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-   -   Flying the SIG Riser (http://www.rcuniverse.com/forum/rc-gliders-sailplanes-slope-soaring-112/10633160-flying-sig-riser.html)

sylvie369 07-22-2011 04:44 AM

Flying the SIG Riser
 
Okay, I've been learning on my little 48" Fling sailplane (see my other thread), but this morning felt ready to try flying the 2M SIGRiser I built over about 6 weeks back in the spring. I balanced her out last night, needing about a ton of nose weight to bring the balance point to where it is on the plans. There were a few other things I was nervous about, as this was my first-ever build, but it all went spectacularly well.

I took her down to a large park with hills surrounding several baseball diamonds, early when there was still no wind. I threw it down the hill twice to check the trim and make sure I had some control, and that went well, except that I'm going to need to trim the rudder a bit. But it was close, and flyable, so I set up the standard High Start, hooked her on, pulled back, and threw her into the air. I needed some right rudder to go straight, but she pulled into the air nicely, dropped the tow hook, and settled into a beautiful, picture-perfect flat glide. I turned her so she crossed over nicely in front of me, and was able to fly a couple of nice flat circles in front of me before coming in for a smooth landing. The thing actually flies, and quite nicely.

I flew it probably 40 times, getting used to the launches and the turns, and I couldn't be more pleased. I finally had to stop when I heard some thunder, and the raindrops were starting to come down by the time I got everything packed into the car, but it was a gorgeous morning of flying. I can't believe how well this all went.

The Riser is, not surprisingly, far more smooth and stable than the little Fling. It doesn't turn as quickly, but the difference isn't as big as I'd expected. I could get her turned around pretty quickly. Because it weighs so much more, it seemed like it was easier to bring it in for a smooth landing - I tend to stall the Fling pretty often, but the Riser came in for a nice shallow descent into the grass every time. She also doesn't zoom into the air off the High Start like the Fling does - i just about had a heart attack the first time, seeing how slowly it climbed (but 40 launches later, that was seeming very normal).

I'll be curious to see how well I handle the Fling the next time Ifly it.

I'm pretty proud of myself right now - I built one "from sticks", and it actually flies.

flexsphincter 07-22-2011 04:53 AM

RE: Flying the SIG Riser
 
now go for the sig riser 100, u will love it.

tlar 07-22-2011 07:00 AM

RE: Flying the SIG Riser
 
Isn't that a great feeling. Seeing your "stick built do its thing" You can be proud.

After a couple of more flights you can work on her trim and start taking a little weight out . See the many threads on trimming (here and RCgroups)so you can get the sailplane to thermal really well.


sylvie369 07-22-2011 07:35 AM

RE: Flying the SIG Riser
 
Oh, now that never occurred to me. Do you mean that I could set a little down elevator on the trim (or by adjusting the linkages), and remove some of the nose weight?

Probably the biggest issue I've had with this plane was getting enough control throw, especially on the elevators. It turned out that I had enough when I flew, though it really looks like hardly any movement. I was very surprised - and relieved - at how well it flew and how controllable it was when I sent her aloft this morning. I guess that's a reason for joining a club - I could have gotten some expert advice, and seen the adjustments on someone else's plane. Instead I just relied on what I could find in the directions and online, and had to just hope that'd work. It did, fortunately. Anyway, I'm not sure Ihave enough throw to allow me to remove any significant amount of weight, but I'm open to suggestion/advice.

I can't wait to take her out and try thermalling. Today I just flew over a grass field, before the sun was up, so there was no real chance of catching any lift. Earlier in the week I flew the Fling in the middle of the day over a reasonably nice thermalling area, and did get some lift. I'm told that the Riser will do better, and I can't wait to see it.

I'm extremely pleased with this hobby right now. I really knew next to nothing about what I was getting into when I opened that Riser kit and started building, and I put a LOTof time and effort into it. I was relatively pleased with how my plane looks when I finished, but I had no idea until today whether or not it would fly. To be honest, it was a thrill just seeing it straighten out and fly level when I threw it down the hill. Iwasn't sure I'd even be able to get that much to work.

