Jerold's Limitless Build

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Honestly, for fan mounts, I still think Powerhobby makes one of the better ones. It's a single clamp that allows the mounting of two 30 or 40mm fans. They come in 3 sizes (40-42mm, 47-49mm and 56-58mm though I've found you can use the 40-42mm clamp on 49mm cans without issue). They only cost $15-17. The amount of air being moved is greatly increased by increasing the distance to the motor so to make it even more effective at cooling you could put some spacers to bring the fans a little further away from the motor.
1676783943911.png
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TBH,
I'm skeptical how much fans help with the temperature since the internal cabin of the limitless is pretty small and doesn't allow for much airflow. I think all the fans are doing is recirculating hot air around the motor. I never seemed to have a problem but I don't do too many back to back runs (3 at the most) so I've removed my temperature sensor and my server fan....
I understand your thinking but I can say with certainty that fans do more than just move a bit of air around (unless you've somehow managed to hermetically seal the internal cabin of your car which is unlikely). After two passes my motor will be around 65°C and I can drop it to 40°C in about 2 minutes with the two fans I have mounted on there running on 12V. And I don't mean that it'll rise back up again after I turn the fans off. The temp drop according to the sensor happens in 15-20 seconds. After two minutes the actual core temp of the motor has stabilized a solid 20-25°C lower. But, to be fair, since I've gotten very rigid about doing only single passes (maybe one and a half in the case of an abort) I know that my temps don't get anywhere near critical levels so I've just removed the motor fans as well. It just isn't needed if you remain disciplined about your passes and giving the motor time to cool down. I did leave the temp sensor though. I still like having the peace of mind of being able to see motor temperature at a glance.
 
Thanks you. Just about everything I learned about this process I got from this exact forum and people here. It's truly a great community.

Admittedly it's a selfish thread as I documented a lot of stuff so I would remember later. I also might over engineer/analyze things just a little bit and it's more of journal than a build thread. But if other's learn from my mistakes and discoveries, I'm happy to contribute to their delinquency.

As a spectator, looking at my build thread, it's probably a bit wordy and sometimes less is more if you want someone to actually ready it. There are a few other people that read the details, but I'm sure most just look at the pictures. Which is OK too.
A build thread is a journal ..of your journey .a recorded document of progress and at times failure.its all intended for everyone to learn .👍😁
 
Honestly, for fan mounts, I still think Powerhobby makes one of the better ones. It's a single clamp that allows the mounting of two 30 or 40mm fans. They come in 3 sizes (40-42mm, 47-49mm and 56-58mm though I've found you can use the 40-42mm clamp on 49mm cans without issue). They only cost $15-17. The amount of air being moved is greatly increased by increasing the distance to the motor so to make it even more effective at cooling you could put some spacers to bring the fans a little further away from the motor.
View attachment 279438View attachment 279439

I understand your thinking but I can say with certainty that fans do more than just move a bit of air around (unless you've somehow managed to hermetically seal the internal cabin of your car which is unlikely). After two passes my motor will be around 65°C and I can drop it to 40°C in about 2 minutes with the two fans I have mounted on there running on 12V. And I don't mean that it'll rise back up again after I turn the fans off. The temp drop according to the sensor happens in 15-20 seconds. After two minutes the actual core temp of the motor has stabilized a solid 20-25°C lower. But, to be fair, since I've gotten very rigid about doing only single passes (maybe one and a half in the case of an abort) I know that my temps don't get anywhere near critical levels so I've just removed the motor fans as well. It just isn't needed if you remain disciplined about your passes and giving the motor time to cool down. I did leave the temp sensor though. I still like having the peace of mind of being able to see motor temperature at a glance

@Diem Turner
yeah, you're right (as usual).

I took off my server fan and temperature sensor and did a few gentle passes on 8s (XLX2/1650-1717). When I looked at my logs I saw a Tmax of 145 degrees and usually it's about 115-120 degrees. In the past I've done 3 or 4 back to back passes with no temperature issues. I did happen to notice that the motor didn't seem to cool very fast in between passes. So I'll probably just put the server fan back on. +1 on the power hobby mount....
 
Sometimes I'll think about throwing the fans back on the motor, but I like that not having them on reinforces my intention to remain disciplined about making only single passes and to make each one as good as I think I can get it that day.

