157" Discus Glider
10-25-2011, 09:45 PM
#479
RE: 157
If I find one we'll BOTH have one!! I HAD one but destroyed it a Soar Utah last year....got caught sideways in the rotor and didn't have enough elevator to keep from hitting the ground. Wingtip caught and cartwheeled. Fuse was repairable but I was just going to purchase a new kit. Now I can't even find an old kit!
11-05-2011, 03:27 AM
#482
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RE: 157
Interesting... are you telling usthe Chinese were ripped off by the Chinese???!!! Seriously, what were the big differences between the "real" 157 inchDiscus and the "711" in the link?
11-05-2011, 07:39 AM
#483
RE: 157
Fit & finish were terrible to say the least. Wingtips did not match the airfoil of the wing. Wings and tail components did not fit flush to fiberglass fuse. Flimsy canopy, no "cockpit", weak wing joiner, wings would crack and pop when flexed, heavy wings with a very noticeable weight difference between them, light, weak glass components for a 4 meter, very noticeable bump where two part fuse was joined in the tail boom. Exposed ends of all control surfaces, (not covered with film). Just not worth my time to try fix up. Pictures and instructions were hijacked from Flyfly website, you will notice Flyfly has watermarked their pictures on the website now and General has removed hijacked pics from their website.
12-02-2011, 07:48 AM
#484
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RE: 157
How do you join the wings? Mine came with only the hole on the fuse and wings for the metal bar that runs through the wings and fus, but no bolts are holding the wing?
04-02-2013, 09:04 AM
#488
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RE: 157
I haven't seen one of these for sale at the retail level for at least a couple of years. There have been a few change hands via various classifieds and FeeBay, but that's about it, so far as I know. I have one that has yet to fly, but it's not for sale. As a matter of fact, I'd like to find at least areplacement wing set, because I'm using the ones from mine on another project.
04-02-2013, 05:32 PM
#489
RE: 157
A good alternative could be the 3m Grob or 4m Nimbus from FlyFly: http://www.hobby88.com/shop/index.ph...sort=5a&page=2
Hobby88 is their retail shop.
Hobby88 is their retail shop.
04-02-2013, 07:21 PM
#490
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RE: 157
thx guy for the reply ,i did check out hobby88 for the Nimbus kind of like it but due to the fuselarge is a bit shorter .but i have order from hobby88 ask21 2.6meter .i will find out see who is selling it .
04-03-2013, 01:20 AM
#491
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RE: 157
Some interesting numbers that Fly Fly has published on the two planes (3m Grob and 4m Nimbus). The 3m has nearly the same wing area as the 4m, but the 4m is potetnially the lightest of the two, by a significant margin! Something wrong here, methinks.
I see there are no reviews on the 4m, and I can't find any mention of it anywhere on the web, aside from the Fly Fly site. Is it so new that no one out has their hands on one yet? I'd like to see some real world numbers WRT weight and wing area.
I see there are no reviews on the 4m, and I can't find any mention of it anywhere on the web, aside from the Fly Fly site. Is it so new that no one out has their hands on one yet? I'd like to see some real world numbers WRT weight and wing area.
04-03-2013, 12:23 PM
#493
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RE: 157
So do u guy think this 4m nimbus from hobby88 is a good choice to get ? is there anyone out there have build one yet .i heard the condor 4 meter is coming out soon .
-G-103 PT-PJE Glider with brake_KIT
[FF-B034] US$178.00
Click to enlarge
Grob-G-103 Glider PT-PJE
Model no. : FF-B034
Specification :
Material : Epoxy fuselage / Balsa wood wings
Wingspan : 3000mm
Length : 1370mm
Airfoil : HQ35-14
Wing Area : 42 dm2
Flying Weight : 1800-2000g
-G-103 PT-PJE Glider with brake_KIT
[FF-B034] US$178.00
Click to enlarge
Grob-G-103 Glider PT-PJE
Model no. : FF-B034
Specification :
Material : Epoxy fuselage / Balsa wood wings
Wingspan : 3000mm
Length : 1370mm
Airfoil : HQ35-14
Wing Area : 42 dm2
Flying Weight : 1800-2000g
05-09-2013, 09:30 AM
#495
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RE: 157
I'm in the process of putting together one of the kits that was the original subject of this thread... advertised and marketed under various titles, but popularly known as the "4m Ventus Discus" (sic). I'm attaching a photo of the label on the box mine was shipped in, to eliminate any possible confusion about which plane I'm referring to. As an aside, I think the box label got it right with"4M Semi ScaleGlider". 