I feel like I've tackled the learning to fly part of this pretty intelligently, starting with just some tosses down the hill with a small ARF (the Fling), moving up to flying that off the High Start, keeping her upwind and practicing turns and landings before moving up to the Riser. I really don't want to say it after having the Riser out just once, but it seems significantly easier to fly than the Fling, because of the much higher wing loading.

tlar 07-22-2011 09:48 AM

RE: Flying the SIG Riser
 
Which weigh more your battery or the added weight? If its the added weight try putting some of thet next to the bulkhead and the battery behind that then re balance. You might lose a couple of ounces this way due to the fulcrum feffect. The farther the weight is from a fulcum the heavier it acts think of a see saw with a light kid and a heavy kid put the light kid farther from the fulcrum and he will offset the heavy kids weight .

Probably the best author to read on soaring , cg and trim is Aejars. He knows his stuff.

By the way It will work out best to get the plane to fly level with neutral control trim. Then you can use Aejars tricks to make it fly perfect! Re commended CG is a safe starting point best soaring cg is much different. The closer you get to the best position the squirially the plane will "feel" Ideally you will be flying just above stall speed so trurning becomes an issue.


tlar 07-22-2011 10:02 AM

RE: Flying the SIG Riser
 
found this on the "other group" worth a read.


<font color="#22229c">http://www.rcgroups.com/forums/showp...53&amp;postcount=2</font>

tlar 07-22-2011 10:03 AM

RE: Flying the SIG Riser
 
oops that doesnt wotk...sorry

tlar 07-22-2011 10:10 AM

RE: Flying the SIG Riser
 
1 Attachment(s)
Maybe this is a better way. My apologies

sylvie369 07-22-2011 12:43 PM

RE: Flying the SIG Riser
 

Quote:

ORIGINAL: tlar

Which weigh more your battery or the added weight? If its the added weight try putting some of thet next to the bulkhead and the battery behind that then re balance. You might lose a couple of ounces this way due to the fulcrum feffect. The farther the weight is from a fulcum the heavier it acts think of a see saw with a light kid and a heavy kid put the light kid farther from the fulcrum and he will offset the heavy kids weight .
That occurred to me over lunch. I'll take 'em out and weigh them and see if that will help matters.

Quote:

ORIGINAL: tlar

Probably the best author to read on soaring , cg and trim is Aejars. He knows his stuff.

By the way It will work out best to get the plane to fly level with neutral control trim. Then you can use Aejars tricks to make it fly perfect! Re commended CG is a safe starting point best soaring cg is much different. The closer you get to the best position the squirially the plane will "feel" Ideally you will be flying just above stall speed so trurning becomes an issue.

I may be too much of a newbie to try flying like that, but I'll read it over and see what might work. I've read some of what Aejars wrote, mostly about using the High Start, and it's definitely good stuff. He's an excellent writer/explainer.

Thanks for the help and links.


skylark-flier 07-23-2011 05:04 AM

RE: Flying the SIG Riser
 
Outstanding!!!!!! See? Told you that you'd have no problems with the Riser - isn't she a great bird?

I'm with Flex, start thinking 100" now. If you like the Riser over the Fling, you're gonna be amazed at how "stately" a 100" bird flies.

My heartiest congrats man, most definitely!!!!

Dave

sylvie369 07-23-2011 06:32 AM

RE: Flying the SIG Riser
 
1 Attachment(s)
Well, it's a little early for me to think about my next build, don't you think?I'm going to try to get some time under my belt with the Riser, and maybe what I learn from that will help me decide on what to work on next. But yeah, I definitely see myself building another one from a kit - or maybe even just plans - over the winter. Do people fly these things in the winter?I can imagine finishing one off and then not being able to wait until spring to fly it.

