some questions about brushed motors
#1
some questions about brushed motors
Been out of the hobby for long time and recently back in. I always thought the lower the turn a motor has the quicker it is. Can someone kinda give me the low down on how brushed works... turns,springs,brushes ect... I tried searching for a thread but have come up empty. I know brushless is the way to go but I'm not fully ready to toss everything aside to replace all my cars. thanks in advance
#3
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Been out of the hobby for long time and recently back in. I always thought the lower the turn a motor has the quicker it is. Can someone kinda give me the low down on how brushed works... turns,springs,brushes ect... I tried searching for a thread but have come up empty. I know brushless is the way to go but I'm not fully ready to toss everything aside to replace all my cars. thanks in advance
#4
Everything you knew back then is still true today about brushed motors. The only news is that they are old technology. Not necessarily obsolete, but old.
Last edited by niznai; 10-21-2009 at 10:17 AM.
#6
Tech Adept
I think what you see is that anyone running "modified" has gone brushless. I think they have down to 1.5 T brushless. Around here only the entry level people are still running brushed and I think it is a preceived budget issue. If you are racing, brushless and lipo are cheaper after even a few months. Price of entry is higher, but you are not replacing things as often or having to have as many packs.
#8
If you are just "bashing", go for it. However, if you plan on racing the Slash, it is best to check with the track you will race at, since most places that race Slashes run a "stock spec" class. This means you have to use the stock ESC and motor.
#9
Tech Master
iTrader: (26)
Here it is oversimplified.
Motor winds:
Lower winds = more power, more RPM's
Multiple winds (double, triple) generally give a smoother feel but attain fewer RPMs due to increased mass.
Brush springs:
More brush pressure = more torque, less brush pressure (up to a point) = more RPMs
As a default; red positive/green negative is still a good universal recipe on 27T motors. Some brands, like Fantoms seem to prefer more pressure so run purple pos/red neg. For on-road I usually run green pos/blue neg for more RPM's. For off-road always red/green as the softer springs sometimes allow brushes to hang when they get dusty.
Brushes:
There are lots of new compounds in brushes in the past decade, I like the high-silver ones (4499)from Trinity for stocks and Reedy 767 (offroad) and 769 (onroad) for 19T.
Laydown brushed motors have more torque and generate more heat, standup brushes (mod only) usually make higher RPM's.
Motor winds:
Lower winds = more power, more RPM's
Multiple winds (double, triple) generally give a smoother feel but attain fewer RPMs due to increased mass.
Brush springs:
More brush pressure = more torque, less brush pressure (up to a point) = more RPMs
As a default; red positive/green negative is still a good universal recipe on 27T motors. Some brands, like Fantoms seem to prefer more pressure so run purple pos/red neg. For on-road I usually run green pos/blue neg for more RPM's. For off-road always red/green as the softer springs sometimes allow brushes to hang when they get dusty.
Brushes:
There are lots of new compounds in brushes in the past decade, I like the high-silver ones (4499)from Trinity for stocks and Reedy 767 (offroad) and 769 (onroad) for 19T.
Laydown brushed motors have more torque and generate more heat, standup brushes (mod only) usually make higher RPM's.
#10
I highly doubt I will ever race any of them since the nearest track is 2+ hrs away but thats awesome that everyone has to use the stock equipment. Makes me wanna go watch some of those one day.
Ok so in the Bandit I have a Quartz 19t (double) and its fun in the little track my daughters and I built. Having trouble getting the Sledge up to par though. I'm thinking its gearing cause no matter what motor I throw in it's not enough torque. Any suggestion for it?
Ok so in the Bandit I have a Quartz 19t (double) and its fun in the little track my daughters and I built. Having trouble getting the Sledge up to par though. I'm thinking its gearing cause no matter what motor I throw in it's not enough torque. Any suggestion for it?
#11
I can definitely argue that lower the turn doesn't mean faster speeds.when i got my tc3 i was looking for lower turns because i was told the lower the better.so i bought a 13t orion sv2 hoping it would outrun my dads rc10l with a 16t motor.in disbelief he went right past me.so i buy a modified 12t LRP v10 spec 4 and change the timing and he still zips past me doing like 50mph.A 16t x3 out running a 13 and a 12t motor.trinity speed gems ruby motor has an rpm of 46k vs my 13t(39k Rpm & 12t 41.1k RPM motor).Its all about the rpms,dont buy becuase of winds buy becuase of rpms...trinity speed gems ruby 16T x3..it has secrets to it.its defiantly a gas car eater.I just got one from ebay myself,hard to find good luck.just switch the armature and magnets onto a brushless motor can for speed. i have a new project call the RSS12 prototype hybrid motor.multiple motor parts from otehr motors into one rs540sd BL can.
#12
If all you are doing is switching out the motor, you may not like the results. You will also have to change the gearing to suit the motor. In general, the lower the winds, the smaller the pinion you should use (if you stay with the same spur). Just dropping the number of turns on the motor with the same gearing will more than likely cause the motor to run very hot, harming the magnets in the can or smoking the motor.
#13
Tech Master
iTrader: (26)
Carbon Joe is right, there's more to going fast than slapping in a lower turn motor. Gearing makes a huge difference as does maintenance. I have 19T's that will easily outrun other's 12 or 13T mod motors on the track, but I rebuild them every 4 runs and dyno tweak them. Likewise my son runs a Tekin 13.5 combo that, when boosted/timed correctly, will hang with 8.5's on the same track.
Different speed controls and profiles also count. For instance, if you're running a stock profile on your speedo it will not allow the lower winds to hit their high RPM's because the frequency is too low and it will make the low end so punchy it's almost undrivable. If you run a mod profile on stock motors you'll lose your low-end torque but get better RPM's and lose your drag brake.
Batteries also make a huge difference. If you're running Nimh cells it's still worth the trouble to re-peak them immediately before running.
Different speed controls and profiles also count. For instance, if you're running a stock profile on your speedo it will not allow the lower winds to hit their high RPM's because the frequency is too low and it will make the low end so punchy it's almost undrivable. If you run a mod profile on stock motors you'll lose your low-end torque but get better RPM's and lose your drag brake.
Batteries also make a huge difference. If you're running Nimh cells it's still worth the trouble to re-peak them immediately before running.
#14
All that is true, but as some have already noticed it's the track that ultimately decides. Some tracks simply do not allow lower turn motors to come into their best efficiency range unless geared down to a point where you can't take advantage of their rpm, so you're back to square one. Off road even more so since grip comes into play and no matter what rpms you pull, you just can't make it stick so it's useless.
But for the initial poster, be careful with brushless. In the long run they win cost wise, but you have to be careful. If geared incorrectly, they go up in smoke a lot quicker than brushed motors, and then it's another 300$ (a speedie) or about 100$ a motor. A lot of people can tell you their story of woe (if only they would admit it).
Lipo is the same. Be careful with the batteries as they don't have clearly visible markers to tell + from - and reversing the wires in the heat of the race costs a speedie again. I dunnit.
But for the initial poster, be careful with brushless. In the long run they win cost wise, but you have to be careful. If geared incorrectly, they go up in smoke a lot quicker than brushed motors, and then it's another 300$ (a speedie) or about 100$ a motor. A lot of people can tell you their story of woe (if only they would admit it).
Lipo is the same. Be careful with the batteries as they don't have clearly visible markers to tell + from - and reversing the wires in the heat of the race costs a speedie again. I dunnit.