I have to be honest...one thing I see happen in many other videos that I've never experienced even once, is people making a second pass shortly after the first and actually achieving several mph more on the seconds pass despite what I perceived to be a first pass on freshly topped off batteries with a solid 2-3 seconds of WOT. Having seen this happen to several other speed runners I've tried it on a few dozen occasions where I thought that maybe my trigger pull wasn't that great or some other reason that I felt justified making a second pass. Without fail, no exceptions, my second pass is always 1-2mph slower than the first (which, logically...at least to my mind...makes perfect sense, I mean...how or why would or could the lipos produce higher voltage after, or by what mechanism are they gaining, sometimes, 4 or 5mph? I can't really make sense of it. The only logical explanation I can come up with is maybe they're reducing their max throttle position on the first pass by just a few percent without mentioning it? While I can come up with reasons why someone might do that, I would find it a bit odd to not say anything about it. Ok, now I'm just rambulating.

But just out of curiosity, is a second faster pass on the same batteries without topping them off a phenomenon that you experience and, if so, what's the mechanism causing it in your opinion?
 
The story of the dead squirrel, a road turtle and an Arrma Limitless.

I finally got back out to make some runs. Nothing has change except for swapping my burnt up connectors. My goal was to just get some driving time and improve my camera skills.

When I watch other videos, it look so easy. They just pin the throttle, the video comes out perfect and it's a great run everytime. Managing a camera or two, along with a check list of stuff to run the car and a lot of batteries to charge gets complex and awkward.

My new camera setup is the Akso attached to my radio. I picked up this little guy on Amazon.
1682195617099.png

Just $13 and it mounts on top of the RadioLink in the FPV screw hole. That screw they are showing is actually a just rubber plug the covers a 1/4" screw.
https://a.co/d/bZBFwMs
1682195777224.png


When I arrived at my usual spot, I usually drive the road and look for things that can damage my car. Large pine cones are common and I've had to kick a few out of the way. But other than that it's been pretty clear, except for today I had something I really didn't want to move.

Meet Mr. Squirrel
Enter Mr. Dead Squirrel. Just lying there occupying my race track. How inconsiderate.
IMG_5137.jpg


To put some perspective on it. The squirrel is just outside where cars would park. It's a pretty wide road (about 45' gutter to gutter). That sill leave me about 10' to shoot the gap. No problem I've go skills, so I decided to just drive around it. :p
S1.jpg


I did a warm up pass with the camera to see how it works, which was just OK as you will see. The car goes by but I don't turn the radio fast enough. Maybe I need to go to a head mount. Yah it looks a bit weird but it seems to works. Other than that the first run smooth, no issues at 101MPH.

Geeze my warm ups are starting at 100mph now and it seemed a bit slow. Went back looked at the video. Then got ready for a new pass.

This time there were some peds down range. Just strolling about. I think they were saying a few words for Mr. Squirrel and lighting candles. But I waited for them to move to the end of the road. Normally I don't see many people, but why are the walking through an industrial area on a Sat morning anyway? The nearest housing is 1/4 mile away across a freeway, which equates to an hour walk to get here?
1682196784908.png


The Main Event
Next run (#2 today). I gave it a bit more juice, got past the squirrel and hugged the center line a bit too much. Which resulted in a minor collision with a road turtle. For those of you with snow, a road turtle is a lane reflector that is glued to the center line. They serve as a more visual divider at night and fog, but they are also raised for the visually impaired to drive by Braille.

The impact sent the car flying but I landed on the wheels and was able to drive it back.

The Damage
The turtle took one of my screws. It looks like it's one of the forward battery tray screws, but I need to look a bit closer.
IMG_5135.jpg


I was able to retrieve the screw head. It's caked with turtle guts. . . which is better than squirrel guts.
IMG_5136.JPG


Also my pinion came loose.
1682198032794.png


Overall there are a few scuffs, but the car is OK.

Now the rando peds are strolling back up the street, I didn't bring any threadlock and called it a day.

The video is below. Unfortunately I didn't get the crash on camera.
 
The story of the dead squirrel, a road turtle and an Arrma Limitless.

I finally got back out to make some runs. Nothing has change except for swapping my burnt up connectors. My goal was to just get some driving time and improve my camera skills.

When I watch other videos, it look so easy. They just pin the throttle, the video comes out perfect and it's a great run everytime. Managing a camera or two, along with a check list of stuff to run the car and a lot of batteries to charge gets complex and awkward.

