RC India

RC Models => Kites, Trains, Free Flight and All Others => Topic started by: K K Iyer on July 20, 2018, 08:03:06 PM



Title: 1st Rubber Power model
Post by: K K Iyer on July 20, 2018, 08:03:06 PM
Hi everyone,
In these days of FPV quads, many members may never have seen a ‘Chuck’ glider.
Or a rubber powered model.
For ‘Chuck Gliders’ I’ve already started a thread.
Time for a new thread on ‘Rubber Power’
The problem with rubber power is lack of rubber and lack of props.
With the help of veterans, we’ll try to tackle that

I request Saikat sir and Glidiator sir to post a few pics, so that members get an idea of what we are talking about!

I’ll start with pics of my Pilatus Porter and Druine Turbulent

Welcome to Free Flight Rubber. I think Glidiator is ready to start you off with a Bobni!

Regards


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 20, 2018, 10:02:48 PM
Yes KK. Is a good idea to have seperate threads for different categories. This is the age of super specialisations. One can delve very deep into each category and still be actually only scratching the surface.
It is not for nothing that the old greying guys say you need to have your basics in order to scale greater heights. If any Aeromodeller thinks a chuck glider or rubber power is kid stuff, he doesn't know his basics for sure.
In this rubber thread I can give inputs on indoor free flight as that is what I have been doing over the past five years or so when I stumbled onto ultra light rubber powered Aeromodelling.
Will give links on where to get essential tools, rubber, mylar etc.
Will scan and upload the Bobni plan. One can make  prop for this from balsa/ plastic as the nose hub and prop for this are not available I think.
Will get down to making a build log of the Bobni.
Will endeavour to generate interest in indoor free flight rubber Power.
Incidentally if all goes well we will have the Second Indoor Nationals organised by the AMAI sometime end of this year. Will be very satisfying to see large participation and keen competition.
Will post pics and links.
Link of a short flight demo of rubber power I gave at the First Indoor Nationals held in May 2017 at Sonepat Haryana.

https://youtu.be/wo-FXkZw-8g

Anant


Title: Re: 1st Rubber Power model
Post by: K K Iyer on July 20, 2018, 10:24:16 PM
Awesome video from Glidiator!
Sir, please tell us about the site. And the event.
Also a few pics of your models...

Got a personal response from Saikat sir too. Requested him for a few of his old pics...


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 20, 2018, 11:20:20 PM
I think I can claim with all humility that The first indoor nationals came to be held due to my constant plugging for  indoor free flight on the AMAI discussion group. Yes the guys in charge of AMAI had the vision to see it's potential in fostering Aeromodelling as a hobby.
The venue was most suitable. It was the indoor facility of the Little Angels School at Sonepat. I was amazed that a school in a small corner had such a venue. in addition to superb facilities for other sports too.
The indoor space was actually 3 badminton courts and the stage retracted into the wall. Huge space. Height was also decent about 30 ft to the lowest obstructions.
It was mid May and scorching outside but the hall was fully AC. But the blowers had to be switched off when I was giving demos of ultra light models. Monsoons or winter is the best time for indoor events as the ambient temperature will be comfortable without AC as blowers cannot be on when flying ultra light indoor stuff.
The school management did excellent coordination and logistics.
This first indoor event was more an awareness campaign than a real competition. Had several workshops and competitions on indoor models for schools. Demos of rubber power, and even indoor RC though the RC stuff was actually outdoor models that were small and slow enough for indoor.
Have a lot of pics of several models I have made. Will have to reduce file size to attach. Will do so. Lot of other stuff to share and will do so as we go along.


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 21, 2018, 09:28:20 PM
Links for resources required for pursuing indoor rubber seriously.

