Brushless motors for large Seaview

[greenman407]

Hi Dave! I am very impressed with your forum and inventive building products and projects. I dont know if you are familiar with a builders thread that I am doing on the Rick Teskey Seaview. You can find it on.....you guessed it.......builders threads listed as Rick Teskey Seaview. I have posted about my search for suitable brushless motors to replace my 12 volt long can speed 400 motors. I am searching for more speed and hopefully extra durability in these motors as the ones that I have get quite hot. I have seen some direct replacment motors of the brushless variety but I thought I would get your input. Thanks

[greenman407]

Here is a link to

Here is a link to the motors.
http://www.hobbybarn.com/proddetail.php ... 00&cat=138

[greenman407]

and two of these speed

and two of these speed controls

http://www.hobbybarn.com/proddetail.php?prod=PHX-25

[junglelord]

Well I for one am

Well I for one am quite familiar with your build.
I look forward to the development of your project with these brushless motors and speed controls. I for one would love a Debor or Teskey Seaview...yup the big ones

[bigdave]

From looking at your build

From looking at your build I would think the motors would be a drop in. The brushless would be more tollerent to the heat build up problem although the heat build up would not be any less. Maybe more if you push it as they would have more power. The ESC you picked has no reverse. If you do not need reverse they are a good choice. I would use the Mamba-25 if you need reverse.
Please let me know how you make out. BD.

[greenman407]

Thanks Dave for your reply.

Thanks Dave for your reply. I may be wrong but I thought I saw in the text that for reverse, reverse any two wires. Anyway what is a mamba and where can I buy them? I was hoping that a more powerful motor would be more comfortable producing the power that I need and thus run cooler. The question is, is it more powerful? Would the gains realized be worth the investment? The other issue is that the brushless motors have a 2mm shaft whereas the speed 400s have a 2.5mm shaft. I would have to check with Dave Merriman to see if he can get me some brass gears that have a 2mm shaft hole. Yes I need reverse as I control each motor on a seperate channel for differential steering.

[greenman407]

Thanks Junglelord, Rick Teskey is

Thanks Junglelord, Rick Teskey is one of your native countrymen, you should contact him. Maybe he can cut you a deal.

[bigdave]

Reversing two wires just changes

Reversing two wires just changes the direction of the ESC if say your motor is spinning the wrong direction. You need a foreword and reverse ESC to make the motor go in reverse from the transmitter.
The Momba is made by Castle too. It is one of their car/marine ESC's.
The motor is definitely more powerful that a stock 400. If it was me and you did not need the extra power I would stick with the 400's. If you burn one out eventually from the heat they are cheap to replace. BD.

[greenman407]

http://www.subcommittee.com/forum/icon_biggrin.gif Thanks Dave! http://www.subcommittee.com/forum/icon_smile.gif

Thanks Dave!

[Guest]

Your motors are too high

Your motors are too high revving for the props you are driving- plain and simple.

You can apply further gear reduction, or seek out a motor with lower RPM but higher torque.

A good brushless motor will out perform a good brushed motor, but at a price. Also low speed operation will be inferior to a brushed motor, unless the motor is equipped with hall sensors and the controller is designed to use them.

[Guest]

On which Castle Creations controller?

On which Castle Creations controller? The Dragon 35 had built in sensor readers for use with Aveox motors, but that is the only one I am aware of and it's now out of production.

Andy

[Guest]

Well that is the problem.

Well that is the problem. The vast majority of brushless motors are designed for higher RPM, even with outrunners you'll have to search hard to find one that winds below 1000RPM per volt. Most subs need a motor capable of about 250-300RPM per volt, assuming a 12 volt system.

You can user a gearbox, that reduces the efficiency of the system a bit, and if using gears adds noise. The other option, is to wind your own motor. This is what some modelmakers in Germany are doing.

The sensorless controllers have improved considerably with low speed running.