I'm a total newbie

[BabyDyke415]

I have the ecx amp monster truck! The last few weeks have been a ton of fun and this is my first time with this hoby and my first time chatting on line like this. Anyway the next thing I want is to purchase a battery charger and a couple lipo batterys (seems cheaper to puchased them together?) Also I will get a couple of thoes low voltage beep things... yeah any comments pleas be as specific as possible as I have learned a lot on line but I'm far from knowing all the terms! Do I need to worry about what the C rating is with getting better batteries? I eventually want a brushless motor, idk like 15t or something... basically I really don't know what I am doing and I appriciate any input on what I should do and in what order. And I think it's called the pinion? I noticed today there is a small piece off one of the cogs on it though it still grabs fine and runs decent... what do I need to watch for with getting a new one? Does the number of teeth mater? What's the difference? And today I think I jumped it from to high up... it still runs normal though I'm noticing a little bit more noise from the back end... I thought it was something with the spur and pinion gear at first though now I am wondering if it's the.... idk what it's called... drive shaft (the bar between the back wheels? Though idk why it still drives fine if something is wrong... but idk what the exta noise is from.. I could keep going here but I will stop here for now and hope some of you will help me out even though I know next to nothing on this. Thanks!

 

[xlDooM]

For a LiPo, you want something that can deliver more than 100A of current. To find out the current rating, multiply the capacity (in Ah) with the C number. Example: 5000mAh 25C battery: 5 * 25 = 125A. You either have to get a battery with the right type of connectors (EC3) or be able to solder (or ask a store guy to do it).

The number of teeth on both pinion and spur matter a lot. They determine top speed, acceleration and the temperature your motor and ESC will run at.

The noise from the back end is probably the piece of gear teeth missing. Driveshafts aren't strong, but also don't make noise in my experience.

Things to look at for the future (apart from LiPo): servo saver eliminator + metal geared servo, stronger driveshafts, better bumpers, brushless kit (motor, ESC and either a new receiver or complete radio set).

 

[Music411]

Sounds like a damaged tranny gear, stock ones are plastic and trash. I ripped mine apart running stock.... upgrade to the metal gears and don't look back.
Id look into a cheap brushless system if your willing to go all lipo and such.
You can a cheap goolrc setup for about 50$
(Motor/esc) around the 3000kv range is a good start.
And grab a cheap flysky gtb3 radio for 30$
As for batteries I picked up a few Gens Ace 2s 5000mah lipo 50c for 50$ a pop, good deal. (Not top of line batts, but I honestly can't tell the difference between them and my 120$ 6000mah 2s 100c smc racing batt)
You want a lipo charger aswell, for about 100$ you can get a decent 5amp charger that will charge those batts in an hour. I get about 30 min runtime out of a full charge 5000mah give or take a few min.
The stock esc/transmitter will inevitably fail on you. Mine caught on fire lol, and my cousins died after about 15 min. (Both running completely stock)
The cheap brushed motors are also pretty cheap and disposable. A brushless lasts much longer.
Bigger pinion = more top speed/less acceleration, more stress on motor/esc.
Smaller pinion = less speed/better acceleration, less stress on motor/esc.

 

[i_r_beej]

First, welcome @BabyDyke415 !

For LiPo batteries you don't need to worry too much about the C rating unless you plan to race. So a 20C or 30C LiPo battery will do fine.

As for a charger, I posted about what I use over in the Electronics forum. Hitec makes some great chargers for about US$50-$60 that will charge your current NiMH battery and charge pretty much any type of battery you might get in the future!

Have fun!

