KP-00 fan unit construction - RC Groups
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Oct 25, 2002, 05:54 PM
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corey's Avatar

KP-00 fan unit construction

O.k guys lets see what we come up with! Any pictures or things of interest post here.
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Oct 25, 2002, 11:14 PM
Grand Poobah of Nothing
Trizza's Avatar
I want to hear more about David's - Have you done some thrust/current draw tests?
Oct 26, 2002, 12:39 AM
Registered User
Hi Trizza,

yes I have.
Weight with lead and capacitor is 6 grams
Thrust is 6 grams
Current is 0.7 amp
3.6 volts
I don't know exactly what the motor is. Came out of a capacitor driven FF model. Measures 8 x 10 x15mm and is thirsty at best, so don't hold consumpsion again fan unit. Only spare motor I had.
I haven't tried any different fans yet.
I believe my scale is good, I thrust tested the mite on it and got 10 grams thrust at 0.7 amp with B2 with 80mm prop on 3.6 volts.
Which is what I should have got according to what I have read.

Oct 26, 2002, 04:57 AM
Thats NOT indestructible
j8m8l's Avatar

Kinder Egg

I know those were good for somthing

Oct 26, 2002, 01:29 PM
Registered User
Hello ,

It is possible to replace KP00 By N20 motor??

Oct 26, 2002, 01:36 PM
Registered User
corey's Avatar
I really like the kinder egg idea, cheap and easy to make. I think I'll go buy some for my "wife" today
Oct 27, 2002, 01:54 AM
Registered User
Five blade fan
Less pitch
Thrust over 7 grams
Current draw has dropped some
I still have to large of a gap between blade tip and duct wall.
Oct 27, 2002, 08:34 AM
Thats NOT indestructible
j8m8l's Avatar

Can we have some spex on the prop, like size of blades, and angle that they enter the hub


Oct 27, 2002, 10:43 AM
Registered User
Chris3D's Avatar
Looks good Dave, hopefully I'll be able to finish my new fan today. You might want to try using curved stator vanes. I'd suspect the straight ones take a bit of the force out of the airflow. If you look at the bottom right hand picture of mine, you can just make out the curvature in my vanes. I think at these small sizes, we need to do everything possible to preserve the velocity of the air.
Oct 27, 2002, 03:35 PM
Registered User
Chris3D's Avatar
Well, my latest prop was a failure. I tried 5 blades that tapered towards the tips, and about 45 degree incidence. The fan made more noise than anything. So far, I've found fewer large blades to be better than more thin ones, and that larger incidence angles make more turbulence than thrust.
Oct 27, 2002, 04:12 PM
Master of the Wind
AIR MOVER's Avatar
Ok.. why dont you just use the gws rotor.. .. as most micro fan heads already know the small 3 blade rotor has been upgraded to a 5 blade rotor.. gws did this as that 4.8v motor was able to handle the added blades.. but the 3 blade version is on the money for this smaller motor size.. you will get the thrust you need and still have enough tip speed to run the lil wonder around the park and a good pace.. let me know just slap the sucker on the motor shaft hold the motor power up ( feel ) the diffrence .. of that prop and your hand made one... if your willing to butcher down the blades you can cut to fit this plastic shroud your useing .. good luck and let me know how you like it..
Oct 27, 2002, 05:06 PM
Sticky Shepherd
Graham Stabler's Avatar
I was talking to our fan man Ray tonight, he is using 5 blades as standard and says he sets them at 45 degrees. He described his contruction technique but it was somewhat confusing so he is going to do some diagrams. Bascically it all comes down to jigs that allow you to set the thing up nice and true and have a close fitting tube. He also curves the fins that hold the motor but you have to do it the correct way.

He also suggested you might be able to cast the blades in a lump of wax and then machine them to fit on a lathe. I'll leave that one to someone else.

Oct 27, 2002, 05:07 PM
Registered User
I have made another 3 blade, much better than other but still not as good as 5 blade. 5 blade holds thrust much longer.

New 3 blade-7 grams thrust on less current
No washout

3 blade- chord 10mm, LE up 4mm, no washout
5 blade- chord 61/2mm, LE up 3mm, with washout.

Thanks Chris, I'll work on that

I'll make another 5 blade and try a four blader today.

To get washout cut blades at an angle on cup. Try 20 degrees as a starting point.
Last edited by david_dewit; Oct 27, 2002 at 05:24 PM.
Oct 27, 2002, 05:30 PM
Registered User
Thanks Graham,

45 degrees doesn't seem to produce good static results.
But may unload in flight and make good thrust at speed.
Oct 27, 2002, 07:25 PM
Sticky Shepherd
Graham Stabler's Avatar
you might be right, either way Ray has flying models with kpoo homebrew fans so must be doing something right

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