1st Rubber Power model

Started by K K Iyer, July 20, 2018, 08:03:06 PM

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Glidiator

Attaching pics of the Peabody Packet.

Glidiator

Another attempt to attach pics

Glidiator

Hi all,

Here's a link of an indoor/ outdoor model - Spinboy- designed by an Aeromodelling friend in Pune.
This model is now available as a kit with laser cut parts. Easy to build with clear step by step instructions.
Flies well both indoor and outdoors.
For Those interested I can give his contact details for purchasing the kit.



A few other models constructed await test flights. Will post them asap.
Anant

Glidiator

Can increase the duration of the flight with a longer loop and more turns. The wind was pretty strong and gusty but the model held its stability well. Will fly even better in still wind conditions.

Free Flight

Congrats. Nice flight. Is the wing flat or slight camber?
Really looking forward to your Peabody Packet flight video. Should be awesome.

Glidiator

Quote from: Free Flight on December 20, 2019, 05:54:20 PM
Congrats. Nice flight. Is the wing flat or slight camber?
Really looking forward to your Peabody Packet flight video. Should be awesome.

The wing has no camber so is simple for construction by beginners. Nevertheless the glide is pretty efficient.
The twin prop Peabody will be test flown soon. Also the high aspect ratio A6.
Lot of flying to do.

Glidiator

#131
This is a cute unique design by the late Bill Brown named Yvette after his daughter. Made it over 2 years ago and flown it in several workshop/demos. Has taken quite a few knocks and undergone minor surgeries as most demos are in restricted spaces-- but still flies pretty well. Somehow never took a decent video of its flight. Got a very short video in a recent workshop.
Plans are on the Hippocket forum alongwith some of his other interesting designs.
Pics being converted to reduced size and format for attachment asap

K K Iyer

@glidiator,
Here's an example from my RCG Vintage forum to support what you are trying to popularise.
Best wishes

https://m.youtube.com/watch?feature=emb_logo&v=02d7-D7-GUk&time_continue=82

Glidiator

These old time designs do fly well. The Jetco kits were pretty popular from what I read on the net.
This model has those wing tip tabs that are useful to adjust trim.
I still have not actually flown my Hangar Rats made quite a few years ago and safely boxed and stored.
A good large indoor venue will have to be found soon to test fly them. The BITS Pilani Goa Campus which is just 10 mins from my place has a large 3 badminton court space. Plan to use that during a workshop for their Aeromodelling Club is planned in January.

Glidiator

Hi all,
Check out these series of YouTube videos on  indoor rubber powered Aeromodelling.
In several parts on this channel covering cutting, covering, glueing, tools required, rubber preparation and winding, etc, etc.
Check out the whole series and your understanding of construction of indoor rubber power models will get a boost.
Get into this fascinating world of indoor free flight this new year.
Happy flying
Anant



K K Iyer

No post on this thread for 20 months!

Last month a teenager, who had recently gone solo under an instructor (on foamies and ARFs) was fascinated by my balsa models. He wanted me to teach him to build balsa models. So I gave him a chuck glider and a small rubber model from Guillow. Told him to get a Guillows kit, and an Apple Box (desi Orange Box) from Sharma Models in Jodhpur.

So he got a Guillow Cessna 150 (24") and the Apple Box.
Last 5 days spent building the Cessna. Once I showed him how to read/understand the plans and instructions, he did about 75% of the build. (I did the covering and wing mounting)

Nearly complete, but for windows.

It weighs 45gms without rubber.
The rubber in the kit is 24"x1/8". 4gms. (Some white stuff, not Tan)
And the plastic prop is 5" dia.

With this prop and rubber, I think we'll get only about 10-15 sec flights.

I have a Peck Polymers 7" prop, and a few feet of 1/16" and 1/8" Tan Super Sport rubber that I got last year.

The question is:
What prop and rubber should I use to try for 1 min flight?

