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157" Discus Glider

Old 11-12-2005, 01:05 AM
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Mooney
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Default 157" Discus Glider

Has anyone bought one of the 157" Discus gliders that's being sold on E-Bay? I'm wondering how the quality is, and how they fly.
Old 11-12-2005, 04:00 AM
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slopemeno
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Default RE: 157" Discus Glider

A friend of mine just finished one. Bottom line-you get what you pay for. While, yes, its a lot of plane for the money, the quality isnt quite as high as some of the eastern european kits. That being said, his came out nice and he's happy with it. If youre buying on price and you dont have plans on spending $600-$1000 for a 3.5-4 meter scale plane, go for it. If you can afford to go above $500, you can look for a clean used 4-meter plane. Spend some time searching "Scale Sailplanes" on google. Theres large kits of vintage sailplanes that are very reasonably priced, Such as the WWII TG-2 and 3.
Old 12-02-2005, 02:08 PM
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deckerv
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Default RE: 157" Discus Glider

Does he have any pics of his sailplane? How does it fly?
Old 12-02-2005, 02:43 PM
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IFlySlowPlanes
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Default RE: 157" Discus Glider

Well, it's really quite simple....

...see, the wing moves through the air, right?....and there's all this high pressure and low pressure stuff going on....never could keep it all straight, but the idea is, if you get it going forward fast enough, it'll probably fly. Until it doesn't anymore. Then you go buy another one! See? Simple!
Old 12-02-2005, 03:29 PM
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erich44
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Default RE: 157" Discus Glider

Hey you, who fly slow planes

That's not how it flies. It's all based on very sound, magic principles. You got that
straight now. OK. Myself I use the Gandalf based, magic levitation spells. But that's
just a personal preference. Pretty much any magic based on the "up is better than down"
incantations, will work. Your mileage may or may not vary.

Green air.

erich
Old 12-03-2005, 08:04 AM
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deckerv
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Default RE: 157" Discus Glider

haha....lol

Ok.. should have said "How well does it fly?"
Old 12-15-2005, 02:13 AM
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kwmtrubrit
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Default RE: 157" Discus Glider

I'm interested in one of these too understanding that you get what you pay for! Does anyone think that this will be hi-startable or winchable?, or is it too heavy for that.

Keith
Old 12-16-2005, 04:03 PM
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Default RE: 157" Discus Glider

I have one.

It seems to be a nice ARF. I had a Robenmodel(SP?) ASK-21 4.2M and have a 4M Alpina, it's lighter than both. It appears to have a lighter glass fuse, it uses a stab pivot like my RnR Genesis, but the stabs servo is in the lower tail which makes for a very positive setup. The wing rod is a 10MM round rod, I like that better than the wing blades on the Alpina, but not as much has the hollow 23MM tube of the ASK-21. I also have their 103 e-sailplane it uses the same rod, a little over kill there, a little under sized here. The wing looks as if the airfoil is a SD-7080, a MH-32 look alike. It seems one guy sells an all white one, the guy I bought mine from had them cover the bottom of the wing in red, so if scale is your thing get the all white one, if you're looking at it as an inexpensive XC ship get the red and white one, mine's red and white.

Rich Border

EDIT...I think the airfoil is a S6063, which is much thinner than the SD7080. S6063 is about 7%, 1.42% camber, it will be fast.
Old 12-28-2005, 03:35 AM
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ACES&8s
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Default RE: 157" Discus Glider

