Thanks Subbu!

Quote from: AEROVISHWA on June 09, 2012, 12:14:15 AM
u said u would need a 15degree  blade  angle... but looking from  the pic i suppose that every   bladeis in straight line  with the center....!!(pic)

also since the angle with the center is zero it will possibly blowout air from all  sides...!
OR AM I MISSING SOME THING

please post  from where are u are referring the  design or is it ur own..!

i am referring the same design and yes aerovishwa the part you missed was that

1- the blades thickness is only 2mm and the breadth is 1.5cm (length being 50 cm) and
2 - also that 15 degrees is not the blade angle but the angle subtended between two successive blades.

these dimension were rescaled from the orginal to fit the 1m wingspan and due to such thin blades contouring the holder to give the airfoil like shape to the blade itself with the balsa would make it break due to very small breadth and make the holder very weak too.

to counteract this the three main blade holders have been offset by about 2-3 degrees from each other thereby gradually bending the blade throughout the wing and creating a blade like structure. kindly refer to the pictures being attached.

i had another alternative to make the exact shaped blades that is using the metallic film used in the measuring tape since it already had the contour.

for any other clarifications please ask since it also helps me scrutinise the integrity of the model at every point thanks

Subbu

Quotealso that 15 degrees is not the blade angle but the angle subtended between two successive blades.

just check this again...!! having all the blades in one  direction(all axis meeting at same place) i have a big doubt on  that...!! of setting will  be not  be of much use  if u wanna to push the air  in one direction... it  will just blow off from all sides

what i suppose  to mean

ooh sorry now i get what you wanted to tell me about

that is one area i had not thought of yet i will definately have to count that one into the design i will design some new blade holders after calculating the exact midline bank angle of the blade from the diameter line tomorrow morning itself.

but i would still love to experiment with the above ideas i had mentioned earlier of the blade holder offset since i did refer to these aircraft photographs too on their website and the second photograph shows no blade angle but has a slightly curved surface kindly refer to the attached photographs.

another interesting thing i noted while i was departing from mangalore airport was that they had an air curtain device which had the exact crossflow fans inside it which i am looking for if anyone has any information on them please mention it here

thanks a lot aerovishwa for pointing it out

Subbu

EDIT - the first photograph shows no blade angle
           the second photograph shows the offset technique

the air curtain exactly....!!!


just drop  by your local super market or any mall...u have that on the entrance ..... just check that out for the blade or  even some thing  like this in someones house...!

http://www.symphonylimited.com/products/DiET-50E.html

the first pic  also has some offset...in  the center  a close look  please...!

yes i see it when i look at the center the blade does have a slight angle to it. tomorrow (i mean today since its already 1 am) i shall be dedicating the whole day to the project and hopefully will get the fan with the new blade angle offset holder ready. and try out the gearing system.

i would still do the original design also and compare them together to see which one performed better. hope to get a lot done today (later after i wake up).

thanks a lot aerovishwa (i would love to know your name so that i could refer to you easier)

Subbu

Edit - i shall also see if i can get my hand on one of those air curtains

alright, i see a lot of eyebrow raised on fan wing. things about fan wing, it is a not a new concept, shelved due to weight penalties (Olden times engines were heavy and had poor thrust to weight ratio), modern laminates and engine tech is reviving fanwing agan for its very obvious advantage of very less Lift Induced drag and therefore small efficient engine and less cost of operation, to understand fan wing you need to understand the Circulation theory of lift. read this and the subsequent post to understand Circulation theory of lift

http://www.rcindia.org/rc-general-topics/basic-aerodynamics-for-rc-flying/msg105113/#msg105113


and this

http://www.rcindia.org/rc-general-topics/basic-aerodynamics-for-rc-flying/msg105115/#msg105115

thank you for the informative post on the circulation theory of lift gusty bhaiya

as for the progress i am posting some of yesterdays progress pictures i cut out all the 24 blades and 4 extra ones.(which i forgot to post)

waiting on sushil uncle's advice on epoxy coating the blade holders to give it additional strength

i have started with the gearing part on the motors side and started with the mounts photos to follow on this soon.

i have attached the pictures of the blades with blade holders the rubberband on blades makes me feel like i am building a kit  

Subbu

Edit : Vishvesh i am thinking of getting the angled blade holders CNC cut in light ply as shall be done for the final prototype as cutting it from balsa takes a lot of time if i cannot get the cnc cut out cheap then i shall cut it out in a few days after testing this prototype

Got a beautiful gift from Subbu / Pickle. Thanks also to Sandeep (If I am not mistaken). Got a bit of my long lost childhood back.

whenever you do maiden the aircraft please take a video of it, this thread would be incomplete without it 


Subbu

hey subbu...! nice update..

just make  a drawing for the blade holders, scan it or directly do it in PC..and send it to  pradeep (PVA models)....  he can get u that laser cut in balsa  ply.... will work out great...

