Small cat problems.

[speedsport]

I have a Nanokat its about 15in long. I'm using a Mystery Pentium 30 esc and a Mystery 4000kv outrunner. On 8cells NIMH with a octura x427 prop set at the bottom of the hull as a surface drive.

I use to use a novak esc and a speed 400 motor. My problem is that this brushless set up is about as fast. I think the motor is a 12 pole design. I tried a bigger plastic prop a y534 and noticed a little better performance. With the smaller prop the boat takes longer to plain out and bounces no matter what I do. The bigger one is the exact opposite. I also noticed with the bigger prop it sounds like the motor is barley spinning.

Neither prop makes any thing hot its just warm to the touch. I got about 30 run time with the small prop and about 20 with the bigger one.

Should I switch to a different motor, prop or esc? I would like to stay with the cheaper stuff as this is just for fun. I'm new to the brushless stuff its greek to me.

Thanks.

[speedsport]

I just realized I worded this weird. I'm trying to figure out if there is a way to make it preform better, faster.

Thanks

[Rumdog]

Switch to lipo. A 2s pack would be plenty.

[Rumdog]

A lower kv motor around 3000kv and 3s lipo would be even better.

[speedsport]

A lower kv motor around 3000kv and 3s lipo would be even better.

Thats what I'm talking about thats the kind of stuff I like to hear.

I'm planing on going to lipo on every thing. I thought about using a smaller KV motor but was not sure. What about the 3000kv on 2s would it work? Or would I have problems?

Thanks

[Simon.O.]

It was noy long ago that i was running Ni cells when the rest of these guys were telling me to go lipo, I eventually fell and will never go back.
The joy of Ni cells is you can add a cell and the effective rpm of the motor increases a bit. Add a cell with Lipo and it all gets a lot faster.
Choosing a motor (kv) is important when specing a power setup with lipo.2S is a lot differet to 3S etc.

You currently have a 4000kv motor with a 427 prop and 8 cells.
Now given that Ni cells loaded will deliver about .9v/cell you are getting 7.2v loaded.
Now take a 2S lipo which has a nominal voltage of 7.4 and you are already ahead.

For a 2S setup I would run well over 4000kv to a 427, it will do but you can do a lot better.
If you are up for a new motor then I would suggest that you look at a high kv motor for 2S or a moderate 2800-3500kv for a 3S setup.

The lower kv and higher cell count setups are lower on amps and therefore easier on components.

I have done a lot of reading on small setups as I am in the process of putting 2 more cats on the water.

I hope this was a bit of help.

[speedsport]

I was thinking on another motor. What about the prop? I could change that to if it will work better.