40 rigger Electric conversion

[hugh hargett]

Man! Im kinda liking that castle ice controller. It seems that the first batch had incorrect cap values thats why they had a few problems. Fletch what is needed to bring up the other stuff that is "N\A" on the graph.looks like you might be able to run a bigger prop?Maybe? Whats you estimate on speed?

 

[fletch51]

Thanks for checking out those graph results Hugh.

To bring up th N/A values is a simple mouse click. The graph's x-axis is time, and it is the amount of time between the last time data was deleted to the last time it was turned off. but it is easy to zoom in on any area of the graph to fill the screen and see the data more clearly.

Since that run, I have tried 2 larger props than the x450.

with an x452 the amps went up about 30 amps on average, average rpm went down from 26,500 to 25,000 but the ESC temp rise rate was much faster. during two 40 second runs one with each prop, the x450 started with ESC temp at 120 and went to 130, with x452 temp went from 115 to 150. top speed was similar, but acceleration was weaker.

I ran a 1450 for about 15 seconds and the power and speed were weak. battery voltage stayed steady, but amp draw steadily went from 120 to 80 amps, watts had almost identical dropoff slope during the run. although RPM was steady at about 27,500.

I have some poorly shot video of a run with the x450, because i taped a camera-phone to the transmitter, and tried to drive and record video simultaneously. But you can get an occasional glimpse of the boat. I'm not sure of the top speed but I DO NOT believe it is near 70mph which is what I would like to have.

http://www.youtube.com/watch?v=GNx_czyL0e4

 

[hugh hargett]

Well It may not be what you want yet but its running good. So, are you going to cup the 450 or try some othe x series props? maybe a x648 ? or maybe even an abc prop. What is you theoretical no load rpm on that motor with 6s? I forgot the kv of your motor.Oh by the way it looks like its handling great too .

 

[fletch51]

motor is 1450kv on a 6S.

Once I get my friend to see it in person, he will be able to tell me what strut or sponson adjustments should me made to get it running as free as possible. and then we are gonna figure out props after that. I know almost nothing about props

 

[fletch51]

I finally got the radar pointed at this boat. 59mph.

Motor is making some heat, and other message boards seem to indicate Neu motors are more efficient/less heat.

Ive tried a few different props and the x450, just does the best.

With even slighlty bigger props, amps go up and rpm and speed go down.

With smaller props, rpm goes up and everything else goes down.

I'm gonna loosen the boat up, and eventually get a Neu motor.

 

[jayt]

You will appreciate the Neu when you get it. When pushing things as you are, efficiency is important. The Neu motors have very high efficiencies compared to Leopards, Feigaos, etc. Castle/Neu motors are not far behind the Neu motors - you do get what you pay for.

It is no problem to see spikes of 250+ amps with a setup which normally pulls 180 amps - the prop leaves the water often in race water and unloads the motor, then bites again, spiking amps. I run a 1521/1.5D in my P Sport Hydro and average 180 amps with a heat race setup, speeds are 60 mph in race water. I use a Castle ICE200 (fan cooled only) which handles things just fine - unlike a certain 'expert' above believes. One potential problem you had was your timing advance. The Leopard 4082 is a 4D wind, and D winds typically do not like timing advance. I run 3 degrees on my 1521/1.5D for example. More timing just adds heat with these motors - Y winds typically want more timing advance.

For more speed - and you are still kinda slow for a 6S rigger - try more prop pitch with the same diameter. An x648 or 1650 may work better for you, as will loosening up the boat. IME nitro riggers do not work well converted to FE without at least changes to the sponson aoa. Many have tried, many have had to work very hard for success. Keep up the good work!

.

 

[lohring]

A little off topic, but Brian Buaas' Raptor P spec rigger ran very well as a 3.5 nitro rigger at the NAMBA Nationals. Both are 65 mph boats in heat race trim. See the orange sponson boat in this picture:




Lohring Miller

 

[fletch51]

Great info jayt.

I was under the impression up until about 10 days ago that leopards were Y-wind. I don't remember offshoreelectrics.com showing the wind type next to the kV rating, But they do now for sure. Also I thought I read on forums there or somewhere a statement simply saying "Leopards are Y-wind". It wouldn't have mattered I already had the motor, and by buying the cheap stuff, it got me going on this project, and it got me learning the brushless Electric realities.

I am also under the impression that Y winds are more efficient, but I really don't want to go more than 6S.

Because only 6S, does this mean I need to get a D-wind motor to get enough kV?

The leopard is rated at 1450kV, maybe thats no-load because data logger is showing around 25,000rpm which would be around 1100rpm/volt, (battery shows 22V under load on logger)

outlined in green are the ones I'm trying to choose from.

Any Help is appreciated.

 

[jayt]

Also I thought I read on forums there or somewhere a statement simply saying "Leopards are Y-wind".

Don't believe everything you read on the internet.

General statements like "Y winds are more efficient" are generally wrong. Both winds can have very high efficiencies, but at different power levels. "D" motors are "generally" higher rpm motors which will produce more raw power at the expense of run time....generally. There is nothing wrong with the motor you have considering its quality - I have run several Leopards and they are not bad motors. You do need to re-set the timing advance to low.

The Kv ratings for the 4-pole motors I've used seem to be taken at low amp draws. IME for an oval racing setup with Neus, consider an average rpm on the water equal to ~90% of the Kv times nominal pack voltage product. It could be a little different with the Leopards, I don't have near the experience with them as I have with the Neus.

IMO the "best" Neu for your application would be either the 1527/1Y or 1527/1.5D. I have both and the 1Y works great for oval racing in 6S cats and sport hydros. The 1.5D may be a better choice in your rigger, but I found it a little too much motor for my cats and sport hydro. But if you want a 65 mph sport boat then the 1Y should work great.

.

 

[fletch51]

Thanks jayt,

Is it just me, or do people on intlwaters just make more sense?

Eventually, I'll want an electric boat that's real fast, at non-race pond for now.

If I can't get this boat screaming, I'll just fire up my 67 boat that has an 84 in it... lol