Best bang for the buck 7.2-7.4 volts single battery?

[CaptPJB]

Was thinking of this motor with standard prop mainly 2s use occasional 3s.
Any and all comments appreciated. Was looking for a "zippy" Rio but not wanting to get in to the torque roll thing

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6525

My thinking was standard prop is relatively big so need low kv and an 80-90 amp esc HK esc would be OK.

Peter

[Diesel6401]

Was thinking of this motor with standard prop mainly 2s use occasional 3s.
Any and all comments appreciated. Was looking for a "zippy" Rio but not wanting to get in to the torque roll thing

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6525

My thinking was standard prop is relatively big so need low kv and an 80-90 amp esc HK esc would be OK.

Peter

The KV you have selected is way to low, rpm is only 8k on 2s, and 13k on 3s. Way to low, you need to aim for around 22k - 30k for sport boating or just messing around. You need a 3000kv motor in that range like Jesse stated above.

[CaptPJB]

The KV you have selected is way to low, rpm is only 8k on 2s, and 13k on 3s. Way to low, you need to aim for around 22k - 30k for sport boating or just messing around. You need a 3000kv motor in that range like Jesse stated above.

Thanks for getting me back on track obviously my kv math was off, was thinking a lower Kv = bigger prop but missed the point, 3000 x 8 = 24000 on 2s

Peter

[Diesel6401]

Thanks for getting me back on track obviously my kv math was off, was thinking a lower Kv = bigger prop but missed the point, 3000 x 8 = 24000 on 2s

Peter

What's the 8, where did that come from?

Rpm is Kv x Voltage. So a 2s lipo is 7.4 volts a 3s is 11.1 volts (3000 x 7.4 = 22,200), (3000kv x 11.1 = 33,300)

Lower KV you can run a loger prop, but you need more voltage for the motor.

[CaptPJB]

Was just rounding up numbers too lazy to do he math at 7.4 besides which a 7 cell nimh is 8.2 so just took 8 as an average as I run both types of batteries.

Thanks I am clear on kv and rpm.

[Diesel6401]

Was just rounding up numbers too lazy to do he math at 7.4 besides which a 7 cell nimh is 8.2 so just took 8 as an average as I run both types of batteries.

Thanks I am clear on kv and rpm.

Copy, I understand now.

[CaptPJB]

Can someone tell me if the stock ESC will run a S600 on 6 cells 7.2v without expiring?
Looks like Tunnelvision changed his ESC to xl-5 not sure if it was because he had it or needed it.

[Diesel6401]

Can someone tell me if the stock ESC will run a S600 on 6 cells 7.2v without expiring?
Looks like Tunnelvision changed his ESC to xl-5 not sure if it was because he had it or needed it.

The stock esc will not handle a s600, it barely handles the stock motor. I run a xl-5 myself reason being it is waterproof and can handle the load. I would imagine it can handle the s600 with no problem. Run the stock esc with that motor and it shouldn't take long before

[CaptPJB]

The stock esc will not handle a s600, it barely handles the stock motor. I run a xl-5 myself reason being it is waterproof and can handle the load. I would imagine it can handle the s600 with no problem. Run the stock esc with that motor and it shouldn't take long before

Upgraded to S600 motor and ProBoat ESC. Presently running stock prop.

Runs well on 7.4 lipo after 5 minutes temp is 117 F in warm Texas water (around 86 F)

On a 6 cell NiMH 105 F after five minutes.

The lipo option gives me what I was looking for in consistent adequate speed as the NiMH drops off as the run progresses but is 117 F too hot?

If it is options appear to be 40mm prop ( not sure what this would do to speed?) and or new cooling jacket, Presently using the stock coils that don't look too efficient compared to a silicon jacket?

What prop are you using with the xl-5 Diesel?

Any comments appreciated

Peter

[Diesel6401]

What prop are you using with the xl-5 Diesel?

Stock Prop.

I didn't/don't spend a lot of time on that boat. I couldn't tell you the last time is has been in the water. Right now it's stripped. I use a PB Apache as my rescue boat now.