Rubber

https://www.faimodelsupply.com/?s=Rubber

http://www.fly-m.com/mobile%20rubber%20motor%20stock.html

Balsa stripper - different prices and different shipping rates.

https://m.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m4084.l1313.TR2.TRC0.A0.H0.Xmaster+airscrew.TRS0&_nkw=master+airscrew+balsa+stripper

Mylar/rubber/ other Free Flight requirements

https://www.freeflightsupplies.co.uk/index.php


Propellers / nose hubs/ prop shafts etc
http://www.fly-m.com/mobile%20rubber%20motor%20stock.htmlGood for beginners till you are motivated to make your own props and nose hubs

http://ikara.eu

There may be an initial investment in these essentials.
Nothing compared to RC stuff.
Balsa requirement in most indoor rubber power is ridiculously low. Just thin strips. Fuselage is thickest dimension.



Title: Re: 1st Rubber Power model
Post by: Glidiator on July 21, 2018, 09:29:40 PM
All this is also applicable to outdoor free flight / rubber.


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 21, 2018, 10:21:18 PM
Plan for the Double Whammy.
A model that is not too fragile. Has good gliding characteristics -- not difficult to trim.
Can use Ikara readymade prop or other ready made prop also. Scratch building prop is also not difficult.
Was a Indoor Science Olympiad model several years ago. So if school students can make it --should be possible by anyone.


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 22, 2018, 08:37:16 AM
Instead of mylar for wing and stab covering one can use the thinnest grocery bag -- less than 10 micron which though banned in many places is still used. It will add some colour to the model also.
Pic attached shows grocery bag adding color


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 23, 2018, 04:37:50 PM
With respect to sakaits observation that you will need more than tan rubber to get good flights.
An article by a seasoned indoor rubber power Aeromodeller concluded by saying there are
 3 most important things when building indoor models
        1) Build it light
         2) Avoid adding weight
          3) Don't make it heavy
Not the exact phrases but the crux is weight, weight and weight.
Also better to have model turn out a bit nose heavy than tail heavy. Nose weight can be removed but tail heavy requires addition of weight to nose Increasing AUW.


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 23, 2018, 04:46:10 PM
In my post regards essential tools and jigs I forgot to add a very important piece of equipment if one is serious about rubber power --- A Torque Meter.
It is not a complicated machine.
Can be made with some scraps of wood, plastic tubing and guitar wire..
Will post plan and pics


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 26, 2018, 09:04:37 PM
Here is some nostalgia-- the first rubber power model for many in the days gone by
The Bobni. Pic of the kit I retrieved form the deep recesses of my Aeromodelling cupboard.
Pic shows the box, the plan, instructions, tissue, balsa bundles for wing, stan, fin, prop and nose hub, undercarriage, two fillets for wing dihedral support.
Will assemble this asap. Plan to use my acquired experience in indoor ultralights and make a modified Bobni with much lower AUW. Will use an Ikara prop and nose ring. Let's see how that works out performance wise


Title: Re: 1st Rubber Power model
Post by: K K Iyer on July 26, 2018, 09:57:43 PM
@glidiator,
Seems different from what I remember.
Must be a later version. Any idea which year?

What I’m certain of (about the 1960s kit)
1. There was no taper in the wing tips. The wings were rectangular.
2. No carboard box. Only a polythene pouch

I’m not sure, but I think it had a rectangular fin, not a triangular one, and the span was 12” not 13”.
Perhaps Rishi could clarify...

And other old timers may search their memory...


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 26, 2018, 10:20:28 PM
Yes KK. This is a later version. Can't remember the date. Got it approx 15 years ago if my memory serves me right.
Yes the earlier version came in a plastic pouch.
The balsa sticks were also not cut to size-- just a bunch of 8" or so sticks that had to be cut according to plan.
Fin If I remember was triangular.


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 27, 2018, 06:33:27 PM
@KK
Found another BOBNI plan. Shows wings without taper.
This seems to be from an older kit (plastic pouch??)


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 27, 2018, 06:35:22 PM
@KK
Found another BOBNI plan. Shows wings without taper.
This seems to be from an older kit (plastic pouch??)


Title: Re: 1st Rubber Power model
Post by: prabal276 on July 27, 2018, 08:09:04 PM
There was a India's Hobby Center Rubber powered kit.
That was the first ever aircraft I had.
I remember it had a truss style wing and tail construction and the wing was essentially a rectangle with some dihedral. It used to fly for approximately 20-30 seconds.
Does anyone Remember this plane?
IHC Kolkata had many of these hanging on their walls.
It would be so great and nostalgic to build it again.....


