Question DIY FFB wheel Problems (lenardo version)

Hello guys am new here since this is the best place for putting my queries, i am putting my problems about my DIY ffb here. I have a my1016 specs(24v @13.7A 250W )motor with emc lite software cuz am poor anyway using it on an Arduino Leonardo , for power I am using smps 24v 15a 360w ,now about the main problem the drivers I was using bts7960 43a h-bridge
I was happy that it worked at the start with the wheel test in (Iracing).

But it only worked for like 5 min in the spring test it would heat up like crazy even when I put thermal paste and put 2 pc fans it did work sadly.So I returned it and like an idiot ordered 2 more to try what someone was else was saying to put them in parallel so it can handle more power.

But I guess the back emf was too strong and both died fyi this was at full 24v not undervolted or anything cuz I read that it may damage the motor in the long run so I got one more bts just to try one last time but this time I changed the PSU to 12v at 5a don't ask me why (saw this shit on YouTube that shit is bs) anyways it worked but the power was completely so low that I could stop it with 2 fingers without any effort. That's how far I got with my ffb so far.

Okay now what I am planning to do is not use the bts completely instead use cytron MD30C-R2 motor drive it is quite expensive compared to the bts but more reliable ( I hope) the only difference is that the bts has 2pwm and one Dir but the cytron has 1dir and one pwm. Luckily the emc lite software allows us to change the type of driver control so that's that(don't have the driver didn't test just a speculation on my part) hope some can having this device can test it thanks in advance.and last but not least the back emf or whatever they call. It may be fixed by connecting Schottky diodes can't say this for sure cuz am not electric engineer so what ever am saying about this emf my not be the best advice I read this stuff in a forum and some other websites can use a P-channel MOSFET too.

I don't know how to do this tho. Btw I was planning on using a Schottky (15A 45V 15SQ045) fyi I don't have much of a choice for this 45v part I would get 30v 45v is kinda overkill. I think it would be way better to use a battery instead of doing all this shit with Schottky diodes or p-channel MOSFETs like paring two 12V car batteries (cuz 24v is to damm expensive for poor me) with a SMPS so this seems the most effective way to prevent back emf and that re-gen breaking nonsense.

Thanks for reading my dumb rant about my FFB wheel plz do help me if possible so this topic can be the best way to make a cheap FFB wheel with relatively okay-ish FFB. it can even be upgraded by either adding swapping the motor and driver for a more powerful one (SMPS and battery too). or twin motors with separate drivers or a 2 channel driver. Your choice.

I think this is a common problem with all that DIY stuff. Theese days, everything is available to everybody for very little money. But only very few people understand what they are doing. If a driver blows up they blame it on BEMF and suggest to put a diode here and there.

That reminds me of stone age people performing a rain dance in the hope of getting a good harvest. It helps sometimes but at the end it depends more on good luck than what they actually do or don't.

The next problem is money. The less money you have the more important it is to do some calculations and research before spending the money. Because if you buy something too cheap it's not going to work and you have to spend even more money to buy something else of better quality, later.

Throwing more power at it without knowing if that's actually the problem could make it worse. Bigger motors have more inertia so you'll get more regenerative energy. IMHO, 250W should be plenty for a FFB wheel. Many people here drive their motion rig with 250W motors.

So I'd suggest we first need to find out how much torque and speed we need. Then we should calculate the optimum gear ratio to make the best use of the torque of the motor. For example, you could attach a string to the outer side of a spoke on your steering wheel. Hang a bucket on the other end and fill it with water until the torque feels good. 10kg at a radius of 15cm means 15Nm of torque. Let's say max speed is 2RPS = 120RPM.
Power = 2pi * torque * speed = 188W. That's peak power. It would be very exhausting to apply so much force for more than a single revolution. I guess max. continous power of <50W is more than enough.

Thanks for reaching out brother I have visited most of the forums and almost watched every youtube video possible (fyi is only gave half assed info ) but it didn't help at all I get what your saying with the torque and stuff my motor will give about 2650 rpm +/- 5% and 0.89nm base torque I think 1:4 /1:5 will satisfy my ffb needs I did the math for this shit and hope it works
But the main problem ain't that it's about that dum piece of shit bts driver that magical works for some ppl while I got 4 of these and even ran them in parallel but that dum thing didn't work any thanks to Amazon return policy I got my money back so money saved.

