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157" Discus Glider

Old 01-29-2006, 11:49 AM
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Default RE: 157" Discus Glider

ORIGINAL: mludwin

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.
My kit had the stab hinge too low also - I fixed it the hard way by grinding down parts of the fuse, but the spacer solution would have been much easier.

In the wing I soldered servo cable on the servos and soldered to a 4 pin deans male connector hanging out the end of the wing.
In the fuse I epoxied a 4 pin deans female - there was plenty of thickness in the side of the fuse to hold it.

Bruce
Old 01-29-2006, 12:50 PM
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Default RE: 157" Discus Glider

I got mine this week and was impressed with the quality. Agreed with everything you guys have posted so far.
Will mount the release about 6" back from the nose unless I hear differently. Feel that it needs a wheel, but do not know about a retract. I'm new to scale gliders. Have a Orlice 137" still in the box and will start it soon also. Is there anyone below Orlando and east of Ft Meyers interested in sharing ideas and flying sites. I have a 1,000 acre sod farm with no way to take off except high grass and a farm lane.
Bill G Stuart, Fl
Old 01-29-2006, 01:38 PM
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Default RE: 157" Discus Glider

What instructions did you get? The two pages from mludwin/ Marty are helpful and I didn't get them a few weeks ago. And the color version PDF of the "plans" are better then the B&W paper one they sent me. I can send that or the seller sent it to me.
Edward
Old 01-29-2006, 03:42 PM
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Default RE: 157" Discus Glider

Here's a few pics of the servo mounts I just made. I plan on making the cover/keeper out of ply, then use the kit's exterior covers. I used a JR 331 micro servo on the speed brake and it's working fine.

Any comments before I glue them in place???

I want to do a wheel also, but not a retract. I'm up for ideas

I like the idea of a deans connector in the fuse, any pics?
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Old 01-29-2006, 05:44 PM
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Default RE: 157" Discus Glider

This is from my 103 incher, but is how I'm going to do the 4M.

The first show the rs-232 jack I used in the fuse. I use the jack as a locating pin also. The dimples clear the screwheads from the wing's jack.

The second pictue shows the male plug.

The servos I used are HS-125s, short straight pushrod run.

My homemade control horn, made from a 1/8 inch brass tube flattened on the end, then drilled with a .055 drill bit, it leans forward a bit to put the hole right at the hinge line.

I'll get rid of the clevus on the 4M, and do it like in the last picture.
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Old 01-29-2006, 05:51 PM
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Default RE: 157" Discus Glider


ORIGINAL: DrDiscus

Very Difficult to balance on the center of lift.
I've got the kit together so I can figure out radio/servo placement & rough-in the CG. I had to add 2lbs, 3oz to the nose for a rough CG. Does this seem right?
Old 01-29-2006, 06:01 PM
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Default RE: 157" Discus Glider

ORIGINAL: mludwin

I've got the kit together so I can figure out radio/servo placement & rough-in the CG. I had to add 2lbs, 3oz to the nose for a rough CG. Does this seem right?
I wouldn't worry about 2 pounds, my 4.2M ASK-21 was 13 pounds and floated, though with a thicker airfoil.
Old 01-29-2006, 06:11 PM
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Default RE: 157" Discus Glider

My first 4m, no idea of how heavy it will be. Nice idea for the connector, easy parts for me, dozens in the tool box at work.

I'm trying a push rod for the horz. Right now I have 48" gold n' rod set in place. The short one is the horz. It does work smooth, but will need to be extended out to the servo.
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Old 01-29-2006, 08:27 PM
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Default RE: 157" Discus Glider

here's a few shots of a rough receiver/servo layout. i'm thinking of placing the tow release so it's easily viewable through the square in the tray. that should place it about 6-7 inches back from the nose
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Old 01-29-2006, 09:11 PM
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Default RE: 157" Discus Glider

You need bigger batteries for those two hour, ten kilometer flights.

