Heavy Racer Looking for Build Advice

I don’t use a jrk or an arduino. However, both the jrk and arduino use a microcontroller of some type and run some sort of code on them in order to do what they do. But, while I have asked before, I have yet to receive an answer on what makes a microcontroller with a pid program on it an “industrial pid controller”.

Without getting an answer, the only three possible answers I can come up with myself are; one, that an “industrial” controllers code is written by someone who gets paid by a company to write the code for it, and/or two, that an “industrial” controller is one that has been used at least once by someone in an industrial setting or is sold for industrial use, or three, an industrial pid controllers code can not be modified by the end user where the others can!

So, if there are not any better answers, I personally don’t see how any of these in and of themselves makes a so call industrial pid controller better than one that is a not a so called industrial pid controller myself other than not having to download a code into a microcontroller yourself. That being said, may people here seem to like the jrks due to the motion their code creates!

p.s. Oh yeah! I guess another thing that may make a pid coded controller industrial is if its ”ridiculously overpriced”.

Luckily it states pid controllers are "widely" used in industrial settings but not exclusively or we couldn't use them. But it doesn't specifically state what makes pid control "industrial" one over one that isn't!

Agreed there, all I know is that JRKS seem to perform better under certain circumstances that Arduino. Not sure about the Roo controller though, I see you have done great work with it on your build.

Thanks @bsft but I don’t use the kangaroo either unfortunately. I say unfortunately because I do use the sabertooth 2x60 motor controllers and I like them! So I had high expectations for the roo so we could have a higher current solution comparable to the jrks for the “heavy racer” and other uses for ease of set up if nothing else. But it has not paned out for me either like several other members here.

After doing a successful bench test with one motor using a standard 270 degree pot using most of its range, all look good! But when I tried to tune on my rig that uses less than 90 degrees throw of the pots, 90 degree hall effect in this case, I couldn’t even get an auto tune to complete without getting an error. I tried doing several different things to get it moving but I never ended up with even close to adequate motion from my point of view.

That is why lately I have not been recommending the roo until someone can provide us with a video of something worthwhile (that is just in my opinion of worthwhile) that works on a racing rig and provides us with how to set up details.

I do have a theory however on how to make a higher current driver out of a jrk. I know they say at Pololu you can’t but they didn’t say it was impossible; at least that’s my attitude! I am quite confident my idea will work though unless an oscillation is invoked in the system that is unacceptable. But I haven’t needed to try it enough to motivate me to buy a jrk to give my theory a test run as of yet.

apologies @BlazinH .
I spoke to Pololu ages ago about running a larger h-bridge off the JRK and yes its possible, but you would need an oscilloscope to watch the waves come out of it to set it to another driver.
I dont have that sort of equipment.

Its a matter of choice as I stated in my previous thread. JRKs can be used as long as the builder is happy with the movements similar to those shown in your videos. However, if a builder wants more.. then there are cards rated to deliver upto 1200 Watts of power such as the infineon BTN7971 $22 on ebay compared to JRKs peak output capability of 360 Watts. These values are given by the manufacturer and it is possible to slightly overdrive them by limiting current with PWM, PID and heavy cooling, and you can still squeeze a little more on top of it by loading it with some industrial PID as in your case. Even with all this, it cannot perform even close to a sim made with some of the latest chip available in the market. Pololu itself have cards with peak power of 1600 Watts. These are real H bridges made with 4 mosfets rather than integrated chips.


I dont have any videos of these as I mentioned in the previous thread, no one want to go first. Anyway, I am making my second Sim based on the Infineon chip. I will give you a video shortly. I am simply giving information and let the reader make a choice, but you are only stating the pros of JRKs without comparing it to any other card, and you are scaring away potential explorers by mentioning about coding when there are ready made codes available on this forum which can be used by the click of a button.

No matter who is overclocking a unit, 1200 watts of power will always perform better than 360 Watts of power. And when we can do it for less than half the cost, there should not even be a discussion in here about JRKs.

@Mazhar Salam cool let us stay tuned

I dont give a jack about power, I was TRUE Realistic movement's and to date the only one to offer that is JRK's. Code is something VERY FEW people are willing to learn or even want to even think of learning. IM NOT one of them so choose the "overpriced" JRK's. And guess what, Do you think i would have ventured down this road without the Ease and simplicity of a JRK, Not likely.

Lol no video, ya good luck with "informing" the readers.

If written by an expert, a code can create wonders. It is possible to achieve a lot of additional control and smooth movement with well written set of codes. Our application is very unique where the motor constantly start and stop and most of the h bridge in the market have many features built in to it such as current sense and temperature sense. However, the arduino code we use utilise none of these and simply move the motor to the position according to the data received. In the case of JRK where the microcontroller is built in to the h bridge. The software developers may have written additional code to check the flow of current or temperature of the chip to control the movements of the motor. This is just theory and I dont know if JRK actually have these additional features in their software. Alternatively, you can simply buy a high current h bridge and not worry about any of these at all

The JRk can be overdriven to nearly 600 watts.
Good info there though

Time for you start building something and show us all then. Information is fine, but results seen in action are far better

Made 1 sim based on several of your advices across this board... plus racingmat tutorial.... Now I am happy u appreciate my posts but no more time+money for this... I think u should have a blog... all ur information is lost inside pages of this site.

I dont time to do my own blog, its been suggested.

seriously, why should I do a blog? To details EXACT builds so others can steal my info? I put enough info on here and if someone asks the question, I answer it and post up info, even if it is repeated.
As you have built ONE sim, you are giving advice based on that and what seems to be just information.
If you WANT to use a higher current h-bridge and arduino, then please do. Most of the builds here dont require massive h-bridges so people dont use them. Dont be hammering common control boards that people use because they dont have enough current for YOU.
Why dont you do a blog, seeing you are such and expert.

I believe I've decided to go with a seat mover instead of a full frame. I would like to share my build with my friends and it seems easier to move the pedals/wheel on a seat mover than on a full frame since I won't have to worry about re-balancing. I also decided to go with the JRKs. While I am a software developer, I will already have my hands full building the unit and getting the mechanicals correct (still unsure how to connect the pot to the motor) to have to deal with code on top of it.

I really like @bsft 's 2DOF with big motors. I like the shoulder mounts and the build seems very stable, something that my GF noticed the orignal full frame I had picked wasn't. I've noticed in some videos (I think it was racingMat's) that the harness was connected to the lower frame and not the seat mover. Is that for an added safety measure, or was it to create a more "pull" feeling when braking?

I'm accumulating a shopping list and will post it here when done. I have lots of time and it makes sense to get as much information before I start than after I mess something up.

@maitez , we can help get you going in no time with the JRKS.
to "make a note for myself" so to speak, I will get back to this in a few hrs.

wiring the JRK

suggested connecting the pot to the back of the motor shaft, and @Nick Moxley , can you please add a pic of your pot setup