Title: Re: 1st Rubber Power model
Post by: prabal276 on July 27, 2018, 08:12:49 PM
Meanwhile,
Why are there no other people posting here other than Iyer Sir and Anant sir?
These are so much better and rewarding!


Title: Re: 1st Rubber Power model
Post by: K K Iyer on July 27, 2018, 09:08:05 PM
Possible reasons:
1. No one is interested. Maybe considered low tech, and meant for kids
2. Never seen a chuck, catapult, tip launch glider, or a rubber powered model
3. Never seen one of those actually flying, so no idea of performance potential
4. Difficultly in sourcing small amounts of balsa, near impossibility of getting rubber or props

We have tried to generate interest in entry level aeromodelling, but found
1. No response to Glidiator
2. Over 5000 views, but not a single attempt at my 1 min /30 sec challenge

Note that sanjayrai55’s efforts in coro, saw more interest abroad than here

For the last 1-2 years, I tried offering cash prizes.
Glidiator doubled them.
Still no response?

Any suggestions?
Regards


Title: Re: 1st Rubber Power model
Post by: saikat on July 27, 2018, 09:35:10 PM
@taksh must not be getting a suitable translation for 'rubber power'



... Just kidding ... !


Title: Re: 1st Rubber Power model
Post by: K K Iyer on July 27, 2018, 09:54:47 PM
Saikat?
Who is this?

An Old Master
A sample here
http://www.rcindia.org/kites-trains-free-flight-and-all-others/free-flight-rubber/msg95125/#msg95125


Title: Re: 1st Rubber Power model
Post by: prabal276 on July 27, 2018, 09:56:54 PM
There was a India's Hobby Center Rubber powered kit.
That was the first ever aircraft I had.
I remember it had a truss style wing and tail construction and the wing was essentially a rectangle with some dihedral. It used to fly for approximately 20-30 seconds.
Does anyone Remember this plane?
IHC Kolkata had many of these hanging on their walls.
It would be so great and nostalgic to build it again.....
Iyer Sir, Anant sir and Saikat sir;
Do you have any idea of this particular model?


Title: Re: 1st Rubber Power model
Post by: K K Iyer on July 27, 2018, 10:02:49 PM
Yes Prabal,
See this
http://www.rcindia.org/kites-trains-free-flight-and-all-others/help-with-original-plans-of-bobni/msg113388/#msg113388


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 27, 2018, 11:22:22 PM
Possible reasons:
1. No one is interested. Maybe considered low tech, and meant for kids
2. Never seen a chuck, catapult, tip launch glider, or a rubber powered model
3. Never seen one of those actually flying, so no idea of performance potential
4. Difficultly in sourcing small amounts of balsa, near impossibility of getting rubber or props

We have tried to generate interest in entry level aeromodelling, but found
1. No response to Glidiator
2. Over 5000 views, but not a single attempt at my 1 min /30 sec challenge

Note that sanjayrai55’s efforts in coro, saw more interest abroad than here

For the last 1-2 years, I tried offering cash prizes.
Glidiator doubled them.
Still no response?

Any suggestions?
Regards

The points you raised may be the reason for lack of interest or response.
But as for availability of rubber and props I don't see any problems nowadays. In my early days of Aeromodelling I did not even know that TAN rubber existed. Now with internet and online purchase facility that is no longer a problem. Even in small quantities.
I have posted links for sourcing  free flight essentials. And they are not actually expensive by today's standards.
The problem may also lie in the fact that HLG, CLG or rubber power are not jazzy or cool. Doesn't have the gizmo effect.
The RTF culture is also destroying the joy of construction.


Title: Re: 1st Rubber Power model
Post by: taksh on July 27, 2018, 11:25:24 PM
@Saikat Sir
 :o
I know English but not very well  :'( and i know rubber powered plane.
I have rubber band powered plane.
I am busy in making blu baby wings so i am not online and due to rainy season in my area, I am trying to search large ground and dry ground for flying blu baby.
And K K Iyer sir & others said my posts are rude so i am trying to not to say anything.
If you want images of blu baby build then i can show you.   :)

Sorry for hijacking thread.