On my 103 incher I ripped out all the wooden parts and layed in a layer of CF, I haven't decided yet on this one.
Old 01-30-2006, 12:27 AM
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Default RE: 157" Discus Glider

I was initially interested in the 4m ship, but as I followed this and other postings I came to the conclusion that that was too much plane for me. Just before Christmas, I called Raidentech to get some info on the Ventus. It has been a few weeks, but if I remember correctly the Ventus ad on the Raidentech site shows what seems to be TWO wing spans available (to me anyway). Back to the phonecall. I called and asked the guy about the two wingspans, one was 2.5m and the other 3m. His response was " I can tell you that 2.5m is big." I asked if there was someone there that knew some info about the planes, his response, "yes, but they are all busy. It is Christmas you know." CLICK (the phone was hung up). Not to be turned off, I e-mailed Raidentech explaining my question and that I would like more info about the plane. I got a fast response from Raidentech. Unfortunately it was the same ad as on their site, but with one difference. IT WAS ALL IN FRICKIN" CHINESE! Not being one that lets go easily, I called again. I got the same guy and he remembered me calling before. I told him that I found the ad confusing and wanted to know.....blah, blah, blah. His response, "Yes, our Chinese ads are very confusing to English speaking people. The Ventus is on back order now. Call again and If we have them in stock I will open the box and tell you what the plane looks like and what it has (flaps or spoilers, 2.5m or 3m wing, etc, etc, etc.) If you want it wI will send it to you." This time I rolled over and played dead!!
Old 01-30-2006, 12:54 AM
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Default RE: 157" Discus Glider

In their picture the one is the 2.3M, the other the 4M. I have both, in real measurements it's 103 inch for the e power sailplane, and 157 inch for the pure sailplane.

Yes the Chinese don't answer emails, can't tell you if it has flaps or spoilers, but they probably could in Chinese, would you understand it then? The 4M would be a $400~500 plane if the instructions were in German. The closest German plane may be an Alpina, I have one of them too, it's now about $800. The plane is very prefabed, so do you really need instructions? My box has no instructions, but I don't see a problem building it. From my quick look in the box, 95% of the work is installing the radio, any points that are of concern should be covered here in the next week or so.

I can't say whether it would be too much plane for you, but from flying a few big planes in the past I think it will turn out to be a smooth flier, the only thing you have to learn is that the big ones really cover ground so landing them you need a little more room than you're used to needing.

Rich
Old 01-30-2006, 04:02 AM
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Default RE: 157" Discus Glider

I'm not real strong in sailplanes and I understand slope soarer's need the weight to cut though the wind. But if lighter isn't better, why put light servos in this ship?? What final weight should we be aiming for here? I guess I can see that it could be too light and just blow over, but at some point.... what is too heavy? If we are going to add wgt up to ~13 pounds I'll need to leave some space at the CG for it.

Re Push rods: Did you try to hold the outer case of the gold n' rod in place any where? Or just run it?

Thanks everyone for the pictures.

Re: Raidentech, I think most of us bought it off of eBay, seller yuejin2002, seems to be fair at English, but ships fast. Don't pay more than ~ $160-170, wait, he seems to have more to list.

I don't think ARF is quite true, it is close, but if you are not a builder, the plan is very limited. It is a nice body and wings, for the money.

What tow release are people thinking of using?

What is the correct name for the wheel we want??? I've been looking on the net but haven't seen anything close to a real sailplane wheel in it own little cowling. Maybe as a replacement part for a more high end sailplane?
Edward







Old 01-30-2006, 04:07 AM
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Default RE: 157" Discus Glider

Rich,
How much did your Ventus end up weighing? How does it fly?
Thanks, Edward
Old 01-30-2006, 08:36 AM
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Default RE: 157" Discus Glider

Edward, so far I have just done tomporary installs on the push rods. Once I'm done cutting holes and figuring things out I'll go back and epoxy the outer tubes in place. I see no problems here, the hatch in the tail leaves plenty of room the get in there to glue both the rudder and horz. tail rods. A brace up front will be needed for sure.

