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Old Jun 12, 2008, 01:11 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by Extreme_RC
Twin 55's are the way to go, with green motors on the current crop of 2200 4s1p 25c packs available the power system will be around the 500-550w mark with 900 grams thrust on tap. The cost of this size pack has come down so much its a no brainer to design something around the proven 55 & 64 fans.

I think its a mistake to continue with the EDF75, the fan requires a lot of work to get it to run smoothly and the output vs power consumption is very average.

Yeah, I think the advantage of setting it up for 75mm is that we can easily put the 70mm fans in it... like the A-4.

The problem I'm anticipating is the exhaust ducting.
The ducting on the A-4 has issues, and required a thrust tube (that was my experience). Making one for a single duct is cake... but having to do a 1-2 duct is a different story.
If they don't do GOOD exhaust ducting, then twins would be better, IMO... that way we just make two straight thrust tubes.

I think the best thing would be... do the ducting RIGHT, and make a foam insert for a 75 (so we can put a 70 in), and an insert for 2 64s... which you could stick 55-68(70? ) fans in.
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Old Jun 12, 2008, 01:56 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,506 Posts
Good grief - realistically you know what it is going to come with. A single 75 mm fan. It would be cost prohibitive to make multiple noses and modules different size single and double fans. And it will have an optional stick mount for pusher folks.

That being said, it will make a great basis for a bash. See what folks did with the F-15? Clip the wings and put all sorts of fans into it. I am positive GWS will produce a good flying kit. Of all the recent ones, the only miss has been the J10. And you will be able to hop this one up and snd down this, and add that, and do all sorts of crazy stuff because it's FOAM!

Jim
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Old Jun 12, 2008, 02:08 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by jamesdr
Good grief - realistically you know what it is going to come with. A single 75 mm fan. It would be cost prohibitive to make multiple noses and modules different size single and double fans. And it will have an optional stick mount for pusher folks.

That being said, it will make a great basis for a bash. See what folks did with the F-15? Clip the wings and put all sorts of fans into it. I am positive GWS will produce a good flying kit. Of all the recent ones, the only miss has been the J10. And you will be able to hop this one up and snd down this, and add that, and do all sorts of crazy stuff because it's FOAM!

Jim
I did see a kit recently that had inserts for a couple of different fan setups...
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Old Jun 12, 2008, 03:12 PM
Registered User
thrashmaster71's Avatar
USA, NY, Buffalo
Joined Dec 2007
619 Posts
Quote:
Originally Posted by jamesdr
Good grief - realistically you know what it is going to come with. A single 75 mm fan. It would be cost prohibitive to make multiple noses and modules different size single and double fans. And it will have an optional stick mount for pusher folks.

That being said, it will make a great basis for a bash. See what folks did with the F-15? Clip the wings and put all sorts of fans into it. I am positive GWS will produce a good flying kit. Of all the recent ones, the only miss has been the J10. And you will be able to hop this one up and snd down this, and add that, and do all sorts of crazy stuff because it's FOAM!

Jim

I agree, it's going to be a 75mm fan, and that is just fine with me as long as all the bugs have been worked out of it (and I think they have.) This will keep the cost down. I don't care what nose they put on it as long as it looks good and flies well. (It does seem as though the long nose is more popular.) If I want a different nose, I will modify it. Thats the beauty of foam! I hope there will be an EPO option.
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Old Jun 12, 2008, 03:15 PM
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Tumbler's Avatar
New Jersey
Joined Feb 2003
8,079 Posts
Bigger is better!! So when can we expect these. Is this soemthing we have to wait until Christmas for??

Thanks!

Tumbler

Quote:
Originally Posted by GWS4CEO
Just back from Shanghai RC model show.

There are many types of F4. But most them are smaller!

But I am not sure how will the others flew?
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Old Jun 12, 2008, 04:11 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by thrashmaster71
I agree, it's going to be a 75mm fan, and that is just fine with me as long as all the bugs have been worked out of it (and I think they have.)

Just curious... what indicates to you that the bugs have been worked out of the GWS 75mm? I've seen recent pics and video of these fans self-destructing in-flight...

No matter, since a HET or similar setup should drop in very easily...
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Old Jun 12, 2008, 04:30 PM
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thrashmaster71's Avatar
USA, NY, Buffalo
Joined Dec 2007
619 Posts
Quote:
Originally Posted by Pancake_1
Just curious... what indicates to you that the bugs have been worked out of the GWS 75mm? I've seen recent pics and video of these fans self-destructing in-flight...

