Rubber motor question

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Rubber motor question

Postby Billy Mc » Mon Jan 13, 2014 2:37 pm

This is my first balsa rubber powered model except the little dime store ones I had as a kid. Is there a reason the rubber is so long? With the ends tied the rubber hangs out the front of the plane 2-3 inches. Thought I'd just tie shorter and cut off the extra, but decided I better ask first.
Billy

BTW
It's a 602 Piper Super Cub 95
Billy
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Re: Rubber motor question

Postby Wildpig » Mon Jan 13, 2014 3:15 pm

More rubber, more power. Yes, you could cut it to the same length as from the propeller hook to the motor peg.
You just will not be able to wind it up as much.
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Re: Rubber motor question

Postby Billy Mc » Mon Jan 13, 2014 3:33 pm

Thanks,
I think I'll leave it long and give it a try. I'm just concerned that the prop could get lost if it falls out in flight when the rubber gets loose. Back to covering.
Billy
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Re: Rubber motor question

Postby WIDDOG » Mon Jan 13, 2014 5:22 pm

A quote from Don Ross's book Rubber Powered Model Airplanes. "Rubber is the motor of your model and should be treated with vast respect. "
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Re: Rubber motor question

Postby kittyfritters » Tue Jan 14, 2014 11:26 am

Billy Mc wrote:Thanks,
I think I'll leave it long and give it a try. I'm just concerned that the prop could get lost if it falls out in flight when the rubber gets loose. Back to covering.
Billy


This is why you have a very snug nose plug. Whatever way you make the nose plug on a rubber powered model, the tighter it fits, the better. Not only does it minimize the possibility of it falling out when the rubber runs down, but it makes sure that thrust line adjustments work. Most of the trimming problems, and poor performance that I have had with rubber powered models have been because the nose plug was too loose.

Howard
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Re: Rubber motor question

Postby Mitch » Tue Jan 14, 2014 2:26 pm

I am curious as to which model you built. I have built and flown all the 400 series. Built to Guillow plans as per instructions they all weigh about 100g (4 oz) The Spit a bit more. They all flew with Guillow's prop and rubber, although not contest winners they will fly for about 10 to 15 seconds in your local schoolyard or flying field.

Note: Lubricate your rubber motor. You can use Armor all. Tie it together with a double knot. Place it in a baggy. Spay a little Armor All and mush it up. Wipe off the excess and you should be good to go.

Do not expect to get more than 6 or so flights from the rubber. You will see it will look very 'stretched' and 'tired' time to replace it!

In competition guys will only use a motor 3 times.

Good Luck and Good Flying... Mitch

PS My "new" Guillow models now weigh between 75-80 grams, I use a larger prop and motor length of 2x hook to peg, 4 strands of tan rubber! They are still not contest winners, but they compete in FAC contests and are competitive!
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Re: Rubber motor question

Postby Billy Mc » Tue Jan 14, 2014 4:34 pm

It's a 602 Piper Super Cub 95
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Re: Rubber motor question

Postby stx44 » Tue Jan 14, 2014 11:48 pm

3 flights from a motor? Wow, I must be under winding, cos I'm getting dozens of flights out of mine!

Maybe I should crank on a few more turns and see what happens!
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Re: Rubber motor question

Postby Billy Mc » Wed Jan 15, 2014 11:01 am

stx44 wrote:3 flights from a motor? Wow, I must be under winding, cos I'm getting dozens of flights out of mine!

Maybe I should crank on a few more turns and see what happens!


Careful winding to the max unless you are using a blast tube. From what I've read a tightly wound rubber motor can destroy your plane if it breaks.
Last edited by Billy Mc on Wed Jan 15, 2014 1:22 pm, edited 1 time in total.
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Re: Rubber motor question

Postby Steve Blanchard » Wed Jan 15, 2014 11:53 am

Billy, you are correct about a blown motor being bad news for a model. As far as number of flights with a rubber motor, for me it all depends on the rubber. I have flown, and won contests on motors that were installed and flown the previous year/contest season. I wouldn't suggest it but if you check the motors before you fly, they can last a while sometimes. When flying mass launch it is definitely recommended to use a new motor because the constant flying and rewinding with very short breaks just for retrieval of the models. Actually the breaks between flights could be several minutes depending on the air and how far of a walk the pilots end up with. A 3 minute flight during a mass launch could take up to 10 minutes to retrieve and to get to the next launch.

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Re: Rubber motor question

Postby Mitch » Wed Jan 15, 2014 5:57 pm

Hi Guys,

I think that model should be a good flyer. Being a High Wing model is good first choice.

I suppose I should warn people to thke what I say with a grain of salt as I am still learning also.

But from my experience with Guillows rubber, I remember getting about 6 to 9 flights and then I noticed it was looking very streached out, and I decided to replace it. This was the grey rubber you get in the 400 series. That is where I have had the most flying expeience with Guillow models.

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Re: Rubber motor question

Postby Steve Blanchard » Thu Jan 16, 2014 10:26 am

Yes, my comments were completely based on FAI Tan rubber whether it be TAN II (No longer in production) or TAN Super Sport. Just to be clear.

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Re: Rubber motor question

Postby davidchoate » Thu Jan 16, 2014 11:48 am

I JUST BOUGHT THAT SAME CUB KIT, AND HAVE A JAVELIN. MY JAVELIN FUSELAGE IS SNAPPED IN HALF FROM A MOTOR FAIL, BUT REPAIRABLE. I CAN'T WAIT TO BUILD AND FLY MY CUB. I'M GONNA GO EXACT TO THE PLAN WITH THE BLUE RUBBER TO START. ITS ONLY MY 2ND FREE FLIGHT PLANE, AND I AM AMAZED AT HOW MUCH MORE THERE IS TO GETTING A GOOD FLIGHT THAN I THOUGHT. IT'S JUST THE BEGINNING OF MY FF EXPERIENCE, BUT IF I DO IT FOR ANOTHER 30 YRS. I 'LL STILL BE LEARNING AND INTERESTED.
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Re: Rubber motor question

Postby kittyfritters » Thu Jan 16, 2014 12:13 pm

davidchoate wrote:I JUST BOUGHT THAT SAME CUB KIT, AND HAVE A JAVELIN. MY JAVELIN FUSELAGE IS SNAPPED IN HALF FROM A MOTOR FAIL, BUT REPAIRABLE. I CAN'T WAIT TO BUILD AND FLY MY CUB. I'M GONNA GO EXACT TO THE PLAN WITH THE BLUE RUBBER TO START. ITS ONLY MY 2ND FREE FLIGHT PLANE, AND I AM AMAZED AT HOW MUCH MORE THERE IS TO GETTING A GOOD FLIGHT THAN I THOUGHT. IT'S JUST THE BEGINNING OF MY FF EXPERIENCE, BUT IF I DO IT FOR ANOTHER 30 YRS. I 'LL STILL BE LEARNING AND INTERESTED.


David,

Get some 1/8", flat, F.A.I Tan rubber! The blue rubber band has way too much torque and releases it's energy too fast. It works, outdoors, barely, on the slip together motor planes, but it will only take a couple of hundred turns before damaging the model or breaking.

Howard
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Re: Rubber motor question

Postby Steve Blanchard » Thu Jan 16, 2014 12:34 pm

Very sage advice Howard. Listen to what he says David. make your free flight experience as easy and enjoyable as possible. Try and find someone close to you who has already gone through a lot of the growing pains for some guidance when you need it most - at the flying field.

Steve
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