Good after noon all my Friends...last night, after working on some models, i started to sketch,about an aircraft wheel, in scale, for the Anti Skid Brake simulator. then was examining some nuts and bolts, to hold the scaled wheel in place..suddenly an idea strikes in my brain..and, when i re examined..it was clear...making a propeller from a nut..!!!  sure, you can see a nut, with 6 sides, and each and every side will be placed in exact direction to 120 degree..!!!
so it was not much to think..started the work..i took a bicycle spoke,with 4 mm shaft..and found a nut, a self sealing nut, actually it came from spare exhaust muffler of an aero engine..

can see the exact angle of each sides...
draw a line in all intermittent sides, in to clock or counter clock direction you need...
then draw a template for blades,on a thick card paper..the size of the blade..all up to you...

now cut out the template..and draw three blades in an aluminum sheet, and cut it out with a meat cutting scissors..i used an aluminum vessel lid..

grind off any unevenness over blades, and sand it smooth with file..
now start making a ridge along the line that we draw on the sides of the nut...take care while making the ridges, as it can damage the thread..

make sure the ridges are in straight line and in same angle..
check out any unevenness..

take the same bicycle spoke, and load the nut on its thread..

now take some industrial cyano glue, and start to attach the cleaned blades one by one..remember..use only industrial grade cyano glue..not domestic..

now complete the attachment...
and it is now in shape...

make sure the three blades are in accurate positions..and apply more glue all over the base of the blades...wait to dry for some minutes...
take the same bicycle spoke, and cut it in to desired needed length..

now..take a nipple for the same spoke, and cut it halves..

oad the nipple as narrow side facing in...
and thread in the prop as shown..tight it with nose pliers..and apply industrial cyano in its root...

make sure it if fixed firm...
and time to test..drill a simple hole along the spoke, and attach the shaft to the motor..and bolt it tight...

we can make a simple motor coupler with same spoke nipple, simply driving to the motor shaft...and drill a straight hole..to hold the shaft...and can grind out the shaft, after drilling on it , so it will give some play inside the nipple, gives us a privilege of an universal joint...

after extensive test i painted it in rust metallic ...

Friends..i took about half an hour to make this with a tea...and working..?..amazing..great than my newly purchased commerical prop...with all motors...i made 6 more and made two in to high thrust, by applying some two part epoxy putty, on the inner side of the prop, and later ground out as in shape of hydrofoils..so..low speed..high thrust...and two with 6 blades, in shape of scimitar...result..even more thrust at low speeds...here you can see how simple is to make a pro is...no cost..no worry..can adjust the pitch up to your need..steep narrow blades for low speed..and flat broad low pitched for high speed...to avoid cavitation..later i made 4 more using washers in appropriate size...and converted it in to high thrust with epoxy putty...try some..and make some lovely craft....unstoppable...

Happy New Year...

man you are genius! really wonderful. with the limited resources you have done something extraordinary.keep it up your DIY work.

Dharmik..i hope my works help you all..to make some good crafts....thank you..

Sir can you 

i have mailed you about my difficulty

just struggling

Rajesh..dont worry..i will help you..

here my high thrust low speed prop..is working very well...
no any extra ordinary materials is used..i made it from three washers, with same idea with a nut...
after fixing the washers as leaves, i mixed some PU putty with hardener, applied it over the blades..(behind )..

after drying the PU putty..sand it to a hydrofoil...
makes it a high thrust one...

you can see the foil structure in this photograph...
and painted with metallic rust...

and after painting it became even smooth...
ready for action...

look how easy it is...anyone can do..and it performs greater than commercial one that i bought...with this i am saving lots of battery power for a long drive.
and it is not feasible to sit in lazy...so we need an even more high thrust prop...for my oncoming tugs...so i just tested with this design..and result..unimaginable..its a scimitar type..with 6 blades...

i made it in to two each for both sides...