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Jan 05, 2013, 10:44 AM
Don't Move I've Dropped My Nut
bamaguy's Avatar
Originally Posted by scunna
Hi have not flown for a while but flew this today . sounds nice
Sure does! What motor are you using?
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Jan 05, 2013, 10:58 AM
scunna's Avatar
dps 10 blade (lander) from hk on 6s. Plenty of power and it sounds good. Im sure its a 22kv. Pulls 73 amps at over 1700 watts with nanotech 6s 3300 65-130 c lipo. Time to put droptanks and stores on.
Last edited by scunna; Jan 05, 2013 at 11:28 AM.
Jan 07, 2013, 06:31 PM
The best in EDF since 2005
Extreme_RC's Avatar
Just an update for all you guys who have been emailing me, new batch of 70mm housings is due in this week, got another 100 on the way and should get the first carton by Wed fingers crossed.
Jan 07, 2013, 11:40 PM
Registered User
Mark, can the Alloy housings (any) take the 12 blade rotor?
Maybe in the housing page blurb add in "Fits CS10 blade rotor", Wemo etc. (it has Wemo mentioned). That would help people going there right away then.
Jan 08, 2013, 06:18 AM
The best in EDF since 2005
Extreme_RC's Avatar
No idea yet as only just got some 12 blade rotors in, but will check tomorrow, I doubt it though from what I have read. I expect I will have to turn down the 12b rotors and offer then as complete fan units. Is it worth the effort though? So far it would appear they are almost identical to the 10b in performance, and sound similar right?

The 7 stator housing was designed to suit the CS rotors, it offers a little more efficiency and seems to be even quieter than the 4 stator housing. No benefit with a wemo rotor from the couple of tests I have run. The 7 stator is slightly lighter, how they managed it is beyond me, the cost increase is in direct relation to the 40 min extra it takes to machine each one due to the complexity of the design.

Oh and a box of housing turned up today, earlier than expected so will update the site tomorrow for all the 70mm combos and parts.
Jan 08, 2013, 08:56 AM
Registered User
I didn't check/test physically myself, but I am fairl'y sure the 12b are stronger made (rotor/blades) - though maybe they did that to later 10b also? But if they are stronger than the 10b then that would be a main reason to head to those, as then they could run higher powers too.
Though a lot easier if a housing suited them instead! Maybe something for down the road whan all the 10b are discontinued and their alloy housings run out too.

Changes make for advances, but also annoyances too! Usually they don't come too often to cause too much grief (to users and suppliers of stuff). Much like I 'wasted' a heap of 5 & 6 blade fans taking them out to only use 10blade! Now the 12b making that attack on the 10b.... but I won't do all those as it is not important (not like the 5/6 to 10b sound difference was for eg) and the 10b are fine in their uses.

I guess anyone wanting an alloy 12b can do the rotor trimming themselves!
I might have a go at that... I think I could do it successfully.... THINK.....
Jan 08, 2013, 09:07 AM
Registered User

sanding a rotor down 1-2mm should be difficult?!?

Hmmm, first thing I do not understand: with few exceptions (like the CS 10- and 12-blade fans) I almost always have to sand the stock rotors because the housings are too flimsy (50mm and 64mm fans) so that the slightest distortion would make blades rub, plus it's a sound issue, if there is a bit of a gap the noise level goes down quite a bit. As has been mentioned, e.g. by Mark repeatedly, 1 to 1.5mm usually does not hurt thrust but messes less with the boundary layer...
So - I sanded lots of rotors, just take sandpaper and do it. Even bigger changes like Haoye 65mm into smaller 64mm stock housings, once even down to a 60mm fan. The 90mm Haoyes and Wemo clones I all had to sand a bit for them not to rub at high power, when the material stretches slightly under stress.
Small changes, one blade at a time, many times, so you get it pretty evenly done
Jan 08, 2013, 09:35 AM
Hey Ya'll!! Watch THIS!!
Michael Paxton's Avatar
Or put the rotor on a drill gun and run it against some curved sand paper. Takes no time at all.
Jan 08, 2013, 09:58 AM
Registered User
Originally Posted by Michael Paxton
Or put the rotor on a drill gun and run it against some curved sand paper. Takes no time at all.
right, of course - but there is more danger of "overdoing" the sanding (not least because it takes more time to take it off and test it against the shroud, so you might do it less often) - happened to me once, so I am back to manual. You won't get it bigger once you took away just a tiny bit too much...
Jan 08, 2013, 10:41 AM
or.......... sand them down by hand until it just fits in the housing , then use sticky back fine sandpaper stuck to a small portion of the housing i.d. and rotate the rotor mounted to the shaft by hand. works great , u can see as u go the clearance that is being created. if u are using a outrunner that sticks out of the back of the housing, i made a adapter w/ a piece of rubber hose to spin the motor by hand or by drill motor. the blades are fit perfectly to the housing radius.

