How Proping Up Effects Motor/Esc Temps

[znus]

Cool thanks for the advise. So the x442 needs to be balanced? If so ill see if I can use some 3/16 tube I got on the way and throw it on my tire balancer. I'm guessing sand off where heavy?

yeah, almost all metal propellers need to be balanced. Octura castings are pretty decent compared to a few other companies but expect maybe one hour of work per prop. As you said - sand of the heavy until both sides are of equal weight. Only remove material from the side facing the transom (this cannot bbe stressed enough!)!! I use a dremel for this kind of work and when it's balanced I wet sand with fine paper (around 500) until i get a god shine. It doesn't have to have a mirror finish but it should be shiny

A magnetic balancer is 30 bucks. Eventually you'll need it anyway because FE boating is really fun and propellers are pure voodoo magic. That little sucker is gonna turn 30000 rpm and a little wobble or off balance can shake almost anything loose. I know it the hard way.

what motor have you got in your boat?

[penz]

I got a 3674 1900 kv motor running on 4s, runs pretty good, will run better with the new prop. I didnt realize I had to balance... crap... Just got the prop in the mail today, gonna see if i can construct my own magnetic balancer. Still waiting on the 3/16 brass tubing that I ordered from elsewhere because ose was out of stock and now they in stock haha!... figures...

[znus]

Just to make things more confusing - a 42 mm prop is about the maximum of what that motor should handle. For more speed I'd try going 5s and actuallt prop down to 39-40. Oh and one more tip, which may work for you or not, I've gotten great results with kyosho plastic props (around 40-42 mm). They look different from octura - almost boring but they really grip. It's like they dont know the words ventilate or cavitate. If you can find them give them a try!

im guessing you can find them as spare parts for kyosho boats?

[siberianhusky]

Sorry I'm with Penz on this one that is a 29mm pitch prop, Octura makes 12 series props which aren't far off 1.114, only one blade of an octura prop is measured as well, measure one blade through 180 degrees and multiply that by 2 to give the distance traveled in one rotation, less slip of course.
GrimRacer props are sold giving the diameter and pitch, no math required. I'm not sure how prather comes up with their numbering, doesn't relate to the diameter and pitch as far as I know.
Octura props are horrible from the factory! About the worst available! bad casting flash, very thick dull blades, way way out of balance, TFL props are better, GrimRacer props are pretty close for a factory job but you can do better even on your first attempt. Just sharpen the leading edge and smooth it all nicely, balance by removing material from the back side of the blade. The hard part is making sure it's balanced through 360 degrees, if the blades are level but the same tip is always pointing down that means that side is heavy! the prop should ideally stop at a completely random spot every time you spin it.
Make sure you use a good respirator and do all the work with the prop wet, berrylium is very dangerous to your health, don't use power tools, you'll never be able to clean all the dust up, I'll only use a file and sandpaper. If you doubt this do a quick search and verify it for yourself. Once it's in you it never leaves your body!

[penz]

Well temps will tell me how much my motor can handle, running the 42mm plastic prop my motor temp only got to 105. So I figured the x442 would have a little more pitch and be the next step up. If my temps still good and I want more speed ill prop up again. Sheesh didn't realize how much went into balancing/sharpening haha, guess I won't be on the water this weekend...

[siberianhusky]

Ya you will! Will be harder to make the balancer than to balance the prop!
One thing that makes it easier to work on the prop, find a screwdriver with a 3/16 shaft, put your drive dog and prop on this, makes a real nice handle for filing and sanding, you can just keep dipping it in water while you're working. Avoids cut fingers also.
I work over an old dish draining tray then rinse all the dust down the laundry sink.

[penz]

Thanks for the balancing tips! As far as making a balancer I got 3/16 steel stock at my work, going to machine the ends down to a point, then make the frame out of wood probably. Just need to find some good magnets

[znus]

Siberianhusky: the turnigy prop hasn't got 1:14 pitch. That was penz's division of 29 mm pitch into inches, which isn't the case. I have a handful of turnigy props (about 20....) and a handful of octura (about 30) and I can guarantee they're not that different. I think octura castings are pretty decent compared to abc. Thy look like a truck ran over them :.smile:

You're right abot the hazards of balancing with a dremel. I do it outside with a vacuum cleaner on full blast next to the prop.

/Z

[penz]

Well made my home made balancer, it works just fine!! 1/2 inch mdf, couple magnets and some 3/16 stock with the ends machined to points. Its not going to win any awards but it will do the trick.

IMG_20110714_164503.jpg

[penz]

Finally got the boat on the water. I adjusted the strut to be level with the bottom of the sponsons and threw on the x442 and wow what a difference! The boat is noticably faster, I can also hear that the motor is running at a higher rpm. I am very pleased so far. Only had time for a short run so hope to run more this weekend.