Some SC700 Motor Questions

[LJH]

I have a few questions concerning the SC700 that Steve sells. First off what is the KV of the motor? Second is it OK to run it on 4S Lipos? I have run a few runs with a X447 and it has really woken up and the case temps are very reasonable, just slighty warm.

Cheers,
jim

[Fluid]

I do not know the Kv exactly, but it is around 1500 rpm. I see no reason it can't be run on 4S, it is done all the time. Just watch the prop size and heat, I destroyed an SS-1 (almost the same motor) by getting it too hot, and I watched four others go away at SAW trails from heat. The comm warps and the motor is never the same again.

Depending on the hull and run time, I have great luck with the M645 and Y545 props.


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[boater76]

What's the size of your boat you run the 700 in Fluid? How many cells?

Ken

[Fluid]

My LSH is 25" long. My LSO is 29" long - see avatar. I use 12 cells only, IB3600s or IB4200s. Both can run a mile on the full-size nitro course with ease spinning an x645, but both run very free of the water.

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[LJH]

Ken,
Running this rig in a old Cesa, she runs VERY loose LOL.

Cheers,
Jim

[boater76]

You might need trim tabs or turn fins. Or have you tried to adjust the cog yet?

Ken

[LJH]

Ken,
Have played with CG quite a bit, Just last week I mixed up some lead shot and epoxy and poured it into the nose that helped a bit. I also played with using ride pads to get rid of some of the rocker......That helped a huge amount. Now I just have to figure out what to use to make a perminent ride pad. I am thinking some sort of glazing puddy that will be easy to sand but also hold up to the flexing of the hull.

Cheers,
Jim

[boater76]

Im working on a SH knock off right now. I am in the middle of adding 1/4 ply to the transom.

Ken

[LJH]

Ken,
Is it the 40" version? When I went to "real" hardware I just used the realmost gearbox plate to make sure the transon heald together. Not sure if the knockoff has the same gearbox drive train though. The real issue with making the Cesa contralable at speed is the rocker. I found as I added power the porposing became worse and worse. I was amazed how well putting a ride pad on the boat calmed it down, now to figure out how to do it so it is clean.

Cheers,
Jim

[boater76]

Its the Purple Light version. Its funny. I cut most of the original molded in radio box area are to get to the transom. The transom was already beefed up with a piece of plastic that was glued to it. The hardware that came was a solid driveshaft with a water cooled 550 with outdrive. I sold the motor and outdrive on ebay. I almost got my money back from spending on the boat with just selling those 2 parts. What is the rocker and ride pad? I'm still learning. I am thinking about putting that expanding foam in the hull to maybe stiffen it up a bit.

Ken

[LJH]

Ken,
If you put the hull on a flat surface you will see that the aft 6" or so of the hull does not make contact with the surface, that is the rocker. With my totally make shift ride pad, I just sanded some 3/32" balsa, it totally changed the character of the hull for the better. I will be working on a better solution over the next week or two and let you know what I come up with.

Cheers,
Jim