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Old Jun 19, 2008, 11:11 AM
To drive or to fly......BOTH!!
FresnoJay's Avatar
USA, CA, Clovis
Joined Apr 2007
6,188 Posts
Dellavex, On the stock fan and motor your kokam should be supplying what it asks just fine. What are you pulling Amp wise is the important question? You are most likely in the 35-40A range and 350-450 Watt range. Most I have seen use a 3000 at least with the stock motor but it still wont be fast 65 mph tops. Still plenty to fly but will seem way slow. It will continue to seem slow till you get into the 550-650 Watt range. Once in the 750-850 Watt range she will be smokin.

My first few flights were in the the 375-400 Watt range and it flew well just slow. Once I got into the 800-900 Watt range where I am now I saw a huge performance jump. Impressive verticals and around 100 mph speeds. I wont go into how I got there in this thread but if interested I can post a like to the thread showing how myself and others got there.

Jason
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Old Jun 19, 2008, 12:02 PM
Registered User
Evansville Indiana
Joined Aug 2006
230 Posts
Jason, I'm pulling 41 amps and 450 watts. It did seem way slow, so slow that I only did one curcit and landed. I've read your other thread with interest, and did some of the mods you listed. I decided to go without a trust tube for right now, but realize that will help with the speed. I want to get my feet wet before I start going for any real speed since this is my first EDF.

Thanks alot

Jay
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Old Jun 19, 2008, 02:48 PM
To drive or to fly......BOTH!!
FresnoJay's Avatar
USA, CA, Clovis
Joined Apr 2007
6,188 Posts
Dellavex, Dont be scared of it. At that power level she will fly well. Rolls and loops should be good. Fly it that way till you get used to it. Then when your ready you can upgrade to get more speed and such. I tell this to all the first time EDF guys that start with this plane. It is actually a pretty easy flying plane.

Jason
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Old Jun 19, 2008, 04:22 PM
Houng-wen Lin
GWS4CEO's Avatar
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,443 Posts
GWS A4 is actually a pretty easy flying plane.

Quote:
Originally Posted by FresnoJay
Dellavex, Dont be scared of it. At that power level she will fly well. Rolls and loops should be good. Fly it that way till you get used to it. Then when your ready you can upgrade to get more speed and such. I tell this to all the first time EDF guys that start with this plane. It is actually a pretty easy flying plane.

Jason
Thanks Jason.

Don't know how to let Pancake_1 believe this.
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Old Jun 19, 2008, 04:33 PM
Registered User
Evansville Indiana
Joined Aug 2006
230 Posts
Jason thanks alot, too bad the wind is blowing now or I'd head back to the field for another flight.

Jay
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Old Jun 19, 2008, 04:58 PM
Registered User
Joined Sep 2007
65 Posts
Quote:
Originally Posted by GWS4CEO
Thanks Jason.

Don't know how to let Pancake_1 believe this.
Oh, Simple like that?

Great Italy scientist Galileo said: " You can never change a person, but tell him the truth".
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Old Jun 19, 2008, 05:13 PM
Houng-wen Lin
GWS4CEO's Avatar
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,443 Posts
What will be the truth?

Quote:
Originally Posted by Bill Young
Oh, Simple like that?

Great Italy scientist Galileo said: " You can never change a person, but tell him the truth".


What will be the truth?

I don't even blam that he had made many RC flyers hesitated to buy GWS A4 that caused by his insist there were some issues...

Can we cosider to make GWS airplanes under 6 Sigma system?

How many RC flyers can buy a foam EDF JET in thousands dollars?

GWS always start a tooling base on sucessful result after many proto types improvements had done.
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Old Jun 19, 2008, 05:17 PM
Registered User
Evansville Indiana
Joined Aug 2006
230 Posts
Mr Lin, I just exprienced the "Fan Explosion" like others have posted. Decided to check everything after my flight this morning, noticed some rub marks on the inside of the fan unit. I pulled the fan and checked the blade balance, everything was still good. I reinstalled the fan and powered it up and poof the fan explodes into a million bits...... So what do I do now? One flight which was maybe a minute and now I'm without a flyable plane.....

Thanks
jay
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Old Jun 19, 2008, 05:35 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by GWS4CEO
Thanks Jason.

Don't know how to let Pancake_1 believe this.

Mr. Lin,

I like the GWS A-4, in general.

I looked for other reasons for this thrust issue, but it seemed to be an inherent problem.

I'm open to other reasons for the issue, but am only getting resistance to the entire idea of their being a thrust problem.

I'll either reproduce it... which could be dangerous... and video it, or I'll just drop the issue entirely.

CorsairNut said that he observed what appears to be a related issue, while watching videos of "stock GWS A-4s" on YouTube.

I guess we'll just assume that none of those people know how to fly properly, and that I can't tell a vectored thrust problem from a CG problem....

The intersting thing is that while I have simply been stating that I think the duct is causing an issue, the people that are desperately trying to shout me down are attributing it to "the A4 having nasty stall tendencies".

Well, I didn't notice any "nasty stall tendencies", even when I ran the battery too low on one occasion, and had to glide it to a ridge across a ravine. It was on the edge of stall the entire time, yet I was able to fly it unpowered to its unintended denstination... I guess I just fly better than the guys that crash theirs with the motor running... and they somehow think that crashing airplanes makes them an expert on flying them...