This is my steering wheel if any is curious I know it bad but will have to do

And this is how I tested the motor:



Without using the steering wheel so make shift DD wheel kinda I guess

Well man u kinda brave here in my opinion, same motor drives crazy cart with me on board (85kg's) to over 20kph no problem, that thing will brake ur wrists....

1:5 with 0.89Nm from the motor will give you 4.5Nm at the output shaft. Although the motor will turn only around 600RPM instead of 2650 that should work quite well. I've found a thread where all the torque calculations are explained.

Haha, and I blamed people for not understanding what they do but I don't either. I thought all that cheap motor drivers like Sabertooth, Cytron and BTS are voltage mode PWM drivers. But for FFB you'd need a current mode amplifier. Is there a schematic somewhere how the leonardo board controls the current? I think there must be a shunt resistor and amplifier somewhere so that the CPU can measure the actual motor current.

With a 1:5 gear you shouldn't have problems with regenerative braking energy. Connecting a large capacitor like 4700uF 35V parallel to the supply should absorb all braking energy. No car batteries required.

Are you 100% sure about this my guy if this can work it will make DIY ffbs a hell of a lot cheaper and easier to build for beginners

and I don't blame you brother about the gear ratio and all I to don't get that shit very well am not a mechanical
engineer or something (FYI am not an engineer of any kind ).

FYI my guy am not brave just plain stupid for doing that I almost lost my pinky for this shit so safety 1st.

for those interested I have made another post in the Arduino forum
link is here.
hopefully, we can make this shit work, ill even make a new guide and document everything in full detail with monthly updates about my own build and how well it works.unlike those half-assed forums and youtube vids that just make you go in circles hunting for answers.Thanks for the support so far guys .
Cheers

is this what you wanted am very bad with these schematics cant understand shit

I'm building a DIY force feedback (FFB) wheel with a MY1016 motor (24V, 13.7A, 250W) and EMC Lite on an Arduino Leonardo, powered by a 24V 15A 360W SMPS. Initially, I used the BTS7960 H-Bridge driver, but it overheated and failed even with cooling. After trying parallel drivers, which also failed likely due to back EMF, I’m now considering the more reliable Cytron MD30C-R2, compatible with EMC Lite’s control settings. To manage back EMF, I plan to use 15A 45V Schottky diodes or connect two 12V car batteries in series with the SMPS for stability.(this is a shortened version of this rant).

So your saying that the capacitor will absorb all the braking energy huh,okay but the power dissipation wouldn't lead to heating of the capacitor? (ps I don't much about this stuff like I said but this can be a possibility that's all am saying) Anyway if it doesn't get to hot I can always cool it down it a fan.

That was the schematic of the leonardo board. I meant the overall schematic how everything is connected. But never mind. I've looked up the data sheet for the BTS7960 driver. It claims to have overcurrent and overtemperature protection. If it failed in spite of this there must have gone wrong something else.

I think this is overkill for a FFB wheel. Other people run their motion rigs on theese motors and don't have problems. I doubt that the problem is back EMF or "too little power". My guess is that it's "too much power" instead. Consider this: The BTS driver has no current feedback. So the software has to guess the speed of the motor and the BEMF voltage and apply a little more or less voltage to regulate the current which it can't measure directly. For this to qwork it depends heavily on the motor parameters like voltage constant and winding resistance to be tuned correctly. If you use a larger motors a mismatch of theese parameters is likely to cause overshoot and oscillations.

A capacitor can store energy. It is charged when current flows into it while the voltage rises. It can give back the energy when current flows in the opposite direction while the voltage decreases. No heat is generated unless you exceed the voltage limit. Think of it as tensioning and relaxing a spring. It can break if you overstress it.

So all your saying is a Capacitor should do the trick and what about the driver it self should I go with much better quality one like cytron cuz the bts kinda annoyed me but at least I can return them lol

At the start of this project I was wondering if the bts7960 would able to drive my motor I had some doubts as it only worked well 12v motors even tho the documentation says a much more higher voltage and current handing capacity. But here is the main catch of this driver it has to many clones in the market that are not full up to the original standards it's hard for me find the original as for many other in different posts I had gone through.

This is what one guy said said in my Arduino post (am not sure about 100A part)ps got to get a multimeter just incase
edit: Got a new multimeter finally.

I think I'll stick with the cytron MD30C-R2 cuz it wouldn't heat as much compared to the bts