realism, imo.

Either way, I think you’ll love the OSW and the tuning needed is usually pretty minimal once you familiarize yourself with the baseline results and feeling.

Thanks for all the replies guys, really! This truly strengthens my tendency to go with the small servo. I guess I’ll get it in the coming month once simracingbay has them in stock again.

Yea, you will sort of get what you get and you will be happy, Generally the more weight you add to the system the more physical damping and the more weighted the wheel will feel, Because a real cars steering has a BUNCH of inertia (weight) in the system generally it will be a little more Natural feeling with less abruptness… Some like the immediacy of the information that a light wheel set-up will give though others like me feel it is a bit too harsh… Generally speaking both servos have more than enough kick to get just about anything moving.

All I can tell you is, I bought a large mige simucube kit and all I have had is,
Cogging/notching and noise, which I can feel in the wheel.

So, Id say get small Mige. Wish I had.

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you can always add dampening if you find the small mige too quick.
you can never remove the extra weight / intertia(damping) from the big mige :slight_smile:

But in my opinion the small mige isnt too quick at all. Another thing, people would never buy the much more expensive kollmorgen motors which are way quicker and have a lot less inertia. and are only 16Nm

iMac…there must be something out of spec with your large mige. Mine is smooth, never notchy. Are you using a drc from an OSW vendor? If our system specs match, I’d be happy to share my drc for Granity.

I have 10,000 encoder.

On the broader question of small vs large Mige . . . I have no basis for comparison of my large to a small, having only used this large. I will say, the extra rated torque of the large would be of no relevance to me were I in the market now. After experimenting and playing with high settings, I have ultimately settled in on running my large 30 to 40 % tops, which would translate to 45 to 60 % or so on a small. At these reasonable power levels sims like AMS produce incredible range of torque, strong feed back, and subtle and detail. While novel, high power settings are neither practical nor enjoyable to me in running more than a few laps.

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Hi manashuttu,
I Will pm you so dont takeover this thread with my problems :wink: