Hello everyone,this is Karthick Ashwath with a long overdue post.

First of all, thank you to K K Iyer sir and Freeflight sir for giving so much input. (not to mention the kit) 
The actual build with mistakes and then corrections of alignment took me over 1 hour. But I spent about 45 minutes making the box jigs for the wings.

Now I would like to make a confession. I was not aware that Iyer sir and Freeflight sir were giving guidelines for different launch styles and flight profiles. I thought they were both talking about the same thing and implemented a mix of both in my model. For some reason it flies well.(I implemented stab tilt,but went for a 45 degree launch with no circling during launch). It would have been better if someone had mentioned this.

During the basic build and during subsequent trimming, I made the mistake of using fevi quik everywhere. Now that prevents me from changing decalage for trimming. I also put on my elevator tabs with fevi quik. Then I thought next time will use fevicol. And even that is hard to remove. Should use fevi stick for the tabs in the future as recommended by Freeflight sir.

After the basic build, the model was performing exceptionally badly. So I added some nose weight and did some outdoor hand launches. There I noticed that my launch technique was poor and the model had to correct for it aerodynamically. So I went for catapult launch to reduce the number of variables.

In my first catapult launch, I was holding onto it form the CG and not from the tail. So I damaged the leading edge of the elevator. Beginner mistake. Post that launch Iyer sir recommended that I put some up elevator.

The model started flying very well after that. The maximum test flight time that I achieved was 9 sec.

Here are links to the 1080P version of the videos uploaded by Iyer sir. (Iyer sir's version is so pixellated due to whatsapp file compression)
1.Slow motion video
2.9 second test flight:
I have also documented every step of the process on video. If there's anyone here who wants to see the build video do subscribe to my youtube channel. https://www.youtube.com/c/KarthickAshwath/Will upload it there.

Hi Karthick,

Good attempts. A few comments after seeing your good slow motion videos:* This applies to everyone trying to get the fine glide:

1) The building technique between Mr. Iyer and me are different. But the flying technique with a catapult has to be the same. If you are a right hander, your glider should climb to the right and glide to the left. This is the only way to start getting duration.

2) In your first video slow motion, at 15 seconds mark you clearly see that your glider is on its back. You do not want that. Just slight past the 90 degree mark. In your glider you have too much incidence. Reduce it. If you gave incidence by putting a tab, sand it down little each time so that when you launch it it just goes a little past the vertical, not much.

3) Your glider after transition always circles to the right and dives down. The way to counter that is to put a tab giving a small left rudder. If the tab is too much to the left, it will dive to the left. Then take little left rudder tab out, till you get a nice left glide.

4) Keep the same angle of launch and bank. In your first video you have a big launch angle and little bank. In your second video you have low launch angle and too much bank. Try and be consistent. That is one difficult part that needs practice.

Karthick, post a close up photo of the back of your glider as it is now . Then after your modification. Perhaps I can see something to recommend.

Hope you have the washin wedge on the left wing, that helps the transition also while it prevents spiral down in the glide.

Looking forward to see your next video.

Dear All,

There are many great YouTube videos on CLG flying. In the search you can type CLG Glider. Others have shown similar to my methods of trimming and launching. Today I found this great video where he trims and flies a glider that is probably the Lunchbox.

 Most important point: right climb, left glide upon transition to get duration. You can go right and right, but it will be inconsistent flights and if you get a thermal in launch, you may get a long flight. But then, can you do it again?

See S174 video #2 in reply # 161. nice glide and turns left. That is what you want. Also very second video from Hitesh, Reply #155,but he needs to have his glider go the left, not right.

As see in all the experts videos, must do a gentle horizontal rubber launch, slight down. I hope you all have done that and you see your glider go with a slight nose up, turn left and nice glide. let us see your videos of the harizontal launch. We can tell a lot by those videos.

Watch again my trim video on page 6. See the horizontal launch.

Then you are ready for the full launch on rubber.

Print this page and take it your flying field to remember right - left flight. Written by  expert Frank Zaic.

@Freeflight ,Given up tab and left rudder . Is that glide okay ? 

S174: very nice: hard throw straight, nose rises and turns left. Good.
Do a horizontal launch, no banking wings,  pulling the rubber about 2 inches. See if you get a similar flight. (may want to see my trim video again on page 6, I think)

If yes, go for the full launch. Start with a 70 degree launch angle and 45 degree bank. do it on a calm , no breeze evening. I am afraid that the glider may get caught in the trees. Can you find a more open space ?

