Help me tune this motor setup

[mickvk]

I have a HOR Deltaforce 32 clone with a 540 class XL motor - a generic red can from HobbyKing. it's 1853kV. I'm running at 5S with an Octura y536. FE Calc says it should draw 77A and do 48 MPH. That's what I was building to - I'd be pretty happy with that. It's on target for the max efficiency amp rating of the motor which is 74.

But in real life I'm drawing a whopping 164A at 40 MPH (I almost needed a fire extinguisher!!!).

Admittedly the CG is a little forward but the rudder and strut are running pretty neutral. The flex shaft and stinger are aligned straight, greased, and aren't binding.

Any ideas why? Much appreciated. -Mick

[D. Newland]

I'm surprised the Y536 got that hull on plane. Is the motor water cooled?

Your data is showing amp peaks that high, but your average amp draw is pretty much in line. You're always going to have high amp spikes.

What ESC, and was it water cooled? It's temp after the run?

Get the running attitude of the boat correct first, and keep your runtimes to 1 minute until you do. Move the weight back, put a little positive in the strut, etc. Once it's running clean, then move up your runtime, paying close attention to temps and battery drain, until you come up with a safe runtime figure.

Other props to try: X438, X440, but that size boat really needs something like an X445 to run well, but that's too much prop for that motor on 5S.

4S would be better w/an x445.

[electric]

I had a simliar problem with a deltaforce copy. It turned out to be, of all things, the trim tabs. They were level with the hull so I thought it was fine. Finally, I lifted them up and the boat took off speed wise and the amp draw went down. Give it a try, maybe that is it.

[electric]

Did some searching and here is the link when I discovered the issue. It has quite of bit of data with it as well.
http://forums.offshoreelectrics.com/...ad.php?t=13316

[Diesel6401]

Did some searching and here is the link when I discoved the issue. It has quite of bit of data with it as well.
http://forums.offshoreelectrics.com/...ad.php?t=13316

Have any pics of the aft of your boat?

[AlanN]

Post a vid of it running. It would be easier to deterimine and hear why your amp pull is so high.

[electric]

Have any pics of the aft of your boat?

Afraid not, that boat is long gone. Just trying to help the other guy out.

[Diesel6401]

Afraid not, that boat is long gone. Just trying to help the other guy out.

No problem man, I have a df clone havent hit the water yet with it and just gaining some info. Thanks though.

[mickvk]

I'm surprised the Y536 got that hull on plane. Is the motor water cooled?

Your data is showing amp peaks that high, but your average amp draw is pretty much in line. You're always going to have high amp spikes.

What ESC, and was it water cooled? It's temp after the run?

Get the running attitude of the boat correct first, and keep your runtimes to 1 minute until you do. Move the weight back, put a little positive in the strut, etc. Once it's running clean, then move up your runtime, paying close attention to temps and battery drain, until you come up with a safe runtime figure.

Other props to try: X438, X440, but that size boat really needs something like an X445 to run well, but that's too much prop for that motor on 5S.

4S would be better w/an x445.

Yep, the motor and motor mount are watercooled by a pickup and the esc separately by the rudder pickup.
Castle hydra 240 - yep, watercooled. Temp was 100F on the main board, 155 on the caps.
I think you may be right about the 4S/x445. I was trying to come up with a system that was higher voltage/lower amperage but I didn't succeed!

Thanks for the help.

[mickvk]

Thanks for the help guys, I was out of ideas - now I have a lot to go on. I'll move the batteries, adjust the tabs, and try some of the other prop combos. Much appreciated.

[ED66677]

where is your COG? no step mono's require COG to be under 30%, my 29" DF copy is just under 27!
and another thing... IMO a 540XL is a bit too small for a 32" mono!

[mickvk]

where is your COG? no step mono's require COG to be under 30%, my 29" DF copy is just under 27!
and another thing... IMO a 540XL is a bit too small for a 32" mono!

The COG is too far forward, like maybe 50%. I have to move it back like you recommend.

I agree that the motor is too small. I did buy a Neu 1515 which I think will be the right amount of power for it. I have a spare KB45 but I'd have to re-do the whole motor mount in order to get that next size in there.

Thanks again. I'll work on it.

[ED66677]

try not to play with trim tabs first, I don't have any on my 29" but they might be necessary for rough water to avoid barrel roll!