No matter, since a HET or similar setup should drop in very easily...

I didn't realize that there were still problems with it. I guess I assumed that the rotor insert that they made fixed the problem. I admit, I haven't been paying real close attention to this. Hopefully these problems get worked out soon. I'd hate to see any Phantoms Migs or Sabres go down because of this.
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Old Jun 12, 2008, 04:34 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by thrashmaster71
I didn't realize that there were still problems with it. I guess I assumed that the rotor insert that they made fixed the problem. I admit, I haven't been paying real close attention to this. Hopefully these problems get worked out soon. I'd hate to see any Phantoms Migs or Sabres go down because of this.

I think most of us that have A4s are just planning on using something different anyway... I was going to test the stock fan with an outrunner, but I'm not risking a jet on that fan...
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Old Jun 12, 2008, 04:44 PM
Registered User
Raleigh, NC
Joined Mar 2008
222 Posts
I want one now When can we expect these babies?
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Old Jun 12, 2008, 05:33 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by thrashmaster71
I'd hate to see any Phantoms Migs or Sabres go down because of this.

I hadn't heard anything about a Sabre.... just about a MiG-17 to go along with the Vietnam era A4 and F4... the F4s can fight the MiGs, while the A4s take out their runway...
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Old Jun 12, 2008, 07:35 PM
Houng-wen Lin
GWS4CEO's Avatar
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,445 Posts
Quote:
Originally Posted by Pancake_1
I hadn't heard anything about a Sabre.... just about a MiG-17 to go along with the Vietnam era A4 and F4... the F4s can fight the MiGs, while the A4s take out their runway...
Both Mig-17 and F86 will be a single EDF75 powered.

May be some day also make the small size for EDF40 ( 300~444g thrust ).
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Old Jun 12, 2008, 07:50 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by GWS4CEO
Both Mig-17 and F86 will be a single EDF75 powered.

May be some day also make the small size for EDF40 ( 300~444g thrust ).

Mr. Lin,

Please ensure that the ducting in these new models is properly aligned with the thrust line, so that there isn't a vectored thrust issue like the A-4 has.
The twin outlets of the F-4 will make it more difficult for us to overcome this issue, as we have had to do with the A-4.

I just saw a video of a nice A-4 crashing due to this thrust vectoring issue, and I have experienced it myself... fortunately I did not crash.

This is a serious issue, and I hope you will give it the proper attention.

Another issue that we have mentioned with the A-4 is that the landing gear is not designed to give the proper wing incidence on the ground.
This leads to rolling takeoffs being very abrupt. This, coupled with the thrust issue, makes the A-4 takeoff very poorly.

Please learn from these mistakes, and avoid them in the design of the new models.

Thanks
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Old Jun 13, 2008, 05:08 PM
Ay up it's warped
mtbrider's Avatar
Derbyshire UK
Joined Feb 2003
1,306 Posts
Forgive my ignorance but would a EDF75 or similar powerplant for the F4 give them the capability to be hand launched?
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Old Jun 13, 2008, 05:55 PM
damn gravity again
supershuey's Avatar
trowbridge, Great Britain (UK)
Joined Jan 2004
664 Posts
Quote:
Originally Posted by mtbrider
Forgive my ignorance but would a EDF75 or similar powerplant for the F4 give them the capability to be hand launched?

hi

we handlaunch the a4 with no prob as with all our gws models
we wish we had a nice runway but dont
didnt know or realise the a4 had thrust lines issues our one
flies brill but we are running gws motor and fan all standard

thanx
Dylan
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Old Jun 13, 2008, 06:37 PM
Foam Flingin' Nitro Pilot
San Diego
Joined Mar 2008
360 Posts
Quote:
Originally Posted by supershuey
hi

we handlaunch the a4 with no prob as with all our gws models
we wish we had a nice runway but dont
didnt know or realise the a4 had thrust lines issues our one
flies brill but we are running gws motor and fan all standard

thanx
Dylan
To clarify, the thrust line is probably correct (someone told me that it is), but the exhaust duct curves up along the bottom side, and this is apprently what is causing the issue. A thrust tube solves this, as long as it is adjusted correctly, as it is a linear taper to the exit, and will allow the exhaust to exit without vectoring.

I'm sure that many people are overcoming this issue with nose weight and/or down elevator trim... however, that would cause other issues in the way it flies, though most people probably wouldn't notice those issues as much.
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