I bought a trx4 with the defender body, unknowing how fast the low speed was gonna be. I'm quite disappointed. I know it's capable of crawling, but it's much faster than I need or hoped for. I've bought a 45t spot and 11t pinion. Should slow "low speed" down. I read 45/12, but didn't see the combination on Amazon (in a word for instant gratification). 2 questions. Is the 11 vs. 12 tooth gonna make a big difference? Meaning is that too much of a step from 12t? And has anybody changed both sets to get low, and super low? Or should I just put the gears in and disconnect the servo. I know the answer is obvious, and the money, and the servo. But if I could slow it down considerably and make it a bit faster than my scx24, that'd be cool.
-
Welcome to RCCrawler Forums.
It looks like you're enjoying RCCrawler's Forums but haven't created an account yet. Why not take a minute to register for your own free account now? As a member you get free access to all of our forums and posts plus the ability to post your own messages, communicate directly with other members, and much more. Register now!
Already a member? Login at the top of this page to stop seeing this message.
2 speed low and lower speed?
- Thread starter Afterbang
- Start date
The defender comes with a 45t spur and 11t pinion from the factory. The lowest you can go pinion wise is 9t, which is what I would recommend on a two speed rig.
After that, your limiting factor will be motor/esc. If you’re wanting to keep cost down, a Holmes Crawlmaster sport is a great motor choice, being a 5 slot motor vs 3 slot will improve low end control.
Other than that, the Hobbywing axe and fusion motors have the slowest /best low end control I’ve ever used.
Sent from my iPhone using Tapatalk
After that, your limiting factor will be motor/esc. If you’re wanting to keep cost down, a Holmes Crawlmaster sport is a great motor choice, being a 5 slot motor vs 3 slot will improve low end control.
Other than that, the Hobbywing axe and fusion motors have the slowest /best low end control I’ve ever used.
Sent from my iPhone using Tapatalk
OnTheTrail
Rock Crawler
As Twade mentioned, get the 9t pinion. See what you think after that. I have a 9t on my Defender, stock motor and a HW1080. Amazing low speed control. Actually didn't think the stock ESC was that bad actually but the adjustability of the 1080 with the mods I did was worth it.
DrIsotope
Quarry Creeper
I despise 9T pinions. They're basically at the point where a gear is no longer round, it's a nine-pointed shape-- it's a nonagon, and the gear mesh will always be... meh.
The problem arises from Traxxas marketing to bashers, so they put a 21-turn 550 in there. That problem is compounded by the XL-5HV having pretty poor low-end modulation. Drop in a cheapo 27-turn Holmes Trailmaster Sport (or a 13T/15T Crawlmaster Sport for another 5 bucks) and it should be a lot more manageable. You can also use a reasonably round pinion.
The problem arises from Traxxas marketing to bashers, so they put a 21-turn 550 in there. That problem is compounded by the XL-5HV having pretty poor low-end modulation. Drop in a cheapo 27-turn Holmes Trailmaster Sport (or a 13T/15T Crawlmaster Sport for another 5 bucks) and it should be a lot more manageable. You can also use a reasonably round pinion.
It’s a common size people run on trx4’s, it’s also listed in the traxxas manual as the lowest ratio possible, and they even provided holes in the motor plate for proper mesh… I think it is just fine. I’ve run them several times without any issues.
Sent from my iPhone using Tapatalk
you can also get lower gears for the axles the "underdrive" gears to slow it down some more
the lower gears in the axle help with alot of stuff like torque twizt and broken parts
i dont know if you can get lower gear sets for the portals but i would look and see thats another potential place to gear down
the lower gears in the axle help with alot of stuff like torque twizt and broken parts
i dont know if you can get lower gear sets for the portals but i would look and see thats another potential place to gear down
You really shouldn’t need lower gearing than 9/45. This is 11/45 but using a fusion 1800kv, it’s almost unusably slow when creeping along. Even stock it should crawl pretty decently in low gear.
Might be worth calibrating the radio/Esc, and making sure the shift servo is actually engaging low gear?
https://youtu.be/07-KlfKtSoU
Might be worth calibrating the radio/Esc, and making sure the shift servo is actually engaging low gear?
https://youtu.be/07-KlfKtSoU
I have a revolver 1800 kv with a 9T pinion using a SW4 ESC. It has amazing low speed control. This setup will be loud/potentially annoying though.
Inspector86
RCC Addict
There is nothing wrong with the 9t/45t ratio and in fact I run this ratio on all of my TRX4s with much better than "meh" gear mesh but you do have to work at it to get it right. That said, I also run the optional 10/35 under drive R&P gears in both the front and rear axles. That drive train paired with a HW1080 ESC and HH Crawlmaster Sport 550 12T motor and you have all the low speed you could hope for.
