News How to use Mige servo motors for motion rig? Please help.

...would that work / does that make sense at all?
I'm thinking about these motors people use for direct drive sim wheels:
Motor / PowerPrice / Peak Torque / Holding Torque / Encoder Resolution / Motor Weight / Motor Inertia / Torque Coefficient (datasheet) / rated speed
Mige 130ST-M10010 / 1.0 kW / US$ 237 / 20 Nm / 10 Nm / 10000 / 11.5 kg / 19.4 kg cm^2 / 2.2 Nm/A / 1000 rpm
Mige 130ST-M15015 / 2.3kW / US$ 332 / 30 Nm / 15 Nm / 10000 / 14.4 kg / 27.7 kg cm^2 / 1.58 Nm/A / 1500 rpm

The concept I got in mind is the same as that vertex2 by diysim (http://diysim.com/products/chassis/...udes-framing-hardware-assembly-manual-motion/) just without the actuators, but the servo motors instead.
Please forgive me if that's completely silly...it's a serious question
Cheers

Hi ,dont you need a gearbox atach to those motors?

I believe that's not necessary...you wouldn't even need a separate sensor. It seems so simple. I really wonder why that's not being done.
Of course these motors aren't really cheap, but still far less expensive than a powerful actuator with some decent travel.
Would be great if some of the cracks here could provide some feedback.
Cheers

Have you considered how you are going to control the motor?
Those motors are PMAC motors which are basically 3phase induction motor but the rotor coils are replaced with permanent magnets.

You cannot control those motors with the low powered H-bridges or controllers that are being used by the usual motion platforms as your motor runs on 120VAC.
Three full H-bridges rated >120V @ 3A and a controller that will commulate( power the 3phases in correct order) will be minimium needed for the 1Kw motor.
You could go down the industrial route and purchase a ready made one eg. granite devices, toshiba etc but that will cost you 2-10x what you are paying for the motors.

Cheers for your reply
So if one motor is $300, the controller for it is lets say $3600 and that adds up to 1.8 - 6.6k for a 2dof rig, right?
That's a lot more than a set of SCN5's, but they wouldn't be able to handle the load anyway.
I'd think you could control that system with Simtools. Would you think that a setup like that is a good and durable one?
Does it have advantages or more drawbacks?
Would that be difficult to build?

@Thirsty
PMAC motors like the ones you list are some of the most effiecient and smoothest(very little cogging) motors available and provide a powerful motor in a compact package which is why they are prerfered motors for direct drive FFB steering wheels. Most automation robots today are using PMAC because of the ease of precision positioning, speed and power.
One of the best advantages would be the precision positioning given by the 2500cpr incremental encoder compared to the pot used by most motion sims. It would be like comparing 10 bit to 16bits resolution or feeling a small bump on the road compared to nothing at all due to low resolution.
Direct or belt drive would also be possible due to the power of the motors which would eliminate the backlash of the gearbox during direction changes (worm drive gearboxes are the worst for backlash)

I cannot see any real drawbacks of using PMAC besides the costs of industrial controller, in which if you use with simtools you will only be using a fraction of the functionality of the controller. You would also need to work out how to get the output of simtools to communicate with the controller which wouldn't be too different to SCNs.
Maybe that you could make your own simple controller which would involve 3 H-bridges, an incremental decoder and a few microcontrollers or using a hybrid motor controller IC and H-bridges.
AFIK the difference between a PMAC and a BLDC is in the way the controller powers the coils. BLDC feeds the motor pure DC voltage while the PMAC uses PWM to simulate a sine wave hence the smoother motion and better positional accuracy.

you can use the very same controller as Direct Drive Wheel, no? 300$ each not 3600$...

For sure this for me would be a great idea as it would simplify building a motion rig so some body could put together OSW type project using similar parts like the IONO,Dragon,Mige servo motors ect
I myself have an OSW wheel and its fantastic but I didnt buy the parts separate I bought them as a kit and put that together as it made sense for me to do it that way.
Its high performance and relatively low cost that I think makes this a worthy project to pursue for my own 6DOF.
What do you guys think?

IONI is 149€ and Pro is 179€
http://granitedevices.com/store/motioncontrol/ioniseries.html

Mige is 410€ shipped to europe


I have read in the IONI specification that it accepts PWM set point
so I suppose that an arduino could drive it

Thank you very much for your explanations. Unfortunately I don't have the skills and knowledge to do that - just lacking basics here, so it's not that I'm just too lazy and invest the time to get my head around this. I brought it up because it seemed to me a simple concept and I would expect it to be of very high quality and much more robust as these SCN5's which aren't that cheap either.
That would be something I was interested in if there was support in the community.
Cheers

IONI can be driven by PWM and Dir (direction) so the usual Arduino codes should work
IONI have to be setup with Granite Device software to be in "position mode" and not "torque mode" as in the Direct Drive Wheel.

it's curious that we don't see on the Internet any example of IONI and motors in position mode ?

Cheers mate. It would be great if that was possible. In this case it would be even cheaper than SCN5's. The SCN5's wouldn't be powerful enough anyway for the type of rig I got in mind.
I hope that someone takes on a project like that sometime in the future and maybe shares his experiences.

Its your thread and idea, won't happen by itself.

Hey mate, of course you're right. Yeah, but unfortunately my knowledge about electronics stuff is just not sufficient.
There is a reason I'm using a Simx kit. I find these real diy rigs much cooler though and really admire people who can do that.
Still not a bad thing to discuss it here imo.

I was thinking of using these i have a spare mige sitting here and am very aware of the capabilities of the ioni and argon ( i've used them on a few project). My only issue with that method is the cost (about $1300 per axis inc PSU Ioni mother board 4x Servo shipping etc). An all that for only 20nm torque peak. but it is a fast accurate 20mn force.

Cheers for the feedback. Just guessing here, but with the right gear ratio 20nm may be plenty for a motion rig. I paid more than 3k for my Simx SCN5 actuators and it seems to me they wouldn't be strong enough for a vertex 2-style rig. So $2600 for the Miges incl. controllers is not too bad imo.

sounds like the price might not worry you then. There will be a couple of other things to remember
the ioni is only a 48v drive so the small mige wont spin at its rated 1000rpm it will top out around 350rpm so any gearing to increase torque will reduce that speed advantage it gives over a dc motor. Maybe look at the big mige with an ioni pro hc that from memory is good for nearly 30nm without gearing and doesn't cost much more and may retain that speed advantage.
Or maybe look at the argon drive its not much more and has a higher output voltage allowing higher speeds and you simplify things by not needing a separate power supply.

it's not a big problem to drive the servo motors , there are kinds of drivers can mach the motors ,like ioni /Argon /some other drivers ect .
but how to control the position of the motors? I don't want to add the potetiometers , is there any method to use the encoder of these motors?
and use gear box is better.

if you use a IONI for example, you can use the MIGE's encoder: it's designed for this!

thank u ,need to add an endstop switch to catch the position ? or just connect to the driver by 232.