get simple SIRON or OSWAL brand iron and a few smd tips for future . costs <150  rs nice to work with. for hot glue gun go for rcbazaar or Indian hobby shop eBay ones preferably a 40 Watt .

check main lead  for your crown .

Solder, flux, iron, hot gun, multimeter etc available at this site which seems quite professional and has reasonable prices. A 25w iron should be enough for your needs.
http://store.vervetechnologies.in/tools
Regards.

Thank you for your recommendations. Any idea on whether to use a different power pod configuration or not? 
The problem with my Crown is that it does become hot, really hot, but no glue comes out of it.

@prabal276
@K K Iyer
Sorry for taking so long. Since you say that 25W is enough, I guess I will use my 25W soldron.

Prabal, I have contacted the shop and they say that one sheet of 5mm depron which is 24" by 39" costs 150Rs. sounds really cheap to me. 4 of these should be enough for my build.They also have mountboard and foam board with tmem.

I have watched some videos on how to tab and solder solar cells and they look pretty easy to me. I will get a tabbing kit soon and I will solder the 4 cells together.

You could expect the test results by next month.

My dream is to create a solar flight which will fly for 24 hours. Now when I was thinking about how to fly throughout the night, I got this idea:
The solar plane will charge the batteries and gain as much altitude as it can during the day. at night, the throttle will be decreased to 30% so that it will consume just 3A. By alternating between gliding and flying, we can get through the night i.e. by cutting the throttle and gliding for 30 minutes then going back to 30% throttle to regain altitude and then doing this over and over again. If this works, we will be able to fly with a total battery capacity of just 17ah (5 NCR18650B batteries) (700g)This is the battery pack with the highest energy density as far as I know.

Maybe the plane won't be able to take off due to the extra weight. If it is so , we will have to do something to solve this problem.

These are just plans for the future.This will take some time to become true.

@K K Iyer
@prabal276

I have found a huge mistake in the calculations!

According to K K Iyer sir's motor selection guide, our plane will not fly! Here's why:

Given:
Weight of plane (AUW) = 1200gms = 42.3oz

Area of plane = (30x20)+(2x5x20)+(pi x 10x10) = 600 + 200 + 315 = 1115 sq. inch (rounded of the circle's area)
= 7.74 sq. ft.

The values correspond to the :
1.Main rectangle at the centre
2.2 Edge rectangles
3.2 Edge semicircles (1 circle)

As the diameter of the circle is 20" , the radius must be 10". There fore the breadth of the edge rectangle is 15-10 = 5"

So we have found the area. Let's calculate the wing loading.

Wing loading = Wing area / weight = 42.23/7.74 = 5.45 oz/sq.ft.

So the stall speed is:
4-5 times the square root of the wing loading = 5 x 2.33 = 11.6 mph = 19 kmph

So the cruise speed has to be :
2.5 - 3 times the stall speed = 3 x 11.6 = 35 mph
35 mph = 56 kmph

So we now know the minimum speed. It is 56 kmph.

Using data by Mortimer from RCGroups, we know that the DT750 motor spins 4080 times per minute at 50% throttle with an APC 12x3.8 prop as load. Therefore, the maximum speed produced by the DT750 at 50% throttle is:
3.8 x 2.54 x 4080 x 60 / 100000 =  23 kmph.
Pitch x 2.54(to convert to centimetres) x RPM @ 50% throttle x 60(to convert minutes to hours) / 100000 (to convert to kilometres)

At 100% throttle , the RPM is 6180, so the speed is 35kmph.

We are going to run the motor at 50% throttle in the solar plane as it fits under the current produced by the solar cells.

19 < 23 < 56
Stall speed < Actual speed < Cruise speed

Conclusion: The plane doesn't fly.

Are these calculations right? Will the plane fly? If my calculations are right , how did the plane fly when it was built by balsa or carbon on RCGroups?

The details I posted in the previous post are wrong as I didn't keep in mind a variable . Now in the corrected one, I have found that the solar plane can't fly for more than 13 hrs continously.

I have attached the plan of the wing of the old fogey.

Please do correct me if I am wrong.

