Question DIY BLDC ffb wheel control (MMos)

Hey all,
This is my first post here,
I have been looking around this thread and learned a great deal from the MMos (non OSW) projects.
I posted this on the virtualracing forums as well, I need a little help in understanding the MMos firmware I/O.

I am planning on doing a project with a BLDC motor and a belt drive for a custom MMos setup for under €200 (without wheel). Unfortunately I cannot dish out the money for Direct drive system. I know the belt drive will not feel as good as a direct drive system but im tired of the reliability issues on my thrustmaster t300, and thinking of making something more reliable and far stronger than that (something along the lines of CSW V2) on a budget. I could go for a DC motor and make my life a little easier but after using both the the T300 and T500, i loved the detail on the smaller base due to the brushless motor.

The 2 motor options i currently have in mind:
1) 188W, after gearing of about 1:8, i would have around 19Nm of standing torque with around 400rpm, but peak current of 45 Amps

http://www.ebay.de/itm/DE-SHIP-ACT-...438.l2649&clk_rvr_id=1275124115704&rmvSB=true

2) 125W, after gearing of around 1:10, 12Nm standing torque with around 300rpm at the wheel, but a much lower peak current

http://www.ebay.de/itm/DE-Free-ACT-...935241490&clk_rvr_id=1275116936734&rmvSB=true

The question i have is regarding the 6 svpwm outputs from the stm32 for bldc control and whether they would be compatible with a sensorless controller like this, this is a 40A version (there is a 50A version as well but they are like unicorns, with a lead time of over 30 weeks):

http://www.mouser.de/ProductDetail/ON-Semiconductor-Fairchild/FNB34060T/?qs=sGAEpiMZZMtKB4wrjsn3lTMkFUy1fcOLk/1a1OfbECQ=

it has 6 pwm inputs with little or no serial interface with the MCU. If i use this with the 1st motor with peak amps of 45, how safe would it be? how frequently is the peak current drawn on an ffb wheel. if not then the other option is to make my own circuit with gate drivers and external high power mosfets, again sensorless (encoder signals going directly to the stm32)

Lastly, can i use the hall outputs from these motors directly to the discovery module? if not i have an alternative for that then too,

I am a mechanical engineer with limited knowledge regarding power electronics so please keep that in mind,

Cheers

I have no answer to your question, but I have the same thoughts also. I have also sent a question to the author of the mmos firmware but no answer. Have you found any answers?

Well for torque control you need some sort of feedback (current sense or position based) to the MMOs from the motor driver, So i dont think it would work since the MMOs does not know when to activate which phase, which is necessary for pure torque control, it might just have 6 PWM outputs for each phase which have a life of their own, might work for speed control but not for an ffb case. Im curently making an arduino controller for the gate drivers that basically reads the exact position of the motor and then gives out a signal based on the rotor stator position, so its going to be MMOs(in PWM, DIR mode) =>Arduino=>Gate drivers=>motor. The code is simple, have had make h bridges myself. testing it out on a TX motor (my TX died). will post here when i have more updates. the motor runs fine, so i think the code logic is good (using sine wave commutation), need to sort out the gate drivers though. Will post here on the progress, if you have an questions feel free to ask

But the MMOs has the encoder connected, so it should be possible if the author of the firmware have code for it. I have plan to a similar solution as you in the future when I find a bldc motor strong enough for direct drive that doesn't cost to much. I realized in my current DD DC motor build project that current loop is a little overrated, so I can't see the need for the expensive driver from simcube or argon.

Well the simcube and argon are highly refined products as compared o what we#ll come up with, as far as the power delivery stage is concerned. the MMos does have feedback, but that is just and encoder signal, its not possible to read the exact position of every motor with that. im using an AS5147, wich sends out an encoder signal to the MMos to read the wheel position and serial communication with the arduino for commutation control, e.g total rotation(0-360 degrees) after measuring the relative positions, i tell it to start phase U Sine wave at say 36 degrees. and im doing his on a much smaller motor, I found a motor on Aliexpress that costs 150$ without shipping, that has 13Nm of torque. for that Mosfets and all have to be very carefully selected

Just curios if you done some progress in your project? I'm still haven't found anything that confirms the function of the BLDC outputs of the MMOs card/software. I know that you at least can choose it from the configuration software.