Quote from: martian2121 on October 21, 2009, 09:56:54 PM
Dear Pankaj, Gr8 work............. but looks like u have really complicated a very simple build model! The bee is not a model basically designed for durability...... except the original Clancy's balsa bee. Urs looks ready for battle. Gr8 effort but seems way too heavy!

Quite right on the overdoing part.... First timer for foam and I was kind of skeptical on its durability - even holding the foam firmly puts a dent. So tried to give extra protection. As per the weight- the AUW should be in the region of 1050-1250gm and with a out-runner capable of delivering 500W, I think it will take off... I am worried about the landing   

Anyways, still some weeks off before I maiden - primarily because, I had left out the battery and ESC while ordering the rest of the parts from HC. I wanted to try out the A123 batteries, but till the end I could not locate an ESC (with guide) that would take in these batteries. Hence settled for Lipo. So the order would probably reach in couple of weeks time.

Till then, would be finishing the model - work remaining is on finishing the wing with flaperon and wing tips. Then giving the model the final sanding and applying WBPU for gloss...

So while I am waiting for the parcel to be delivered - which contains ESC,Prop and Lipo, I decided to try my hand in painting the model (not that I am good with brush anyway).

First part of the deal was to get hold of WBPU. I had read this is available easily, but it turns out that the local paint/harware shops had not heard of it. All PU they had was thinner based. I went the Home Town stores and did locate a water based Polyurethane called Varthane (seems to be a US brand). 1ltr was being sold at Rs.2700/- so I gave up the idea. Then I tried calling the Pedilite industries - the folks who make fevicol and acrelic paints. It turns out that they do have a WBPU - in fact two versions, interior and exterior. The product range is called SHOWCASE AQUA. It is a milky liquid and quite colorless when applied.

I bought the interior version for less than Rs.400 for a lt.

The first attempts to apply WBPU for finishing, did not go too well. I noticed that the liquid was entering pores of thermocol which meant that a) there would be more consumption and b) the finish would not be smooth.

So I tried another route.

I got hold of thin tissue paper for covering the balsa frames (the one that was used as a material to apply dope) from India Hobby center in Delhi. The intent was to cover the model with tissue and then apply WBPU. Since there was no frame hence the entire paper was getting wet and also since this paper expands when wet, I was having trouble covering large portion. So I came up with a plan......

I cut the tissue into series of 8 inch by 5 inch pcs and then applied a coat of WBPU after slight dilution with water. Then placed the tissue and ironed out the wrinkles from the surface - to the max extent possible. The next tissue was placed with a slight overlap of about 2-3 mm and followed the same process. After the entire surface was covered, 2 coats of diluted wbpu was applied and left to dry.
The finished surface looks like this..... (the second is a close up)

Next part was to apply paint.

First  attempt was made with universal stainer mixed with WBPU. I was thinking that maybe both are water based, so the result might be acceptable - turns out I was wrong. Next I got hold of acrylic colors and applied the same with suitable masks and sufficient dilution

The result after the first couple of coats is this.

This is the bottom of the fuse, with color applied except on the battery bay. Notice how tight the paper appears along with the few wrinkles..

The wings looks like this....

And finally the finished model looks like this......

GOD, Where is the parcel from HC.... 

That looks awesome   

Thanks Anwar!!! Words of encouragement from more experienced folks always help...

As they say it - Fundoo Pankaj. Do share the link for the plan etc for RC toddlers like me.
when did you placed HC/HK order ? did you chose EMS or Air parcel ? packages getting held at customs for little less than month is not uncommon.

May be you can still fine tune CG etc in the meanwhile 

-Ujjwal

Superb!!..

Must fly better than how it looks.. Enjoy.

Hi Pankaj,

Nice build there , I just wanted to know How many man hours did you invest in building that plane, and also as Ujjwal requested can you please share the link for the plan? I would also be interested in building it, of course once I get the license that I have been waiting to get for flying in bangalore.

Quote from: vinay on November 10, 2009, 09:20:42 AM
Hi Pankaj,

Nice build there , I just wanted to know How many man hours did you invest in building that plane, and also as Ujjwal requested can you please share the link for the plan? I would also be interested in building it, of course once I get the license that I have been waiting to get for flying in bangalore.

