Crossroads: Brushed or Brush less

[Drunken Pirate]

I am looking for some advice or information about brushed or brush less setups.

I have some serious cooling questions about my particular brand of ESC. It's for a brushed motor and built for a car. The FETs and heat sink are set up in the worst way. So I am thinking on getting a better ESC. One already built with cooling in mind.

If I am going to buy a new ESC (I was thinking of the Jeti Navy 600 Water Cooled ESC) for my 17 wind 2 turn Kyosho Atomic Force motor I am worried that my motor kind of sucks as well. And that gets me to thinking about a brush less setup.

What are the advantages of going brush less (besides not having to replace brushes)?

Does anyone have experience with brush less systems in a 1/16 hydro?

Does anyone have any advice one way or the other?

I plan on running anywhere between 6 and 12 Sub C's.

I don't want to spend money just because something might be more trendy than useful.

Thanks

[Steven Vaccaro]

Brushless motors are about 5-10% better in efficiency. They are also longer lasting. The esc's are the weak point but over the last 4 months lots have changed. The are getting better and better.

[Drunken Pirate]

Brushless motors are about 5-10% better in efficiency. They are also longer lasting. The esc's are the weak point but over the last 4 months lots have changed. The are getting better and better.

Steve,

What exactly comes to your mind when you say the ESC's are kind of weak? The ESC is the base of this decision. a $70 ESC for brush compared to a $150 for brush less. If you could expand a bit on the statement.

[Steven Vaccaro]

In the past the esc's have burned up. But I'm hearing that much, much less these days.

[boater76]

Steve you talking bout the Jeti 600?

Ken

[SJFE]

A good number of early esc's had heat issues. Most of the newer stuff is fine. You can tell whats better by the price in most cases

[Steven Vaccaro]

Steve you talking bout the Jeti 600?

Ken

Jeti? No way. They are rock solid. I sell a bunch of those. In the last year I have had about 2 issues. Both covered by the warranty.

[RMZDADDY]

I switched from brushed to brushless last year, I'll never go back. In my experience I found that if you over amp a brushed setup the failure occurs at the motor, since the most heat is generated at the commutator. A brushless motor can pull alot more amps before overheating so I think this made the esc the weakest link. It seems the manufacturers have worked hard to make this less of an issue. With my brushless setups I listened to some good advice and started out conservative on prop choice and worked my way up in size and pitch until I achieved the speed I was looking for while still keeping amp draw at an acceptable level. I now have two boats that run faster (and more reliable) with brushless than I ever did with a brushed setup. It was a bigger investment to start, but I'm having more fun and I've yet to kill a brushless esc.

[Doozie870]

It really depends on what your main goal is. If you want a true work horse go with brushed, what Im seeing is not so much the controllers are better (which they may be) its a much more conservative brushless set-up for oval racing, Im noticing a lot more gear reduction transmissions on brushless for some reason.

[SJFE]

I am about to find out for myself Dooz. Got a 7xl on direct goin in the bullet. We shall see what happens when i dump 22+ volts in it.

[Drunken Pirate]

Wow, Lots of good information out there.

so....
Brushless handles amperage better than brushed, but in so doing shows the shortcomings of the esc.

Cooler running and cooler looking than the brushed but not as much low end torque. I think thats what you meant by being a workhorse.

Well I am still at a crossroads. In my own mind I feel like I want to be able to switch out the ESC and Motor with relative ease and slip in a different set. Then I can run whatever I feel.

does anyone switch out their electronics often?

[Fluid]

No. BL motors have more power than brushed, high or low rpm. It depends on the motor chosen, some are high rpom, some are low rpm/high torque. A BL system will outperform a comparable brushed in almost every catagory except cost.

BL systems run cooler due to their better efficiency, but the result is the cells can get very hot. You have to monitor ceel temperaturees after each run and prop accordingly. When we first started running BL systems this is what I noted first - hot cells, cool motor.

SJFE - that 7XL will be stressed running direct drive on 22 volts (6S LiPo?). If you expect it and the ESC to live, keep run times short and the prop small - 36-38mm to start.


.

[Doozie870]

SJFE, if you want we could shed a little light on this, can you run your new boat on 12 cells or lipo equivelent? Ill run my brushed Arrow on 12, lets break out the data recorders and gps when the boats are done.

[Drunken Pirate]

No. BL motors have more power than brushed, high or low rpm. It depends on the motor chosen, some are high rpom, some are low rpm/high torque. A BL system will outperform a comparable brushed in almost every catagory except cost.

BL systems run cooler due to their better efficiency, but the result is the cells can get very hot. You have to monitor ceel temperaturees after each run and prop accordingly. When we first started running BL systems this is what I noted first - hot cells, cool motor.

SJFE - that 7XL will be stressed running direct drive on 22 volts (6S LiPo?). If you expect it and the ESC to live, keep run times short and the prop small - 36-38mm to start.


.

Fluid, thanks for this information. I have another (in a long long series of) dumb question(s). Has anyone thought of building a water jacket or other type of inflow cooler around the batteries? Or is that like throwing a toaster in a bathtub?

[Rex R]

2 problems (that I can think of) 1) nimh cells like to run warm(120-130F) 2) much of the heat generated is in the center of the cells where it is difficult to cool effectively.