 

[BabyDyke415]

Thank you all of you, I have a great feeling this forum and all of your help is going to be great for my learning experience as well as continuing to watch you tub videos (some repeatedly lol) I took the transmission apart and it absolutely is the differential gears (or rather the small ones next to the big one in there) and WOW... I absolutely shredded thoes little plastic gears.... so my list of what I'm getting and in what order just changed. I will get a metal one (though it will be my first time putting that together) 2 friends of mine built it for me to begin with both because I don't know what I am doing and (more importantly) because I am disabled and it would have taken me at least a week to build! So what do I get for grease for these gears? I noticed it needs that! Also I do want a brushless motor.. so what's the BEST to get for that before spending more money doesn't make that much of a difference? I don't understand the esc and controller stuff at all yet as I have not looked that part of this hobby up yet. The chargers I have been looking at will charge any type of battery and I've been looking at deals that come with 2 batteries as it seems to pay off for the price. Can I run 12v battery with replacing the 2 main parts I'm wanting to do right away... oh and better slipper clutch as well!? Also thank you so much with the math and what to look for for a battery and I do know how to solder it's just been a long time so I could go either way with that... should I get or is there better connecter to be using once I start modifying? Thicker cords maybe? Idk does that matter? What does any one suggest for #of teeth on the gears? I do like going fast though above that I want power of the start to get up slopes and such and through a rougher course... so I welcome your input on this!!! Knowing a 20c or 30c will work great in looking at batteries is also helpful... I've been looking at 50c and higher as I really don't know. Thank you again and I appriciate all the help and input I can get! Looking forward to more replies and suggestions. Also this feels weird, I'm in a chat and it's kinda bringing me back to AOL chat rooms and dial up Internet except I get to do it on my phone and not a giant pc hahahaha!

 

[i_r_beej]

Welcome to the ECX MUSH.

 

[BabyDyke415]

Welcome to the ECX MUSH.

MUSH?

 

[i_r_beej]

Sorry- I guess I set the Wayback Machine too far. Your mention of AOL and chat rooms recalled the MOOs, MUDs, MUCKs, and MUSHs of the 90's.

 

[BabyDyke415]

How come some motors of the same brand that are brushless cost more money with a lower kv#? In descriptions on the Hobby site everything seems the same except for their kv... though some specify a voltage and others don't... also why is this? Not like I can afford one for a while but at the same time I am trying to be informed and decide what I want to get!

 

[BabyDyke415]

Also how come castle creations cost so much more than dynamite motors with esc?

 

[i_r_beej]

A lower kv rating does not mean that the motor is somehow less of a motor. Lower kv is inversely related to the number of turns: lower kv/higher turns means more torque with lower top speed; higher kv/lower turns means less torque, but higher top speed. As for the difference in price? Features, quality, engineering. A sensorless 3500kv motor does not have a Hall Field sensor nor sensor wire and is thus a little simpler and less costly to produce compared to a similar sensored motor. Sensorless motors can also use cheaper materials, the cases usually have less machining/cutouts (labor costs), and probably use cheaper less precise bearings. Sensored motors aimed at racers will make use of better-quality everything because that's what racers want and they're will Ingram tompay for it. Think of a Honda Pilot and CRV: they're both the same brand and both SUVs, but why does one cost more (or less) than the other?

 

[i_r_beej]

As for Castle vs. Dynamite? Castle is a brand associated with badassery and bashing and over-powered cars. Dynamite is a house-brand of Horizon Hobby and is targeted to cost-conscious hobbyists. Is one necessarily better than the other? Yes. No. Maybe- it's all marketing. Buy what will do what you want and can reasonably afford. Also: you DO get what you pay for and the best values are to be found right in the middle of the price range. That's why I run Hobbywing: good stuff at good prices. There are certainly more poncy brands that cost more, but do they perform better? Not necessarily. The super cheap stuff you might scrape off the heels of Ebay? "Caveat emptor" was coined for EBay.

