45" Dumas Scarab

[flraptor07]

My guess, with the cavitation and cool temps you need more prop but I'll wait to see the video.

[srislash]

Your video on that photobucket tiny URL Ken?

Sorry I missed so much here buddy, I have been so busy. Should be a calmer week coming.
I have not run into that program box issue where it asks for an upgrade, odd.

Based on your temps it sounds that you can prop up but you should get to tweaks and tunes first and get a few runs under the belt.

[Ken_NJ]

Have this on YouTube guys. Took forever to upload, just finished. Every video I do this to I loose quality, always looks fuzzy, damn. Watch it to the end.

https://www.youtube.com/watch?v=clp37K9KD-M

So this is an overhead of the lake. I was running the oval, the white ovals are where the boat seemed to die, lose reception. I have the antennae stretched under the port gunwale from the stern to the bow. The white spot at the top of the picture is the fountain in the video.

[tlandauer]

Good maiden, congrats!
If I may say, try to make some full throttle passes, it did not sound like you had pull the throttle all the way most of the time, although I could be wrong. Part throttle runs like that is actually making the ESC work harder.
Can't wait to see runs with the deck in place.
Just so you know, quality isn't as bad as you think, this is standard You Tube. lol...

[srislash]

Yes, a great maiden. Perhaps the antenna externally mounted will be best. It is 75mhz. I think it moves out fairly well for just a 450 prop. Runtime is certainly good.

[Ken_NJ]

I was thinking of that also Shawn. Although I'm more of a fan of hiding the antennae.

Your right tlandauer, I did not open her up much except near the end. Even that was not all the way.

My biggest issue is sucking air which makes it difficult to get the boat going. Look at 10:10 and 10:35-10:50, you can hear the slurping sound of the prop sucking air. At 10:35-10:50 you can see the column of air behind the boat, once the boat goes, that tube of air goes away. Also at 15:50.

I think with either prop it did OK, will have to try both again. Think the boat is trimmed OK? I might try moving the batteries forward a little.

[srislash]

Yeah Ken, she needs a little trimming. Just wouldn't be fair to get it right, right off the table,lol. I seem to recall props pulling air off the bottom of the hull in this configuration.

[Ken_NJ]

Just wouldn't be fair to get it right, right off the table,lol.

Why not! I aim to strive for that. But alas. I'll move the batteries forward a tad. See how the next run is, maybe pretty soon, anxious to run again. Will go to another lake this time.

Maybe that air is something that just needs to be shaken off. This is for fun, no competition.

[flraptor07]

Ken, That was Awsome, we all wish our maiden voyages went that well! Deffinetly prop up, I'd go something in the 52mm range next. Trim wise, I wouldn't change anything yet till you see how it runs WFO and then I'd probably just drop the insidetrim tabs very very slightly. It looked like the faster you went the smoother it got toward the end of the video. Also with 730kv you could go to 10s with no problem at all, I'm running 910kv and 950kv on 10s in my 1/8th Hydro and my Vern Kilmer Viper they are 44 1/2" and 49" boats. If you listen in the begining of this video it cavitates just a little with a Prather stainless 250 which is almost 59mm and 1.6 pitch https://www.youtube.com/watch?v=hCeYpy4NUyM

[Ken_NJ]

Thanks Chris.
Wow, fast, nice control you have! I have to get use to this speed, new to me. Your cavitation went away fast. Think I'll try again as is in another lake Wed or Thursday. Near the end I might have been getting some confidence. I don't have the tabs down at all yet. All for fun.

[Ken_NJ]

For a larger prop, 52mm, would I be looking at x452 or x455? And I would need to balance it.
http://www.offshoreelectrics.com/pro...?prod=oct-x452

Also, when running the boat, I did not see much cooling water coming out, although the ESC was barely warm. In the video at 13:30 water is coming out of both ports. But don't see anything at slower speeds.

[srislash]

Sometimes it is only a dribble that will roll down the hull Ken. Try to get a good look at it or place a GoPro on facing the outlets. I had to do that once to check my 'hidden' outs.

Check the first of it.

Now with the prop, how do you feel your speed is Ken? If you up the voltage a bit the runtime will most likely increase as will your speed. And , are you planning that?

[Ken_NJ]

I'll just have to watch the ESC for heat then.

For now going to stick to 8s. I'm happy with the speed and the runtime seems to be pretty long. I have not opened it up all the way yet either. Going out shortly to run again at another lake, will open it up tonight. You both think I should prop up. Can you suggest a prop please?

I have one of those keychain camera's, will have to stick it someplace on the boat.

[flraptor07]

I'd go with a X452 next, and yes you will need to sharpen and balance it unless you get it already done. If you've never done it then you probably should buy one already done. The way I learned to do props was, I bought some used props off Ebay and started playing with them.

[srislash]

Yup,452 or maybe a Prather 235(51mm). Prather has slightly more pitch but usually not enough to upset a mono.