Title: Re: 1st Rubber Power model
Post by: K K Iyer on July 27, 2018, 11:42:01 PM
@taksh
Nice post!
I’m glad you didn’t leave this forum.

Start a new thread for your Blu Baby build.
Post photos step by step.
A lot of members will be interested.

If you have a rubber powered model, please post a picture here.
Regards


Title: Re: 1st Rubber Power model
Post by: Glidiator on July 28, 2018, 06:59:58 PM
Pics of the Chaser from IHC. All part of the archeological findings while clearing the Aeromodelling cupboard.


Title: Re: 1st Rubber Power model
Post by: Dreamliner on August 02, 2018, 08:02:38 PM
Catapult launch free flight glider with folding wing mechanism.  Wing unfolds at top of the height when air pressure reduces.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 02, 2018, 08:16:26 PM
Catapult launch free flight glider with folding wing mechanism.  Wing unfolds at top of the height when air pressure reduces.

Which brand is it??.
The wing dihedral seems a lot.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 02, 2018, 08:18:09 PM
Zoomed the pic and saw the Guillows logo.


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 02, 2018, 08:18:41 PM
@dreamliner,
What’s this?
Never seen it before!


Title: Re: 1st Rubber Power model
Post by: Dreamliner on August 02, 2018, 08:43:40 PM
Yes, it is a Guillows kit.  Picture taken in folded wing state.  When the wing unfolds, dihedral is approx 5 degrees.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 02, 2018, 08:46:27 PM
What is it called?? Can look it up in their catalogue.


Title: Re: 1st Rubber Power model
Post by: Dreamliner on August 02, 2018, 09:03:09 PM
It is called 54 just the digits “54” as printed on the wing,


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 02, 2018, 10:26:57 PM
@dreamliner
Good to see you active.
Those plastic models would make nice prizes for youngsters...


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 05, 2018, 06:35:48 PM
One more Bobni plan dug out from a long forgotten box. This one was in a pouch.
I have dated this as 06/2009 based on the mfg date on the quick-fix packet that came with it.(Getting good at carbon dating!!)
Interestingly this plan shows added wing tips. No balsa for them, perhaps need to use card paper.
So IHC has been doing some modifications to the original plan as time went by -- tapered wings, rounded wing tips etc.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 05, 2018, 07:33:11 PM
Wonder why they did not have aerofoil ribs. Would have improved performance significantly I feel. Plan to do that keeping the other dimensions the same. Ofcourse TAN rubber will make a big difference.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 05, 2018, 07:36:16 PM
I guess as a beginners model it is better to keep things simple while providing decent performance.


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 05, 2018, 11:31:45 PM
Just some duffer who drew this plan.
Forgot tip rib!  ;D


Title: Monokote vs tissue
Post by: K K Iyer on August 06, 2018, 02:31:32 PM
Recd a query from Dreamliner re pros/cons of Monokote vs tissue, especially for small rubber power models of 15” span or less.
Responding here as it may interest a few others too.

The main advantages of Monokote are that it is easy to get a good finish, it is fuel proof, can be cleaned with soap and warm water, is puncture resistant, and lasts for decades.

But it requires the basic structure to be quite strong, like a typical RC wing with sheeted LE, TE, tips and center section. Usually found only in models of say 40” or more span.

Rubber power models usually have only about 10% structure (balsa strips) and 90% open area.
Such structures will buckle when the Monokote is tightened.

As an experiment, you can build, say, two Bobni wings. Cover one with Monokote, the other with tissue. You’ll be able to see that tissue is preferable for small, light, open structures...


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 03:08:05 PM
What is the weight difference between the two.
As far as indoor rubber models are concerned it's all about reducing weight. So material that will add to weight may not be suitable. May be okay for fun flying and where you want a durable model that can take some knocks. For competition weight is critical.