Very Difficult to balance on the center of lift. Canopy is not scale and is flimsy. Tail-post was not epoxied in well and had to be re-done, adding weight to the tail. Wing tips are not a good fit. Very strong Fuselage and wings, nice fiberglass fuse, wings are true and resilient, but the airbrakes are not flush in the surface of the wing. Flying stabilizer pivot block was crooked, and the stab had to be shimmed. Design calls for a servo in the tail to acuate the flying stab, should be a cable or pushrod to keep the tail light.
Overall, a very pleasant looking and airworthy plane, but some flaws in design and manufacture. An experienced builder would find this ARF a great project starting point. I have yet to fly the Discus 4 meter ship, since my field is too small. I think the airbrakes need work, operation and also in that the profile doesn't seem to have effectiveness on a ship this size and weight. They may not slow the ship much. I may incorporate mixing on the ailerons to provide flap or "crow" deflection of the ailerons to slow the ship for landing. This plane could be difficult to land, and landing fields are few and far between, and a modeller on the ground must usually land near himself, just to be able to see the plane well enough to maintain the ships attitude close to the ground, considering ground effect, and it's my opinion that the approach may have to be very, very long. [sm=thumbup.gif]
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Old 01-04-2006, 02:47 AM
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PA11
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Default RE: 157" Discus Glider

I just purchased one in late November 2005 at eBay Auction offered by "New York Grace Inc's eBay Store" / "Excel Hobby" - imported Chinese 4 meter (157") ARF Semi Scale Discus . . . The over all quality is acceptable and actually exceeded my expectations; the fiberglass fuselage is very good; the wings are true and strong. The overall quality is better than my expectations as I was a bit skeptical when I bid on it because several in our group here over the past several seasons have received some real Junk ARF's mfg in China of several similar ARF's from other sources. This plane is from the same product line offered through a dealer in the UK http://rchobby.co.uk/discus_4_0m.html . . . The plane has no Flaps, but the Air Brakes are 17mm high x 440mm long; they work OK, but are not perfectly smooth working so I will use the same JR Premium Digital Coreless Hi Torque Digital Mini DS3421's with 65 oz/in torque on them that I am also using for Ailerons, Rudd & Elevator.
OVERALL for the money, it most certainly has overall good worth and value (at least in my opinion and for my intended purpose).
MY major irritation, was that NO Assembly Drawings/Instructions arrived with the plane, nor any drawings showing the CG position, trimming information, or anything! I emailed them at once, and PROMTLY received a reply with a .pdf file attached that is adequite for any soaring enthusiast with at least intermediate experience with building and flying sailplanes; but, then 4 meter class sailplanes arn't really a beginners project anyway!
I am setting-up mine to be my first large Aerotow trainer and will "BELLY MOUNT" the Tow Release using the "neat" hi-quality Tow Release mechanism offered by "Z Mark Enterprise" http://mysite.verizon.net/vze2qbfc/ .
One could cut Flaps into the wing should you want to go to all that much trouble if you must have camber and reflex trimming; with the huge spoilers, however, Flaps arn't really a necessity for landings.
Wishing you all "GOOD LIFT" all-the-way-through-the "BANK!"
- John Bittle AMA 26317 "Minnesota RC Soaring Society" [email protected]
Old 01-04-2006, 09:16 AM
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Default RE: 157" Discus Glider

John Bittle

Could you post the PDF that you recieved? My kit had a small paper that said balance at 74mm back, but it was the same paper that came with my 103 inch e-sailplane by the same manufacturer.

The lower tow release looks like it works better than the nose releases that I've used, you seem to be able to get above the two plane easily. I had a ASK-21 by Robenmodel(SP?) with a nose release and it took full up to get above the towplane.

I think I'll use the little slit in the fuse way of doing tow release, but it will be down low. My Alpina has a nose release, it will be an interesting test to see how they compare.
Old 01-20-2006, 11:06 AM
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emerckx
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Default RE: 157" Discus Glider

Did you add a wheel? Or is that a shadow? If yes, which one? And what servos did you use? Anything you'd do different now in building? How is the tail servo attached? How are you holding the wings on?

