Outrunner motor for boat

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Ericehess

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Hey all. Relatively new to rc. Got big into it last year and am constantly upgrading rc cars and boats. I upgraded my vector Sr 48(esc, driveshaft, servo, 35mm metal prop, metal fins, bigger motor. Originally I put in a 4000kv outrunner with 3s. It worked great, super fast..pushed 50. No issues until saw the motor smoking, some copper wrappings came undone. So I switched to an inrunner 2845 motor I had, 4500 kv with 2s. Now the esc lvc keeps getting tripped with new fully charged batteries. Works fine with lvc shut off.

Question is do outrunners have more power than inrunner? Could the inrunner not have enough power and be causing the esc to trip lvc detection. Or is my esc maybe malfunctioning. It's a 60amp hobbywing seeking.
 
the problem is the battery does not have enough C to maintain a steady voltage so it drops to lvc cutoff.. the setup you have is just to much for battery. either change prop or battery to a higher C rate
 
the problem is the battery does not have enough C to maintain a steady voltage so it drops to lvc cutoff.. the setup you have is just to much for battery. either change prop or battery to a higher C rate
Thanks TNT. I'm curious if the switch to an inrunner is causing this. They have much less torque than outrunners so are put under more strain. I'm hoping the new 3000kv outrunner will be able to handle the load better.
 
Thanks TNT. I'm curious if the switch to an inrunner is causing this. They have much less torque than outrunners so are put under more strain. I'm hoping the new 3000kv outrunner will be able to handle the load better.
I'm also wondering about the outrunner. I've never used kits that use them so I know very little about them compareed to the inrunners. One thing I did notice is the water cooling portion of the motor mount is designed to cool outrunners not inrunners. One of the things I read is that if you switch to an inrunner motor you also need to switch to a water cooling jacket for it.

As much as I hate directing folks to other forums heres an upgrade thread I found on your boat. Might want to give THIS a read.
 
I think I looked at that when I upgraded it originally..used most of the same stuff. He mentions inrunner may not have enough torque. Wish I had gotten the 3200kv motor he shows instead of 3000 but difference shouldn't be too much for speed. Thanks! Should get new motor in a week or two. I'll check back in
 
I think I looked at that when I upgraded it originally..used most of the same stuff. He mentions inrunner may not have enough torque. Wish I had gotten the 3200kv motor he shows instead of 3000 but difference shouldn't be too much for speed. Thanks! Should get new motor in a week or two. I'll check back in
200kv wont be much of a noticable difference. In fact 3000kv will have slightly more torque so it may be a good thing since you upgraded prop size but yeah, please keep us posted...You have me vested in the outcome now lol
 
Nice! I get to share the blame if I fail! This is the fun part of RC right?
 
Hey all. Relatively new to rc. Got big into it last year and am constantly upgrading rc cars and boats. I upgraded my vector Sr 48(esc, driveshaft, servo, 35mm metal prop, metal fins, bigger motor. Originally I put in a 4000kv outrunner with 3s. It worked great, super fast..pushed 50. No issues until saw the motor smoking, some copper wrappings came undone. So I switched to an inrunner 2845 motor I had, 4500 kv with 2s. Now the esc lvc keeps getting tripped with new fully charged batteries. Works fine with lvc shut off.

Question is do outrunners have more power than inrunner? Could the inrunner not have enough power and be causing the esc to trip lvc detection. Or is my esc maybe malfunctioning. It's a 60amp hobbywing seeking.
Take a look through this: https://www.radiocontrolinfo.com/brushless-inrunner-vs-outrunner-motor/ It shows the differences between an inrunner and an outrunner. Me personally, i have never used an inrunner on a boat. They are great for dones, but, the smaller motors especially dont have the power a boat really needs. I tend to stick with 3000KV to 3500KV (typically 3660 size) outrunners for all of my 2S 30" and shorter boats, although, i have seen guys run 3800KV in boats up to 48".
 
I think I looked at that when I upgraded it originally..used most of the same stuff. He mentions inrunner may not have enough torque. Wish I had gotten the 3200kv motor he shows instead of 3000 but difference shouldn't be too much for speed. Thanks! Should get new motor in a week or two. I'll check back in
After reading that article Id try the inrunners you have again only thing is, this time Id use a water cooling jacket on them. Experiment between 2S and 3S.

Take a look through this: https://www.radiocontrolinfo.com/brushless-inrunner-vs-outrunner-motor/ It shows the differences between an inrunner and an outrunner. Me personally, i have never used an inrunner on a boat. They are great for dones, but, the smaller motors especially dont have the power a boat really needs. I tend to stick with 3000KV to 3500KV (typically 3660 size) outrunners for all of my 2S 30" and shorter boats, although, i have seen guys run 3800KV in boats up to 48".
That was a good article. I knew some of the general info about outrunners but not much detailed info. Learn something new everyday.

As for using a 3660 sized motor I dont believe that is possible with this kit. A 3660 is a 1/10 scale 540L can sized motor. His motor mount only fits a 380 sized motor.
 
I could fit a 540 size but it would be real tight and add a lot of weight. Boat is only about 18 inches. The mount I use is water cooled which is good for an outrunner but I don't think works for an inrunner which would need the water cooling jacket. I have a jacket I could try but I don't think it will help with the lvc issue. I'm just gonna wait for the new outrunner motor.
 
I could fit a 540 size but it would be real tight and add a lot of weight. Boat is only about 18 inches. The mount I use is water cooled which is good for an outrunner but I don't think works for an inrunner which would need the water cooling jacket. I have a jacket I could try but I don't think it will help with the lvc issue. I'm just gonna wait for the new outrunner motor.
I'm surprised it would fit a 540 but like you said its really not meant to hold a 540. Gotta my figures crossed for the new outrunner
 
It wouldn't fit well, I would have to shim it up to fit then the driveshaft wouldnt be straight to the motor shaft..with a flex shaft it could work but would put more strain on the motor. Not a good option.
 
Got the 3000kv outrunner in it and it ran like a champ today. No esc lvc issues. Ran it about 10 mins, no issues. Goes about 40 with 3s. Motor was hot but not burning up after. Outrunner is the way to go for boats.
 

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Got the 3000kv outrunner in it and it ran like a champ today. No esc lvc issues. Ran it about 10 mins, no issues. Goes about 40 with 3s. Motor was hot but not burning up after. Outrunner is the way to go for boats.
Awesome! I'm glad you were able to get that sorted!
 

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