[tunnelvision]

Xl-5 with S-600 is a reliable setup. Here's a quick vid of mine with the stock prop on 2s lipo. http://www.youtube.com/watch?v=JRlE4...eature=channel

[CaptPJB]

Looks good about the speed I was looking for. What batteries are you using?

Mine was running very hot with stock prop and 7.4 lipo although speed was good. Waiting on a 40 mm prop to see if that helps. With the vent holes in the S600 and the Rio mount I have not found any better cooling method than the coils. For sure a silicon cooling ring does not work.

S600 and ProBoat ESC (which runs cool)

[tunnelvision]

WHen I use a 7.4 lipo, the motor is hot after 10 minute runs. hehe. But if i run for 5 to 7 minutes its just warm. I also use a 7 cell 3000mah and its quick with that too and everything stays warm after 5 to 7 minutes. I used to use the proboat esc but it got too hot. Motor runs MUCH cooler with the xl-5. I used this setup most of the summer and have had no problems(knock wood).

Have been wanting to change to a 40mm prop so I can run longer and keep things cooler. Let me know how it works out for you.

[CaptPJB]

WHen I use a 7.4 lipo, the motor is hot after 10 minute runs. hehe. But if i run for 5 to 7 minutes its just warm. I also use a 7 cell 3000mah and its quick with that too and everything stays warm after 5 to 7 minutes. I used to use the proboat esc but it got too hot. Motor runs MUCH cooler with the xl-5. I used this setup most of the summer and have had no problems(knock wood).

Have been wanting to change to a 40mm prop so I can run longer and keep things cooler. Let me know how it works out for you.

Put the 40mm on today and it did drop the temps some. I am certainly envious of your temps. . With a 2200 mah Lipo I was hitting 150 f after five minutes on stock 42mm but with a 40mm it is around 130F. However it did appear to reduce the speed a little but still acceptable.

Maybe the 84 F water I am running in is not helping, I would like the temps around 120 F for peace of mind although I have not been able to find what numbers others call acceptable or hot. ESC and battery run around 105F. Certainly seems the xl-5 runs things cooler than the Proboat if your water temp is anywhere near to 80F

Peter

Just done another 5 minute run after adjusting motor angle to shaft at coupling . Battery 2000 NiMH 110F , ESC 105 and motor 119F at hot end by coupling . Speed stayed pretty consistent only dropping a little during the last minute of a 5 minute run. Certainly getting better consistent speed performance run times with 40 mm, at a guess 40mm and S600 is slightly faster than stock 42 mm and stock motor but lasts longer on same battery. Will comment further when by buddy gets his stock Rio out. ( have to say his always slightly outran mine both stock and using same battery 2000 NiMH.)

[tunnelvision]

Put the 40mm on today and it did drop the temps some. I am certainly envious of your temps. . With a 2200 mah Lipo I was hitting 150 f after five minutes on stock 42mm but with a 40mm it is around 130F. However it did appear to reduce the speed a little but still acceptable.

Maybe the 84 F water I am running in is not helping, I would like the temps around 120 F for peace of mind although I have not been able to find what numbers others call acceptable or hot. ESC and battery run around 105F. Certainly seems the xl-5 runs things cooler than the Proboat if your water temp is anywhere near to 80F

Peter

Just done another 5 minute run after adjusting motor angle to shaft at coupling . Battery 2000 NiMH 110F , ESC 105 and motor 119F at hot end by coupling . Speed stayed pretty consistent only dropping a little during the last minute of a 5 minute run. Certainly getting better consistent speed performance run times with 40 mm, at a guess 40mm and S600 is slightly faster than stock 42 mm and stock motor but lasts longer on same battery. Will comment further when by buddy gets his stock Rio out. ( have to say his always slightly outran mine both stock and using same battery 2000 NiMH.)

40mm sounds to be a bit better but I like more mph's. Where did you get yours? I think I'll give it a go. I usually run it with my 7 cell nimh, save my lipo's (5000mah 25C) for my Supervee. Definitely, want to run it a little longer.

Curious how it stands up to a stocker with the same battery. I really need a GPS to get a better grasp on mods.

Rob