Title: Re: 1st Rubber Power model
Post by: prabal276 on August 06, 2018, 07:40:34 PM
Quote
One more Bobni plan dug out from a long forgotten box. This one was in a pouch.
I have dated this as 06/2009 based on the mfg date on the quick-fix packet that came with it.(Getting good at carbon dating!!)
Interestingly this plan shows added wing tips. No balsa for them, perhaps need to use card paper.
So IHC has been doing some modifications to the original plan as time went by -- tapered wings, rounded wing tips etc 
This is the one!
Nostalgic!
Can we get a scan of the plans?
Please?


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 06, 2018, 08:19:53 PM
What is the weight difference between the two.
As far as indoor rubber models are concerned it's all about reducing weight. So material that will add to weight may not be suitable. May be okay for fun flying and where you want a durable model that can take some knocks. For competition weight is critical.

For small models built mainly of balsa strips (much smaller than 1/4”sq), the Monokote vs tissue issue is not about weight. It’s about the shrinking power. Stick constructions will get crunched when you tighten the monokote. The experiment suggested (cover one Bobni wing in Monokote, another in tissue) should reveal this. Incidentally, Monokote will pull off from stick structures during shrinking due to lack of adequate surface for adhesion.
And, though I have no data, I guess Monokote will be 3-4 times as heavy as tissue/dope, partly due to adhesive on the entire surface.
Incidentally, for dope one can use NC Clear Lacquer (Rs 60 for 200ml), diluted with NC Thinner (Rs 50 for 500 ml).

To summarize, Monokote is not recommended for small models and weak open frame structures.



Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 08:23:15 PM
Sure Prabal.
Will scan and upload as a PDF in actual size. Will tile it so can print out on A4 printer.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 08:26:06 PM
Have never used monokote so my knowledge of that material is zero.


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 06, 2018, 08:30:14 PM
@prabal276,
A full size plan is hardly needed.
Pic posted by Glidiator is enough, once you know that the span is 13”!


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 08:31:24 PM
Would suggest using the thinnest grocery bag plastic. Less than 10 microns (banned by many states) It is durable as well as light and can take more knocks than tissue. No need to dope also which will add weight.
But if you want to adhere to the original classic construction then will have to use tissue.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 08:33:18 PM
Can adhere the plastic to the balsa using 3M Spray glue or even a thin coat of gluestick


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 06, 2018, 08:37:24 PM
@Glidiator sir,
I have a Miss World wing (54”, 0.19 power) whose Monokote (original, not clone) covering has survived for 35 years despite the balsa tips being chewed by rats.
Monokote is FANTASTIC.
Just not meant for small open frame models.



Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 06, 2018, 08:43:26 PM
Meanwhile, no one seems to have tried document lamination sheet!
Even I haven’t, but I have a sample a friend gave me.
Will try it and report.

On RCG, I found some people using this, and then also covering with tissue. Not sure of the purpose.

So, a lot of scope for experimentation!


Title: Re: 1st Rubber Power model
Post by: 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.


Title: Re: 1st Rubber Power model
Post by: K K Iyer on August 06, 2018, 09:23:32 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.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 10:35:17 PM
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.


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 10:41:12 PM
Pic of Spray 66


Title: Re: 1st Rubber Power model
Post by: Glidiator on August 06, 2018, 10:46:10 PM
Spray 66 uses LPG as propellent so it will not create holes in the ozone layer as will other aerosols!!


Title: Re: 1st Rubber Power model
Post by: ssk320 on December 27, 2018, 07:59:19 PM
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.


Title: Re: 1st Rubber Power model
Post by: Glidiator on December 27, 2018, 08:31:32 PM
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
https://youtu.be/wo-FXkZw-8g
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


Title: Re: 1st Rubber Power model
Post by: Glidiator on December 27, 2018, 08:53:03 PM
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.
https://youtu.be/znkB566ck6U

Anant


Title: Re: 1st Rubber Power model
Post by: K K Iyer on December 27, 2018, 10:50:28 PM
@glidiator,
Larger than Navy hangar sites?


