Using a Graupner Speed Cam prop 5.5x4.3 here on a 3 turn warp motor. Pulls about 29A static on the wattmeter, and is fast as hell

Originally Posted by mcba

The numbers here suggest that the 3 turn Warp4 is in just about the right range. On 3s it states:

10.46V, 26.7A, 23310RPM for a 4.75x4.75

It doesn't give numbers for a 5.5x4.3, but I imagine they would be similar, with perhaps a few more amps.

Matthew

It only takes approx. 200W (output) to spin a 4.75x4.75" at 23.300rpm, while it takes 270W (35% more) to spin a 5.5x4.3" at 23.300rpm.

Jürgen

Originally Posted by Jurgen Heilig

It only takes approx. 200W (output) to spin a 4.75x4.75" at 23.300rpm, while it takes 270W (35% more) to spin a 5.5x4.3" at 23.300rpm.

Jürgen

Wow, that much difference. I'm surprised.

The figures seem to be telling me that the 3 turn is on the slightly-too-hot side of things, while the 4 turn isn't hot enough. Sigh.

Matthew

Originally Posted by Bigplumbs

I do think the 6 x 4 APCe is the best prop on a Mega 16/15/4 though

From my flight testing about every prop in the 5" to 7" range I could find, on both a Stryker and a Unicorn wing, the APC 6x4e was the best combination of current draw, speed and thrust (vertical) for that motor.

The FunJet has a more slippery air frame and that may change which prop works best, but it will be fun doing the testing! - I am still in the sand/paint stage.

FC

FoamCrusher, I found this to be the best prop too, for my motor at least. (260 W, 2000 kv)

I think at least one other person found this to be true as well. It may not be the fastest, but it is a very good balance that is still fast, but has a lot of thrust.

Most people are going smaller & "pitchier", in the attempt for more speed.

Originally Posted by Jeremy Z

Most people are going smaller & "pitchier", in the attempt for more speed.

If you want more speed, go to 4S packs with the smaller prop. The Mega's love the extra voltage but the smaller prop is a must....and watch the BEC on the ESC.

Now if you really want speed and your pack will take the current draw, drop down to a Mega 16/15/3 and clean your glasses.

FC

Originally Posted by mcba

Wow, that much difference. I'm surprised.

The figures seem to be telling me that the 3 turn is on the slightly-too-hot side of things, while the 4 turn isn't hot enough. Sigh.

Matthew

Try the-4T on 4S with a 6X4, 6X5.5, or 7X4 and it will warm rlght upto you-about 30-amps.
Eric

If you want outright speed you should go for a prop with very little pitch. A higher reving motor and a prop with little pitch will give you the better top end. You never see a pylon racer with a high pitch prop. A 5.7x3 is a good prop.

Mark

Originally Posted by MarkJayne

If you want outright speed you should go for a prop with very little pitch. A higher reving motor and a prop with little pitch will give you the better top end. You never see a pylon racer with a high pitch prop. A 5.7x3 is a good prop.

Mark

Hi Mark,

Where did you pick up this "weird theory"?

Pylon racers usually use props where diameter and pitch are identical. Deviations from this ideal prop size are only used to match the motor/model used. For a model with higher drag, you increase the diameter, for a very low drag model you may want to use more pitch.

Jürgen

sorry, do not have any videos just yet.

the Warp 4t with 4S may be a bit overkill for that motor since it's rated for 22-26 amps, if I am not mistaken.

did not try the 6x4 yet, however I am a bit worried it will be slower prop than what I am after.

the Warp 3t with the 5.2x5.2 is real fast. I would start there. like Mark said, for speed you prefer a high rev motor with small prop than a lower rev motor with a high pitch prop.

let's sum up the hottest motors for the Funjet - Kontronik 400-28 (being the first one), Mega 16/15/3, Multiplex permax 480 (5d, 6d ?), Warp 3t. anything else ?

good luck.

Hi Jurgen,

Sorry you are right about the Pylon racers they usually do use a 1:1 ratio but its also worked for me on my Easystar and Funjet. When I used a 5.7x3 I had much better straight line speed than with a 5.7x4.5. With a high KV motor 2700+ a higher pitch prop could end up wasting the power. Are you saying that less pitch will give you less speed.

Mark

Originally Posted by MarkJayne

Hi Jurgen,

Sorry you are right about the Pylon racers they usually do use a 1:1 ratio but its also worked for me on my Easystar and Funjet. When I used a 5.7x3 I had much better straight line speed than with a 5.7x4.5. With a high KV motor 2700+ a higher pitch prop could end up wasting the power. Are you saying that less pitch will give you less speed.

Mark

Used motor calc with these props. Easy Street used at reduced weight to give comparative figues for Fun-jet. result for 4.5 very similar to my fun-jet check with speed gun.

Model Tony...

Mmmm, I can't say I'm convinced with those figures ( I've never been a fan of motocalc ). There seems to be a huge margin between those two props which does'nt tally up when you see them fly in the flesh. The 5.7x3 deffinatly gave me more level speed on both my EZ and Funjet no doubt.

Mark

Originally Posted by MarkJayne

Model Tony...

Mmmm, I can't say I'm convinced with those figures ( I've never been a fan of motocalc ). There seems to be a huge margin between those two props which does'nt tally up when you see them fly in the flesh. The 5.7x3 deffinatly gave me more level speed on both my EZ and Funjet no doubt.

Mark

Ah Wales. The land of Witchcraft and Dragons. But in the rest of the world, normal physical laws apply.

I'll agree with you on half of that comment

Mark