Motor questions...

[mschaffer66]

Ok, so I've got this 34" H&M cat...
I'm running the gear drive geared 45T on the pinion and a 66T spur gear with a 2200kv mamba monster motor, 180A Turnigy esc, 4S, and a X448 prop

It had a ton of get up and topped out at 44mph on the gun.

Well I had bought one of these the other day:

http://hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=6677

I figured I'd throw that in and see what my current draw, heat, etc... was like.

Dropped it in, took it to the lake and it was a pooch.

I guess my question is why does going up 600KV suck so much. It wasn't pulling much current. To me I figured it would pull more current, generate more heat, not has as much low end, but be a lot quicker up on plane. None of that happened...

Am I totally missing something here?

[ED66677]

ok first of all a XL size motor is not big enough for a 34" hull
this motor is given for 110A max but that's what is reasonnable or at its max efficiency, it can basically pull a lot more
you can turn it all around the way you want, if you need a certain amount of power to move this hull to a higher speed, you will need to pull more amp... or go for higher voltage with a much lower KV
in addition to the above, with today's brushless motor and KV choices, gears are not needed anymore, go for a bigger motor, a Feigao580 10L for example, under 6S, it will require 33% less amp than under 4S at the same power!

[Alexgar]

the cheap motor cant keep up with the castle i have both motor and the castle is king of my fleet, followed closely by a proaboat motor the 6xl is about nimber 3 of the six motors i have

[mschaffer66]

While I welcome all input that didn't even come close to answering my question.

The gear drive is staying, its in there already, it works, I'm happy.

I was just screwing around and wanted to see what a different motor would do.

It seems like to me it would have gotten very hot considering its undersized for the hull and it wasn't.

[Alexgar]

its a 2 pole so the torque isnt even close to the castle/neu

[Alexgar]

i would change up the gears with the mamba monster

[mschaffer66]

the cheap motor cant keep up with the castle i have both motor and the castle is king of my fleet, followed closely by a proaboat motor the 6xl is about nimber 3 of the six motors i have

Yeah thats to be expected considering the 6XL is like 20 bucks and a castle motor is like 150.

[mschaffer66]

its a 2 pole so the torque isnt even close to the castle/neu

So what you are saying is that because the cheapy chineese motor doesn't have the torque that the castle does it isn't able to spin the prop to its full 2800KV where as the Castle is able to spin it to the full 2200KV?

[JMSCARD]

Just to let ya know I run a 9xl in my H&M drifter L.... it is not to big a hull for a xl motor.... I have pushed mine to almost 50mph with the xl motor.... yeh a neu would push it harder..... but I am happy at that speed.... as this is more of a sport boat for me...... I have a lehner 2250 too for sale in the swap shop, just in case you are looking for a 70mph cat:) the 2250 is recomended as the "big" motor for the H&M drifter L... which it sounds like is what you are running....

Also 2800kv on 4s is HOT...... are you sure you are not having esc issues(cutting out).... you need to prop way down if you are running the 2800kv motor..... you are spinning that motor 47,000 rpm on 4s..... eeesshhh thats scary on that cheapy motor, those bearings are lucky they are still on the earth after one run...

[Alexgar]

in not so many words thas my opinion and the fact it has less moving mass

[mschaffer66]

Mine is the supercat.

I was actually very happy with its performance with the 2200kv motor...I was just bored so I figured I'd experiment.

To me it should have gone like a bat out of hell for a few seconds then something poof....but neither of those two happened.

[Alexgar]

i love my castle finally some made a motor we can afford with power i may try one of those lepeords next

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140418992493&ssPageName=STRK:MEWAX:IT

[mschaffer66]

I think I have justified the failure of this experiment the following way:

The castle motor has less rpm's, but more torque, the 6xl has more rpm, but a ton less torque.

So its like taking a big 3/4 ton pickup, pulling out the V8 and putting a Honda Civic motor in its place.

Does that comparison make sense?

[Alexgar]

sound right enough i learned this when i first started my 3500 and 4800 kv l sized motors pushed bigger props with more pitch i dropped in a 7700 kv and after 20 second the esc would shut down the motor couldnt get the timing right kind of like catch up or it would overspin it self if that makes any sense. so in whole i didnt learn anything about bl motors except what not to do

[Make-a-Wake]

"I guess my question is why does going up 600KV suck so much. It wasn't pulling much current. To me I figured it would pull more current, generate more heat, not has as much low end, but be a lot quicker up on plane. None of that happened...

Am I totally missing something here?"

Those motors are not even in the same class.................... The big castle is a 40mm x 75, which is bigger to start with, 4 pole, oversize bearings, and the efficiency level is very high. If you want more speed, just drop the gearing and go direct, or go 1:1 on the gearing............