Brushed motors..much of difference?

[themagicnumber]

Would I see much of an improvement going from a 27T Saturn motor to a 15T Firebolt?

[Deafty]

if by improvement u mean speed?

 

Then,.... yes

[NuttyProfessor]

Just don't forget to change the speedo if the turn limit on yours don't drop that low. Runtimes will be around half or less too of a 27t.

[chewbacca]

What Deafty said. 

 

 

Can your ESC handle the change?

[themagicnumber]

Just don't forget to change the speedo if the turn limit on yours don't drop that low. Runtimes will be around half or less too of a 27t.

Ah thanks..I didn't know it had that effect on runtimes.

So I learnt something today

 

What Deafty said. 

 

 

Can your ESC handle the change?

Yeh it's a HPI SC-15WP..a 15T limit I think.

[NuttyProfessor]

Cutting it fine, you need something around the 12 turn, bit of headroom if you run heavy gearing or get bogged down. Dynamite Tazer 12t is good, got lipo cut off built in so you can run brushed with a 2s, bit more perk.

[themagicnumber]

Cutting it fine, you need something around the 12 turn, bit of headroom if you run heavy gearing or get bogged down. Dynamite Tazer 12t is good, got lipo cut off built in so you can run brushed with a 2s, bit more perk.

I thought the ESC rating went down TO 15T..so 12T would be out of it's limits? Or am I being daft?

 

EDIT: Yep, daft as a brush..You meant the ESC. D'oh.

Edited April 30, 2015 by themagicnumber

[NuttyProfessor]

Exactly, lower the turns, faster motor so the esc has to match or top the motor turns to run with no excess power draw I like brushed,very smooth but brushless is next to no maintenance.

[themagicnumber]

Yeh I have a brushless set up that as long as it stays dry needs, as you say, no maintenance.

Edited April 30, 2015 by themagicnumber

[Tamiyacowboy]

brushed motors are made slightly differnt to a brushless. 

 

the copper windings are ON the main rotor shaft in a brushed motor.

so to get them charged with electric to make it turn you must somehow transfer the electrical charge to the main rotor.

this is done via a set of two carbon pads that rub on the top of the main rotor shaft, we call it a communicator. 

and your magnets bonded to the inside of your motor can. 

 

inside a brushless motor its been flipped round the other way.

we glue bond the magnets to the main rotor and place the copper wire windings inside the motor can.

we can now do away with those carbon brushes ( ie its brush -less ), it works in the same way.

but its more efficent , less current is lost due to sparking etc etc. 

BUT the esc must change it needs to send pulses of electric to the windings to make the rotor magnets attract and repell each other.

as they pass over charged up coil windings. 

 

 

its why brushed esc have two motor wires and brushless have three wires ( brushed has a pos and neg terminal , and brushless has a 3x positive and a shared ground)

[Geeze]

Quality of motor makes a difference too, the ball raced 21T open can motor that replaced the 20T sealed can in my eldests RTR was noticeably quicker despite being supposedly slightly slower according to the number of windings

[Tamiyacowboy]

yep like the old tamiyas came with two differnet 540 stock cans

 

one was a johnson silvercan 

 

two was a mabuchi silvercan

 

both great but the mab was preffered ( the mabs were like a stock upgrade quicker than the johnsons) 

[Si Coe]

Quality is far and away the biggest factor. The very highly tuned open endbell, short stack 27t motors designed for the old 'Stock' racing class were actually quicker than closed end bell 15t motors found in RTR's.

More than that though brushed motors performance deteriorates over time due to the brushes burning on the commutator. The rebuildable 'stock' motors could be cleaned and skimmed, therefore maintaining peak performance.

 

However the reality in 2015 is that brushless systems are now so cheap if you want to upgrade performance you might is well go brushless. Getting a new, faster brushed motor and a new ESC to support it as suggested costs the same as a knockoff Ezrun 35A and 9t combo off ebay.

Edited May 1, 2015 by Si Coe