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Old 07-21-2006, 01:32 AM   #1
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Default Cheap Brushless Stuff on Ebay

I was looking on ebay for my brushless for my next build. Probably in a Kyosho Lazer Z5. But anyways I was wondering if this, or something like this could work well, it is for rc planes, but why so cheap? Even if it can't be used in an rc car, why is plane brushless so cheap? What are your thoughts. It's so cheap I almost just want to try it!

http://cgi.ebay.com/30A-Electronic-S...QQcmdZViewItem

http://cgi.ebay.com/TowerPro-BM2030-...QQcmdZViewItem
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Old 07-21-2006, 05:15 AM   #2
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Cheap, probably because all they have to turn is a plastic propeller and not a 1500g car over rough terrain. Also, due to the fact their probably junk
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Old 07-21-2006, 07:36 AM   #3
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Normally planes are low RPM, but high torque, which means less amps and cheaper to make. Also, the throttle is more constant, they get alot of the speed up before leaving the ground, while cars are on and off the throttle a lot. The easiest way to see it for example, the first ESC has specs of:
Continuous Output Current: 30A
Instant Max Current: 40A
Inside Impedance: 0.0045

In comparison the GTB:
*Rated Current (Brushless): 540A/phase
*Rated Current (Brush Mode): 1620A
*On Resistance (Brushless): 0.00040 ohms
*On Resistance (Brush Mode): 0.00013 ohms

It cost quite a bit more to build something to handle that level of power. A car ESC that will only handle 30A is also a cheap ESC.
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Old 07-21-2006, 07:43 AM   #4
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the thing that makes airplane esc's cheaper, brushed or not, is that they only go forward, and rarly have brakes. the esc is also designed to use ALL of the trigger movement as throttle. that means that if you put an airplane esc in a car reciever, with a car transmitter, it will go at half throttle until you go all the way back on the trigger (full brakes) THEN you will be at neutral.

trying to use an airplane esc in a car, i would find to be a nightmare. plus, those esc's are designed for smaller motors.

i saw some website though, where a guy made a reversable esc with the insides of a servo, and a few mosfets.
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Old 07-21-2006, 02:57 PM   #5
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yeah on rccrawler.com I saw some guys that were using modified mini servo's as esc's for their 1/25 scale crawlers, they were super slow but pulled up anything.
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