Brushed Vers Brushless

[JERRY2KONE]

I pulled this from another forum thinking that the info may be useful for anyone on the fence about economical choices for motoring your RC vehicles. I think the info and the links are very useful.

picking the suitable motor(s) - practical reasoning...
before we start picking motors,we need to clarify the application properties involved here. a monster truck is a heavy vehicle with heavy and large wheels [rotating mass]. such a vehicle needs the appropriate powerplant: motors that can deliver a sheer torque load along with good rpms. an efficiency is a must to keep the runtimes reasonable [since heavier, those MTs require more power to move in contrast with other types of vehicles, which means less runtime]. using a typical modified 540size motor is not recommended: 1.low efficiency, 2.relatively low torque, 3.frequent + high cost maintenance [brushes,commutator cut]. that is the point where 550motors step on the scene: 30% longer armature and magnets + larger commutator surface = more torque, 30% longer copper windings + 30% longer can + fan mounted = higher heat tolerances and ability to handle high-voltage and deliver more power without compromising the ease of almost zero-maintenance and relatively long lifespan. although that specific category of motors existed for many many years, it has only started to be used in RC cars during the past few years. their most usual application in RC was with boats and large aircraft. besides the 550sized motors, another similar category is the 'pure' powertool family: the motors that companies used to power their [mainly cordless] drill and dremel products, actually fit the needs of eMTs better than the rc-bred ones...


[C.2] the debate chart...
RV=Recommended applicable Voltage [volts]
RG=Recommended Gearing [pinion range -assuming stock wheel setup]
*=it is recommended that you also use a smaller spur or larger wheels to gain more speed. for the stock wheels, you should use a pinion gear up to 25t.
**=it is HIGHLY recommended that you also use a smaller spur or larger wheels to gain more speed. for the stock wheels, you should use 25t or larger pinions [up to 30t].
Comp=Compatibility [DF=direct fit, mm=minor mod, Mm=Moderate mod]
EP=Estimated Price [$]
ES=Estimated top Speed [xx-xx mph -based on gearing,applied voltage and quality&number of cells used]
RPM=revolutions per minute [unloaded]
Eff=efficiency [percentage]
EL=Estimated Lifespan [number of runs. vastly depends on cooling and maintenance as well. all estimates are the minimum ones. the motor(s) will probably live much longer but that depends...]
DE=Dual ESC necessity [you will need a second ESC to drive both motors due to high-current drain. note that the 'no' value doesn`t mean necessarily that you may not need to: sometimes due to high-end cells and/or gearing and/or ambient temperature situations, it becomes imperative that you use dual ESCs with motors exceeding 250-300W each. the oposite stands as well.]
NOTE#1: all values are approximate values
NOTE#2: all rpm, efficiency and power values are based at each single motor seperately. multiply power by 2 since you will be using twin motor setup.
NOTE#3: the johnson st550 motor is the stock e-zilla motor [identical performance specs].
NOTE#4: the 'peak power' values for the traxxas titan550,johnson st550,kyosho x-s550evo,johnson m63725, multiplex p600,kyosho magnetic mayhem, are based on a 12v voltage dyno-test. all other peak power values are based on a 14.4/16.8v [depending on the motor] voltage feed.

________Motor____________RV_______Power_____RPM___ _Eff___Comp___RG_____EP______ES______EL______DE
Johnson M63725_________14.4-16.8___158W_____35300___70%___DF___18-21___3-10$___30-36___50-200___no
GreatPlanes S600F_______12-16.8_____300W_____39600___72%___DF___17-20___12-15$__35-42___30-60____no
GreatPlanes T600F_______12.16.8_____240W_____35700___73%___DF_ __17-20___12-15$__33-38___40-80____no
Multiplex P600___________12-16.8____180W______33200___79%___DF___17-20___8-12$___32-37___40-80____no
Master Airscrew s550_____12-14.4_____220W_____35700___71%___DF___17-19___8-15$___33-38___40-80____no
Johnson st550___________14.4-16.8___149W_____33700___70%___DF___18-21___3-10$___30-36___50-200___no
Kyosho Magnetic Mayhem_12-14.4_____181W_____32100___70%___DF___19-22___5-20$___30-38___40-80____no
Traxxas Titan 550________14.4-16.8___129W_____31200___70%___DF___18-21___10-20$__26-30___50-150___no
DeWalt 820 PowerDrill____16.8-18______321W_____31900__80%___Mm___22*____15-30$___32-44__50-200____yes
Johnson BP03028________12-14.4_____330W______29000__78%__DF___20-22*___5-20$__32-44___20-80____yes
Johnson PT03006________12-14.4_____280W______38300__70%___DF___17-20___5-20$___34-42___20-80____no
Johnson PT03005________12-14.4_____370W______46400__68%___DF___17-18___5-20$___36-45___20-80____yes
Johnson PT03016________14.4-20_____500W______22000__85%___Mm___22**____5-20$___36-45___60-120___yes
Johnson PT03010________14.4-18_____520W______26000__68%___Mm___22**___10-25$__36-48___60-400___yes
Johnson PT03008________14.4-16.8____300W______31100__70%___DF__20*-22*_10-25$__36-43___60-400___no
Johnson PT03015________14.4-16.8____310W______30400__65%___DF__21*-22*_10-25$__36-43___60-400___no
Johnson PT03007________14.4-16.8____410W______25000__76%___DF___22**___10-30$__36-46___60-400___yes
Graupner BB700Turbo____14.4-16.8_____280W______26000__80%__Mm(?)_22*____15-50$__36-42___60-400___no
Kyosho X-S 550 EVO_____14.4-16.8____164W______36900__72%___DF___17-19___15-30$__32-37___60-160___no
JP powerspeed 660_______14.4-16.8____220W_____38100___76%___DF__18-20___15-30$__32-38___60-160___no