Title: Re: 1st Rubber Power model
Post by: Glidiator on December 27, 2018, 11:31:10 PM
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


Title: Re: 1st Rubber Power model
Post by: Glidiator on December 28, 2018, 10:41:23 AM
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.


Title: Re: 1st Rubber Power model
Post by: Glidiator on January 27, 2019, 08:49:33 PM
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


Title: Re: 1st Rubber Power model
Post by: K K Iyer on January 27, 2019, 09:15:43 PM
@glidiator,
Full speed ahead please!


Title: Re: 1st Rubber Power model
Post by: Glidiator on January 27, 2019, 09:19:31 PM
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,


Title: Re: 1st Rubber Power model
Post by: Glidiator on January 27, 2019, 11:03:23 PM
@glidiator,
Full speed ahead please!
Aim to consciously make time to do some regular construction and flying.


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 02, 2019, 08:43:23 PM
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.




Title: Re: 1st Rubber Power model
Post by: Glidiator on February 02, 2019, 08:48:20 PM
Is there a facility to reduce pic file size on this forum as is there in the Hippocketaeronautics forum.??


Title: Re: 1st Rubber Power model
Post by: 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


Title: Re: 1st Rubber Power models
Post by: Glidiator on February 02, 2019, 10:38:46 PM
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.


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 08:20:29 PM
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













Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 08:22:20 PM
Some more pics

Card elevators

Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 08:24:25 PM
Need to add card / balsa wing tips.

These I don't recollect were in the original plan

Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 08:31:16 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.
https://www.youtube.com/watch?v=Tm6wVxYUFtI

Will post some more pics of it.
Anant


Title: Re: 1st Rubber Power model
Post by: K K Iyer on February 05, 2019, 10:50:24 PM
What was that magic?
More details please.


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 11:05:32 PM
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


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 11:12:20 PM
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.


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 11:23:15 PM
KK check out this link of the thread on soda can nose bearing.
I think even non registered guests can access it.
http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=20755.0


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 05, 2019, 11:29:17 PM
Useful to have a Jewellers’s nose plier - the one with rounded jaws to do such work.


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 06, 2019, 09:25:04 PM
Some pics to explain what I did to make a nose bearing from a soda can ring

This can be a viable alternative for the nose bearings that are being sold from the US.

Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 07, 2019, 09:16:01 PM
Some more on Soda Can Nose Bearing

Some pics to show weight of the bearing and a comparison of size and weight with nose bearings made of aircraft aluminium I got from the USA that are used in used in F1D , Penny plane and Science Olympiad models.

My bearing compares well with them in terms of size and weight.

Making nose bearings can be a separate topic but since it is used in rubber powered models being on this page is useful and relevant.
Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 07, 2019, 09:20:38 PM
Some more on Soda Can Nose Bearing

Pics showing comparative size

Anant


Title: Re: 1st Rubber Power model
Post by: K K Iyer on February 07, 2019, 11:41:18 PM
Saw the details on hippocket. (I’m a member there too ;D)
But I fear this level of work is too fine for my capabilities.
(My daughter used to make books with written content and a stitched spine, the size of a thumbnail!)

I’ve only recently started on Peanut Scale...


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 10, 2019, 08:17:19 PM
I’ve only recently started on Peanut Scale...

Must get into scale FF models too. They are time consuming to build and need attention to detail. Some of them can also be difficult to trim to get decent performance. Nevertheless a good finished scale model with authentic colour scheme is a work of art.


Title: Re: 1st Rubber Power model
Post by: K K Iyer on February 12, 2019, 12:50:37 AM
Druine Turbulent, Pilatus Porter and 1945 Iambus ...


Title: Re: 1st Rubber Power model
Post by: Free Flight on February 12, 2019, 06:49:13 AM
Congratulations on a wonderful build. They look good! Wish you terrific maiden,if not already.
Cheers,
Free Flight


Title: Re: 1st Rubber Power model
Post by: K K Iyer on February 12, 2019, 09:58:55 PM
@Free Flight,
Thanks. But these are not exactly new models...
Regards


Title: Re: 1st Rubber Power model
Post by: Free Flight on February 13, 2019, 08:40:00 AM
Ouch, my bad. Sorry about that Mr. Iyer. Coming back to Free flights after a while. But they sure look good, any flight videos?


