Extreme Newbie question

[freedomflyer]

Have the Trx4 Defender and was suggested to me to do a couple of upgrades.
1, change out the steering servo and 2, drop in a brushless motor.
I was looking at the Traxxas 2255 waterproof metal geared servo but was told that was overkill. That the Feetech 35kg servo would be sufficient.
It was then suggested that if I was going to put in a brushless motor that I put in the Hobbywing quicrun fusion. I read that it has very strong BEC, not sure what BEC is. Is this something that is going to cause issues for the stock radio system and/or this other Feetech servo that I would put in? And if I add a light system is that going to add issues? I just don't know enough about this stuff yet. Any information and advice would be greatly appreciated. Thank you. FF

 

[tntpoof]

bec supplies voltage along with amps to power servo and make esc turn on

 

[freedomflyer]

So will that cause issues for the stock system?

 

[ferrebee88]

That quick run fusion is programmable and can be set for 6v or 7.4v. From my experience 6v is plenty and that is what the Stock traxxas receiver will require. Check out the link below. It is a video that rccaraction.com did about installing and tuning a quickrun fusion in a TRX4. You will also need to buy the programming card, which I beleive is just a little over $10. I would also suggest not going lower that the 2300kv fusion or it will be a bit slow in your defender.

https://www.rccaraction.com/hobbywing-fusion-pro-install-setup-tuning-video/

 

[WickedFog]

That HW Fusion system looks really good. The BEC in it can be set to 6V/7.4V @ 4A. So you just need to make sure you pick an appropriate servo. Getting a 7.4v capable servo will get you into better torque and speed than running the same servo at 6v.

Stay away from Traxxas servos. You can get much better servos from Savox or Hitec for the same price. Even the cheap 35kg servos off Amazon would be a better choice in my opinion. But for a crawler, you want metal gears for sure. And as much torque as you can afford. Standard servo size.

If the Traxxas receivers only handle 6v, go with 6v setting on the BEC. Or buy a Flysky GT3B or similar radio and upgrade.

 

[Doom!]

Bec is a good thing.. this might explain it better.
BEC Explanation

 

[ferrebee88]

It was recommended for you to go brushless, but... what are you actually doing with your Defender? For just bashing around, light crawling, and trail running I have found the stock motor/esc to be plenty in 3S. If you want more "slow control" then the fusion would be great.

Brushless is cool and all but even the hobbywing 1080 is a great option to pair with the stock motor and it is $43

https://www.amainhobbies.com/hobbyw...brushed-crawling-esc-23s-hwa30120202/p1466194

 

[freedomflyer]

Thanks gentlemen for the quick response! Will knix the Traxxas servo idea. Will see if the Feetech has metal gears or not.
It looks like I may be dropping in a quicrun fusion! I do have a friend that can give me some guidance. Thank you.
Well, I'm just getting into it so not sure what all I'll be doing. I like the slow technical crawling I've done so far. The snow driving was an absolute blast. Very touchy as far as throttle control so as to not spin out and to not slip off the side of the snow mounds. So would like to have some good throttle control.

 

[ferrebee88]

Thanks gentlemen for the quick response! Will knix the Traxxas servo idea. Will see if the Feetech has metal gears or not.
It looks like I may be dropping in a quicrun fusion! I do have a friend that can give me some guidance. Thank you.
Well, I'm just getting into it so not sure what all I'll be doing. I like the slow technical crawling I've done so far. The snow driving was an absolute blast. Very touchy as far as throttle control so as to not spin out and to not slip off the side of the snow mounds. So would like to have some good throttle control.

It's a slippery slope! Before you know it you will have 2 or 3 of them with different setups

 

[freedomflyer]

That's what I'm afraid of wife ain't gonna like it

I did find out the Feetech servo does have metal gears so have one on order.

 

[ferrebee88]

I just built a Vanquish VS4-10 Phoenix and put a Castle Mamba X paired with a Holmes Hobbies puller pro 2200kv. The is the smoothest setup I have tried. The throttle control is insane and you can program throttle curve to give you even more control. The auxiliary wire that allows you to do extra things is amazing too.

 

[Doom!]

Thanks gentlemen for the quick response! Will knix the Traxxas servo idea. Will see if the Feetech has metal gears or not.
It looks like I may be dropping in a quicrun fusion! I do have a friend that can give me some guidance. Thank you.
Well, I'm just getting into it so not sure what all I'll be doing. I like the slow technical crawling I've done so far. The snow driving was an absolute blast. Very touchy as far as throttle control so as to not spin out and to not slip off the side of the snow mounds. So would like to have some good throttle control.

Your doing it right, always good to ask questions before a purchase, to make sure what your looking at is really what you need or want.

