TRX-4 Sport - hill hold

[dempy]

Hi everyone,

I just bought a TRX-4 Sport and set the ESC to crawl mode (5 blinks).
Normally the esc should have hill hold to keep the car from going forward on an incline.

Does this feature block the wheels 100%? I noticed the car still rolls slowly on steeper inclines (+15% I would say).

I’ve made a small video:
https://youtu.be/z2-Km0DjPCc

Is this normal?

FYI, I’m running a 2s lipo. I tried a 3s lipo, but this doesn’t change anything.

[lkvisser]

Ya, that’s rolling a little to easy on my opinion. I would try resetting to first mode and than crawl mode (5 blinks). See if that helps


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[Inspector86]

I would not spend much time messing with the stock ESC. Just up upgrade to the HW1080 ESC. BTW, the HW1080 and stock Titan 550 21t motor make for a surprisingly nice combo.

[lkvisser]

Mine was all stock.., added an external bec and finally a cheap Arrma servo. Seems fine so far...,


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[lkvisser]

Did you ever find a fix?

Just had the same issue on my SCXii.., my throttle adjustment on my radio was set too high.., powering the rig just enough to let it roll down any inclines; neglecting the drag brake.


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[Browneye]

My drag brake works just okay on mine, at least forward. Reverse is really weak though.
HW1080, 100% brake and freewheel, Crawlmaster Expert 16T.

Sure crawls over everything though.

[HumboldtEF]

The strength of the drag brake is a function of the gearing and the sport is geared higher than a 2 speed TRX4 (using 1st gear) so its bound to be less effective. The stock setup is just not strong enough to hold the truck 100% still.

Your drag brake is definitely working its just weak, a better motor and ESC can improve it. Though the stock motor isnt bad at all, start with and ESC if you replace anything. Also try to reset it to mode 5 again as suggested above just to be sure.

EDIT: Hill hold is just a bad name for this, on the first release they were referred to as 70% and 100% drag brake IIRC

[lkvisser]

Hasn’t responded since first post....

... his time zone may be slightly different


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[dempy]

Thanks for the help guys.

I am in a very different time zone, but I have just been out of the RC game for a few weeks because of other priorities.

I have ordered another pinion and spur gear to lower the gearing and make the “hill hold” function more effective. The parts should be here in a week or 2. After testing I will update in this tread.

[lkvisser]

Originally Posted by dempy

Thanks for the help guys.



I am in a very different time zone, but I have just been out of the RC game for a few weeks because of other priorities.

Look at you acting all mature and such


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[dungeonracer]

I have ordered another pinion and spur gear to lower the gearing and make the “hill hold” function more effective.

Not to be "technical", but you should be raising the gearing to make the hill hold function more effective, meaning the gear ratio should be a higher numerical value than what you started with.

[Inspector86]

Originally Posted by dungeonracer

Not to be "technical", but you should be raising the gearing to make the hill hold function more effective, meaning the gear ratio should be a higher numerical value than what you started with.

A "lower" gear has a higher numerical ratio and also increased braking. This is why you downshift a manual transmission to a lower gear in order to increase engine braking in a full sized car for example. The term "lower" refers to the relative speed of the driven gear as the drive gear , running at a constant RPM, gets smaller. If you're going to be "technical" you need to be "accurate".

[dungeonracer]

If you're going to be "technical" you need to be "accurate".

Whatever...
Pretty sure I was "accurate" when I stated....

meaning the gear ratio should be a higher numerical value than what you started with.

[Browneye]

Ya, that's called 'lower' gearing.

[Still Bill]

I initially went from the stock 17/39 to 14/45 gearing using Traxxas parts. But, you also need to buy the #8254 Rebuild Kit to get the slipper pads (stick-ons) for the new spur gear. Huge improvement. Later, I installed a Hobbywing 1080W ESC for all its adjustable parameters. Maybe $75 for all.

[keecrawler]

Originally Posted by dungeonracer

Whatever...
Pretty sure I was "accurate" when I stated....

Which is lowering the gearing.

You said "raising the gearing."

So no, you weren't accurate.

[nymtber]

Originally Posted by Inspector86

I would not spend much time messing with the stock ESC. Just up upgrade to the HW1080 ESC. BTW, the HW1080 and stock Titan 550 21t motor make for a surprisingly nice combo.

This!!!

I put an HW1080 in my Everest 10. The ability to fine tune the settings yourself, and the great drag brake/hill hold really makes it stand out. $40 or so on Amazon...or most other places.



I'll own a TRX-4 sport myself someday. When that day comes, I'll put an HW1080 ESC into it. The tune-ability alone is worth every penny!