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Old Aug 02, 2012, 08:00 PM
Too many numbers
United States, OH, Troy
Joined Oct 2010
1,774 Posts
Flew mine again tonight. Love it. I'm about 10000 rpm lower than you guys, but still peforms really well. Putting in an order for a 3000kv motor to "pump up the volume".
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Old Aug 02, 2012, 08:15 PM
Extreme CNC Alloy EDF
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Australia
Joined Mar 2006
11,476 Posts
Quote:
Originally Posted by clive45 View Post
Since when have the CS70 fans been $30, never paid more than $16?????
16 is about the cost for most of us small importers, add shipping and 30 is not unreasonable.

I have bags of current model (4 set screw) 3.17 and 4mm adapter sets with screws, nut etc to clear out, must be 20-30 of them, 5 bucks each, if there is enough interest I will stick them up on the clearance page of the website.
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Old Aug 02, 2012, 08:47 PM
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United States, PA, Doylestown
Joined Sep 2010
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2 questions - does each bag contain 1 each 3.17 AND 4mm? And got any idea what shipping, say, 3 bags to the good ole USA would run?
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Old Aug 02, 2012, 09:14 PM
Too many numbers
United States, OH, Troy
Joined Oct 2010
1,774 Posts
Mine came with two adapters, but I don't know their size. If you want to find out shipping, put one in your cart and check out. When you get to the part where you chose shipping, you can exit the browser (or just click on the home page) and you'll get out of the order.
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Old Aug 02, 2012, 09:32 PM
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Great plan! Thanks, hadn't thought of that.
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Old Aug 03, 2012, 12:54 PM
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Denmark
Joined Sep 2005
864 Posts
I modified a CS 90 to a 70mm version, I started by cutting the motor mount and the stators out, it was sanded to fit a 70 fan-house that I made of fibreglass. Then I cut the rotor to fit, whit about 0.8 mm spacing to the fan-house wall. I borrowed a 1850KV out runner spec. to max 1600W. ( Still trying to find the right motor). First try with 7 cells gave me 2.1Kg at 2KW... I noted that the air was hot at high power, so I guess the efficiency of the motor is low at this point. The scale was not moving all that well, so after fixing this and with full charged batteries I got 2,6 Kg peak at 2,3KW ( for a very short time)
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Old Aug 03, 2012, 02:41 PM
You are a "go" for reentry
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High Orbit.....
Joined Jun 2009
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Videoooo
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Old Aug 03, 2012, 03:20 PM
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United States, TX, Grand Prairie
Joined Nov 2005
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Quote:
Originally Posted by frank40 View Post
I modified a CS 90 to a 70mm version, I started by cutting the motor mount and the stators out, it was sanded to fit a 70 fan-house that I made of fibreglass. Then I cut the rotor to fit, whit about 0.8 mm spacing to the fan-house wall. I borrowed a 1850KV out runner spec. to max 1600W. ( Still trying to find the right motor). First try with 7 cells gave me 2.1Kg at 2KW... I noted that the air was hot at high power, so I guess the efficiency of the motor is low at this point. The scale was not moving all that well, so after fixing this and with full charged batteries I got 2,6 Kg peak at 2,3KW ( for a very short time)
Pray tell, how were you able to cut the blades down and balance them?

Regards
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Old Aug 03, 2012, 03:32 PM
You are a "go" for reentry
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High Orbit.....
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Edit dumb me can't count.
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Old Aug 03, 2012, 04:07 PM
Big gov never Works
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Skunk Water, Rhode Island
Joined Jul 2002
12,303 Posts
Good luck with this mod, Frank. I thought of doing this with the 8 blade rotor that Gary sells at Efflux. While it seams to work well on strait type blades, like the WeMo or HET, etc., trimming a scimitar shaped blade lost a lot of thrust. As compared to the WeMo or HET types. That little foot, at the end of the blade adds a lot of load. I had the same findings with trimming APC-E props, also.

Just always seams to be cavitating(sound).

Fuzz
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Old Aug 03, 2012, 06:08 PM
Extreme CNC Alloy EDF
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Australia
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Quote:
Originally Posted by PikeStaff View Post
2 questions - does each bag contain 1 each 3.17 AND 4mm? And got any idea what shipping, say, 3 bags to the good ole USA would run?
Yup one of each, with all the associated screws and nut etc.
Airmail for flat items is AUD$13.00 for up to 150g, should be able to send 4-6 in one pack I reckon.
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Old Aug 03, 2012, 06:11 PM
Extreme CNC Alloy EDF
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Australia
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Why would you bother cutting a 90 down? Its heavy, slow to accelerate, motor is heavy, and it obviously sucks power, the 70mm does 2.1kg on 6s at 1400 watts.

If it was to run with a 7 stator housing I got that covered in my new design 7 stator housings are in my new order of housings due in about 10 days. In fact I have 150 mixed housings due in
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Old Aug 04, 2012, 04:52 AM
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Australia, QLD, Toowoomba
Joined Oct 2011
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Here's a quick vid of my a320 airliner taxi testing with the cs 10 blades added and 2300kv out runners motors, will fly it tomorrow weather permitting, I like the sound, not perfect but still nice, the weight is just over 2kl (retracts added)

A320 taxi test after upgrades (0 min 36 sec)
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Old Aug 04, 2012, 05:58 AM
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Denmark
Joined Sep 2005
864 Posts
Erh7771: I had a old 90mm FlyFly fan that I modified to cut the fan by removing one half of the fan house, and I Fan was in balance after it was cut.

St. Martin: It is only natural to loss thrust when you remove areal form the rotor regardless of the shape of the blades, but I must emit there is a limit to how much you can remove from a scimitar shape... After cutting the fan I ended up with a pitch of just over 45 degrees at the tip, so it is not to bad.

Extreme_RC: The reason for me is to try to gain airspeed not just thrust, for that I needed more power giving me a need for a bigger motor and a more power full rotor. Sense the CS 90 rotor is build more vigorous it is the first choice for me. And when cutting it down the centrifugal force work with my witch allow me to up the rpm's.
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Old Aug 04, 2012, 06:54 AM
Extreme CNC Alloy EDF
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Australia
Joined Mar 2006
11,476 Posts
Yes but thrust equates to velocity, and you are introducing more weight in both the fan and the rotor, plus you are removing a lot of the blade design by cutting 10mm off it. Need to see it in a model, video!
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