20A Quality ESC?

[prototype3a]

I admit this is not for a heli but a tugboat. I'm looking for a pair of Kontronik Jazz level quality escs that are much less expensive to control a pair of small outrunners. I'm considering the Hyperion HP-Z2213/24 (kv850) running off a 2s A123 battery pack. I'm trying to find one that is a good deal as I need 2 of them as the tug will have 2 azmuthing 65mm props. I'm trying to make sure it has plenty of power to prevent bogging in any situation. I figure I should need 20A escs.

The manufacturer of the drives recommends a speed 900 brushed motor but I really want to use an outrunner. If anyone has an idea for a better suited motor I'd really apreciate any guidance on that matter as well.

Thanks

[Danal Estes]

You've kinda answered your own question: Pay for Jazz or run something else. Castle would be another choice... not the same quality but certainly cheap enoug to run 2 and their customer service is EXCELLENT.

Sounds like you are experimenting a little... I'd go with the Castles for their programmability and, if you burn one up, chances are they'll replace it free and they'll ALWAYS replace it 1/2 price, even if you send them a baggie of ashes!

[prototype3a]

Well the Jazz is out of the question as the smallest they make is the 40 and that's $180 and there is no way I'm gonna put 2 $180 escs in this thing. At the moment I may not be able to build it as the shipyard doesn't seem to be willing to give me a copy of a couple pages of their plans. Currently, I'm leaning towards the CC phoenix 25 escs. At $80 it'll make each shaft cost about $250 to outfit.

How are they for low rpm control of outrunners? I've learned that it's important on a tugboat to have fine control of the low rpms for really accurate slow speed maneuvering. The high end doesn't matter so much as you only use that when you need speed/push power.

[Danal Estes]

CC is a good as anybody else at low speed. All sensorless brushless have a minimum RPM. Consider gearing?

[damyxz]

I have seen a water cooled ESC somewhere before for boat use. It's a hydra water cooled ESC sold at BP hobbies. Check it out. http://www.bphobbies.com/view.asp?id=A0780193