@karthick ashwath,
Good that you have got into critical thinking instead of fanciful thinking.
Remember that there are several different issues:
1. Is the selected model flyable? Thousands of choices.
2. Will you be able fly itwithout prior experience? Choice narrows to a dozen or less.
3. Does it have enough flat area to accomodate the number of solar cells required to produce the reqd voltage and current? Choice reduced to 1, for smallest airplane with reqd area (unless you are prepared to build a Solar Impulse type with huge wings)
4. Don't get fixated on DT700/750. Look at alternatives like emax cf2822.

The first thing you need to do is to find out how much area of solar cells gives how many volts and amps.
You can do this before your other stuff arrives from Singapore in Dec!
Eagerly await results.
Regards

Thank you sir.
Are my calculations right? Will the plane fly? If not, then how did it work earlier?

I am looking at a few kits to solder the solar cells together. Will order one soon.Maybe I could try soldering it next sunday.

I feel that the DT750 is a very good motor. I have checked that motor, but its maximum thrust is just 22oz whereas the weight of our model 43oz. So it is not sufficient. Maybe I will also try looking at different motors. Hope to release the test results as soon as possible.

Feeing frustrated.Can't find a good motor. But this keeps puzzling me : the speed of the plane seems to be lesser than 40kmph but it still flew for balsa and carbon.
Please help me with the motor.

@karthick ashwath,
This thread already has 159 posts without a single step of progress.
And lots of discussion unrelated to the objective.

The first step for a solar flight is what size of cell produces how many volts and amps in actual tests.

Till then, in my opinion, discussion is just social talk!

@prabal276

I have some good news and some bad news.Let me start with the good one, move one to the neutral one, then the bad one.
Good news:
No need to buy depron in Mumbai! I found a seller of depron. I am not sure whether it is depron or some other foam, so I will post some pictures of it when I visit that shop on saturday. Thanks to your advice, I found a seller here!
Please confirm whether it is depron or not after my next post.

Neutral news:
Our school is a part of the Microsoft create to inspire programme. One of its topics is environment. My QC Project on Global Warming has already been nominated. My solar plane has also been nominated. You can learn more about the programme here: http://www.microsoft.com/en-in/mobile/about-us/people-and-planet-page/create-to-inspire/program/

Bad news:
I just visited the solar shop which I mentioned before to get the cells soldered together.(I took this step only because I was not able to find tabbing wire of a bit short length on ebay. The only one I found had a 200ft roll of it, which is way more than what I need. ) The person in the shop told me that they don't solder cells to make panels or anything, they just sell solar products. Even though it ended in vain, I was able to find people who make solar cells and people who make solar panels.

Seems like I should just use some single core wire instead of tabbing wire and worry about the tabbing wire later when I make the whole plane.

I have received all the equipment which I have bought. Tested them out. Works fine, except for the FPV. Before I go into the glitch/overlook, I will give you the list of equipment which I presently have.
All components:
Battery:
Turnigy 3S 2200mah 20C Li-Po pack x 2

ESC:
Hobbyking 60A 2s-4s ESc with 4A BEC

Receiver:
OrangeRx R61x DSm2 compatible 6 channel receiver

Transmitter:
OrangeRx T6 Mode 1 transmitter with 3 Position flap switch

Motor:
NTM 28-36 3000kv 2S-4S 366W brushless outrunner

Connectors:
Hobbyking XT60 connectors

Servos:
Hextronic HXT 900 9g 1.2kg torque servos x 3

Charger:
Turnigy Accucell 6 80w 2S-6S smart balance charger

Power supply:
12V 10A SMPS

FPV
Tx and Rx:
Skyzone FPV 5.8 ghz AV tx and Rx set

Camera:
Mini CMOS FPV Camera with 120deg. FOV (NTSC)

So, the problem is that I ordered a NTSC camera which doesn't work with PAL TVs used in India. What do I do?

Could I use an AV to USB converter and view it on my Laptop? Would that solve the problem?

Will post the solar cell test results in a few days.

Today I am going to solder the cells. Practiced soldering for the first time yesterday on the broken solar cell. What should I use as a load to test it?

Charge your batteries or run a 50w halogen bulb or run your motor.

@rcrcnitesh
Sorry for the delay. I soldered the cells yesterday. But I can't use what you mentioned as a load because the test setup of solar cells gives only 2.5V.

Some good news and a lot of bad news.
Good news:
Solar cells soldered and tested! Yes!

Solar cells' voltage is underrated. It gives more than that is expected.