Tow release, I thinking of using a cable with the end soldered to stiffen

more info @ http://www.soaringissa.org/aerotowsheet2.htm

Old 01-30-2006, 08:42 AM
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Default RE: 157" Discus Glider


ORIGINAL: soarrich

You need bigger batteries for those two hour, ten kilometer flights.
...and a lawn chair and plenty of beer
Old 01-30-2006, 07:31 PM
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Default RE: 157" Discus Glider

Someone PMed me to ask about my 103 inch e-sailplane, now I can't find the PM, so here's the answers.

It weighs 5.0 pounds. I broke the supplied prop when it started on the workbench[:@] so I put one I had, 7x3 grupner(SP?), it was too small and hardly flew the plane, so I landed after about 50 foot flight, seamed to handle well though. Today I tried to fly it again, but the motor wasn't making any power. Now I have to figure out if it's the motor, ESC, or battery.

I start on the 157 incher tonight.
Old 01-31-2006, 04:17 AM
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Default RE: 157" Discus Glider

After I asked that I found a site with a German made Discus at 158 inches wing span that lists it as 9 pounds all done. So maybe 9 pounds is a good starting point?
Edward
Old 02-01-2006, 01:34 AM
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Default RE: 157" Discus Glider



My stab/rocker was supplied level and has clearance, but the front screw is too long, no big deal, but I hate messing with metric bolts, they're hard to replace.

I got a red/white plane, but it wasn't from seller yuejin2002, his seem to be all white ones. I like the red/white to see easier in the hi humidity here in NJ during the summer, all white can just fade away.[X(]

I don't know if I'm going to use the rubber wing mounts, I may turn some brass grommets down, never seen a airplane with a flexible wing mount, that makes it hard to use fixed aileron wiring jacks.

I don't think I'm going to use the spoilers, I'll just tape them closed and use spoilerons. I used spoilerons on my ASK-21 4.2M they worked fine.

I made a foam stand for the fuse, all the little hardware pieces are in the one picture.
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Old 02-01-2006, 01:51 AM
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Default RE: 157" Discus Glider

ORIGINAL: soarrich

Someone PMed me to ask about my 103 inch e-sailplane [snip]
Today I tried to fly it again, but the motor wasn't making any power. Now I have to figure out if it's the motor, ESC, or battery.
I toasted the motor when I landed it the other day. I put the motor on a switch so that I could use the throttle stick to activate the spoilerons, when I landed in the grass I shut the throttle stick to idle, then walked over to it, by the time I got to it I could smell that electical smell, then relized I had just rasied the spoilerons, not cut the power to the motor. I've replaced the motor, it pulls strong now, I hope to fly it tomorrow.

Rich
Old 02-01-2006, 08:05 AM
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Default RE: 157" Discus Glider

Ahh the smell of burnt electrics in the morning...never mind I won't go there. I hope the second motor, does the job! Good luck Rich.

I can see wht you mean about the flex in the mount and a fixed connector. I looked at that for a bit after seeing your pics and decided to go with long cables and 4 pin deans inside of the fuse. I stopped at LHS last night and have all the parts to hopefully wrap this kit over the next weekend. I still have to finalize a plan for a wheel, either solid blocks or modify a spring loaded wheel mount I have laying around.

What the consensus of using the hooks & rubber bands supplied with the kit for attaching the wings? They seem a little weak to me?
Old 02-04-2006, 12:11 AM
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Default RE: 157" Discus Glider


First corrections:

The 157 inch uses a 10 mm wing-rod, the 103 uses a 8 mm wing-rod.

The two planes use different airfoils, the 157 incher is thicker, looks like maybe a E-195 or Clark Y, I'll try to print out both and hold them against the wing root.
----------------------------------------------------------------------------------------------------------------------
I put the wing rod in today[:'(], it's a ***** to get in, you'll be keeping the wing-rod in the fuse.

I don't think you got to worry about the rubber bands holding the wings on, the wing-rod and wing-rod tube are a TIGHT fit.

I cut the front stab hold down bolt about 1/4 inch, now I find I'm going to have to cut the rear hold down bolt also. If the rear hold down bolt isn't cut it's going to interfere with the stab drive clevis. My fin seems to be overbuilt, or is that just strong, I don't know?

