Dfgt motor mod

[Megamarcx84]

So I've searched on google and was even led to a few threads within GTPlanet but have yet to get a definitive answer. The situation is this: I bought a new DFGT in Aug 2010. I've been using it for drifting on on FFB setting 10 pretty much nonstop since Nov of that yr, and it is finally starting to show signs of the motor burning out. I'm at the point where I refuse to buy another wheel(this is dfgt #2, have had three DFPs since GT4), so I will gradually just replace components and mod them as I see fit. Eventually I'll have an ebrake, a relocated sequential shifter, maybe even a button box and a new wheel rim, but none of that will matter if the motor is not there for feedback. I imagine logitech used some industrial no name motor because there's no indication of any parameters necessary to procure a replacement motor. So I ask, doth anyone at least know the current and voltage draw? I've spoken to a few RC shops in the area and from what I described of the wheel they're telling me its going to be a low turn, high torque motor; they have lots of assorted ones ranging from $15-30 and i figure a sawzall and a little circut board relocation can accommodate a range of sizes.
So anybody?

 

[GUMP07]

See if there is a part number on the motor and google it like "01010101 electric motor.

I don't have experience with the DFGT motor but I do know that the aftermarket RC vehicle motors can draw a lot of power probably destroying the electronics in the DFGT.

 

[sesselpupser]

I looked at my DFP's logic board to see about replacing the 12V motor with a higher power one and came to the conclusion that... Er... I'm not sure if I ever did come to a conclusion. I can tell you that the DFP, G25 and G27 and therefore most likely the DFGT use MOSFETs to 'isolate' the motors from the board. A MOSFET is kind of like a voltage-controlled variable resistor, so in theory if you could get a 'bigger' (i.e. higher-rated) MOSFET and a bigger power supply, you could use whatever motor you want and the DFGT's logic board wouldn't mind. The problem there is the higher the current the MOSFET and motor are dealing with, the hotter they get; that's why some modified wheels using bigger motors have cooling fans and heat sinks. If you try and hook up a motor which will draw too much current to an unmodified DFGT logic board, you'll blow the MOSFETs but the rest of it will be safe, probably.

I recall reading one man's account of how he left his G25 alone in a humid room for about a year, came back, plugged it in and it blew up. He opened it up and found the commutator in the motor had been gunked up with a sort of carbon paste (as a result of carbon dust from the brushes mixing with humidity in the room) which shorted it out, in turn blowing a pair of ICs on the logic board. To get it working again all he had to do was look up the ICs' part names, they turned out to be MOSFETs; one IC was a pair of N-channel and the other was a pair of P-channel. He ordered a pair of them, desoldered the old ones, soldered the new ones in, cleaned out the motor and that was all he had to do.

With the right test equipment you could probably ascertain the spec of the Logitech motor, but I imagine there are other resources on the internet which would tell you all about that. It might be easier to work out the MOSFET input voltage and then go and find some MOSFETs that will drive any motor of your choice with that voltage input, and to be safe make sure you cool them properly. You'll also need to work out how to power it, but I suspect you could make up an entirely separate circuit (as long as you make sure the ground is shared with the DFGT itself) with it's own power supply rather than trying to redesign the DFGT to work with a higher voltage. That does mean the wheel will need two mains sockets, but hey ho.

 

[bevo]

I bet the easiest place to find the best way to do what you're wanting to is to go to Rc car forums. As you know These wheels use Rc car motors and guys stack the fets all the time in mini z cars so that they can use bigger motors.
Try going to a site called mini z racer and ask around there. They will have pictures of how they did it to the boards on their cars and I imagine it would be the same as to what you're wanting to do.
Rctech is another good site with alot of information that would probably apply to your mod.

 

[Infinital-NG]

I'd take the wheel to an rc shop and let them look at it.

 

[Megamarcx84]

I looked at my DFP's logic board to see about replacing the 12V motor with a higher power one and came to the conclusion that... Er... I'm not sure if I ever did come to a conclusion. I can tell you that the DFP, G25 and G27 and therefore most likely the DFGT use MOSFETs to 'isolate' the motors from the board. A MOSFET is kind of like a voltage-controlled variable resistor, so in theory if you could get a 'bigger' (i.e. higher-rated) MOSFET and a bigger power supply, you could use whatever motor you want and the DFGT's logic board wouldn't mind. The problem there is the higher the current the MOSFET and motor are dealing with, the hotter they get; that's why some modified wheels using bigger motors have cooling fans and heat sinks. If you try and hook up a motor which will draw too much current to an unmodified DFGT logic board, you'll blow the MOSFETs but the rest of it will be safe, probably.

I recall reading one man's account of how he left his G25 alone in a humid room for about a year, came back, plugged it in and it blew up. He opened it up and found the commutator in the motor had been gunked up with a sort of carbon paste (as a result of carbon dust from the brushes mixing with humidity in the room) which shorted it out, in turn blowing a pair of ICs on the logic board. To get it working again all he had to do was look up the ICs' part names, they turned out to be MOSFETs; one IC was a pair of N-channel and the other was a pair of P-channel. He ordered a pair of them, desoldered the old ones, soldered the new ones in, cleaned out the motor and that was all he had to do.

With the right test equipment you could probably ascertain the spec of the Logitech motor, but I imagine there are other resources on the internet which would tell you all about that. It might be easier to work out the MOSFET input voltage and then go and find some MOSFETs that will drive any motor of your choice with that voltage input, and to be safe make sure you cool them properly. You'll also need to work out how to power it, but I suspect you could make up an entirely separate circuit (as long as you make sure the ground is shared with the DFGT itself) with it's own power supply rather than trying to redesign the DFGT to work with a higher voltage. That does mean the wheel will need two mains sockets, but hey ho.

I drooled a little bit....potentially by replacing MOSFETS and adding cooling fans and a secondary power supply, I could have a substantially torquier motor? Makes me wonder how much the plastic components that limit wheel rotation could take...sir, you've inspired me to look for a cheap used dfgt come tax return time!

 

[sesselpupser]

I drooled a little bit....potentially by replacing MOSFETS and adding cooling fans and a secondary power supply, I could have a substantially torquier motor? Makes me wonder how much the plastic components that limit wheel rotation could take...sir, you've inspired me to look for a cheap used dfgt come tax return time!

In theory, yeah, but in practice... I'm not 100%. I stopped investigating modding the DFP because I was struggling to determine what exactly was going on without an oscilloscope, but I'm hoping to get one soon so I might come back to it. Motors aren't cheap though, but maybe I was looking in the wrong place.

As for the the steering rack (which limits the rotation), I reckon that could take a fair whack, it's stripping a gear or cracking a tooth that's the problem. I imagine there's a reason for the belt drive conversions or even direct drive conversions where the wheel is mounted directly on the motor spindle... I think Leo Bodnar's $5,000 CNC stepper motor conversion was direct drive. Then there's the screw method like the Frex Sim Wheel... That thing is a work of art as far as I'm concerned.