Glidiator

Hi,
Good to see you mentoring a youngster in rubber power free flight.
Firstly the suitable prop. Here is a useful insight I got from the review of the AMA Alpha model on endlesslift.com.  — quote:
" the required propeller size depends on the area of the wing. There is a relation between the area of the wing that supports the airplane's weight and the area of the swept disk of the propeller that pulls it through the air. As a rule of thumb, the propeller diameter should not be less than about the square root of the wing area and as much as 1.5 times the square root of the wing area. "
2) As for rubber width — depends on AUW
For 45gms weight of model 1/8 rubber I estimate to be underpowered unless multiple loops are used.
I have a XL sheet that you fill in various parameters and it gives suitable rubber width. Will dig it out of my Aeromodelling folder on the PC and see what parameters are needed. My guess is for 45 gms minimum needed would be 1/4"  rubber - that may also require multiple loop. Try a flight with 1/8" tan rubber and see if power is enough. In order not to waste rubber in testing — can use motor loop that is half the hook to hook distance and use a hard balsa stick with hook at either end to cover the balance distance between hooks. With this short rubber lesser winds will give high torque to demonstrate how the model behaves before taking a full length loop and winding to similar torque.

Glidiator

Also to increase duration rubber loop should be stretched to max and kept stretched for about 5 mins. This increases flexibility of rubber. Loop should be lubricated - some silicon based lubricant or even very soft liquid soap. — hand wash
Follow the stretch winding technique to get more winds into the loop— i.e. stretch loop to about 80% and start winding — and slowly come closer as you wind and rubber tension increases. Careful not to break rubber. Can use a hand drill with a hook fixed in the chuck for this.

Glidiator

My good friend and fellow Aeromodeller Madhav Khare of Pune has a kit called Spinboy. Costs   around 300/-. Suitable for indoor and outdoor (in light winds).
Comes with tan rubber. Tissue covered model. Another modelling friend in New Jersey who was sent this model just sent a video of it doing a 1 min plus flight indoor.
It has all laser cuts parts and ideal for beginners in rubber free flight.
Link of my first test flight of this model . Wind was pretty stiff - 15 kph atleast - Model did quite ok in these conditions.

Glidiator

@KKAwait update on your students Cessna build.
Sent some XL Sheets by mail that helps to decide on rubber width etc. Hope it was useful.
Anant

Adarsh Lakshman

Hi all, I was looking for some Tan supersport 3/16" rubber. Since we don't get them in India, and it is lockdown period, is anybody willing to sell me some of the rubber?

Thanks
Adarsh Lakshman

Glidiator

There is an Aeromodeller friend in Pune who supplies various kits and accessories.
Will check if he has stock. How much length do you need. Note that even our postal system is not normal and since flights are disrupted lot of delays. Where are you based.?

Adarsh Lakshman

Hi. Thanks! I am based in Hyderabad,telengana.

Regards
Adarsh Lakshman

Adarsh Lakshman

I was thinking of getting around 5-7m

Regards
Adarsh Lakshman

Glidiator

Hi Adarsh
Will check if it is zvsible and can be posted to you.
Which model are you going to use it for. Indoor or outdoor. Any pics?
Anant

Adarsh Lakshman

Thank you. I was planning to use the rubber for my peanut scale Sopwith Camel,and 24" senior dart. I was also planning to keep some extra for future builds.

Glidiator


Adarsh Lakshman

I never got any of my guillows kits to fly.
The Sopwith camel is from vintage model company and the senior dart actually from rc bazaar
The Sopwith flies great,but the senior dart has a very weal airframe,and it came with a pretty rubbish prop,so I'm using another nose block for it.

Glidiator

Hi Adarsh
Have you made / trimmed/ flown rubber free flight earlier?
Lot of stuff on YouTube that will give you inputs on getting good flights.
Any info you need I can provide whatever has been my experience.

Adarsh Lakshman

I have attempted to build rubber powered balsa kits,but these were the only succesful ones.the Sopwith especially flew well making nice circles. As for trimming I just use clay to weigh down the nose/tail/wingtips.
If I ever have a problem with the planes,I will surely consult you!