Vinay,

Actually I did not count the hours..... there were a lot of them, specially trying to figure out the wing join. I started around end of August and then there was one month where I could not attend to this as I was on tour. My usual time was an hour or two almost every day.

The plan itself was downloaded from rcgroups - the original plan belongs to Scott. I have forgotten the exact location of the plan, but the build log is here http://www.rcgroups.com/forums/showthread.php?t=245311

The plan (which I downloaded from rcgroups ) in pdf form is 1.25mb which I am not able to attach (Anwar !!!! Help ). It called for 6mm depron and since I had 10mm compressed thermocol and 2.5mm biofoam, made some alterations - like increasing the size by about 30% and adding aileron ( hope it flies though). But go ahead and build and do let us all know how things go.....

Pankaj

Quote from: PankajC on November 10, 2009, 10:25:23 AM
The plan (which I downloaded from rcgroups ) in pdf form is 1.25mb which I am not able to attach (Anwar !!!! Help ).

Just paste the link to the original PDF, where ever it is.  It does not make any difference to your browser where you download the PDF from, and saves us from being in the shadow of plagiarism 

Anwar,
Like I said, I kind of lost out on the link where the plan was downloaded. Hence was trying to upload a the file itself. BTW, I did mention the original owner and the post where it was downloaded from just to be safe.

Pankaj

Gosh!! That thread by Scot is two parts of 32 pages each and i have already doenloaded around 30 Zip/PDF/images!! It would be great that people post a consolidated Zip file containing all the files and a Doc form building guide... I know this is much of an ask. Even in SW industry, we barely maintain any decent doc of product containing over a million lines of code!

I would try go thru the entire post and create consolidated package.

-Uj

Would prefer it to be hosted on a free file hosting service, and then we can put a link here, along with proper source/copyright attribution as suggested by Pankaj.

Folks some help/ideas required.

BTW, the battery and the rest of the package finally arrived and was trying to fix everything when I got confused on where the balance point should be - 25% of the chord from the LE or 33%? If the bird get slightly tail heavy, then as I see it I have the following options
1) move the battery forward
2) move the wing back
3) redo the tail and try to make it lighter
4) increase the cord
5) add weight to nose.

Which of the options should one chose and why?

Pankaj

Move the battery forward if possible  Why  the easiest thing to do provided you have space . If that is not enough or possible , I would add  nose weight like the lead you get at Wheel balancing guys  . Normally these two should work for  cases up to  around 45% from LE  .
You should be OK with CG any where between 30 - 35 % from LE.

Thanks Sai,
One question I was actually trying was why the weight addition instead of moving the wing back? Adjustment in the wing position does not add weight to the model. Is there a problem in doing so?

Pankaj

From the looks of your models it looks like wing  movement might  not be that easy OR might spoil the aesthetics if that is  a possible option then it is preferred to weight addition

Quote from: PankajC on October 07, 2009, 04:43:44 PM

Anyway, finally ordered Lipo from HC. Was wanting to know about A123 cells and how to program the ESC for these, but for the lack of knowledge ordered Lipos instead. Have also ordered TowerPro ESC after seing the pictures of them on Subbu's space shuttle log.

So the order looks like this
  2 x 3AH batteries
  2 x 40A Esc - one extra just in case!!!!
  11x7 props
  50W charger
  charge bag
  4 mm bullet connectors - and some more bits and pcs.....

So another long wait for the materials to arrive - I don;t think they have dispatched it yet.

Pankaj

Quote from: PankajC on November 12, 2009, 08:07:19 PM
Folks some help/ideas required.

BTW, the battery and the rest of the package finally arrived.

Pankaj

Hello Mr. Pankaj,

Slightly off topic, looks like it has taken literally 35 days for you to get your package? Just Asking because its been 21 days and Iam still waiting for my package(Air Parcel) from HC. Were all the items available when you checked out or were there any back orders? I was wondering if I should check at the local post office or wait for another week?

~Vinay

Vinay,

In general I have noticed that after the Hongkong post's site says that the material has landed in India, it takes about 25-30 days to land up at my door. This time, the package was possibly opened by the custom authority as the packing was ripped open and the entire parcel was tied by rope. Luckily, all components were intact.

Pankaj

Thanks Mr.Pankaj, That clears my major doubt.