Anyway, I've recentlysearched (nay, I'veread) this thread and many other lengthy treatises about this plane, but I don't see any reference to someone replacing the somewhatless-than-ideal stabilator arrangementwith a conventional stab/elevator setup. I think that's what I want to do, but I'd like to have some clue asto where to set stab incidence, relative to the wing. If nothing else, I'm hoping someone can furnish those numbers for a stabilator (in cruise trim) on a proven flier. That's why I'm tagging onto this thread - hoping that some of the builders of thisparticular plane will stillbe subscribed.
.
Anyway, I've recentlysearched (nay, I'veread) this thread and many other lengthy treatises about this plane, but I don't see any reference to someone replacing the somewhatless-than-ideal stabilator arrangementwith a conventional stab/elevator setup. I think that's what I want to do, but I'd like to have some clue asto where to set stab incidence, relative to the wing. If nothing else, I'm hoping someone can furnish those numbers for a stabilator (in cruise trim) on a proven flier. That's why I'm tagging onto this thread - hoping that some of the builders of thisparticular plane will stillbe subscribed.
.
05-09-2013, 10:23 AM
#497
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RE: 157
I'm not concerned about the travel, as I had read aboutthe shiimming required to get that taken care of. I simply don't like the design. I've already removed the pivot pin, drilled out the the holes to a larger size and installed a new, better fittingpin. But despitethis fix, there is just too much wiggle in that assembly to suit me. A lot of it comes from flex in the vertical stab, which will be helped immensely with a horizontal stab bolted solidly to it.
05-10-2013, 11:06 AM
#499
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RE: 157
Found! Seems a fellow in Australia did this same mod, mounted the stab at1.5 degrees incidence. This apparently worked fine, since he only needed a few clicks of elevatortrim on the maiden flight.
Now... where's that razor saw?
Now... where's that razor saw?
06-06-2013, 02:08 PM
#500
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RE: 157
Okay... so the horizontal stab mod is done, we're getting pretty close to flying this thing. I'm puzzled though, with respect to CG on this bird:
.
- The instruction manual says CG should be set 74 mm aft of the wing root leading edge.
- I've seen references in this thread to "... cg at the wing rod", which would be less than 70 mm.
- In other threads on RCG, I'veseeneverything from55mm(that's no typo... fifty-five!) to 80mm.
- Now for the good part.
Using two different CG calculators - Sailplane Calc spreadsheet and http://adamone.rchomepage.com/cg_calc.htm- I come up with CG's of 122mm and 114mm aft of the root LE, respectively. I've measured and re-measured all input parameters, and made sure (Ithink!) my inputs make sense to both myself and the calculators. And BTW, these numbers are the result of using a conservative 15% static margin. How can there be so much difference between a conservatively calculated CG and what everyone seems to be using, including the factory recommendation (for what that's worth)?
So has anyone out there actually tried flying this thing with a CG aft of 80mm behind the root leading edge?
.
- The instruction manual says CG should be set 74 mm aft of the wing root leading edge.
- I've seen references in this thread to "... cg at the wing rod", which would be less than 70 mm.
- In other threads on RCG, I'veseeneverything from55mm(that's no typo... fifty-five!) to 80mm.
- Now for the good part.
Using two different CG calculators - Sailplane Calc spreadsheet and http://adamone.rchomepage.com/cg_calc.htm- I come up with CG's of 122mm and 114mm aft of the root LE, respectively. I've measured and re-measured all input parameters, and made sure (Ithink!) my inputs make sense to both myself and the calculators. And BTW, these numbers are the result of using a conservative 15% static margin. How can there be so much difference between a conservatively calculated CG and what everyone seems to be using, including the factory recommendation (for what that's worth)? So has anyone out there actually tried flying this thing with a CG aft of 80mm behind the root leading edge?