Jan 08, 2013, 10:50 AM
Registered User
now that's a good idea - will do next time, thx!
Jan 08, 2013, 02:45 PM
Registered User
Greetings all,

I'm fitting 2x 70mm changesung 10 bladers into my tomcat...

going to use 4S 4000, 4500mah...

Should i get the turnigy 2300kv?

or the turnigy 2800kv?

thanks in advance!
Jan 08, 2013, 03:22 PM
Registered User
anlucas's Avatar
Originally Posted by T-BONEZ
Greetings all,

I'm fitting 2x 70mm changesung 10 bladers into my tomcat...

going to use 4S 4000, 4500mah...

Should i get the turnigy 2300kv?

or the turnigy 2800kv?

thanks in advance!

The 2x2300kv will pull 80amps between them.

The 2x2800kv will pull 120amps to give you 1lb or so more thrust.

It's up to you and whether your batteries can handle the load.
Jan 08, 2013, 04:32 PM
Registered User
I wouldn't even attempt sanding a fan down "manually" at all! It is fraught with imperfection.

When you want to turn something down (an item having a perimeter face) accurately you mechanise BOTH parts... the item and the 'machiner'.
You would run a rotor in a drill. whether drill press or hand drill in a vice. And the sander being possibly a belt sander, otherwise a rotary device, brought to bear and the item to be sanded. So the rotor will be running a hundreds of rpm and it is very easy to control the 'machiner' to within 0.5mm approx..
I do that for modifying motor shafts all the time... making circlip, or grooves into them or other things. So 3mm items can be done to high accuracy.... a 70mm fan will be much much easier.

If an outer surface needs to be 'flat' for sure, then you use a 'flat faced machiner'. And its motorised direction may even be best used across the rotating direction of the item.

A 'fixed' machining face (eg as per a tool in a lathe does) can be used too, but a motorised one gives higher accuracy. Motions in both means all face imperfections are 'averaged away' because of the constantly changing faces. Plus having both faces in motion means you have a higher 'met speed differential', thus more work done per less pressure, which in this sort of case is preferred (softish flimsy blades on the item).

Very easy to machine a fraction, test, do more....a very fast cycle, and a very fast total time.
Manual would have to be a big time waster and PITA.
Jan 08, 2013, 08:40 PM
jcdfrd's Avatar
well it is quite easy to reduce a rotor in a safe, precise manner if done properly. here's how I do it. first you need to have a table top belt,disc sander see pic. we use the disc sander with the table guide. now you need to make up the jig which is just a piece of aircraft ply approx 6x8in then drill a 5mm hole approx 2in from one of the edges, get a 5mm spare shaft and install it into hole in the plywood. so now you should have a flat piece of ply with a 5mm shaft sticking straight up.....ok now you will need to cut down the length of the shaft so that when you slide the rotor/shaft adapter on the shaft that it goes down and lays flat on the plywood and you are able to spin the rotor freely (do not tighten the adapter set screws) now place the jig on the guide table of your disc sander and clamp it down with a c-clamp. the rotor should be flat on your ply base and able to spin by hand, now just adjust the rotor to the sanding face and clamp down the ply jig, turn on the sander and by hand slowly rotate the rotor and take off as much or little as you like by adjusting the ply jig in or out of the sanding face, go a little at a time it is easy to remove material but impossible to put it back lol!!!
after resizing your rotor it is now time to rebalance

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