Of course if I seriously damage the Fling in my learning attempts, I'm sure I'll have an order in to SIG or Tower Hobbies the next day. I live in a fairly small apartment, and it's already full of electronics gear and high power rockets (I design and fly rocketry telemetry equipment), so I can't get too gung-ho with sailplanes.

Thanks for the congrats, and to everyone, thanks for the advice. It's nice to have a community and some experts to go to. You've already been very helpful.


tlar 07-23-2011 08:18 AM

RE: Flying the SIG Riser
 
Yes there are thermals in the winter. All the sun has to do is warm a parking lot, roof top or something darker than the surrounding (I assume snow).
Being smaller the Fling would be great for a quick run to an atheletic field for a mid afternoon flight.

sylvie369 07-23-2011 08:48 AM

RE: Flying the SIG Riser
 

Quote:

ORIGINAL: tlar

Yes there are thermals in the winter. All the sun has to do is warm a parking lot, roof top or something darker than the surrounding (I assume snow).
Being smaller the Fling would be great for a quick run to an atheletic field for a mid afternoon flight.
Thanks. That's great news, since winter here is 8 months long.

It is nice to have that little Fling to throw into the car for some quick flying, though the Riser wasn't as much of an ordeal as I'd thought it would be. When I started loading the car yesterday I was planning to drive about 45 minutes to a very large field, but I checked the weather one last time and saw the storms coming in, and I'd have just about gotten to the field when they hit. Fortunately, there's a smaller field just a 1/2 mile from here that turned out to be plenty large enough for some practice flying, so I went there and got a good hour and a half of flying in. I would like to use more of the High Start string next time and get some more altitude off the launch - hopefully later this week.

Monday I'm going up to the EAAAirVenture in Oshkosh, so no flying of my own, but I'm sure to get even more aviation fever. A buddy of mine married into the "inner circle" (as it were) of the EAA, so I'll be up there with an expert insider. Looking forward to it - if you've never been to Oshkosh for this, you should try hard to make a trip in. It's aviation paradise.


uliner 07-23-2011 09:09 AM

RE: Flying the SIG Riser
 
If you live in bayview, there are places along the lake that you can slope soar from and the fling would work for that. I have done it by the old powerplant before they built the condos. down by the gun club was good too. Lake brezes are often enough.

google slope soar milwukee.

sylvie369 07-26-2011 09:45 AM

RE: Flying the SIG Riser
 
I took the Riser out again this morning, to a bigger field this time, and flew it about 25 more times, finally stopping when a landing on a hard area knocked the tow hook out of position (it'll take about two minutes to fix - no problem).

I rebalanced and trimmed her this morning. Among other things, I did weigh the battery and the extra nose weight I'd added, as tlar suggested (thanks), and was able to switch their positions and take out a fair amount of that weight - maybe about 1/4 of the weight I'd added. It balanced fine like that. It did fly more squirrely than before, and I'd say both ways were interesting. I think I got some feel for the value of ballast.

While I was flying, the wind shifted from the north over to the east. Now, I know that launching into the wind is a good thing. I learned that launching into the sun is a very bad thing. I guess that's part of the learning curve. I completely lost sight of the plane as she pulled up and released, and it took me several seconds to get her back, at which point I had some frantic correcting to do. That was the launch that resulted in a landing on a hard area, a gravel runway next to the grass/prairie plants where I was flying, as I recovered at a place where the choice was the runway or a pond. I'll definitely be more careful to pay attention to my launch direction vis-a-vis the sun from now on.

Regardless, it was another fun morning of flying. I see I was dreaming a bit whenI hoped to pick up some thermals. I think I flew through some, but was so busy just keeping control and keeping her in the area that I didn't really have time to try to use the thermals.