I used four 1.2 ohm 5 watt resistors in parallel to have a current consumption of 20W.

V = I R

2 = 8 * x

x = 0.25

Four 1 ohm resistors in parallel = 0.25ohms.

I used the closest match as a load.


Neutral news:
Solar cell test results

Time Volts Amps Watts

7.00  2.14  0.42   0.89   Diffused sunlight readings
7.30  2.22  0.61   1.35
8.00  2.23  0.69   1.53
8.00  2.34  1.3     3.0    Direct sunlight readings
8.30  2.41  1.75    4.2

End of results

Bad news:

When I was measuring the current at 9.00, due to the wind, the solar cells were blown way. 3 out of four of the cells broke. I now own 1 good cell and the seller will send me a replacement cell for the one broken cell which I received.


Now I really do not know what to do.

Stats:
I soldered 4 of the cells together in series and checked the joints with a multimeter.

I soldered the four load resistors in parallel and checked the joints with a multimeter.

Results:
Though the sun was still rising, it gave more voltage than expected. Yay!

The solar cell didn't reach full power even at 9.00, when the solar cells crashed. I believe that this is because it was not under fully direct sunlight, which would take some time(the sun was still rising).


Question:

What am I to do now?

@karthick ashwath,
This is NOT a failure.
It is a STEP TOWARDS SUCCESS!
How many trials did Edison do before he got the light bulb to work?

What I understand from your test is that each cell can give 0.6v and nearly 2amps.
Is that correct?

So for 12-15 volts you need 20-25 cells in series.
And for 8amps, you need 4 such strips in parallel.
Or 80-100 cells.

What is the size of each cell?
How much did each cell cost?
What did you use for the tab wires?

Carry on. Do not give up!

OK sir.My parents too said a similar thing.
But I want to be more clear in presenting my findings.
1. I used monocrystalline 6x6 solar cells
2. I used multicore wire as the tabbing wire.
3. Actually, the cells would have produced even more volts and amps if they had survived till 12 o clock, when the sun is directly above the cells.
4.So, as of now, we do not know the actual capabilities of a single solar cell.

Anyways, it definitely is a step towards success as I gained experience in soldering. I also learnt from my mistakes.

Hoping to post the complete test results after the second testing soon.

Sir what can I do about the FPV setup? I have a NTSC camera but Indian PAL TV's don't support it. What can I do?

Would the problem be solved using an USB to AV converter and viewing it on my laptop? Or is there some other way?

I am in the process of acquiring new solar cells. Hope to post the test results in a month.

Hello everybody!

Some general info for everybody:
The website Vibrant hobbies no longer exists. It has been moved to rchyper.com. I will buy my DT750, heat shrink and bullet connectors there.

I will also purchase an USB to AV converter to try fixing my FPV setup.

I will also purchase the solar cells required.

I will do all these things on Friday if the propeller issue is solved.
The problem is that:

I need to use a 12x3.8 prop. But I have searched some Indian online RC stores but I can only find a 12x4.5 prop. What shall I do sir?

Won't it(12x4.5 on DT750) consume more current? Can anybody test a DT 750 running a 12x4.5 prop before I buy one? It will be really useful to me.

v2eagle, I was wrong! The maxeon cells are the most efficient. I will test those too.

All the best everybody for the 6^th RC India sweepstakes.

Hoping to hear form you soon.

at the risk of inviting a flurry of calculations and internet data .....

use the props.

if you are worried about current ... use less throttle.

Quote from: saikat on March 01, 2016, 08:19:14 PM
use the props.
if you are worried about current ... use less throttle.

The simplest valuable advice you could get.
Karthick, check out the person who posted this advice.
You'll be immensely benefitted!

Thank you sir for your response. Thank you @saikat sir.

I also had another idea. What if we strap bottles containing hydrogen to the plane? It would give us extra thrust and we will need to spend lesser current.(just asking )

The hydrogen can be produced from water through electrolysis.

I will go ahead with my plans.

@saikat sir, please check Reply no.169. Any solutions sir?

hydrogen and helium.
Both are bad.
Hydrogen- It is light and that's what makes it volatile. Can be use to create a mini Hindenburg disaster just by just using some static electricity.(the flames are not visible ) (actually, Hindenburg was also filled with the same gas but yours would be a small tank.)
Helium- @ Words: Hard to find;Expensive.