Last edited:
I appreciate all the info. It kinda sounds like unless I replace either the motor or esc,I can't slow it down much. I'm not sure I made it clear in my first post, so I'll try to rephrase it. My truck seems to have plenty of power to crawl, it's goes up my little hill I built, pretty good. But id rather not have the speed. Honestly, I did lots of research(I thought) but I guess I never thought to look at actual speed of the truck. I was expecting a more significant change between the two gears. I didn't want a basher.i was hoping for a low speed crawler that went faster in high gear. I guess the actual question is, how can I slow down my crawler? Slower motor? Different esc? That's kinda what I've gathered but I guess I'm just trying to figure out my options. Is there anyway to change how much power goes to the esc?
OK, I've thought about it, and the question I was trying to ask is, how can I get my trx to go as slow as my scx24? Change the esc to control voltage? Change my motor to less turns. I'd like to get rid of the speed because I'm still new and if I start to go over an obstacle and looks like it's gonna roll, I push forward and it goes backwards with way too much power. I don't want the speed, but the torque is great.
Are you using a 3s battery? You could always use a 2s instead.
Without seeing exactly what you mean, or are referencing, it sounds like maybe you just need some more drive time to get a better feel for throttle control.
As you scale up the size of the rig, power and speed scale also. I wouldn’t limit overall speed so much, because often times momentum will get you further than lug by lug crawling.
If possible maybe take some video of both rigs and demonstrate more of what you’re after.
Sent from my iPhone using Tapatalk
Without seeing exactly what you mean, or are referencing, it sounds like maybe you just need some more drive time to get a better feel for throttle control.
As you scale up the size of the rig, power and speed scale also. I wouldn’t limit overall speed so much, because often times momentum will get you further than lug by lug crawling.
If possible maybe take some video of both rigs and demonstrate more of what you’re after.
Sent from my iPhone using Tapatalk
DrIsotope
Quarry Creeper
Fellas, there's a reason they don't make pinions smaller than 9 tooth-- because a 9 tooth is just barely round. Will it mesh? Sure. Will it sound bad? Usually. It is always preferable to motor down and gear up, because (and this is NOT an opinion) the larger the gears, the better they mesh.
Why run a nonagon of a pinion? Just because you don't want a lower turn motor? If you need to underdrive and run 9/45 with a 12T, you could have normal diffs and a 15 tooth pinion with something like a 27-turn.
Why run a nonagon of a pinion? Just because you don't want a lower turn motor? If you need to underdrive and run 9/45 with a 12T, you could have normal diffs and a 15 tooth pinion with something like a 27-turn.
Ninomaniac
Rock Crawler
I got 9/45 on a crawlmaster sport 10t. And UD in the rear. Definitely slow enough. But really needs the 2nd gear to pop over stuff. I think I ran it 11/45 too, but prefer 9/45. I'm aware that the mesh on the tiny pinions is less than perfect but aside from possibly more noise (the transmission howls like a bastard anyway) and probably reduced efficiency - it works fine.
I thought they didn't make 3.17 32p pinions under 9 teeth because there wouldn't be any material left to cut the teeth.
I thought they didn't make 3.17 32p pinions under 9 teeth because there wouldn't be any material left to cut the teeth.
That may be true if your top priority is gear mesh…
Regardless, I feel we are getting off track from the op’s original question.
Sent from my iPhone using Tapatalk
OSRC
I wanna be Dave
I run this same combo pretty much in all my TRX's, and first gear is slow, slow slow. Not sure how much slower you'd want it to be. Maybe try a 15t 550?
Can also limit throttle electronically if it comes to that - throttle EPA would be the easiest. Bit of a pain in the arse with the stock radio, but certainly doable.
Personally, I think the gap between 1st and second is way too wide, I'd love the option of a lower second gear. I love asuper- low creeper gear, but t's nice to have second on the trail when moving from place to place. It's a bit too tall for me though, even at 9/45.
OSRC
I wanna be Dave
Switch to an Outrunner on 2S... excellent torque and low speed control, none of the RPM. A Holmes 1000kv will drop you down from walking pace to snail pace.
Inspector86
RCC Addict
The TRX4 does not run anywhere near 40mph out of the box somewhere between 10-15mph if I had to guess. Your question has been answered several times.
1. 9t pinion 45t spur,
2. 2S battery
3. HW1080 ESC and HH Crawlmaster Sport 550 12t motor.
4. Slower still, under drive ring&pinion gears in both axles.
5. After that if you still want slower you will have to spend some significant money on a quality brushless ECS/motor combo.
One last thing, TRX4 questions should be posted in the TRX4 specific section below.
Last edited:
theres only 2 ways to fix that
1 buy a new vary exspensive esc and program your throtle curves
2 learn to deal with it stick time will do wonders for your twitchy reverse
ive never herd anyone say that ever although its not wrong if your motor is to fast and your running the smallest pinnion you could a slightly slower motor and a bigger pinnion might be a good idea
personaly i would run a second gearbox before the trx4 gearbox somehow i know there is a kit to do this but ive never seen anyone actualy do it on a trx4
Last edited:
