Kanuk's first foray into the world of motion simulation...

@kanuk - I can’t really see how you are sinking the bottoms of the boards in those photos but folks here have pretty good luck sinking the chip itself so anything you add through the bottom of the board will certainly improve on that. Just be sure that your thermal pad material doesn’t let anything short to the bottom heat sink. That’s one thing you need to be careful of with sinking through the bottom of the circuit board.

But I only have sinking on the bottom of my JRKs - nothing at all on the top save some scavenged heat sink air that gets ducted to blow over the component side of the boards. No failures so far with fairly extensive, multi hour continuous use, and everything is running cool. Running with both should keep yours very happy.

@Zed - Nothing touching at the bottom. I have used those very same type of heat sinks on top but tow at the bottom joined length ways and avoiding any other part of the board by a great margin. I read the datasheet in your post on the sinking of these Pololu's and you are definitely right. The board is utilised as a damping heat absorption pad, but without donig any tests I'm not quite sure what the dissipation of the heat is like via the bottom. Thus I thought it would be prudent to have a heat sink on top as well. Can't have too much heat sinking right? Plus its thermal padded to the chassis for anything extra that may or may not be of further assistance.... Not to mention the 200mm fan blowing right in front of them and the twin 80mm's extracting at the rear... Should be plenty of airflow!

I'll take some clearer photos tomorrow and post it for your viewing sir...

Cheers!

@kanuk - When I was figuring this stuff out I used my wind fan motors as a load. At full tilt they were rated at 6 amps each for 12 amps total in parallel and that is the spec on the 12v12. When I would fire that up with no additional cooling or heat sinks, the base of the 12v12 would get warm quick and the bridge chip would get warmish but slower. Certainly not quantitative but it's further verification that their heat dissipation design works well. But you are also right - it doesn't hurt to keep these things cool especially considering how expensive they are.

Good luck with your build!

@Zed
Pics for your perusal. how the JRK's are mounted

The 'JRK's in the box' is almost complete bar a couple of minor details.

I used 4 pin mini DIN's for POT feedback (so any s-vhs cable will do for the connection) and also wired up the Pololu's for the rest box.

Everything in place now so next stage setup!

And my RESET Box...

@kanuk - I’m guessing those are self-adhesive thermal pads? One thing to watch out for if you don’t also have some kind of mechanical clamp is if heat can loosen that up and they can come off the heat sink and possibly short. On the other hand, you’ll have the extra cooling helping to get that heat out. Was the heat sink on its side to fit within the through-hole pins? Looks good!

Thanks @Zed
I have utilised 2 pieces of meccano bent to shape bolted over the heatsinks on the pololus to keep em in place.

Just changed my mounts for my pots as I have 50:1 gearboxes on the worm drives and there's no way on earth in moving the levers to adjust the min max values! @noorbeast linked me archie's and bsft's tips on how to adjust the pot and the min max travel for these so that's in progress as we speak...

Rebuilt the pot mounts so that I have access to adjust them using the bodies instead of the shaft itself....

I just ran the JRK CFG Utility and voila! A working sim rig! W0000!

As an aside, would anyone have any asseto corsa presets I could use or a set of defaults that would be generally functional?
Still not quite wrapping my head around the assignments but I thought if I got to play with a preset it would make that chapter quicker...\

I followed the documentation but for some reason the roll feels like pitch and pitch feels like roll....

Pitch and roll are the Track...dont think of them as the car so much, and gaining the knowledge on how to adjust the Axis on your own, is a wise idea...start with 1 at a time, play around and see what you can make happen. Its really the only way to learn properly.

Park on an incline then park sideways on said Incline, Increase and decrease the roll/Pitch in the profile editor, Its a Dead easy way to tell if your axis are going in the right directions. Obviously heave, sway and surge require actual driving...so dont pick a F1 car or a Potato slow POS car, pick something in the middle, Test and tune around said car, then use the Profile editors -50/0/+50 sliders to maximize the full range of cars you might drive.

axis assignments will vary from rig to rig aswell, so again hard to just copy and paste numbers.

Thank you sir @Nick Moxley

I intend to certainly gain the knowledge. And I think setting up a dual pc setup may aid this process greatly....

Quick Q to all the Pololu guru's out there... How hot do your 12v12's get? Mine are getting quite warm over 30 or 40 minutes... no indication of shutting down though, and no overshoots etc....

I got some values plugged in last night and what a journey it was working out the axis directions! LOL! My little daughter came and led me out of my man cave by my hand in order to get me a coffee and take a break... I think she was getting worried that her daddy was on breaking point!

I did check a few things eg. rig balance etc. and waht I found was moving the GameMgr's profile from 80% down to 70% cooled the Pololu's by a huge amount.... Should I be putting in some ammeters to keep an eye on things?

@Zed

I have downloaded your Pololu cases and am about to modify them by placing turbo duct fans in them. Any ideas on further cooling Zed? I am inches away from water cooling these babies!

i STRONGLY suggest you NOT Run your Game manager down @ 70%

You are SEVERELY limited your data points your getting from the game.

@Nick Moxley

Understood. In fact that was clear from my adjustments. Limit my axis in Axis assigments then? AND THANK YOU FOR THE CAPITALS. I heard you loud and clear.

But on a serious note, what is your advice?

@kanuk - My JRKs stay nice and cool just using the heatsink/fan assemblies. I’m not sure what you mean by turbo duct fans, but in my rig, pulling the heat out through the bottom of the circuit boards with a good thermal pad into the heatsink/fan assembly works great. Everything stays cool at just a few degrees above ambient. I measured the temperature of the H-bridge and it hardly gets warm at all.

On the ammeters question, I built my own bar graph ammeters and they are very valuable for getting balance right which helps reduce current loads and heating.

@kanuk - Here is a link to the bar graph ammeters thread. It's a custom circuit but everything is there. I bought the bar graph displays on eBay. https://www.xsimulator.net/communit...o-do-motor-current-sensing-for-balance.10510/

They seem an extravagance and you can find your balance point and just use that, but this lets me recline or sit up depending on flying, driving, or seat reclined racing and just adjust the seat forward or back to compensate. I've found that proper balance is pretty important to minimize motor current in the extra load configuration. Noorbeast mentions balance a fair amount when people ask and rightfully so. It makes a big difference and it is surprising the amount of current you can draw when out of balance even with the worm gear motors.

Digital ammeters could also be used for setting the balance point statically and are much cheaper plus you don't need custom circuit boards. Before things get rocking, minimize the current by adjusting your seat and you are balanced. Digital ammeters won't work when bouncing around though because the numbers will be changing too fast in general. But ammeters of some kind are very handy.

@Zed
Thank you sir! I am reading your link as we speak....

@Zed

This is the housing I ended up making....

with a radial turbo fan. Anybody want noise??!! It's hella loud!

but the JRK's are running below ambient now... hehehehe

So tonight, after 3 hours with axis limiting @ 80% and decent settings on the assignments (which wore out my 18 year old boy... pansy....) I did 3 continuos hours in a 190E Evo2 at Imola. No errors reported, no overshoots, no exceeding PID's (Thanks @noorbeast !) and temps on the heatsinks were at 21 degs and temp on the side surface of the H-bridges were 26.8 and 27.1 respectively left and right. I think its good.....

I am still tuning though. Calling on the knowledge of increasing gearshift changes and braking effects. Any advice anyone?

And seriously, thanks to ALL those who helped me. I am very grateful for the time, the expertise and the kind words of encouragement I have received along the way. Thank you.

Now, as I finish this rig, I will now continue the build on my flight sim rig that I originally posted to begin with on this thread. cant wait.....