 

[BabyDyke415]

A lower kv rating does not mean that the motor is somehow less of a motor. Lower kv is inversely related to the number of turns: lower kv/higher turns means more torque with lower top speed; higher kv/lower turns means less torque, but higher top speed. As for the difference in price? Features, quality, engineering. A sensorless 3500kv motor does not have a Hall Field sensor nor sensor wire and is thus a little simpler and less costly to produce compared to a similar sensored motor. Sensorless motors can also use cheaper materials, the cases usually have less machining/cutouts (labor costs), and probably use cheaper less precise bearings. Sensored motors aimed at racers will make use of better-quality everything because that's what racers want and they're will Ingram tompay for it. Think of a Honda Pilot and CRV: they're both the same brand and both SUVs, but why does one cost more (or less) than the other?

Wow, you are super helpful!!! Thank you for all the help!! Ok... so I'm not sure what exactly I need in a motor. I definitely want good torque!!! I also want to be able to go at least 30mph... I would love to go 45mph though and still have good torque!! So what are your suggestions on kv and T to get that result? This is also the first that I am really hearing about sensored vs not... so I take it sensored is better?

 

[BabyDyke415]

As for Castle vs. Dynamite? Castle is a brand associated with badassery and bashing and over-powered cars. Dynamite is a house-brand of Horizon Hobby and is targeted to cost-conscious hobbyists. Is one necessarily better than the other? Yes. No. Maybe- it's all marketing. Buy what will do what you want and can reasonably afford. Also: you DO get what you pay for and the best values are to be found right in the middle of the price range. That's why I run Hobbywing: good stuff at good prices. There are certainly more poncy brands that cost more, but do they perform better? Not necessarily. The super cheap stuff you might scrape off the heels of Ebay? "Caveat emptor" was coined for EBay.

How long have you been using hobbywing? Would you say that's your favorite when it comes to affordability and performance? Or is there another brand that might cost a little more but is noticeable with performance... like what about kinexsis, velineon, ripper.. or (I think these ones were more expensive) tekin & posiden?

 

[BabyDyke415]

What would you say the best shock oil weight is? I want to do a lot of jumps and still fly down a smooth surface. I thought I needed a 20 or 15 weight but now I'm wondering if that isn't enough support? Also I'm looking at getting good shocks, are the Aluminum shocks they suggest in my manual a good fit (I know $ is decent) or is it better to get some that cost a bit more? Also is it worth getting a bleeder cap vs dealing with the rubber bladders? What should I get when it comes to motor cleaner spray? Grease (for drive shaft)? Not just what would be good to use with stock parts but will be decent to use with upgraded parts... so far I just upgraded my differential gears to metal as the plastic stock parts... well... I shredded them lol. Working on slipper clutch upgrade... still waiting for some parts to come for that though I didn't have enough for decent metal slippers after getting everything else! What is a good pinion to get for what I want with torque? I am waiting for the one I ordered.. it's a 48P 16T pinion gear, also a 48P 81 T spur gear.

 

[BabyDyke415]

This is what I ordered so for...

 

[BabyDyke415]

https://ecxforum.com/members/i_r_beej.114/ I know I'm asking a ton of questions... you have been really helpful to me though in this new hobby that I've found myself in for almost a month now!!! And I knew nothing coming into this... well what a battery, motor, shocks look like but that's it lol. I don't think I'm doing to bad concidering that anyway thank you so much for taking the time and helping me out with this stuff!

 

[i_r_beej]

This is also the first that I am really hearing about sensored vs not... so I take it sensored is better?

Short answer: It depends. Sensored motors have a better, smoother low-end/low-speed response. Sensorless motors will tend to "stutter" a little. In practical use, the "stuttering" is virtually unnoticeable UNLESS you are driving a crawer. That's one reasone why Crawlers still tend to run with brushed motors (but there are sensored brushless motors being created for crawline applications). Additionally, there are hybrid systems on the horizon that start sensored and once they reach a certain RPM switch to sensorless.

I'm a racer so the finer control afforded by sensored systems is preferred (and the only legal system outside of the Novice class).

For general "bashing" around, a sensorless system is all you need!