Hello Mr Pankaj, Exprianced Builders,

Prior to getting my radio stuff, I had some time to go through the theory. Iam writing this based on my readings and not based on my experiance(as its 0 ), All the stuff that I have written below may be totally wrong.

1)As I measured from one of the photos posted here by you. I measured using the scale on my monitor and noted that the right wing is a tad smaller than the left wing? Is this on purpose or PROBABLY due to some inclinaiton occured during taking the photograph. Just a second thought, is it there to counteract the torque or something?

2)From what I measured the ratio of length to breadth is 6.42:1, And based on what you have mentioned on the first page, 46". Based on that Iam calculating the chord length to be approximately 7.1 Inches
 and the area to be 44 X 7 = 308 sq inches. = Approximately 20 Dm. 44" wing span and not 46" because of the curve at the wing ends.
 
3)Considering Approximately a wingloading of 35 to 40 Grams per Dm and since its a trainer let's consider it to be 40 Grams/dm = 40 X 20 = 800 Grams AUW.
And at 35Grams/Dm, lets consider it to be 700 AUW. Considering the AUW from 700 Grams to 800 Grams, It would be equivalent to 1.54 to 1.76 Pounds.

4)Consiering the trainer charecterisitics that it should fly slowly and steadily, the power per pound should be approximately 80Watts that should be around 123 to 140 watts for the above weights. Let it be at 160 watts maximum for now so as to prolong the battery life and keep it light so a small battery would suffice. Since its a trainer we need more thrust than speed. So a lower KV High torque Motor should do fine.

From what I see from your order from HC

 2 x 3AH batteries (Assuming 3S 1P) = http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9265 = 260Grams.
 
 1 x 40A Esc = http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=2165&Product_Name=TURNIGY_Plush_40amp_Speed_Controller = 33 Grams
 
 Considering you ordered this motor = http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=7076&Product_Name=TGY_AerodriveXp_SK_Series_35-30_1400Kv_/_470w = 100 Grams Including Prop
 
 4 X 17 Grams Servos = 70 Grams + A reciever 10 Grams So AUW of electronics = 260 + 33 + 100 + 70 + 10 + 27(Misc) = 500 Grams.
   
 Prop 11 X 7. I cant really comment there since Iam unsure of the Motor KV/Model you might have ordered.
 
 That means this allows the AUW of the model Alone to be around 200 to 300 Grams to Fly considerable well and fly at slow speeds.
 
 Unable to calculate flight time due to lack of KV/Motor info.
 
6)I was wondering If the following gear would do:
 
 1 X 1.3 AH = http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9272 = 115 Grams Battery. = 1.3 X 20C = 26 A peak Discharge current. So its safe for the motor we are using below.
 
 1 X 30 A ESC = 25 Grams
 
 1 X http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=2111 = 65 Grams with Prop
 
 3 X 9 Grams HXT Servos = 27 Grams
 
 Prop Size for the above motor
 9x4.7 10.7V 12.2A 8574rpm 730g
 10x3.8 10.4V 16.0A 6717rpm 850g
 
 Since the above thrust is almost equal to the weight of plane calculated above(very good thrust) we need not even go to full throttle to avoid buring the motor or better use a smaller prop.
 
 Now considering the AUW of the electronics I mentioned = 115 + 25 + 65 + 27 + 10 + 18Grams(Miscellaneous, small since smaller elctronics) = 260 Grams.
 
 That means this allows the AUW of the model Alone to be around 440 to 540 Grams to Fly considerable well and fly at slow speeds.
 
 Flight time calculation at half throttle = 70 Watts = 11.1V X 1.3 A = 15 Wh approx. 15/70 = 0.214 * 60 Mins = 12 .8 Mins. Let's consider it to be 11 Mins.
 


Guys all the above calculaitons is based on the Theory I have read and including the electrical losses what so ever. I have NO PRACTICAL EXPERIANCE WHAT SO EVER

Everybody Please COMMENT!!!
Comments are very useful for beginners like myself

Ashta Sir, Expecting your comments also, As you are still the only one I have met in person who has built so many planes from Scratch.

 

Now my question is, whats the AUW of the model Alone that you built Pankaj sir? Only you can tell us that.

Pankaj sir, looks like you forgot to blur out your phone number ON the parcel Pic