Quote from: Ajay Sarwan on August 06, 2018, 09:12:53 PM
If i may, what about using cling wrap? It sticks well to most of the surfaces and is also thin & light weight.

Worth trying, especially on glidiator's type of models.
What to stick it with? Rubber solution?
Wish I had 3M 77 spray adhesive. Too expensive.

Yes lamination sheet comes in various thickness.
I have a roll that is about 8 microns thick. Have used it on my indoor capacitor powered model. Worked pretty well as I was not aiming to keep weight down. A youngster from Nagpur whom I have been mentoring on indoor free flight used the lamination painstakingly peeled off from the brown paper one uses to cover school books as he did not have access to mylar.
Have tried cling wrap. The problem with it is it tends to stretch as it has a lot of elasticity. So after fixing to wing if you apply pressure on some portion of the surface it will stretch and create a sag at that area. That thin grocery bag is the easiest to procure and suits the requirement. Even the die had indoor flyers on hippocket recommend this when mylar etc is not available and one is not in serious competition.
There is another firm - Sprayway India who have a aerosol spray glue SPRAY66 which is an all purpose spray glue and half the price of 3M. They have been concentrating on B2B business for the textile industry. I got a couple of can two years ago and still using it. Will ascertain retail availability now from their Bengaluru India office.

Pic of Spray 66

Spray 66 uses LPG as propellent so it will not create holes in the ozone layer as will other aerosols!!

To everyone working on indoor rubber freeflight, or thinking about it, I can assure you that this may be the most cerebral and challenging forms of aeromodelling. It requires great understanding of flight principles, skill, dedication and oodles of patience. Most of the "masters" of this esoteric form of flight are at the top of their academic and professional careers. I've been fortunate to attend some of the world class sessions including the World Championships at West Baden Indiana in 2018. I also coach the local middle school and high school kids here for the Science Olympiad rubber power freeflight contest. Will post some pics and videos if others are interested.

Hi ask
Great to hear from a fellow indoor FF enthusiast. Have been advocating this aspect of AEROMODELLING for almost half a decade now especially in our Aeromodelers Association of India group. This finally resulted in a first ever Indoor National event in May 2017. Was more an awareness campaign as I was the only serious contestant— so it was basically a lot of demos and talks on techniques, rubber usage techniques, torque meters, etc, etc.
Link of my demo at this event

I have been following the Indoor championships happening in your side of the globe and also the happenings in the Science Olympiad scene. Have been advocating that we should start something on similar lines here in India.
Lot of discussions on SO aspects on the Hippocketaeronautics forum.
I had even made a thrust bearing  suitable for SO weight rubber models using a the opening ring from an soda can.
Can see the discussions on this at this link
http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=20755.0P

Check out some of my rubber powered flight videos on the Foldnation channel on YouTube.

Trying to get about a half a dozen serious indoor free flight enthusiasts so we can have a meaningful indoor event.
The mission to get indoor AEROMODELLING into the consciousness of the Aeromodellers  here continues.
Anant

Hi all,
On the topic of indoor free flight - those interested would be thrilled to know that the worlds largest geodesic dome in terms of height and diameter- that is absolute nirvana for any indoor enthusiast has been recently inaugurated at the Maharashtra Institute of Technology at Pune. Much much larger than the West Baden dome where the last FAI F1 D event was held.
A fellow Aeromodeller in Pune is pursuing the use of this venue for an indoor event.
Let's see where this goes.


Anant

@glidiator,
Larger than Navy hangar sites?

KK,
Navy hangers also have good height but have girdersrunning across where you can get your model stuck.
A geodesic dome has no obstructions.So the model can actually hit the roof and nothing will happen.
Anant

Military fighter aircraft are pretty small compared to commercial planes which gave tail fins that reach considerable height off the ground. Their hangars are therefore much larger and have more height than navy or airforce aircraft hangars. Now the airforce has large transport aircraft but I don't know if they have hangars for them.

Hi guys,
Back to doing some construction after a bit of a haitus.
Construction of a house (my sons) blanks out time for most other things.
But today very determinedly got back to basics. Pulled out the Bobbi pouch and got down to building it.
The Bobni of our younger days did not have the luxury of the TAN Super Sport rubber. That was a major limitation in its performance.
Now with that rubber available  and a much better understanding of trimming rubber models would like to see how it flies.
Also plan to make a Bobni with cambered ribs and compare flight performances. With a cambered wing it seems like a scaled down version of the Hangar Rat,
Build pics being reduced in file size to post
Anant

@glidiator,
Full speed ahead please!

