I have been corresponding with Dinkar who has been making Squirrels and so forth from scratch in India. He has making model planes as a school project.
I sent him a box a while back which was not received yet. So I decided to send his next box now so he won’t have to wait as long.
I included a hand full of Squirrels a winder and some lubrication for the rubber. This will go in the mail tomorrow as soon as the post office opens.
The first box has a hand full of Squirrels so they can get them going and have fun with hand winding. This box will move them to the next level.
He made these wings out of thin bamboo. He says they didn’t work and he feels it’s because the bamboo was too thin.
It’s pretty clear he is resourceful and I’m sure the kids are excited about this project. They should be receiving their genuine Squirrel kits in the mail any day now. I hope they enjoy them! If anybody would like to donate, I’ll send them another box of goodies.
A Squirrel can fly quite well with simple hand winding.
Here is a nice flight from last summer that was done with hand winding.
Once you have your Squirrel tuned up nicely you can make it fly longer using the following techniques.
1) You can lubricate the rubber band. Get some Armor All from you nearest hardware store. After the elastic band is tied you can add a couple of drops to the rubber band. The trick is to take the elastic off the model then roll it around in your hand with the product.
This alone will allow the elastic band to take more winding. This reduces the friction on the surface of the elastic.
The elastic will also last longer.
2) You can use a mechanical winder to “stretch wind” the elastic. Here is a video of myself stretch winding a Squirrel. As you can see I have hooked the propeller onto a stationary “winding stooge”. I then take the knot end of the elastic and stretch it (it is still hooked onto the back of the propeller). The winder is used to wind up the elastic very quickly and as the tension builds up I am letting the elastic pull me in towards the model. Once it is wound up enough, I am unhooking the elastic from the winder and then hooking it onto the hook at the back of the model.
3) You can wind the elastic considerably more with these techniques. The rubber that comes with the Squirrel can take about 97 turns per inch before breaking if it is well lubricated and stretch wound. So if the elastic is 8 inches that comes to 776 turns. 9 Inches comes to 873 turns. You’ll want to use about 80 percent of the maximum since the rubber is stressed out quite a bit above 80 percent and will not last very long.
The Squirrel should also work well with an elastic that is as long as 15 inches. That’s a 30″ loop tied. That can accept 1455 turns.
Also a slightly thinner elastic will accept more turns (but it will not provide as much torque) for the propeller. You can shave some of the plastic off the flat surface of the propeller to make it lighter. Some of the motor stick can be removed sometimes as well to save weight. If you do all that you may be able to get the Squirrel to run on 3/32″ rubber instead of the 1/8″ standard. 3/32″ Rubber can take 129 turns per inch. So a 15″ loop can take 1935 turns.
4) If you don’t wait too long after winding I find it helps a bit sometimes as well.
5) In an indoor environment it helps if your plane has a gentle turn. As you can see in the video below it allows the plane to keep flying without hitting anything.
I’m doing some experiments with shipping small orders. The idea is to try and get them into an envelope size with stiffeners. If they survive this could be a good solution for reducing shipping costs for orders from 1 through 6 Squirrels.