So, the people that are trying to say that there cannot be any thrust issue, are actually trying to make it seem that the A-4 is inherently less stable.... I find this to be totally incorrect, as even with the thrust issue that I have mentioned, I was able to get the aircraft to fly reasonably well by lowering thrust and adding down trim. I never felt that it exhibited any odd stall tendencies. Now that I have fixed the thrust vectoring issue, I think it flies very well.

The two issues that I have had with performance are:

1. The landing gear is designed improperly, causing the wing to have a negative incidence relative to the ground, thus making takeoffs awkward.

2. The thrust issue that I have mentioned, which may or may not be inherent to design. I have found no other reason than the duct design, but I'm open to other possibilities. At this time, considering the results of my testing, I am attributing it to the duct design. However, I do not attribute it to thrust line, as my thrust tube is inline with the thrust line, and it performs very well.
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Old Jun 19, 2008, 05:40 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by dellavex
Mr Lin, I just exprienced the "Fan Explosion" like others have posted. Decided to check everything after my flight this morning, noticed some rub marks on the inside of the fan unit. I pulled the fan and checked the blade balance, everything was still good. I reinstalled the fan and powered it up and poof the fan explodes into a million bits...... So what do I do now? One flight which was maybe a minute and now I'm without a flyable plane.....

Thanks
jay

Well, that makes me want to run right out and test with the stock fan!
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Old Jun 19, 2008, 05:44 PM
A-4 nut!!
skyhawk's Avatar
Vancouver B.C.
Joined Apr 2002
4,633 Posts
And yet no one else has the problems you do.

I'm not saying it's you - but 1 person with a problem does not make it a manufactuing problem that they need to change.





But i forgot......................your god's gift to aviation.
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Old Jun 19, 2008, 05:57 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by GWS4CEO


What will be the truth?

I don't even blam that he had made many RC flyers hesitated to buy GWS A4 that caused by his insist there were some issues...

Can we cosider to make GWS airplanes under 6 Sigma system?

How many RC flyers can buy a foam EDF JET in thousands dollars?

GWS always start a tooling base on sucessful result after many proto types improvements had done.

Let me reiterate Mr. Lin,

I'm open to other explanations for a vectored thrust issue.
I haven't gotten any other explanations, only people trying to say that my aircraft did not experience a vectored thrust issue.

The fact that this issue existed in my aircraft is undeniable.
The reason for it is debatable.
I'm still waiting for suggestion and/or ideas on what might cause a vectored thrust issue.

1. Wiring in the duct?
2. 75mm fan able to create the issue?
3. The duct itself?

Those are the only obvious possibilities that I see...
Unless I have some constructive input, I can only go with my own conclusion, which I came to by correcting the wiring issue, and dismissing the fan as a possibility.
Other people that looked at my aircraft said that they didn't feel the wiring or the fan would cause an issue, and that they felt that the duct is the most likely cause.

BTW, If you want your aircraft tested properly, send me one.
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Old Jun 19, 2008, 06:01 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by skyhawk
I'm not saying it's you - but 1 person with a problem does not make it a manufactuing problem that they need to change.
You're still fixating...
I have stated many times that "there could be another reason"...
I'm just not getting any... and certainly nothing constructive from you.

Quote:
But i forgot......................your god's gift to aviation.
Well, at least you're starting to pay attention...
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Old Jun 19, 2008, 06:10 PM
Houng-wen Lin
GWS4CEO's Avatar
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,443 Posts
Quote:
Originally Posted by Pancake_1
Let me reiterate Mr. Lin,....

BTW, If you want your aircraft tested properly, send me one.
So many flyers arround the world had asked me to get them free test samples!

Tell me what's your back ground of aviation engineer and experience?

I give many test samples to whom won my respect and they support to GWS very much, even they never ask me to do so.
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Old Jun 19, 2008, 07:04 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by GWS4CEO
So many flyers arround the world had asked me to get them free test samples!

Tell me what's your back ground of aviation engineer and experience?

I give many test samples to whom won my respect and they support to GWS very much, even they never ask me to do so.

Hehe... I don't think I'm winning your respect

However, I did learn to fly RC many years ago with some very, very experienced pilots and builders.
The head of our club back then is a career Fighter Pilot, and a Master Craftsman, as were others in the club. So I've been shown how to build, test, and make an aircraft fly properly, by some of the best in the hobby.

I've been shown how to tell if an aircraft's CG is just right (for its intended purposes), as well as the details of wing incidence, thrust line, etc.

I have received many kudos from very experienced pilots on my flying skills with both RC aircraft, and real aircraft...
My flying is better than any that I've seen in your videos...

11 years as an Aircraft Technician in the USAF gave me a good deal of insight into Aviation Engineering as well.

BTW, what is your "real" aviation experience?
Have you built "real" planes?
Do you fly "real" planes?
Just curious....

I was only kidding about sending me one, but I guarantee I would be at least as good a test pilot as most others you could find.


BTW, I support GWS by buying GWS.
However, if I perceive a problem I will tell you about it.
That is not bashing your product, it's trying to give you feedback to make products better.
That's what a Test Pilot does...
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