Best scale crawler kit
 

Hi all, I have been considering purchasing an RC scale/trail rock crawler kit. A few have stood out to me: Traxxas TRX-4; Traxxas TRX-4 Sport; Axial SCX10 II.

Currently, I am leaning towards the TRX-4. The TRX-4 Sport is cheaper, but doesn't include electronics, and by the time all electronics are added to the kit, it looks like it will be even more expensive than the standard TRX-4.

I would appreciate it if someone could give me some advice as to which of these three options is the best pick. Please note that the SCX10 II and TRX-4 Sport need additional purchases of electronics, so any advice on which parts to get would also be appreciated.

Thank you!

Re: Best scale crawler kit
 

All the electronics in a stock TRX4 are rubbish and you will replace them eventually. I would go for the Sport kit, put in a Hobbywing 1080 esc, a Holmes Hobbies brushed motor and a decent steering servo, say a Savox, and you have a very capable truck.

Transmitters and receivers can be had for £30-£40 and then you are done.


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Re: Best scale crawler kit
 

The TRX-4 RTR electronics are OK except for the servo. Mine died quickly. But building is part of the fun for me so I'd suggest the Sport kit. With a HobbyWing WP 1080 ESC ($40), Holmes Hobbies CrawlMaster 550 or TrailMaster 550 ($20), DS3225 servo ($20) and a take-off transmitter you'd be set and have a better truck.

The Sport doesn't have the 2-speed transmission or remote, locking diffs. That's fine, but it is fine to play with the remote, locking diffs. I couldn't care less about the 2-speed transmission honestly.

Either way, the TRX-4 is the best choice for trail truck IMO.

Re: Best scale crawler kit
 

Ok, thanks very much!

It looks like my choice will be the Sport with HobbyWing 1080, DS3218, Holmes Hobbies Crawlmaster 550, Gens Ace 2200 mAh 2s and a Flysky GT3B.

These components seem to be well regarded in the RC crawling world, but if you know of any better parts, please let me know!

Thanks for your help!

Re: Best scale crawler kit
 

You won't get a better electronics package for the money.

Only suggestion would be to get a 3s lipo right away. Those 2200mah packs are fairly cheap either way and the extra wheelspeed will be nice since you won't have a taller 2nd gear.

Re: Best scale crawler kit
 

Sounds like a solid package to me.

Re: Best scale crawler kit
 

Thanks for the suggestion! I’ll probably use 3s.

Re: Best scale crawler kit
 

I'm new to this myself, so I'm no expert - maybe let others chime in and correct me if I am wrong. But as I understand it ...

A 3S vs. 2S will only increase speed basically. If your crawling, maybe you don't much need the speed. If getting the Sport kit with only one gear, maybe you do want the extra speed of a 3S. I can't help there because I bought the RTR TRX4 Blazer so I have the 2nd gear and have no idea how the single geared units drive. Something to consider.

Regardless of 2S vs. 3S, another consideration should be mAh ... buy more mAh. More mAh = more run time. My TRX4 runs 2-3 hours on a 7200 mAh battery, depending on what lights I have on and my driving.

Not sure what's available for how much in AU, but many here run the Goldbat batteries (about cheapest battery on Amazon) with no problems at all. My 7200 mAh 2S Goldbat was only US$20 and it runs/charges/discharges great with no issues at all.

Re: Best scale crawler kit
 

Another benefit is a 3s will have a significantly longer run time than 2s of same mAh as well. For example roughly 50% longer with a 5000 mAh (if all things identical and 100% efficiency).

Re: Best scale crawler kit
 

Great! I’ll consider 3s Goldbats with a higher mAh.

Re: Best scale crawler kit
 

I didn't know - good info to have!

Re: Best scale crawler kit
 

Definitely run a 3s lipo


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Re: Best scale crawler kit
 

3S does a lot more than increase wheel speed, it also increases torque, which is a major benefit when crawling. Having more torque at low wheel speed allows for a smoother, more predictable startup, especially in situations that require more torque, like having a wheel against a vertical object or are on a steep incline. In some of those situations, it's critical to be able to start or accelerate smoothly and not require a fistfull of input to make the wheels move.

Another benefit is that because 3S does provide more wheel speed, it means that you can gear down more compared to 2S without sacrificing wheel speed. Gearing down gives even better low speed startup and torque. Gearing down and volting up also increases runtime, which means that you can get away with a smaller battery. 7200mah batteries are somewhat huge. A 3300mah 3S on a truck that's geared down will still run all afternoon, and will be lighter than a massive 2S battery, so it won't disrupt your handling as much. Comp crawling guys usually run a really small battery with just enough capacity to get them through the course. It's not unusual to see some guys with a 1300mah battery.

Re: Best scale crawler kit
 

If you volt up (using 3S instead of 2S) you're probably also going to have to gear down to get your speeds down to crawling speeds.

I wouldn't go smaller than 2200mAh batteries on 3S. 2200mAh 2S batteries will have less run time. It all depends on if weight savings or run time and less battery changes are more important to you.