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Old Jan 02, 2010, 05:29 PM
EDF all the way!
bruff's Avatar
Gilbert, Az
Joined Jun 1999
8,041 Posts
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Formost 150 & XPS Dynamax fan system

Flew the Formost 150 today with the XPS Dynamax fan system installed.
Looking at the pictures below you can see it is smaller than the Hoaye 5" fan. So basically it has no inlet on the fan. Fan sounds great. Flew it 3 times this morning. Here are the numbers from the Hacker/Spin 200 ESC. They were consistent between the flights. See here for the video.

Voltage 39.7
Amps 74.8
RPM 22,300
Timing 0
RTF weight 18 lbs
Exhaust dia. 4.25

Bob
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Last edited by bruff; Jan 03, 2010 at 02:12 AM. Reason: correct voltage callout
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Old Jan 02, 2010, 07:35 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
15,941 Posts
Don't believe the SPIN 200 numbers. If you are flying with 10S then there is no way that you are seeing only 29.7 volts - that is only 2.97v per cell!

Also, since the fan housing is smaller (weird?), you should use an inlet ring if you can fit it... you will gain at least one more pound of static thrust.

Your exhaust cone is almost 1 full inch to large! You need shrink that to 3 3/8th (3.375"). Your top end speed is really suffering.

If you make these changes, you will find a totally new plane!
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Old Jan 02, 2010, 09:26 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
22,848 Posts
i was going to say the same jim. i saw the id before i saw this post, and i said to myself...man, that tail pipe must be REALLY big! and it is! i agree bob, shrink that puppy down to atleast 3.5". and a simple foam lip for the upper portion of the fan wouldnt hurt either.
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Old Jan 02, 2010, 09:39 PM
5kW Club
racer1's Avatar
United States, AZ, Tucson
Joined Feb 2007
840 Posts
Bob may have the same problem I did when I first set up the Dyanmax on the Falcon. I only had a 6 inch thrust tube and when I had a 3.5 diamater it choke the thrust down and the plane did not perform.

Later testing I did using the T-jet was the tail cone needed to be at least 12 inches long before I could use the 3.5 exit.

Using a 6 inch exhaust I had to use about 3.75 for the exit.

Clay
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Old Jan 02, 2010, 09:49 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
22,848 Posts
that lip is probably really hurting it too.
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Old Jan 02, 2010, 09:57 PM
5kW Club
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United States, AZ, Tucson
Joined Feb 2007
840 Posts
At least I had an intake ring to help the Falcon work really well.

Clay
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Old Jan 02, 2010, 10:43 PM
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mpope1's Avatar
gilbert,az
Joined Dec 2005
3,950 Posts
It seems to perform much better then the hoaye did!
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Old Jan 03, 2010, 12:12 AM
Average Joe 2 Semi-Pro n Back!
FL62's Avatar
United States, AZ, Queen Creek
Joined Feb 2004
1,148 Posts
I might have a special NACA 96005 inlet bowl around still that should fit the Dynamax fan - I just need to clean the cheerios out of it!
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Old Jan 03, 2010, 12:15 AM
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mpope1's Avatar
gilbert,az
Joined Dec 2005
3,950 Posts
That is a very aerodynamic bowl, I think NASA uses them!
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Old Jan 03, 2010, 12:34 AM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
21,277 Posts
i have a inlet ring that fits the dyna max ,heres a pic
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Old Jan 03, 2010, 01:46 AM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,668 Posts
I can hear the video but can't see it Sounds good though
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Old Jan 03, 2010, 02:15 AM
EDF all the way!
bruff's Avatar
Gilbert, Az
Joined Jun 1999
8,041 Posts
I'm, going to put the fan in the Venture (improved Formost 150) it has a full inlet ducting. I will reduce the exit diameter down also. You need a Divx codex for the video.
Bob
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Old Jan 03, 2010, 12:36 PM
Xtreme Power Systems
Lake Havasu, AZ
Joined Jun 2005
15,941 Posts
Air Sally's ring is PERFECT for the Dynamax. Slips on and just works... and it looks good too!
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