Is This A Bad Idea ?????

[b.mcdaniel.2009]

Latly I've seen guys running crazy amount's of RPM in there set-ups and was wondering would this be a bad idea......????

DF 29 Leopard 2000kv- T-180-X448 on 5s= 42,000 rpm.

I've made some HARD runs on 4s with the same prop and have no heat issue at all.....Cant even tell it was ran LOL.... So bad idea or not?

[Diesel6401]

Latly I've seen guys running crazy amount's of RPM in there set-ups and was wondering would this be a bad idea......????

DF 29 Leopard 2000kv- T-180-X448 on 5s= 42,000 rpm.

I've made some HARD runs on 4s with the same prop and have no heat issue at all.....Cant even tell it was ran LOL.... So bad idea or not?

Spinning that size prop at 33k is a lot different then spinning it at 42k. Your amp loads are gonna skyrocket. I ran a leopard 4074 2200 on 4s with a x447 and spiked over 170 amps. I don't think the rpm is gonna be your problem I think the combo of prop and rpm maybe a issue. I would get a datalogger if you don't have one and start with like a x442 then a m/x 445 and check your data. You don't want to risk your motor and esc. I just smoked a seaking 120 with a leopard 4074 1774kv on 4s with a x447/3.

* On the leopard 2200kv and seaking 180 I was having a few esc issues that I worked out so that boat wasn't running wot the whole time (throttle calibration was off). But nonetheless it's information...

[Flying Scotsman]

Latly I've seen guys running crazy amount's of RPM in there set-ups and was wondering would this be a bad idea......????

DF 29 Leopard 2000kv- T-180-X448 on 5s= 42,000 rpm.

I've made some HARD runs on 4s with the same prop and have no heat issue at all.....Cant even tell it was ran LOL.... So bad idea or not?

Yes, a bad idea, unless you are making one saw run.

Douggie

[Simon.O.]

As you can see, huge rpm itself is not a bad thing, I have cleared 40krpm more than once, and indeed setup a few of my hulls with high 30krpm setups.

With a prop as big as a 448 it will take a lot of power to spin it that fast.
As you know Power (W)= V x A so it will be gobs of amps or gobs of volts to do that.

I like lots of volts and lots of rpms but I always do my maths, as you are doing
I do some crazy stuff too !

[Fluid]

First off, you will not be spinning anywhere near 42,000 rpm. Under load you will be closer to 33,000 rpm. As above, it is not the rpm that is bad but the amount of watts it takes to spin a given prop that fast. A setup which is actually capable of 42,000 rpm will be very sensitive to load. Just a bit too much prop and you'll spike high amps and eventually blow something.




.

[b.mcdaniel.2009]

Spinning that size prop at 33k is a lot different then spinning it at 42k. Your amp loads are gonna skyrocket. I ran a leopard 4074 2200 on 4s with a x447 and spiked over 170 amps. I don't think the rpm is gonna be your problem I think the combo of prop and rpm maybe a issue. I would get a datalogger if you don't have one and start with like a x442 then a m/x 445 and check your data. You don't want to risk your motor and esc. I just smoked a seaking 120 with a leopard 4074 1774kv on 4s with a x447/3.

* On the leopard 2200kv and seaking 180 I was having a few esc issues that I worked out so that boat wasn't running wot the whole time (throttle calibration was off). But nonetheless it's information...

Ya i seen that in your thread D. Your right i do not wanna burn my power plant up.

[b.mcdaniel.2009]

First off, you will not be spinning anywhere near 42,000 rpm. Under load you will be closer to 33,000 rpm. As above, it is not the rpm that is bad but the amount of watts it takes to spin a given prop that fast. A setup which is actually capable of 42,000 rpm will be very sensitive to load. Just a bit too much prop and you'll spike high amps and eventually blow something.




.

So if i stepped it down to a M445 on 5s it SHOULD be okay? Or should i just scratch that 5s idea and do with a lower kv Leopard? Fluid, i read alot of your opioion and fact's you've post here on OSE and I'm glad i caught your attention on this question i have!

[Fluid]

I would try the m445 but be careful and limit the first run to about a minute and check temps. A lot depends on how freely the hull runs and how long you run it. You may find you can go bigger with the prop, but it is best to never start off with the same prop you used with a lower voltage.


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[b.mcdaniel.2009]

I would try the m445 but be careful and limit the first run to about a minute and check temps. A lot depends on how freely the hull runs and how long you run it. You may find you can go bigger with the prop, but it is best to never start off with the same prop you used with a lower voltage.


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Thanks guys for the info! Going to try a m445 first and I'll post results.