Originally Posted by mikes68charger

I wish you posted sooner that was a wast of $18

Right. I can't wate

Thrust is real important number for me.

I had a rig set up when I was spending all that $$ on EDF set ups I'm going to use to test these props. It keeps me at a safe distance

I will admit that the ARC 28-58-1 on a 70mm wemo fan would make the most thrust/watts for 110amps/5 pounds EFFLUX around 180ish

But same motor with a prop rocks.

Mike,
Are you testing the thrust on the bench?

Testing thrust on the oversquare props like 7x10, 7x13 or 8x23 won't give a very good idea of how they'll perform in flight.
These props will give you horrible static thrust results below 100mph airspeed, but start producing big thrust once they're moving forward and the relative angle of attack to the blades starts decreasing.

You could blow a leaf blower on your test rig and THEN measure static thrust!!

how does static Amps general compare with inflight? for these props..

Assuming you fly fast and in a sleek model..

Is static Amps always more ?

Originally Posted by sebbe

how does static Amps general compare with inflight? for these props..

Assuming you fly fast and in a sleek model..

Is static Amps always more ?

I'd say 15-25% unloading in flight as a rule of thumb with these props. I've tested a bucketfull of props and static A is always more than in-flight.

Originally Posted by Arcteryxxx

I'd say 15-25% unloading in flight as a rule of thumb with these props. I've tested a bucketfull of props and static A is always more than in-flight.

how does unload compare between a "normal" prop like 8x8 to a over squared like 8x17.... can we se any pattern, like the oversquared always unloads more ?

A "undersquare" prop seems to unload more than a square as a general statement, but there are many variables to consider, so generalizing is a game of chance. Such variables are eg. the make (design) and pitch, rpm (as a factor of rigidity and airfoil) etc. etc.....
The data from folding prop is very much dependent on rpm and the size of the spinner it's attached to....

So my 7x13 folders mounted on a 45mm Turbo spinner are a 8x..something?

You need to measure the width... The prop will draw more amps on a 45mm middle piece than on a 32mm... obviously....

Like stated before I can't find any high pich 7in prop. And as I'm trying this motor I don't want to speed the $$ on folding props untill I find out ruffly what prop I need

That's good to know about unloading and low thrust numbers

I know my ARC 28-58-1 with a 6x4 prop is 5.5 pounds. I'm hopeing this big ARC will do an 8x8 with 9 pound. If so I may get 2 of them for my big falcon as in EDF set up I was going to use 12s 5000 mah set up

Mike: have you contempated a gearbox for your 28-58-1? I have the same motor turning a 15x18 prop on 5S with a Kontronik KPG 5.2:1 gear

Mike grab an APC Sport (Nitro) prop in either 7x9 or 7x10 and throw that on there and lets see what the numbers show. Those numbers that Murdo posted back on page 2 are Sport or Pylon props. Won't know what you need until you spin her up with something....gotta have a base line.

Originally Posted by arcticflyer

Mike grab an APC Sport (Nitro) prop in either 7x9 or 7x10 and throw that on there and lets see what the numbers show. Those numbers that Murdo posted back on page 2 are Sport or Pylon props. Won't know what you need until you spin her up with something....gotta have a base line.

<<<<<<<<<<<<<<<true, so true!

Originally Posted by jackosmeister

I have one of those 7x7 aeranauts somewhere, I remember working out the max rated rpm was only like 14k! so threw it in the bits box...

Hmm, well I flew a plane 190 mph with one. It worked for me.

I never tried it Steve, just read the 14k rpm rating and thought screw trying that

Originally Posted by arcticflyer

So my 7x13 folders mounted on a 45mm Turbo spinner are a 8x..something?

Well, Koch:s props are made for 45mm spinners and above,, So I guess its a 7x13 on that spinner..