 

[i_r_beej]

How long have you been using hobbywing? Would you say that's your favorite when it comes to affordability and performance? Or is there another brand that might cost a little more but is noticeable with performance... like what about kinexsis, velineon, ripper.. or (I think these ones were more expensive) tekin & posiden?

I've been using Hobbywing just over a year now- I got back into RC after about 20 years away just last March. In my research Hobbywing was favored among racers and had a good reputation for reliability. Additionally, there are more expensive systems but they didn't seem to provide any benefit besides "brand prestige." As with any type of gizmo, there will be a price range for you to choose from. The best cost/benefit ratio always seems to come from the top of the mid-range. Cheap is cheap and expensive is stupid.

Kinexis is Horizon Hobby's inexpensive/budget brand, with Dynamite being a tiny step up (maybe). This is not to say that it is garbage. Horizon Hobby has some of the best, "No BS" customer service I've ever experienced.

 

[i_r_beej]

What would you say the best shock oil weight is? I want to do a lot of jumps and still fly down a smooth surface. I thought I needed a 20 or 15 weight but now I'm wondering if that isn't enough support? Also I'm looking at getting good shocks, are the Aluminum shocks they suggest in my manual a good fit (I know $ is decent) or is it better to get some that cost a bit more? Also is it worth getting a bleeder cap vs dealing with the rubber bladders?

For loose, bumpy surfaces with small jumps a less viscous (thinner/lighter) oil is better. This allows the shock to respond more quickly to all the little bumps that would throw the car around.

For smoother surfaces with bigger jumps, go with a more viscous (thicker/heavier) is better as it will absorb the big hits better. But the car will bounce around more in rough terrain with smaller bumps.

I race on carpet and astro (indoor) that is on concrete with medium height wooden jumps. (But we're typically not landing flat on the ground, the goal is to land on the descending face of the jump- it's smoother.) So I run 30wt front and 35 (or 37.5wt) at the rear in the ECX aluminum shocks. In my TLR 22 buggy, it's more like the opposite: 35/37.5 front and 32.5 rear.

My recommendation: Using the stock springs, start with 30 front and 35 rear. Experiment. Unhappy with rear-end bounce? Try 37.5.

The ECX aluminum shocks are great. I highly recommend them. You can pay more for Traxxas Big Bore or Pro-Line or whatever, but they won't really perform that much better. I install Kyosho "x-ring" o-rings in all my ECX shocks and it greatly improves their sealing performance without a lot of drag.

The bladders in the aluminum shocks are good: keeps air out. They are a little fiddly to refill and set properly, but you'll get it with practice. Bleeder caps are not needed.

What should I get when it comes to motor cleaner spray?

Any brand is fine. I actually use a commercial electric motor cleaner spray I got at an auto parts store. But it wasn't any better value than buying RC-specif stuff from Dynamite.

Grease (for drive shaft)? Not just what would be good to use with stock parts but will be decent to use with upgraded parts...

If you're running in the dirt... avoid adding any unnecessary grease as it will attract dirt and wear away the tiny RC parts like sandpaper. That kind of biz if for actual cars with CV boots and sealed systems. Or, grease and just be prepared to clean, clean, clean after every couple of runs in the dirt.

What is a good pinion to get for what I want with torque? I am waiting for the one I ordered.. it's a 48P 16T pinion gear, also a 48P 81 T spur gear.

Generally speaking, any given motor will have a "sweet spot" for gearing. You can go up or down on the pinion for more torque or higher speed, but you pay a price for it in increased heat/decreased efficiency. Keeping a large spur (87t) will provide the optimal torque. Using a smaller spur will actually "gear up" the car and make it go faster and have less torque.

And a 16t pinion with an 81 spur might not even mesh. The AMP has a rather limited range of adjustment for moving the motor back and forth.

Bottom line: This is a hobby, a pastime and is made to experiment. Try something. If it doesn't work, try something else. You learn from both outcomes!

Enjoy!