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Old Jul 24, 2008, 06:23 PM
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Leesburg, VA
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Just finished my EPO FW-190

First let me say that I like the EPO, it's easy to work with and assembly was a breeze.

Next a question. The plane weights in at 27 ounces AUW. Will a 330 watt motor turning a 10X7E prop have enough power to ROG?

Pictures to follow..
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Old Jul 24, 2008, 06:28 PM
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Doubletap's Avatar
PRC (People's Republic of Commiefornia)
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Are you serious? That's close to 200W/lb. It's generally accepted that 150W/lb will give you unlimited vertical. 330W will be WAY MORE than enough for that model to ROG.

Doubletap
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Old Jul 24, 2008, 07:10 PM
DELTAS RULE
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tehachapi, CA
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yeah, in about 3.5 ft! :O
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Old Jul 24, 2008, 07:59 PM
Houng-wen Lin
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Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
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Dear Topspin, what is the 300W motor that you used?

GWS RD tested with GWS 30XX motors, they are all OK to match her.

Pretty soon, you will find how strong the EPO is!

The harder you carsh her, you find EPO will be worth to pay this cost.

GWS RD Tommy tested with heavy crashed accident, it's proove EPO is great!
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Old Jul 24, 2008, 08:57 PM
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Oh good, it won't be underpowered , I was afraid of that..

Mr. Lin, I'm currently flying it with an AXI 2212-26 and it is just enough to fly it but not aerobatic.

The motor I just got for it is a Great Planes Rimfire 35-30-1250. I also have a Phoenix 35 ESC and use EVO V2 (20 C) 3S 2100 Lipos. I'll also be using an APC 10X7E prop and a Park Zone Spinner.

I was going to go with less motor but figured what the heck, so I powered it up.
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Old Jul 25, 2008, 08:20 AM
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There is never enough power. I think ChrisF has a 750+Watt Formosa II
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Old Jul 25, 2008, 10:59 AM
Houng-wen Lin
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Shijr, Taiwan. DungGwan, China. City of Industry, California.
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Quote:
Originally Posted by wedge98
There is never enough power. I think ChrisF has a 750+Watt Formosa II
The thrust must enough to take off vertically like 3D flyers!

May be Formosa-II also have to be EPO?
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Old Jul 26, 2008, 03:00 PM
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Just enough, you better prop up, or add a cell.

Tommy D
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Old Aug 01, 2008, 12:45 PM
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Well the maiden flight was a disaster. I took off and immediately lost control of the airplane. Before taking off I checked all controlls to make sure everything was right so I just don't know what happened. Anyway there was minimal damage to the airplane and it has been repaired. I have also installed the new motor so hopefully the next try will be more successful..
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Old Aug 01, 2008, 04:33 PM
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Fort Collins, Colorado, USA
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I have noticed that with more power, the CG in the manual will end up giving you a tail heavy "like" experience and this is probably what happened to you.
I built my first GWS FW-190 with a 640 watt motor on 4s and set the CG at 82mm which is within the range in the manual. On take off...it simply shot straight up and i had to add in about 24 clicks of down just to get level flight.
It was pretty scary there for awile. Motor used was the Rimfire 36-35-1200kv
The 2nd one Im building will be set with a CG much more nose heavy.
I am also building a 3rd one with no landing gear with a smaller rimfire 36-30-1450kv that will be 3s only just for park use.
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Old Aug 01, 2008, 06:39 PM
Houng-wen Lin
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Shijr, Taiwan. DungGwan, China. City of Industry, California.
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An EPS-28BL with 2825 may be will get over 2kg thrust?

I need to let GWS RD try out some more datas...
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Old Aug 08, 2008, 12:04 PM
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Quote:
Originally Posted by kahloq
I have noticed that with more power, the CG in the manual will end up giving you a tail heavy "like" experience and this is probably what happened to you.
I built my first GWS FW-190 with a 640 watt motor on 4s and set the CG at 82mm which is within the range in the manual. On take off...it simply shot straight up and i had to add in about 24 clicks of down just to get level flight.
It was pretty scary there for awile. Motor used was the Rimfire 36-35-1200kv
The 2nd one Im building will be set with a CG much more nose heavy.
I am also building a 3rd one with no landing gear with a smaller rimfire 36-30-1450kv that will be 3s only just for park use.

Thanks for the tip, that's exactly what happened. The plane nosed straight up and dropping the nose did no good since I didn't have sufficient airspeed to regain control. I'm using the 300 watt Rimfire but that should be more than enough. I also set the CG at 85 MM so I'm convinced that you're absolutely correct. This time I'll ease the throttle on takeoff but I will add some down elevator just to be on the safe side. I can allways trim it once I get it in the air.

My Formosa is a completely different story. I dropped an AXI in it and it flys like it's on rails. It's also incredibly fast, way faster than I expected..
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Old Aug 08, 2008, 02:38 PM
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Quote:
Originally Posted by TopSpin
Thanks for the tip, that's exactly what happened. The plane nosed straight up and dropping the nose did no good since I didn't have sufficient airspeed to regain control. I'm using the 300 watt Rimfire but that should be more than enough. I also set the CG at 85 MM so I'm convinced that you're absolutely correct. This time I'll ease the throttle on takeoff but I will add some down elevator just to be on the safe side. I can allways trim it once I get it in the air.

My Formosa is a completely different story. I dropped an AXI in it and it flys like it's on rails. It's also incredibly fast, way faster than I expected..
Ive built the hand launch version first before doing another with full house controls. I wanna make sure I figure out a good CG point before putting all that work into another plane. I set the CG on this one at 70mm. Even without the extra weight of tail wheel, rudder servo/linkage, flaps, bomb drop, and oversized 60amp esc in the nose, I still had to add 1 oz of lead in the tail just to get the CG at 70mm. Had I not added the lead, the CG would have been at about 60mm. I could have put the silver series Electrifly 35amp esc under the cockpit area and that may have helped some for the CG, but thats NOT a good place to keep cool something that runs kinda hot like an esc. I even added(drilled) 4 extra holes through the front of the foam firewall into both the battery bay and the servo/rx area just to make sure.
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Old Aug 09, 2008, 12:06 PM
Houng-wen Lin
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Shijr, Taiwan. DungGwan, China. City of Industry, California.
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Hope you had seen how strong EPO is during crash.
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Old Aug 09, 2008, 01:24 PM
Confused? Who, me?
Roger Lombard's Avatar
United Kingdom, England, North York
Joined Jan 2005
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Don't forget that with much more than the "design" power, then the "design" down and side thrust in the motor stick will not be enough.

You could check this out by launching at a low power setting and then see if opening the throttle affects the pitch of the plane.

A bipe I built recently behaves beautifully on 2 cells and about 50w. Change to a three cell (which moves the cg forward) and without changing the trim settings the plane becomes almost unmanageable - eager to perform continuous loops!

Adding weight, under those circumstances, isn't the right solution.

It's a variation on the Zero problem. Zero was originally designed for a much less powerful motor. Fitting even a 350 brushed makes it want to climb uncontrollably even though technically the CG is in the correct place. Most people solve the problem by changing the wing incidence but you could probably get a similar outcome by changing the down thrust on the motor stick - but that's actually harder to do.
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Last edited by Roger Lombard; Aug 09, 2008 at 01:29 PM.
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