**some direct fit motors were designated as 'mm' or 'Mm' [example: bpo3028 and such] while really Mm and mm motors were marked as DF [e.g: pto3016]. this confuzion was part of the table/chart being resized and manipulated when the chart was transferred from ezcomm to this site. most of those 'corrupted' spots were fixed at the very first day of this forum; however some others remained, so thanks to 'slapyourself' for the making a notice of that and reporting this issue. btw, since the graupner 700bb seems to have many variations [one at least of which is known to be DF, and another known to be MM], it will be designated as Mm(?) to let the reader know that compatibility will depend on the version/revision of the model to get...



[C.3] where to buy...

Johnson st550:
http://www.allelectronics.com/cgi-bi...DC_MOTOR_.html

Johnson M63725:
http://www.allelectronics.com/cgi-bi...DC_MOTOR_.html

DeWalt 820:
http://robotcombat.com/marketplace_dewalt.html

GreatPlanes S600F:
http://www2.towerhobbies.com/cgi-bin...&I=LXJ766&P=ML

GreatPlanes T600F:
http://www2.towerhobbies.com/cgi-bin...&I=LXJ765&P=ML

Master Airscrew s550:
http://www2.towerhobbies.com/cgi-bin...?&I=LXZ902&P=0

Graupner 700BB Turbo, Traxxas Titan550, Kyosho Magnetic Mayhem:
{hobby shops carry these}

Johnson driller 700series pto3016:
http://www.allelectronics.com/cgi-bi...DC_MOTOR_.html

all other Johnson models:
www.johnsonelectric.com
here you can find a local dealer near you, or order a large quantity of any motor model you are after:
http://www.johnsonelectric.com/conta....php?page=html

JP powerspeed 660:
http://www.birminghammodelcentre.co....CanMotors.html

Multiplex P600:
http://www2.towerhobbies.com/cgi-bin...?&I=LXEXU3&P=7

other motor links if you are interested in your own research:
http://www.modelmotors.cz/index.php?id=en&nc=produkty
http://www.mmeu.com/storefront/grx.asp
http://www.fastelectrics.com/motors.asp
www.maxxprod.com/mpi/mpi-26a.html


[C.4] conclusions regarding closed endbell motors...

their pluses: extremely powerfull [some of them proved to be as powerfull than their expensive counterparts -brushless motors], relatively long lifespan [1-2years of intensive use], very low cost [3-20$], compatibility with the vast majority of brushed ESCs, virtually no maintenance [their commutator and brushes are made of carbon/steel/copper compound so they require no lathe,brush replacement,etc], and (as with all brushed motors) they can work in very harsh conditions -as oposed to many other brushed and brushless motors which aren`t as rugged.

their minuses: relatively low rpms but tons of torque [that is why they must be geared high to see speed improvements], some of them have shaft incompatibility with common pinions [since the diameter of the shaft of some powertool motors is 5mm -towards the standard 3.2mm], they REQUIRE 12cells or more [which makes them useless on cars using 6 or 7 cells because these motors provide poor performance with low voltage] and as with most brushed motors they have [contrasted to the brushless ones] relatively low efficiency -meaning short runtimes. especially the last one. most of them reach a peak efficiency of 70% [which means 70% of power gets to the shaft rotation (rmp*torque) and 30% is thermal losses], they are no match for the 90%+ peak efficiency of many brushless motors. which means you will get relatively short runtimes. keep in mind though, that the efficiency of modified low-turn brushed motors is around 50-60%. that is a very stiff reason not to use 'plain modified' 540 motors in such applications.

i have used many powertool motors throughout the past years, and my experience has shown that most powertool motors are a really good choice if you have good packs -actually a bunch of them...