Thanks, Edward
Old 01-20-2006, 11:19 AM
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emerckx
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Default RE: 157" Discus Glider

Anything you'd do different now in building? How is the tail servo attached? How are you holding the wings on?
Thanks, Edward
Old 01-20-2006, 09:44 PM
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emerckx
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Default RE: 157" Discus Glider

Got the PDF he sent today, it is the same as the plan in the box but in color and you can enlarge it. All those black line on the printed one are a little confusing, the color helps clear things up. I'd post it but they won't let me post a PDF here. Did everyone use the hardware that came with it? Or upgrade it?
Edward

Old 01-22-2006, 07:53 AM
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mludwin
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Default RE: 157" Discus Glider

I have one on the bench right now. For $200 dollars I don't feel so bad as it's my first attemp at a towable glider. If that copy of the PDF could be pasted on that would be great. It took me hours to figure things out with just that little piece of paper.

My copy had all of the same issue listed above, tail hinge, canopy, missing a few small parts. But once I figured things out the basic assembly including fixes took an afternoon. I am just at the point to start installing the radio gear and I agree with using the JR Premium Digital Coreless Hi Torque Digital Mini DS3421's

The idea of a pushrod for the tail sound good. Has anyone done this?

Marty
[email protected]
Old 01-22-2006, 09:03 PM
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mludwin
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Default RE: 157" Discus Glider

Edward, thanks for the PDF.

Hey gang, I bought mine a while ago, and I have additional instructions they are 2 pages and the name Houstan Model Manfacturing on it. I have scanned them. If you need them drop me note.
Old 01-22-2006, 10:12 PM
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emerckx
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Default RE: 157" Discus Glider

Marty's 2 pages were missing from my box, (bought Jan,2006, yuejin2002, ebay, shipping was very fast) and they really help explain some stuff, not enough for a beginner but better then the drawing I had.
Thanks, Edward
Old 01-23-2006, 07:55 AM
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mludwin
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Default RE: 157" Discus Glider

This has been a tough kit to find info on. I had mine in a box for over a year before I stated it last week. This is the first good thread I've found. Here's a link I did find in my travels

http://www.raidentech.com/4vedi4marfgi.html

They are selling the same kit as a 4 Meter Ventus Discus. There are some good pics to look at.
Old 01-23-2006, 09:40 AM
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Default RE: 157" Discus Glider

It's interesting that they make it and don't know it doesn't have flaps, and wood over foam is not state-of-the-art hollow-core molded wing.[&:]

The first to break a wing please post and let us know if there's glass under the venier.

What's the rubber suspension system for the wing rod?

I'm cleaning the workbench off now to start my kit.

Rich
Old 01-24-2006, 09:35 PM
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mludwin
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Default RE: 157" Discus Glider

Here is a pic of the spacer I made for the horz. I also had to taper it to get a square install to the vertical
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Old 01-28-2006, 02:29 PM
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Default RE: 157" Discus Glider

Did anyone get one that has a stab/elevator like this:

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Old 01-29-2006, 04:15 AM
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emerckx
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Default RE: 157" Discus Glider

Isn't that the tail from the 103" Wing Sailplane, Ventus? My Discus has a one piece stab wing, the whole thing moves.
Edward
Old 01-29-2006, 10:04 AM
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Default RE: 157" Discus Glider

Yea, it looks like the stab/elevator from my 103 incher, but it's in the ad for the 157 incher. I was just trying to find out if you could get it either way.

http://cgi.ebay.com/NIB-157-Wing-Sai...QQcmdZViewItem
Old 01-29-2006, 10:41 AM
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mludwin
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Default RE: 157" Discus Glider

I wonder if every kit has the same problem with the horz hinge being mounted too low. It did take long to make to make the spacer, in fact I still have some of the plywood I ripped left. Stop on by and I give it to ya

I'm about to start mounting the servos in the wings. How is the hardware on your kits? The hardwood blocks supplied with mine look like they were cut out with realy dull teeth. I am planning to make new out of stock I have laying around.

Ideas for wiring the wings? I'm thinking of using bulk cable and soldering to the servos so I could hide the leads inside the wing wiring channel.
Old 01-29-2006, 11:15 AM
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mludwin
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Default RE: 157" Discus Glider


ORIGINAL: mludwin

It did take long to make to make the spacer,
typo... it did not take long!!

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