How Proping Up Effects Motor/Esc Temps

[penz]

From my experience with land riggs gearing up will normally have more of an impact on motor temps than esc. I'm still new to boating and I'm guessing the same does not apply. With a 1.14x42 prop my esc is running around 120 on 4s with a 1900kv motor. I'm. Going to be throwing on a x442 prop and are concerned/curious how much the change in pitch will effect my esc temps. Of course the best way to find out is to just run it and see, but untill then any thoughts?

[Doby]

Increasing pitch and prop size generally will always put more load on your setup resulting in more heat.
Run a lap...bring boat in,,,check temps....repeat several times.

[penz]

Yeah that's what I figured. Is one lap enough to warm up the electronics enough? I would think like a few speed runs, and by that I mean 5 sec full throttle.

By the time I get the boat out the water and the tape off the hatch to check esc temp I would say close to a min has gone by. During that min would the esc be cooling off because its not in use? Or would the temp be higher due to residual heat and no water flow?

[siberianhusky]

those two props have the same pitch the number prop will have more lift that the x series prop. There shouldn't be much difference in load between the two, the difference would result in the hull running differently, depends on the boat setup.
If it's a tfl 1442 then it's an octura x442 copy. I've worked on a few tfl props now and really like them.

[AlanN]

If your boat already rides well and you want to change the prop, it is most important to raise the strut to offset the larger diameter and load. Most people don't want to adjust the strut becouse "the boat runs perfectly but I wanted more speed". When a larger diameter prop will want dig deeper and load up the motor more. Also, diameter and prop shape effect the handling of a hull. There's alot more to just putting on a bigger wheel.

[penz]

I believe it is a 1.14 pitch.. or basically 1.1. Its a turnigy aquaprop, hobbyking lists the pitch at 29...mm I believe, so 29/25.4=1.14. I could be wrong but if their specs are right then the x442 has more pitch.

Here the link.
http://www.hobbyking.com/hobbyking/s...x29x15mm..html

Oh and they are crappy props... only lasted 5 min then a blade sheared off...

[penz]

If your boat already rides well and you want to change the prop, it is most important to raise the strut to offset the larger diameter and load. Most people don't want to adjust the strut becouse "the boat runs perfectly but I wanted more speed". When a larger diameter prop will want dig deeper and load up the motor more. Also, diameter and prop shape effect the handling of a hull. There's alot more to just putting on a bigger wheel.

I think I got strut adjusted pretty well with the cheap plastic 42mm prop i had on there, im replacing it with a metal x442, so same od, but more pitch,

Good tip though

[siberianhusky]

you're right, I just never think people are using those props with a setup that has any power. There will be a huge difference between those two props. More than likely you will need to adjust the strut, the difference in lift characteristics between those two props will be massive! The boat will ride very different!

[znus]

Those Turnigy props are measured in a strange way, with half a rotation or one blade, or something like that. I believe Graupner does (or did) the same. Anyway, you need to double that 29 mm pitch to get a correct pitch reading, which makes it a 1.38 pitch prop (which makes more sense).

29 x 2 = 58 mm / 42 mm = 1.38

The pitch is realtive to the diametre. It's not inches (25.4 mm) or anything like that.

The Octura x442 will get up and go a whole lot better!! Plastic is for dialing in - then go metal.

[penz]

you're right, I just never think people are using those props with a setup that has any power. There will be a huge difference between those two props. More than likely you will need to adjust the strut, the difference in lift characteristics between those two props will be massive! The boat will ride very different!

Haha yeah... they were only a buck so I figured id give it a go and see how temps were to get a good idea of what metal prop to go with, and yeah I agree it will be a big difference with the x442 and some adjustments prob will be needed.

[penz]

Those Turnigy props are measured in a strange way, with half a rotation or one blade, or something like that. I believe Graupner does (or did) the same. Anyway, you need to double that 29 mm pitch to get a correct pitch reading, which makes it a 1.38 pitch prop (which makes more sense).

29 x 2 = 58 mm / 42 mm = 1.38

The pitch is realtive to the diametre. It's not inches (25.4 mm) or anything like that.

The Octura x442 will get up and go a whole lot better!! Plastic is for dialing in - then go metal.

Uhh... I'm not understanding. You saying the pitch divided by the od is....the pitch?...

Dividing 29/25.4 converts mm to inch. So a 29mm pitch prop is 1.14... if I double that its 2.28 and there no way it has that pitch...

[znus]

Uhh... I'm not understanding. You saying the pitch divided by the od is....the pitch?...

Dividing 29/25.4 converts mm to inch. So a 29mm pitch prop is 1.14... if I double that its 2.28 and there no way it has that pitch...

Oh man, did I open a can or worms here Sorry for my english, I'm swedish.

Anyway, the Turnigy pitch of 29 mm can not simply be transformed to inches, like the way you did. The 1.4 pitch on Octura propellers is not a measurement of inches. It's 1.4 times the OD.

An Octura x442 prop is 42 mm across and has 42 x 1.4 (pitch) = 58,8 mm thrust in one revolution. A x457 prop has 79,8 mm. Bigger prop, same pitch. It's a measurement of the angle/thrust of the blades in one revolution, not inches.

Turnigy specs their props with one blade = 29 mm. The prop has two blades (well, in your case - it hasn't anymore ) so, to get a reading comparable to Octura props, which specs their props with two blades, you need to double that 29 mm and get 58 mm.

With me so far?

So, we have a 42 mm OD blue plastic Turnigy prop with 29 mm x 2 = 58 mm of thrust. We divide thrust with the od (58 mm thrust /42 mm od) and get the "Octura way of pitch" = 1.38.

I hope you understand what I'm writning?

So, by going with a Octura X442 you'll get a better propeller but it will not make your boat go much faster. It'll accelerate better because of the bigger tounges and it might gain a few mph in top speed since the beryllium copper doesn't flex like plastic but it will not be a world of difference, since they both are more or less of the same pitch.


To make everything simpler - If Turnigy spec'ed their props the way Octura does, it would have 58 mm. (29 times 2)
/z

[penz]

OH WOW haha... well thanks for the explanation, I get what your sayin, this is still all new to me... It would be helpfull if turnigy would state that the pitch is only half of the full pitch... oh well.

Well my X442 is on the way so ill see how it runs with that, if temps are still good ill look at some 3 blade props.

[znus]

No problem man.

If temps are still good also try X640 (1.6 pitch), M445 and X445. Two bladed are usually faster! Not to mention easier to work with in terms of balancing and polishing (imho)

The X props are good all around props.
The M props are detounged. Doesn't hook like an X from the starting line but good for speed and nicer to your motor & esc.

[penz]

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?