Go Back  R/C Tech Forums > General Forums > RC Boating
Brushless motor for 1400 mm double jet boat >

Brushless motor for 1400 mm double jet boat

Brushless motor for 1400 mm double jet boat

Old 03-22-2021, 06:51 AM
  #1  
Tech Rookie
Thread Starter
 
Join Date: Mar 2021
Posts: 5
Questions?? Brushless motor for 1400 mm double jet boat

Hi, I'm new at this forum. I'm building a kind of RC rescue boat powered with 2 water jet thrusters with 40mm nozzles.
Now I have two Flycolor 120A ESC powered from 4s Zippy LiPo packs. But currently installed motors X-Team XTI-3665 2650KV get overheat when I try to tow any person.
don't need to reach great speed (it would be nice if it goes up to 40-50 km/h) but i need some motors with higher torque. I didn't see any specs about motors available on the internet sites.
The main problem is that the motor wires becomes very hot and unsolder from connectors :P
Are there any unexpensive (one of this project issues) motors i could use? What should i look for? I cant change battery (only 4 cells) or esc.

Xantus is offline  
Old 03-22-2021, 08:23 AM
  #2  
Tech Elite
 
the rc guy's Avatar
 
Join Date: Aug 2016
Location: Detroit
Posts: 2,629
Default

why do you need a recue boat that goes 30mph. My recue boat will do just faster than the 7mph that my local river runs(about 12). Id drop the kv in you motors
the rc guy is offline  
Old 03-22-2021, 08:45 AM
  #3  
Tech Rookie
Thread Starter
 
Join Date: Mar 2021
Posts: 5
Default

Originally Posted by the rc guy View Post
why do you need a recue boat that goes 30mph. My recue boat will do just faster than the 7mph that my local river runs(about 12). Id drop the kv in you motors
I mentioned "it would be nice to reach 40 km/h" - it's not necessary .
I think about decreasing KV but it usually means higher motor voltage, and i am afraid about torque loose then.
How much KV should it be? 2000 or less?
I noticed that these motors only overheat when towing, without load there is ok.
Xantus is offline  
Old 03-22-2021, 02:09 PM
  #4  
Tech Elite
 
the rc guy's Avatar
 
Join Date: Aug 2016
Location: Detroit
Posts: 2,629
Default

if they over heat when towing only the drop kv down. 1900 should be a good amount of thrust so you can tow whatever you need,,
the rc guy is offline  
Old 03-22-2021, 04:00 PM
  #5  
Tech Rookie
Thread Starter
 
Join Date: Mar 2021
Posts: 5
Default

Originally Posted by the rc guy View Post
if they over heat when towing only the drop kv down. 1900 should be a good amount of thrust so you can tow whatever you need,,
Ok, do You recomend something? Motors like SurpassHobby or similar in 36xx class with KV smaller than 2000 are officially designed for higher voltage, and there are no charts showing their voltage to torque relationship. Or i can't find them.

Maybe some of these :

Surpass Hobby 4074 2000KV with max 30V,

Surpass Hobby 3670 1850KV with max 24V,

They come with original cooling jacket, But could they work with 4s batterypacks?
Xantus is offline  
Old 03-23-2021, 12:51 PM
  #6  
Tech Elite
 
the rc guy's Avatar
 
Join Date: Aug 2016
Location: Detroit
Posts: 2,629
Default

id pick this..
US SHIP SURPASS 4074 Waterproof Brushless Motor + Water Cooling Set for RC Boat | eBay
the rc guy is offline  
Old 03-24-2021, 02:40 AM
  #7  
Tech Rookie
Thread Starter
 
Join Date: Mar 2021
Posts: 5
Default

So this max voltage (here 30V) means I can use 4s instead of 6s battery? Neither sellers or manufacturer don't provide any info about it
Xantus is offline  
Old 03-25-2021, 03:48 AM
  #8  
Tech Elite
 
the rc guy's Avatar
 
Join Date: Aug 2016
Location: Detroit
Posts: 2,629
Default

it says 26v..you can use 6 cells...you just have to scroll down a tad 60k max
the rc guy is offline  
Old 03-25-2021, 09:14 AM
  #9  
Tech Rookie
Thread Starter
 
Join Date: Mar 2021
Posts: 5
Default

So it will have 14.4*KV=27360 turns/min? It's enough for me

However when i was buing a motor for plane (some redox) both max and min voltage were mentioned in documentation.

So I'm ordering these 4074 2000KV motors. Very big thanks for help I'gonna put final effects here
Xantus is offline  

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.