I decided to use the spoilers, then I found the left one was stuck, (big time), I was checking the right one for how it operates, and while pulling it open and closed I broke it. The inboard diagonal cut, there's two if I remember correctly, was cut to within 1/16 of an inch of the bottom edge of the blade, that's where it failed. I give myself 50% of the blame for it braking, the other 50% for it being made so poorly. It's no Multiplex spoiler, you get what you pay for! Back to plan A, Spoilerons.

I spent about and hour ironing down the covering on the wing and stab, I'm going to change the rudder to white, mine's red. The covering is really cheap stuff, I thought about recovering the whole wing, but let's see how it flies first. On that note, I test flew the 103 inch e-sailplane, it also has a flat wing, it seems to need dihedral, it was very windy during the test flight so I test again on a calmer day.

The wing skin appears to have fiberglass between it and the foam, it should be layed in at a 45* angle, but it isn't, it runs at 0, 90*.


Old 02-05-2006, 08:50 AM
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Default RE: 157" Discus Glider

Yes sir, the wing rod was a pain in the @$$. I ended up with a little greese on the rod to help it slide in.

Bummer about the airbrake Rich. I be working on my later today, maybe there's a way to savalge it.


Help!! Tow line release position. I've made a firm decision to bale on a wheel for now, I want to leave my options open in case a tow hook for hi-start has to go in. Hi-starts hooks I understand where to place after many kits, but a release for towing I'm not sure. I've searched all over and there seems to be to schools of thought. One group sezz in the nose, the other is underneath and back from the nose. From the videos I have seen, underneth and back seems better.

Help me out here, please [sm=drowning.gif]
Old 02-05-2006, 10:34 AM
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Default RE: 157" Discus Glider

ORIGINAL: mludwin

Bummer about the airbrake Rich. I be working on my later today, maybe there's a way to savalge it.
The build quality of the spoiler is about a 1 on a scale of 1 to 10, not worth saving. The good one would have taken a 100 in/oz servo to drive it, a Multiplex takes about 5 in/oz.

[quote]ORIGINAL: mludwin



Hi-starts hooks I understand where to place after many kits, but a release for towing I'm not sure.
You sure about that? On the big scale sailplanes you want to draw a line down 45* from the wing rod to the bottom of the fuse to position the towhook. If you place it right under the CG as the plane rotates the line of force will be at about the back of the wing. 45* worked great on my ASK-21.



I've made a firm decision to bale on a wheel for now
Why not use two armpit hooks at the wingroots? You can put them in the fuse or one in each wing, then use a bridle with two towhook rings. I've heard of some guys using one armpit hook, but I''ve never done it.



I want to leave my options open in case a tow hook for hi-start has to go in.

I hope you're saying hi start and meaning winch, It would take a garden hose to histart this.






I've searched all over and there seems to be to schools of thought. One group sezz in the nose, the other is underneath and back from the nose. From the videos I have seen, underneth and back seems better.

Help me out here, please [sm=drowning.gif]
Don't panic, they will both work. I'm going to use the slightly back under the nose method, because I had the release right in the nose on my ASK-21 and found that it was very hard, (read full up), to get above the tow plane. With the pull point slightly lower I think it will be easier to raise the nose and climb.


Rich
Old 02-05-2006, 10:57 AM
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Default RE: 157" Discus Glider

Thanks for feedback Rich,

Are you sure it's even a 1? I'm going through the motion of hooking them up, but my gut does tell me they will fail at some point.

And yes the hi-start would be a winch, but I do have plenty of hose the garden to be at our new house is a few 100' away.


Underneth it will be and behind the nose it will be! If you look at the pic I posted earlier the front bulkhead is 5 3/4" back on my kit. (the ruler is off in the pic do to camera angle) If the hole is drilled behind the bulkhead that will put the tow release at 6' back +/- a 1/4"

I'm wiring up the wings right now. When I'm done with I'll post some pics.

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