Hi guys,
Back to doing some construction after a bit of a haitus.
Construction of a house (my sons) blanks out time for most other things.
But today very determinedly got back to basics. Pulled out the Bobbi pouch and got down to building it.
The Bobni of our younger days did not have the luxury of the TAN Super Sport rubber. That was a major limitation in its performance.
Now with that rubber available  and a much better understanding of trimming rubber models would like to see how it flies.
Also plan to make a Bobni with cambered ribs and compare flight performances. With a cambered wing it seems like a scaled down version of the Hangar Rat,

Quote from: K K Iyer on January 27, 2019, 09:15:43 PM
@glidiator,
Full speed ahead please!

Aim to consciously make time to do some regular construction and flying.

Hi all
Bobni completed.
What should have been done in one hour took 3 days.😔😔.
Growing old and slow??
Some modifications-  used thin grocery bag plastic instead of tissue. Tissue tends to warp the wing especially in the high humidity we have in Goa during monsoon. I aim to keep this model for some time to come so warps have to be catered for.
Drawing room Test flights showed very poor glide ability. And model could not keep in the air well. Suspect wing loading is too much. Larger wing area for the AUW of the model would definitely give better lift performance. Or if much thinner cross section of  balsa sticks is used for frame work should improve performance . But then this is a novice beginners model so needs to be sturdy enough to withstand rough handling.
Adding card elevators improved glide considerably. Model tends to turn left — effect of prop torque??
Used 1/8 " TAN rubber and this seems to provide the right thrust/torque.
Don't forget the plastic prop may not be balanced and the washers between the prop and hub are a bit rusted after all these years in storage. Was akin to resurrecting and old Vespa scooter.
Can still make it give decent duration using the indoor rubber trimming bag of tricks.
Build pics and flight video soon after reducing file size.

Is there a facility to reduce pic file size on this forum as is there in the Hippocketaeronautics forum.??

Sir,
I think a Bobni could be made with flying surfaces from a depron dinner plate...
I know it can be flown with common rubberbands tied together.
Then what's reqd is a fuselage, a prop and a a prop mount..

Let me see if I can make suitable props and prop mounts.
Then we can consider having a Bobni build off!

Regards

Yes Bobni with foam plate wings is feasible.
Fuselage could be two skewer sticks glued together. Would also then get some flat surface area for glueing wings. For Glueing foam one cannot use super glue. May be better to glue  a thin strip of balsa to underside of wing joint that inturn can be super glued to fuselage.
Prop blades from plastic cup— toothpicks for prop spars.
Prop hanger can be made from coke / beer can aluminium sheet.
Must make a prototype.
Regular rubber bands can be used — will take less turns so duration will be limited.

Hi all ff rubber enthusiasts,

Some pics of the Bobni build and model

Grocery bag thin plastic used in place of tissue.

Card elevators seems to have sorted out the glide performance.

Test flight in drawing room encouraging.

Flight in larger indoor space soon

Anant

Some more pics

Card elevators

Anant

Need to add card / balsa wing tips.

These I don't recollect were in the original plan

Anant

Quote from: K K Iyer on February 02, 2019, 09:42:53 PM
Sir,
I think a Bobni could be made with flying surfaces from a depron dinner plate...
I know it can be flown with common rubberbands tied together.
Then what's reqd is a fuselage, a prop and a a prop mount..

Let me see if I can make suitable props and prop mounts.
Then we can consider having a Bobni build off!

Regards

ni and


Talking of the foam bobni. Prop bearing can be made from coke / beer can opening ring.
See this video.


Will post some more pics of it.
Anant

What was that magic?
More details please.

That KK was a nose bearing made from the ring that one sees on a coke/ beer can for opening.
Snip off just the ring - cut circle in half —. Flatten cut tips— curl carefully around a very thin drill bit — and that gives a very light nose bearing through which prop shaft can be threaded. A small glass bead acts as friction reduction washer. Found that this was lighter than the nose bearing made of aircraft aluminium that is being sold online by an experienced US Indoor Aeromodeller.
Moreover the can ring is not just a flat sheet but a cylinder so the strength is much more for taking the rubber tension
This one I managed to make a split rear end so the prop shaft can be removed for changing props.
Have pics of its construction- will reduce file size and post.
When I posted this on the Hippocketaeronautics forum the indoor guys are quite amazed as no one had thought of this use of a can ring.
INDIAN jugad mindset has its uses!!
Anant

Also since it is a semicircle one can adjust the down thrust angle required for the prop as many indoor models require a few degrees of down thrust to trim well.