 I am very hopeful for your glider,
Videos soon, I hope? Go for it.

S174: Can you post a close up photo of your trim tabs , back of the glider? Thanks

To all the seniors here who are guiding us here, I have a doubt. When I want to reduce the amount of up elevator that I have implemented in my glider, should I sand it down or should I reduce its area? And should I reduce area through chord reduction or span reduction?
By the way, my glider weighs 9-10 gm now.

Here are some photos of the glider:
https://iiitaphyd-my.sharepoint.com/:f:/g/personal/karthick_ashwath_students_iiit_ac_in/Er0lhxbNO_1Euempr6s9OZUBdboP7pTdUmZ6PGw6W8xwQQ?e=SCP4xq
In one of the photos, the elevator tab is double the width of that in other photos. I reduced its chord by half as it was doing loop the loops. Then realised that it was a Cg issue.
Here's the build video of my glider:

Complete chuck glider playlist:
https://www.youtube.com/playlist?list=PLcliCjJxS5BY6_1q2iCCbGhjDtKtRIsU6
@Freeflight: No sir, yet to implement washin. Will do it soon.

Karthick: you got the idea. A few suggestions. Keep the original design of spans, chord  . Mr. Oldenkemp, designer of this glider was an expert and many time winner. this is one of his famous glider that has been made around the world.

Thankyou for posting the pictures. You got the correct concept.  I understand now what you are experiencing.

First, your tab is too heavy. Can you instead use a matchstick? Secondly to remove loopiness, cut down the tab  length wise. Cut equal amount on both sides, little by little (as you cannot stick it correctly back again) until it no longer loops. See my photograph of my tab in the previous page, reply 151. The tab is about 4 playing cards thick and only a few mm in length. A light matchstick so thin, attached with glue pen lightly should not affect CG much.

Put the washin wedge for sure. In your case, put a left rudder tab. That should give you the gentle left turn. Based on your previous videos, once you reconfirm the glide and horizontal rubber launch, you too should be good to go.

Keep up the good work. You will get there soon.

Don't worry about the weight now. Your goal is to get it flying good.

PS : See the video I posted in reply # 177 .He talks abut how small the tabs are.

I am using a wooden coffee stirrer for a tab...it doesn't loop now after I added noseweight.

Coffee Stirrer. Yes I had mentioned it before, but that was to make the launch peg bigger, not tab.

Anyways, do not worry, keep it and redo the glide test, followed by horizontal launch and then full launch. Good luck.

Karthick: Just started watching your build video. Bravo, excellent job. So happy to see it. Thumbs up !

Will do in a few days sir..need to travel to flight testing location from build location.

My lunchbox.
Need to go to an open space to do test glides. Problem is open spaces near by are on a height not far from the sea so there is always a stiff breeze. Ideal for slope soaring.
Will have to get up early morning an see if things are calm then.
Weight 5.35 gms
Have attached nose hook after taking these pics.

@Freeflight , This is it . Throw was hard since I was in a hurry since it was 7:45 morning . Here last few days it was raining and it’s dark by 6 PM , so not able to shoot . And yes , when I launched it (by hand) stuck to tree and somehow I managed to find it ( very dark by 7PM) If I want to take videos , it should be in the morning , but too sleepy in the morning to get up from bed - and since I ‘ll have to sacrifice my precious evening hours then . Most of the large grounds have restricted entry -since school grounds and I am afraid what local people might think of me if I fly early in the morning - here I haven’t seen anyone else flying . That’s why I am waiting for a perfect time to test a full glide . Unlike US , our state is so overpopulated , and plain lands are not easy to find . But I’ll try to take a video of my CLG by this weekend .

  Iyer sir , that was quick !   Point noted .
@Karthink , excellent build video , I wish I had seen this before my build , too good , explains how and what should be taken care of .

It’s afternoon and my Lunchbox is ready for maiden.  Gave less dihedral than recommended in anticipation of better lift.  Turns slightly left on indoor launches which hardly noticeable.  Glides good (perhaps it is amongst the many lucky pcs that will require less trimming).  Will check outdoors.

Still tempted for indoor test flights Hard to resist , isn’t it ? , even after @Freeflight’s warnings

Yes very tempting - but the wing will surely get dents and dings.