Title: Re: 1st Rubber Power model
Post by: Glidiator on February 13, 2019, 01:38:31 PM
Druine Turbulent, Pilatus Porter and 1945 Iambus ...

Like the offbeat designs like Iambus.
Can you post the plan link — on Outerzone??
Check out the offbeat designs / plans of models by Bill Brown on HPA.
I have posted pics of his Yvette rubber power. An ideal model to convert to capacitor power. There is a topic on this in HPA.
My BOBNI awaits full power trials in a suitable space.


Title: Re: 1st Rubber Power model
Post by: K K Iyer on February 14, 2019, 12:41:18 AM
Ouch, my bad. Sorry about that Mr. Iyer. Coming back to Free flights after a while. But they sure look good, any flight videos?

Look up andiyerlko on youtube (that’s my wife).
Some nice videos there, incl a few free flight...
Regards


Title: Re: 1st Rubber Power model
Post by: Free Flight on February 14, 2019, 01:32:35 AM
Thanks. Truly good videos, specially the jet landing not needing any net after all, but always be safe. Also loved your living room rubber powered scale flyer. I do that home too before I can get to the field, cannot resist.

You have a great flying field. Happy for you. A bit envious about that (..just joking). , my RC field is 3 miles away and my FF field is 40 miles away. So I fly FF at the local town soccer field/s. Have to fly at dawn and out by 8 as when kids come in.

Here is my soccer field video.
https://www.youtube.com/watch?v=RVOwPDpGvBI


Title: Re: 1st Rubber Power model
Post by: K K Iyer on February 14, 2019, 01:53:41 AM
One does what one can.

http://www.rcindia.org/free-donations-and-sweepstakes/can-small-cash-prizes-encourage-attempts/msg298081/#new

We have a new airfield, but posting that here would divert this thread too far afield...
See “RC Aiport, Indore” thread


Title: Re: 1st Rubber Power model
Post by: Glidiator on April 28, 2019, 11:32:42 AM
Hi all
Back after a bit of an haitus.
Check this link for some useful info on wing design.

http://www.razvanapetrei.com/reasons-behind-the-shape-of-aircraft-wings/

By the way has any one used “Paulownia wood”.
It is also very light and very stiff and strong. Heavier than balsa but much stiffer. Ideal for fuselage of catapult gliders and other categories.
Got some sample sheets from a China supplier.
Sheets I got are 1 mm, 2 mm and 3 mm can get other thickness and rods dowels etc.
Used for boats models and architectural models too.


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 07, 2019, 08:04:35 PM
Hi all,

Managed to get back to doing a bit of construction.
This one is a old design. A delta flying wing model called the “Flailing Arrow “.
It is a torqueless and tailless model.
It has two props - front and back and the elevon runs the whole length of the trailing edge.
Have use “Paulownia wood” for all components.
Some pics of the build. Fuselage stick, props and elevons to be added.
Will post better pic of plan.
I think it will be a challenge to trim it for stable flight and get satisfying duration.
Await further updates.
Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 07, 2019, 08:10:08 PM
The pics don’t seem to have uploaded properly. Trying again


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 07, 2019, 08:13:07 PM
One pic went thru.
Trying others agsin


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 07, 2019, 08:19:47 PM
What the finished model should look like


Title: Re: 1st Rubber Power model
Post by: Free Flight on May 09, 2019, 12:10:37 AM
Arrow build is looking great. Please kindly share the trimmed out flight video at your convenience. Looking forward to it.
PS: indoor flyer, i am guessing?


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 10, 2019, 10:15:36 AM
Hi
Build getting along well. Prop blades put on cylinder for getting helical curve.
Covering done with very thin grocery bag plastic.
Glide without props — only motor stick with nose weight seems good.
Will post pics
Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 10, 2019, 10:37:28 AM
Yes indoor flyer.