On the way out of the park I stopped over by some guys flying powered R/C planes at an area designated for that. I'd thought the area was too small for me to use with the High Start, but it was larger than I'd thought, and they were very encouraging about coming out to fly there with them. Next time I'll try it. They had a much better landing area, though the field is oriented east-and-west in a way that would make it very hard to fly if the wind were from the north (south might be okay, though). One of them had a nice electric-powered sailplane, a 2Mjob.
==================
Re. slope soaring along the lakefront, I'll try it sometime, but I want to be much better at flying before I do that.I sure don't want to have to climb down the bluffs to recover my plane.

tlar 07-26-2011 10:31 AM

RE: Flying the SIG Riser
 
flying w3ith other guys is more fun than alone make some new friends.
Unfortunately I fly alone since the nearest flying club is 70 miles round trip versus six for me

flexsphincter 07-29-2011 06:29 AM

RE: Flying the SIG Riser
 
Also sylvie as mentioned in your first post,, "tons of nose weight" to balance.,,,i have drilled out the nose of my balsa nose cones from the front to get the weight i needed farther forward,,,as was mentioned in the article the fulcrum effect.  the lighter the plane if balanced proberly flies better and should be able to fly/glide with no control other than to turn when wanted.  and if wind comes up you employ ballast,,,ballast is your friend on those windy days,
instead of your plane after launch "standing still" in air from the wind/breeze it will "penetrate".

davevh 08-16-2011 08:36 AM

RE: Flying the SIG Riser
 
Sig airplanes are just fantastic to build and fly!
I had a Riser 100" way back (around 1992) when I was learning to fly. It was equipped with an Enya .15 engine on the nose and had an aluminum landing gear initially. This was a great way to learn powered flight (before moving on to a 4 channel Super stick). It allowed practice of many touch and goes, and if you happened into a thermal could power back to idle and soar with the birds. A while after that I converted it to a pure glider and it had many happy flight until I eventually sold it (not voluntarily, I moved countries).

I plan on buying and building another kit in the future, mounting a brushless outrunner on the nose and putting a landing gear on. It is pure relaxation, and inspiring doing touch and goes all day!

David

BMatthews 08-16-2011 05:54 PM

RE: Flying the SIG Riser
 
One way to set your balance point is to use dive testing to test for the amount of pitch stability you have. The idea is to squeek the balance point (BP) back a little at a time then re-trim the elevator for a nice glide (or low throttle level flight for power models).

To do a dive test you set the model trim for a nice glide or low power level flight for a power model. Then push the elevator forward to dive at about 30 degrees. Hold it for a half to full second to let the speed build then release the stick.

The model will either;
A- Recover by lifting the nose to a stall
B- Continue in a straight line
C- Try to dive to an even steeper angle.

"A" is a stable situation and most models will react this way. "B" will occur when the model is neutrally stable. This happens when the BP is located at the design's Neutral Point. "C" will occur if you're flying with the BP behind the design's Neutral Point.

Now the closer you can get to the neutrally stable "B" situation but still be stable the more efficiently the model will fly. The idea is to try moving your BP back about a 1/4 inch then fly it again. Re-trim the elevator with a bit of down trim to go with the new BP in the first part of the flight to achieve that nice slow glide then do a dive test. What you want to work towards is from a 30 degree dive with good speed the model takes about 100 feet to recover just back to level from where you let go of the elevator stick. For a two meter model such as the Riser, Gentle Lady and other similar designs this represents a good point.

Along the way you may find that your elevator becomes a little more sensitive during normal flying than you like. If so just move the clevis on the pushrod out to the next hole on the control horn to reduce the elevator travel. Another oddity you may run into is that as you work towards this "performance balance" that the elevator may end up with a lot of down trim compared to the stabilizer. Don't worry about this unless you end up with the final elevator angle being 10 or more degrees different from the stabilizer. At that point you may want to consider doing some sort of modification to the model to reduce the angular difference between the wing and staibilizer to reduce the angle. If you do this the "droopy" elevator can come back up somewhat to get back to flying nicely in trim.


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