esc amps?

[98greensi]

hi i've been creeping this site for awhile now and it has tons of good info. but i cannot find the info i'm looking for.

i have a scx10 rubicon. that was stock with a xl5 and rc4wd 45t motor i recently bought a ax2 2 speed tranny for it and it works awesome the 45t motor was way to slow for me so i installed a titan 12t and 11 tooth pinion 60 tooth spur. it works awesome, first gear is about the same speed as stock tranny and the 45t and that's what i'm after. i tried to gear up the 45t but that just sucked, no power in first and no speed in second. my issue is that with the 12t my run times are down to 20-25min:shock: per 4000mah 2s pack where i was getting over an hour before. from what i read the 12t is about 2800kv so i'm looking at the turnigy waterproof systems 3000kv

Will a 3000kv brushless give me the same performance as the 12t and the long run times i'm after?

How will a 45amp 3000kv system differ from a 80amp 3000kv?

i run: trails, snow, climb rock i'm on 1.9 super swampers,soon to be pitbulls. thanks"thumbsup"

 

[svt923]

First, the amp rating of the ESC will have little to no effect on the way the truck will perform. An ESC rated for more amps will be able to run a more powerful motor or run a little more cool than a lower amp one but trailing does not really push an ESC that hard.

Secondly, those Hobbyking waterproof combos are unsensored which means they will not perform as smoothly in low speed situations as a sensored system. At full throttle, the 3000KV motor will perform like the Traxxas motor but the low speed feel will not be there. The best way to go brushless in a scale truck is with a sensored system. There are several options for waterproof sensored ESCs but they are not cheap and many more options in budget priced sensored ESCs but they are not waterproof. There is a huge amount of sensored motors available and can be waterproofed rather easily, check out the electronics section of the forum.

 

[snapon boy]

You might try a 13t Holmes hobbies motor. It's made for crawlers but has good speed in my scx10 with 87 spur and 12t pinnion I'd say it 5to7 mph. The slow speed torque is awesome. Just a thought

 

[98greensi]

First, the amp rating of the ESC will have little to no effect on the way the truck will perform. An ESC rated for more amps will be able to run a more powerful motor or run a little more cool than a lower amp one but trailing does not really push an ESC that hard.

Secondly, those Hobbyking waterproof combos are unsensored which means they will not perform as smoothly in low speed situations as a sensored system. At full throttle, the 3000KV motor will perform like the Traxxas motor but the low speed feel will not be there. The best way to go brushless in a scale truck is with a sensored system. There are several options for waterproof sensored ESCs but they are not cheap and many more options in budget priced sensored ESCs but they are not waterproof. There is a huge amount of sensored motors available and can be waterproofed rather easily, check out the electronics section of the forum.

do i need a sensored system when i have the 2 speed tranny? i'm sure cogging will be almost nonexistent with 5.05:1 ratio in the tranny and 5.3:1 spur pinion.

and how will 2 different rated systems not preform differently? when one has almost double the amp. these are brushless systems (motor and esc) not just esc's

 

[98greensi]

You might try a 13t Holmes hobbies motor. It's made for crawlers but has good speed in my scx10 with 87 spur and 12t pinnion I'd say it 5to7 mph. The slow speed torque is awesome. Just a thought

i have considered the 13t too what version do u have? and how is the run times?

 

[svt923]

See responses in red

do i need a sensored system when i have the 2 speed tranny? i'm sure cogging will be almost nonexistent with 5.05:1 ratio in the tranny and 5.3:1 spur pinion.

The tranny has nothing to do with cogging, it comes from the ESC trying to determine which segment it has to energize in order to get the motor to move. A sensored ESC knows what position the rotor is in so it energizes the right segment much faster.

and how will 2 different rated systems not preform differently? when one has almost double the amp. these are brushless systems (motor and esc) not just esc's

An amp rating on an ESC and motor combo just refers to the ESC. A lot of motors are not given an amp rating since amp draw will vary wildly depending on load. Assuming the same motor is used, then they will perform the same. The motor draws the power and the ESC will only pass through what the motor needs. It doesn't matter if the ESC is rated for 60 amps or 160 amps if the motor only ever uses 20 amps.

 

[sdmf]

The only time amp rating is important is when you are racing, or in a lot of high speed bashing. Cogging can be somewhat reduced with, sometimes extreme, gearing changes. Sensored must be used in crawling. Traxxas 12t and traxxas xl5 are not crawling electronics, they are for 2wd monster trucks and sct's. Even an axial ae2 or ae5, which you can probably find on fleabay for 30-40$, with the hh 13t will be 1000% better than the traxxas stuff. If you go near mud and water, go brushed anyways.

 

[Eric0424]

See responses in red

Gearing can and will effect cogging, lower gears generally cog less and it's less violent than with higher gearing in the same car/truck. With low gearing the cog, in some cases, is nothing more than an annoying little noise.

Some sensorless ESC's have a raised start RPM for the motor to help avoid cogging, these systems usually just cog when there's a bind on the drivetrain. Unfortunaltely that's about 98% of the time in a crawler with the drivetrain all locked up.

Of course all of this is dependent on the particular ESC, motor, gearing, vehicle weight, ESC settings, etc., etc..