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 10, 2019, 12:26:11 PM
Some pics of the build progress of Flailing Arrow


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 12, 2019, 07:07:36 PM
The Flailing Arrow completed
A bit of jugaad for the prop hubs, used the Ikara prop shaft and hub cylinder, did not have the nose ring so tired it down to motor stick. not too neat but does the job well.
Test flights in drawing room quite encouraging.
Full test flights in indoor space asap.
Some pics
Anant


Title: Re: 1st Rubber Power model
Post by: K K Iyer on May 12, 2019, 08:17:38 PM
@glidiator,
Great stuff, sir. Hope it inspires some newbies.
How did you decide the prop pitch?
Regards


Title: Re: 1st Rubber Power model
Post by: Free Flight on May 12, 2019, 10:04:36 PM
Hi Gladiator,

Looking great. Are you going to install the landing gear and perhaps ROG? Or too my drag on the first test bed? Either way wish you the best on your maiden.
 i guess too much weight to install your capacitor power plant? Although same capacitor could power both props? Looking forward to your video.


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 12, 2019, 10:46:07 PM
Prop pitch and pitch station given in plan. Pitch 45 deg. Used my pitch guage to set angle.

Yes need to put in the landing gear and tail skid. Installing capacitor power not a bad idea. Maybe be okay for single prop. Two motors may be a bit too heavy for the wing area to give enough lift. Maybe enlarge the size proportionately and two props powered by single cap could work.
The article on this also suggests final trimming flights using ROG as it is a bit awkward to launch properly holding two props.


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 12, 2019, 10:51:52 PM
Plan and article of model attached
Anant


Title: Re: 1st Rubber Power model
Post by: Glidiator on May 12, 2019, 11:07:10 PM
Article file size beyond limit. Will reduce file size and post


Title: Re: 1st Rubber Power model
Post by: Glidiator on June 17, 2019, 10:43:59 PM
Was in Nagpur in 26th May to participate in an indoor event that was mainly held to try and set some good benchmarks in rubber power duration.
I was gradually cranking up the turns in each flight and reached a max of 2 mins 30 secs when a little carelessness caused a damage to the trailing edge spar of the wing. That put an end to further flights. Was hoping to reach atleast 4 mins but that was not to be.
Venue was a huge indoor facility- 12 badminton courts and height about 30 ft. Temperature was 45 degs and A/ or blowers could not be switched on. But was so concentrated on getting the rubber wound and ensuring the trim settings on the model were correct before each flight that Idid not feel the heat.
Video of one of the initial flights

https://youtu.be/dYuSaYF77b4


Title: Re: 1st Rubber Power model
Post by: K K Iyer on June 17, 2019, 10:59:33 PM
Sir,
I’ll be your shishya.
After I send you my guru dakshina...
Regards


Title: Re: 1st Rubber Power model
Post by: Glidiator on June 18, 2019, 07:36:42 AM
Hi KK
Will be more than happy to share my experience and knowledge of indoor rubber power gained over the years.
If all goes well a major indoor event is planned by AMAI at the end of this year in Pune or Nagpur. Open to all Aeromodellers. Would be happy if more participants join the event. Now is the time to start preparing and getting things ready.
Anant


Title: Re: 1st Rubber Power model
Post by: manojswizera on June 20, 2019, 11:41:14 AM
Super flight sir. :hatsoff:
these models need small detailed attention and lot of patience.


Title: Re: 1st Rubber Power model
Post by: Glidiator on June 20, 2019, 12:08:54 PM
Manoj— see my post on the capacitor power model thread and see what happens when a little detail is missed out.


Title: Re: 1st Rubber Power model
Post by: manojswizera on June 20, 2019, 06:33:47 PM
sir, saw that nose dive also.
summer heat makes glue melt and less sticky.


Title: Re: 1st Rubber Power model
Post by: Glidiator on June 20, 2019, 08:55:45 PM
Not so much heat affecting the tape glue. More because I had used silicon lubricant for my earlier rubber power flights and fingers had traces of silicon which got rubbed on to the wing post so tape was not sticking very well.
That silicon lubricant is very slippery stuff and just a small speck is enough to make things slip.