PS: pradeep, please  do that for him....

thanks a lot vishvesh for the contact i will surely contact him, i was only wondering where i could get that done from.

as for the update i got the main spur gear and the motor with the pinion assembled in a mount. testing them out right now

here are a few pictures


Subbu

one question stands is....! how are u  going to  mount that on a  plane....?

u said  u are going for a profile fuse...?? u need to have a entire  built up for this...!

again send the  plan(of fuse) to pradeep.. he will get it laser cut..!

vishvesh that is true. but before i went in for a full fuse model i decided to test it as below

the crossflow fan section i have built until now is only half (50cm) of the complete 1m wingspan of the aircraft. i am planning to split the present section in two then use my above gearing section to have it connected at the centre to drive the two 25cm crossflowfans. then i shall finish the fans by adding the airfoil curve behind the fan and undercovering of the fan. then i plan to mount it on my 1.9m glider (picture attached) and onto that mount this setup as a semi biplane wing and then see the performance of the fanwing design with glider power OFF and fanwing motor ON and all other combinations. if the design works i shall get the lift i need and then shall move on to the full fuse.

as of now the gearing system works beautifully here are some pictures attached video being uploaded to youtube right now


Subbu

Quote from: Pikle6 on June 14, 2012, 11:02:23 PM
then i plan to mount it on my 1.9m glider (picture attached) and onto that mount this setup as a semi biplane wing and then see the performance of the fanwing design with glider power OFF and fanwing motor ON and all other combinations.

this is what i am worried  about....!
ISKE TOPI USKE SAR....!

just design a new fuse and get it done....! also u need to  consider the position of the tail( elevator) u cant have it in the glider.... it should be lifted..remember....

i dont want to put your tail in the wing wash... ( its gonna be a hell lotta turbulent...!)

oops i forgot about the downwash the tail would have to be elevated you are right i will have to design a full fuse i shall get with designing the drawings right away for the cnc. thanks for the reminder  

l have no experience in built up fuses as far as i know you have bulkheads and balsa strips to get the basic skeleton and then you have to cover or sheet the plane is that right ?

17 more minutes for the video to upload


Subbu

this one is going to be a long one

i am posting a build log,....! just planning away to  compress the photos u can have alook on how it is done there....!

u have formers and sides...! no strips( atleast in  simple ones...)  PVA models can do that for u..!

thanks vishvesh which build log are you referring to?

Edit : Found it will keep an eye out for the sonic

i will speak with pradeep from PVA models tomorrow morning.


Subbu

i am planning to finish my quad build (not configuration) tomorrow after that have to finish up the tilt mechanism for V22 osprey

check i have posted...!

looks like u have lots of things in  hand...!!

one  suggestion.... do one thing at a time... else u will  end up in  confusion..! like u forgot about the tail in this case..!

i really do have a lot of things at hand since i am leaving for college at manipal in exactly a month, i wanted to conquer as much as i could  

your suggestion has been duly noted

the video has been uploaded here it is


the audio quality is very bad i am not sure why

Subbu

what battery  are  u  using 2s or 3s.... u  need low RPM here...! ( else  there will  be a huge vibrations..!)

i am using a 3S this is just a mock up as mentioned i shall have it cnc cut and also shall order some ballbearings for the perfect fit of gears and blade holders

ball bearing will be good.... just goto your  local SKF  store.. u will get whatever size bearing u want..!

also try and use 2s...!

as of now i dont have any 2S battery but will order one tomorrow from an LHS or HK.

SKF???


Subbu

SKF is an  indian  bearing company... known for  precision bearings and quality..... they have outlets allover india..!  I replace my motor/engine  bearings got from  them...!