 

[WickedFog]

I just built a Vanquish VS4-10 Phoenix and put a Castle Mamba X paired with a Holmes Hobbies puller pro 2200kv. The is the smoothest setup I have tried. The throttle control is insane and you can program throttle curve to give you even more control. The auxiliary wire that allows you to do extra things is amazing too.

That's good to know. Greywolf and I were just talking about crawler setups for his AX10 Scorpion. Do you happen to have any video of the Mamba X/Holmes combo running? I'd be curious to see the low speed capabilities of that setup. I'd love to build a Vanquish one of these days.

 

[freedomflyer]

Is there a lot of difference between the fusion 2300kv and the 1800kv and would it really matter in my application?

 

[ferrebee88]

Here is a video of the puller pro 2200kv paired with a mamba x installed in an axial capra. Holmes Hobbies has a ton of videos on different rigs and different motor/esc setups.

 

[WickedFog]

Is there a lot of difference between the fusion 2300kv and the 1800kv and would it really matter in my application?

The 1800kv is going to be a bit slower, but by changing your pinion gear and/or spur gear you can tune your overall speed to how you want it. So you could go with the 1800kv and gear up, or go with the 2300kv and gear down.

 

[ferrebee88]

Is there a lot of difference between the fusion 2300kv and the 1800kv and would it really matter in my application?

You will get more wheel speed with the 2300kv, which you may want in the future if you are just driving around a trail or need the extra wheel speed to help through a tough spot. Me personally... That is why I didn't get the fusion. I want to be able to put a different motor in if I am unhappy with the performance of the current motor. With the fusion, you are stuck with the one motor choice unless you buy a whole new setup. With the mamba X, you can set the auxillery function to increase/decrease drag break or my alltime favorite crawler/rock racer mode. Crawler/Rock racer mode switches between full drag brake with crawler reverse and normal driving mode.

 

[Greywolf74]

Have the Trx4 Defender and was suggested to me to do a couple of upgrades.
1, change out the steering servo and 2, drop in a brushless motor.
I was looking at the Traxxas 2255 waterproof metal geared servo but was told that was overkill. That the Feetech 35kg servo would be sufficient.

Traxxas servos dont have a very good reputation in general. That one looks like it might be better quality than their much more common 2075 or 2075x servos. The servo you ended up going with is a cheap Chinesium piece of crap imho. Its supposedly about 500oz/in or torque but Id be surprised if it wasn't really more than maybe 300-350oz/in. That being said thats still plenty of torque for that kit. Your stock 2075X servo is only 125oz/in. (Higher is better) The bigger downside to the Feetech imo is that its a super slow servo. its .19sec compared to the already painfully slow .17sec of the stock 2075X servo. (lower is faster). Will the servo work? Sure, but personally Id either put a name brand servo like Savox, Hitec, or Protek. If I didnt have the budget for that then Id look at something like THIS JX brand servo from Amazon. Cost $45 compared to the $22-$23 that the Feetechs you bought cost but I've used a couple of these now and had pretty good results with them. The one I linked there is about 450oz/in and .12sec speed. I havent used that exact one but thats the one Id use for a crawler if I was going to use a Chinesium brand servo.

It was then suggested that if I was going to put in a brushless motor that I put in the Hobbywing quicrun fusion.

I've read that the Fusion is a great system and the Castle Mamba X/Holmes Hobbies puller pro 2200kv I'm sure would be a great system also. Castle Creations and Holmes Hobbies are well respected brands in the RC world.

I read that it has very strong BEC, not sure what BEC is.

Normally a rigs servos, lights, and any other electronics besides the motor are powered by a BEC. Now normally that BEC is internal to the ESC but the internal BECs a lot of times are weak and they typically dont have the ability to vary the voltage output. High end ESCs will have beefier BECs and some will have minimally adjustable voltages but generally a good stand alone BEC like THIS 10A Castle Creations brand BEC will be stronger and more adjustable than any internal BEC. It can also be programmed to output anywhere from 4.8-9v although you do have to buy a "Castle Link" in order to program it but those arent very expensive. Sometimes you can find people in forums even giving the Castle Links away because you get a free one when you purchase certain ESCs. You only need one so some people will give their extras away to newer folks that need one. Another ancillary benefit of running an external BEC is it takes the extra strain of running your additional electronics off of the ESC so the ESC only has to worry about powering the motor.

Is this something that is going to cause issues for the stock radio system and/or this other Feetech servo that I would put in?
And if I add a light system is that going to add issues?

A BEC wont interfere with anything. They can be a tad confusing on how to hook them up but if you decide to go that route we can help you get it sorted

 

[freedomflyer]

Thank you guys so much will be in touch with what I decide to do.

 

[Xraycer]

No such thing as "too much" servo on a crawler. As others have suggested, don't waste your money on Traxxas servos.

Here's a 2300kv Fusion system in my Redcat Gen8v2. Fantastic in it's intended design, which is crawl, but if you're looking for more zip, this probably won't cut it.