Finally got down to hand launch test flights in a place with no gusting beeeze.
Good floating glide with good low sink rate- no hint of stall . No videos as it was getting pretty dark. Will get some asap.
Tendency to go right in but some chucks some goes left. Was it due to faulty chucks? tab on rudder and a spot of clay on left wing plus wash in.
Will try some horizontal catapult launch and see flight path.

Free flight - your comments will be appreciated
Anant

Thank you for your feedback Sunil sir.

Great amount of  catch up read for me today. Got busy today, so comments are late. Sorry.

S174: Ok I see your tab. that is a very big tab. Usually it is only 0.5 to 1 mm long, 2 mm wide and 1mm thick. Will repost a picture below. This time my rudder tab is colored black in the photo for contrast. That small tab is enough to hold in the launch and put it to start for a left glide. You should put it very close to the end of the rudder, not a bit away from it. If you stuck your rudder tab with a glue stick only, remove it and put one like mine. Then restart glide test, horizontal tests.
The reason  of my asking you to make this change is that if the rudder tab is too big like yours, it becomes very difficult to trim in catapult. Everyone : Moment to observe from S174: At very high speeds, a small deviation like the rudder tab, has a huge , very huge effect. At low speed (glide test) it may  have a deceptive small an effect. Hence all the tabs shown in the original plan call for 1/32" bend. Very very small.  The CLG IS THE  FORM OF FREE FLIGHT FLYING , WHERE YOU GO FROM ALMOST 70 MILES PER HOUR LAUNCH TO AROUND 5 miles per hour in  GLIDING SPEED. Be aware of that.  This rudder stab acts as an elevator in the launch, kind of holding the glider in a knife edge. We can discuss this later, but just take the recommendation. Same on your elevator tab. But I see you did it correct, diving, so put the up tab on stab on the right hand side. Congrats that is a correct move on your part.

Dreamline: Hopefully you have not taken out too much dihedral. Mr. John Olednkemp was a master of free flight who designed it. I am not sure (not an aero engineer) about less dihedral giving more lift, but dihedral gives stability, which we are after. So lets see what happens, specially if your dihedral is just a very little less.
Turns very slightly left in hand toss / glide test. Hopefully a lower power hand launch. Then , that is very good. Your glider looks good and happy to hear that it has wonderfully passed the glide test. Eager to see your video.

Mr. Glidiator: Great glider at 5.5 grams, sir.
"Tendency to go right in but some chucks some goes left. Was it due to faulty chucks? tab on rudder and a spot of clay on left wing plus wash in. Will try some horizontal catapult launch and see flight path"
 Yes it most probably in the chuck, I do it so many times. All: repeating: do not make adjustment based on a single glide or flight. Make sure it happens all the time before you make an adjustment.
Please put  a washin tab not  clay on the left wing to begin with. Eventually if your turn is too wide (because of less stab tilt), then a bit of clay on left wing will help make a more desirable smaller circle. Left circle better controlled by modifying rudder tab, just a little bit. Clay will diminish some of the washin tab effect, could spiral in. So, if I were you, no clay, just a washin  on the leftwing. Both my Lunchbox's had NO CLAY ON THE PORT WING. All in all, you are on the right track. Eagerly awaiting your video.

Wow: cannot wait to get up in the morning and see more of everyone's post, photos and videos.

Ciao.. talk soon.

Regards

PS: Remember the Mantra" right climb, left glide" for all of the right handed guys like me. Left handed, go opposite, and looks great flight too.

 

Rudder & Elevator tabs. Small! Also see photos in reply#151 , previous page.
If the tab is not quite effective as you want it, then go a little thicker versus longer. If it is too much effective, use nail file and sand it a small amount each flight.

After each adjustment, start again with the glide test, to assure nothing else has happened.

Please Note: I hope all of you will get beautiful flights. I do not wish you guys to just one or two good long flights, but a good long flight for always. Hence a little "sticky" in my comments, sorry.

Question for all to think about: Please let me know your answer / opinion / thoughts so we can discuss.
Q) What happens if your washin tab is too big? I bet the glider will fly good, but what would you expect in the glide phase of the flight?

Do not be shy, please answer, thanks.

Points noted. Will correct and test fly. Will get some videos.
A basic doubt - To achieve the 1/32 stab tilt effect using tabs - are the tabs on port side top or stbd side top?