Proper brushless set-up

[kongluc]

Ok. So its said to tune your kv to your desired wheel speed. I tune for maximum runtime; with 4p brushless there is wheel speed. My problem that i'm having is that i have the smallest pinion and the only spur for my particular RC. I get abot 7mins of runtime on a quality 2s 5000mah pack. I know there are "slightly" higher mah packs that will fit my RC, but from experience i know that it will only add about 2 or 3mins of extra runtime...

The motor is a 4p 3500kv gearing is 47/12 it is a 4x4 sc and there isn't a battery extension made for it. It weighs stock 5.5lbs.

My motor temps after a full pack are about 135-140* mid-day and about 85-93* for the esc...

Is the only option go with 2 super shorties in parallel? I can't remember the mah ratings of the last ones i saw...but i think it was around 4000mah.

Also will Lowering the C-rating increase run time; as it's not pushing all the amps/capacity out of the pack? The C-rating of my pack is 65c 120c burst...

I'm going to test my overkill motor theory...i have a 2150kv 6s capable 70mm 4p motor that should be arriving any day now. I don't plan on running it on 6s but with the gearing i was running a brushed 21t on and same cell battery should yeild great results...At least thats my hypothesis.

T.I.A.

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[EeePee]

7 minutes of run time in a crawler? That's pretty bad.

 

[mikemcE]

7 minutes of run time in a crawler? That's pretty bad.

Totally agree. Noticed you said sc.....
Short course go fast ?
I'm lost my slash4x4 give 25 min run time on a 5000mah. And it's a speed monster.
High c batteries increase run time in a high draw rig


Hang up and Drive

 

[EeePee]

Totally agree. Noticed you said sc.....
Short course go fast ?

He's on the wrong website.

rcshortcourse.com

 

[kongluc]

He's on the wrong website.

rcshortcourse.com

No i like this site...not a lot of judging by most...and informative...this is a builders site to me.. I like to hang out and soak in the mostly positive vibes/threads

And anyways it's being converted to a rally car and it's in the rally section...you should stop being so closed minded peepee
Why'd you move my thread eepee?

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[kongluc]

It belongs in the electronics forum peepee

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[EeePee]

No it doesn't, it's not a crawler. I moved it because it's not a crawler. If it was a Rally car thread, it should be in the Rally forum (which makes no sense on a crawler site either, but that's another can of worms...).

 

[kongluc]

No it doesn't, it's not a crawler. I moved it because it's not a crawler. If it was a Rally car thread, it should be in the Rally forum (which makes no sense on a crawler site either, but that's another can of worms...).

It's a general electronics question...it could relatively be helpful info as to how to get your yeti to run longer on a brushless motor... I should not have to explain this to a Moderator...

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[EeePee]

I should not have to explain this to a Moderator...

No need, I've been here 13 years now. I understand how this place works, unlike you who doesn't grasp the concept of this being a RC Crawler website (with stupid sub forums that are irrelevant other than money grabs). The Electronics Forum is for RC crawlers. Imagine if it were for everything electronic in the world, so how would that relate to RC crawlers? It wouldn't.

 

[kongluc]

I'm not going to argue with you...get-yourself-off on someone else

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[kongluc]

I think you're just intimidated...and happy all you gotta do is sit behind your keyboard...

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[maslin]

It's a general electronics question...it could relatively be helpful info as to how to get your yeti to run longer on a brushless motor...

7 mins on a 5000mah! That's groundbreaking, tell us more.

EeePee has a pretty firm grasp on how the site works. Usually best not to start shit just to start shit.

Running a big motor on lower volts will not be super efficient. Big motors are heavy, everything inside is heavy. Getting that going and keeping it going takes power.

Matching an appropriate ESC, motor and battery to your rig will produce the highest efficiency.

 

[kongluc]

7 mins on a 5000mah! That's groundbreaking, tell us more.

EeePee has a pretty firm grasp on how the site works. Usually best not to start shit just to start shit.

Running a big motor on lower volts will not be super efficient. Big motors are heavy, everything inside is heavy. Getting that going and keeping it going takes power.

Matching an appropriate ESC, motor and battery to your rig will produce the highest efficiency.

It's only about 5mm longer than the castle 2400kv made for same scale RC's...yet draws less amps and slightly lower kv(for better runtime) and has a higher voltage rating...kinda like a Tekin pro4hd... yet sensorless

As for the other motor it is a 50mm 550 4p 3500kv...it is stock and that's the one i'm trying to get to run longer...

I've talked with manufacturers C.S. agents and they'd claimed that 1/8 offroad buggy's run about 15-20mins on similar 4s packs in mains...i'm just trying to scale it down...

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[maslin]

It's only about 5mm longer than the castle 2400kv made for same scale RC's...yet draws less amps and slightly lower kv(for better runtime) and has a higher voltage rating...kinda like a Tekin pro4hd... yet sensorless

As for the other motor it is a 50mm 550 4p 3500kv...it is stock and that's the one i'm trying to get to run longer...

I've talked with manufacturers C.S. agents and they'd claimed that 1/8 offroad buggy's run about 15-20mins on similar 4s packs in mains...i'm just trying to scale it down...