My new camera setup is the Akso attached to my radio. I picked up this little guy on Amazon.
View attachment 294745
Just $13 and it mounts on top of the RadioLink in the FPV screw hole. That screw they are showing is actually a just rubber plug the covers a 1/4" screw.
https://a.co/d/bZBFwMs
View attachment 294747

When I arrived at my usual spot, I usually drive the road and look for things that can damage my car. Large pine cones are common and I've had to kick a few out of the way. But other than that it's been pretty clear, except for today I had something I really didn't want to move.

Meet Mr. Squirrel
Enter Mr. Dead Squirrel. Just lying there occupying my race track. How inconsiderate.
View attachment 294748

To put some perspective on it. The squirrel is just outside where cars would park. It's a pretty wide road (about 45' gutter to gutter). That sill leave me about 10' to shoot the gap. No problem I've go skills, so I decided to just drive around it. :p
View attachment 294749

I did a warm up pass with the camera to see how it works, which was just OK as you will see. The car goes by but I don't turn the radio fast enough. Maybe I need to go to a head mount. Yah it looks a bit weird but it seems to works. Other than that the first run smooth, no issues at 101MPH.

Geeze my warm ups are starting at 100mph now and it seemed a bit slow. Went back looked at the video. Then got ready for a new pass.

This time there were some peds down range. Just strolling about. I think they were saying a few words for Mr. Squirrel and lighting candles. But I waited for them to move to the end of the road. Normally I don't see many people, but why are the walking through an industrial area on a Sat morning anyway? The nearest housing is 1/4 mile away across a freeway, which equates to an hour walk to get here?
View attachment 294751

The Main Event
Next run (#2 today). I gave it a bit more juice, got past the squirrel and hugged the center line a bit too much. Which resulted in a minor collision with a road turtle. For those of you with snow, a road turtle is a lane reflector that is glued to the center line. They serve as a more visual divider at night and fog, but they are also raised for the visually impaired to drive by Braille.

The impact sent the car flying but I landed on the wheels and was able to drive it back.

The Damage
The turtle took one of my screws. It looks like it's one of the forward battery tray screws, but I need to look a bit closer.
View attachment 294752

I was able to retrieve the screw head. It's caked with turtle guts. . . which is better than squirrel guts.
View attachment 294753

Also my pinion came loose.
View attachment 294757

Overall there are a few scuffs, but the car is OK.

Now the rando peds are strolling back up the street, I didn't bring any threadlock and called it a day.

The video is below. Unfortunately I didn't get the crash on camera.
Still a nice pass .👍
 
Still a nice pass .👍
I'm still on 8S for this one. You guys are doing 126 on 3S

What I can't figure out is how the heck you do it. I'm putting out about 500A and 12KW with 8S. It takes the same amount of energy regardless of the how many S's I have. But I'm sure y'al aren't cranking out 1875 Amps?
 
Radiolink steering speed,slow steering speed works way better for me than adjusting D/R every single time to turn around..

16695663421991259485445763798731.jpg

I can see why turning down the manual steering would be helpful for speed running, but does this setting also affect the gyro functionality? Or can the gyro still correct at normal speed?

I'm using the R7FG receiver/gyro in case that matters.
 
I can see why turning down the manual steering would be helpful for speed running, but does this setting also affect the gyro functionality? Or can the gyro still correct at normal speed?

I'm using the R7FG receiver/gyro in case that matters.
Not sure,never use the gyro feature...
 
I can see why turning down the manual steering would be helpful for speed running, but does this setting also affect the gyro functionality? Or can the gyro still correct at normal speed?

I'm using the R7FG receiver/gyro in case that matters.

On the Limitless I'm reducing the steering D/R and the gyro is only like 5% max if any. Anymore than that 5% and I get the wobbles. Turning the D/R down will effect the ability for the gryo to correct the skid, becuase it limits the range, but you have less of a chance of over correct manually.

My Limitless is super stable (unlike my Rlaalro) and the gryo doesn't do much. Part of that is I still have a bit too much aero on there. I remember having an oops moment and the car just stuck to the ground at 120mph. Personally I would leave the aero intact until your feeling comfortable with it and it's effecting your top speed, then start cutting it down slowly. It has more effect on stability than the gryo any day of the week.

This is really a compromise between stability and speed. It depends on what you like.
 
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