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Brushed vs Sensorless Brushless on TRX4

LoganW347

Newbie
Joined
Feb 10, 2020
Messages
3
Location
Boise
I’m planning on getting a TRX4 Chassis Kit soon and wondering if it’s a viable option to use a sensorless brushless motor. I already own a 50A ESC & 3000kV 4 Pole Motor that’s completely waterproof. I ran it on a short course for a while but I kind of destroyed that car...

Basically I’m asking if the stock 21T brushed motor that the TRX4 Chassis Kit comes with better than a Sensorless Brushless 50A ESC & 3000kV 4 Pole Motor for crawling and trail driving.

AND...if the brushless is a good option, what gearing ratio would I want for the pinion/spur gear.


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I would not recommend a sensorless system as much if not all the driving happens at slow speeds. I know a few companies sell some sensorless systems but those are few and far in between. A lot of ppl use brushed simply because the low speed control is unmatched even by sensored brushless and at roughly $20 a pop for the basic ones you dont have to worry about thrashing on it. I was actually running a sensored castle system in my scx10.2 until recently as I saw it was just way overkill for what I wanted my crawler to do. The sensored system will get far more use of its capabilities in my 1/10 buggy. I would suggest going with a HW 1080 esc($40) and a Holmes Hobbies trailmaster ($20). Turn count of the motor depends on what your personal preferences are honestly.
 
Sensor less is fine for high speed, really bad for low speed control. So they are kind of the opposite of what you want for a crawler. You can use it of course, but expect a lot of cogging and rough starts
 
i have a brushless sensored motor running on a cheap sensorless esc and it dosent cog at all it was only slightly better with the mmx with sensor hooked up so in my opinion the motor makes a big differance i how the system works

why not.give it a try get the smallest pinnion gear that will fit and give it a go theres always low range for crawling the lower gearing will help with start up
 
I’ll bite! Ferp, can I ask what you were running to get an acceptable throttle response for that crawler application you had working pretty well? Anecdotally, like two years ago now I bought a Hobbywing 3660 SCT10 sensorless combo for a Slash 4x4 that was on EBay from a guy who said that same combo hadn’t worked out real copacetic for his crawler. At the time I was totally oblivious to the crawler scene, but our brief email exchange left me thinking it was probably, at least generally speaking, a non-starter for crawlers. It was a 3600Kv motor, if I recall. Worked brilliantly in a Slash on 3S. Probably far too fast for any crawler, right, so where would you recommend a fella start.

What was your baseline setup, man, if I can ask for some pointers? I might give it a shot if I have a couple hours and a ballpark pinion to drop in either an Enduro or SCX10ii. Especially with that ready made IFS option Element has shipping soon.
 
For competitive Crawling I prefer a brushed motor for the buttery smoothness and low speed control. For Closed Course racing, Tough Truck or Rock Bouncing I like a sensored BL motor for it's quick powerful response and top end.

As far as cost, an inexpensive brushed motor and ESC will perform better than a inexpensive BL system.

The one fact that remains a constant regarding drive motor and speed control is "you get what you pay for".
 
I am running a Kinexisis 4 pole 3000kv motor and controller in my Scx10II based Trail truck. It works great and the addition of the rc4wd 2speed it has enough gearing so the start up is slow enough to crawl technically. The cogging is so minor it is only noticed when I am against a rock or wedged into a hole in high gear. Startup is a little faster than I like, and run time is about half of what I like for my trail trucks though. But the mud/snow slinging action more than makes up for it imo.
 
To be honest the stock Titan 550 21T motor works very well when paired with a HW1080 ESC in a slow speed crawler with a 9t pinion and 45t spur gear.
 
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The 21turn titan is the only decent piece of electronics Traxxas makes. People been running them for years before the Trx4 existed. I wouldn't swap it for any senseless system short of a revolver. When it wears out a Holmes 21t 550 is a better replacement for the money. It's what I'm running in both my Trx4's. Plenty of torque on 3s and good lifespan.
 
I ran the Traxxas 21t 550 in my old Wheely King crawler conversion... I had good a good one, then a bad one. Overall though I agree, the Traxxas 550's are good motors, HH motors are better for less money.
 
I’ll bite! Ferp, can I ask what you were running to get an acceptable throttle response for that crawler application you had working pretty well? Anecdotally, like two years ago now I bought a Hobbywing 3660 SCT10 sensorless combo for a Slash 4x4 that was on EBay from a guy who said that same combo hadn’t worked out real copacetic for his crawler. At the time I was totally oblivious to the crawler scene, but our brief email exchange left me thinking it was probably, at least generally speaking, a non-starter for crawlers. It was a 3600Kv motor, if I recall. Worked brilliantly in a Slash on 3S. Probably far too fast for any crawler, right, so where would you recommend a fella start.

What was your baseline setup, man, if I can ask for some pointers? I might give it a shot if I have a couple hours and a ballpark pinion to drop in either an Enduro or SCX10ii. Especially with that ready made IFS option Element has shipping soon.


the novak hd8 2200kv 1/8th scale motor is super smooth ether sensored or not ive run it with the mamba moster x and the momba moster 2 and cheap chineese escs and it works great even unsensored on no name brand escs

so a good motor can make a big differance i have some cheap motors on the same cheap no name brand escs and they cog alot at low speeds

i think the lower kv rating helps too
 
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