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You're trying to scale down part of it. An electric motor runs efficiently at a certain voltage regardless of kv. 1/5 scale motor will roll along at 12s, throw 3s at it and it may not even start up.

A complete 1/8 scale system on 4s in a 1/10 truck will work fine. It will be heavy and produce more power than you reasonably need. Putting a 2s in to slow it down will just make for a heavy, slow, unnecessary power system.

Like I said, match the complete system to your requirements. A tiny ESC won't like a huge motor. A huge ESC won't like 7.4V.

My 1/8 scales will run for a long time bashing around on 5200mAh batteries, 30+ minutes. That's with proper 1/8 scale systems, running 4s and 5s on 11lb rigs.

 

[kongluc]

You're trying to scale down part of it. An electric motor runs efficiently at a certain voltage regardless of kv. 1/5 scale motor will roll along at 12s, throw 3s at it and it may not even start up.

A complete 1/8 scale system on 4s in a 1/10 truck will work fine. It will be heavy and produce more power than you reasonably need. Putting a 2s in to slow it down will just make for a heavy, slow, unnecessary power system.

Like I said, match the complete system to your requirements. A tiny ESC won't like a huge motor. A huge ESC won't like 7.4V.

My 1/8 scales will run for a long time bashing around on 5200mAh batteries, 30+ minutes. That's with proper 1/8 scale systems, running 4s and 5s on 11lb rigs.

I'm sorry that you have not been paying attention...but these are 1/10 scale motors, for 1/10 scale RC's, in 1/10 scale RC's and 1/10 scale esc's

The 70mm can will be run at 3s. It's a 550

The 50mm can "is" mostly run on 2s.
It's a 550

They are different brands.

Just like the castle 3800kv is not considered a 550 but it's significantly longer than a 540...still a 540.. but a few mm longer for they heavier duty..


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[maslin]

I'm sorry that you have not been paying attention...but these are 1/10 scale motors, for 1/10 scale RC's, in 1/10 scale RC's and 1/10 scale esc's

The 70mm can will be run at 3s. It's a 550

The 50mm can "is" mostly run on 2s.
It's a 550

They are different brands.

Just like the castle 3800kv is not considered a 550 but it's significantly longer than a 540...still a 540.. but a few mm longer for they heavier duty..


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2100kv 6s doesn't scream 1/10 scale to me, sorry I wasn't paying attention :roll:

Good luck, your attitude will get you far.

 

[kongluc]

2100kv 6s doesn't scream 1/10 scale to me, sorry I wasn't paying attention :roll:

Good luck, your attitude will get you far.

I've been told this..

So you are saying the new castle slate does not come 1900kv and is not 4s capable even though it's a 540 and the manufacturer specs it as so?

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[kongluc]

I have no reason to lie...bc i don't lie

36mmD 70mmL read the specs...
But one would be looney to run it on 6s
Same size as castle 2400kv

http://m.ebay.com/itm/GoolRC-S3670-...%3A7097401115d0aa12ed55b752fff8daa0%7Ciid%3A1

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[allanon1965]

I have no reason to lie...bc i don't lie

36mmD 70mmL read the specs...
But one would be looney to run it on 6s
Same size as castle 2400kv

GoolRC S3670 2150KV 4 Poles Brushless Sensorless Motor for 1/8 1/10 RC Car Q5P4 | eBay

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Neither does Maslin, the specs you linked to show it as 1/8 and 1/10 scale...those specs scream 1/8 scale to me and just like all cheap manufacturers they toss in 1/10 scale to get more sales.

a 1/8 can certainly run in a 1/10 scale rally providing it fits with or without modification. That being said, as long as the entire system is matched as Maslin suggested, you will get good run times. It is painfully obvious that you dont have a good match with regard to the ESC and Motor.

"Also will Lowering the C-rating increase run time; as it's not pushing all the amps/capacity out of the pack? The C-rating of my pack is 65c 120c"

The c rating does not measure how much the battery "pushes" batteries dont "push" anything, its a measure of how easily and quickly they will allow the current to flow as needed. The demand comes from the ESC/Motor

 

[kongluc]

Neither does Maslin, the specs you linked to show it as 1/8 and 1/10 scale...those specs scream 1/8 scale to me and just like all cheap manufacturers they toss in 1/10 scale to get more sales.

a 1/8 can certainly run in a 1/10 scale rally providing it fits with or without modification. That being said, as long as the entire system is matched as Maslin suggested, you will get good run times. It is painfully obvious that you dont have a good match with regard to the ESC and Motor.

"Also will Lowering the C-rating increase run time; as it's not pushing all the amps/capacity out of the pack? The C-rating of my pack is 65c 120c"

The c rating does not measure how much the battery "pushes" batteries dont "push" anything, its a measure of how easily and quickly they will allow the current to flow as needed. The demand comes from the ESC/Motor

Why on earth would anyone epect a 36mm can to perform in an 1/8 scale the 1/8 is the gimic...it's the same size as the castle 2400kv; would you attempt it in a 9lb RC? I wouldn't

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