Rubber

jander14indoor
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Re: Rubber

Postby jander14indoor » March 14th, 2010, 5:35 am

Tan Super Sport is considered the best because it has the highest energy storage of any rubber currently available in strip form. But, it is based on natural rubber and varies from batch to batch so you have to know which batch you have.

Good batches tend to have the characteristics you saw, lower torque for the same turns. But, they take a lot more turns, storing more energy overall. So, yes, you may have to adjust rubber size.

Side note, I'm pretty sure Sig rubber IS Tan of some unknown vintage and grade. Another reason Tan Supper Sport is considered tops, boxes are labeled by batch.

Jeff Anderson
Livonia, MI

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Re: Rubber

Postby Taran » March 14th, 2010, 7:11 am

How come armor all is so good but it's not a lube?

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Re: Rubber

Postby jander14indoor » March 14th, 2010, 1:42 pm

But Armor-All is a lube. It has the same basic constituents as silicone oil which is what makes it a good lube. On top of that it has a lot of water, fragrance, etc that evaporates on the motor leaving the lube behind.

The nice thing about Armor-All is that it's fairly easy to find. Almost every Auto parts store, or the auto parts section of department stores, has it on the shelf. And its relatively cheap. Pure silicone oil is a little harder to find.

Jeff Anderson
Livonia, MI

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Re: Rubber

Postby Littleboy » March 25th, 2010, 2:05 pm

On a 15:1 winder how many winds on average can put into a 0.093, 0.088, and 0.083 rubber bands?
What is the point of unwinding?

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Re: Rubber

Postby jander14indoor » March 25th, 2010, 2:57 pm

On a 15:1 winder how many winds on average can put into a 0.093, 0.088, and 0.083 rubber bands?
What is the point of unwinding?
As usual, it depends. What batch/brand of rubber do you have? How's it been stored? Any cuts? Lube? Winding technique? Torque meter in use?

That said, in the range of 100+ cranks on the winder handle. More for the thinner rubber, less for the thicker.

Unwinding lets you wind the rubber harder and get the winds (fuel) into the rubber without launching on such a high torque that you bang into the ceiling in low sites. Best way to see this is to wind a motor with a torque meter. Take data on way up till breaking. Then take a second identical motor up to just short of breaking, again collecting data, and then unwind taking data. Plot all this. Winds independant variable (x-axix) to torque is dependant variable (y-axis). You'll find you follow a higher torque curve on winding, and lower torque on unwind (its called hysterysis). By winding past the target launch torque and unwind back to it, you can get MANY more turns in the motor without banging the ceiling.

Jeff Anderson
Livonia, MI

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Re: Rubber

Postby eta150 » March 25th, 2010, 2:58 pm

I'm not sure of the actual numbers for those sizes, but I know that I can get at least 1300 winds on a lubed 0.090" rubber motor. Also, the point of unwinding is to get the broad torque plateau of a high torque launch without sending it crashing into the ceiling.

EDIT: Sorry, didn't see Jander's post...
#ACESWILD

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Re: Rubber

Postby jander14indoor » March 25th, 2010, 3:17 pm

But you said it so much simpler than I. Your words give the concept, so mine have some opportunity to explain it.

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Re: Rubber

Postby Littleboy » March 26th, 2010, 5:21 pm

On a 15:1 winder how many winds on average can put into a 0.093, 0.088, and 0.083 rubber bands?
What is the point of unwinding?
As usual, it depends. What batch/brand of rubber do you have? How's it been stored? Any cuts? Lube? Winding technique? Torque meter in use?

That said, in the range of 100+ cranks on the winder handle. More for the thinner rubber, less for the thicker.

Unwinding lets you wind the rubber harder and get the winds (fuel) into the rubber without launching on such a high torque that you bang into the ceiling in low sites. Best way to see this is to wind a motor with a torque meter. Take data on way up till breaking. Then take a second identical motor up to just short of breaking, again collecting data, and then unwind taking data. Plot all this. Winds independant variable (x-axix) to torque is dependant variable (y-axis). You'll find you follow a higher torque curve on winding, and lower torque on unwind (its called hysterysis). By winding past the target launch torque and unwind back to it, you can get MANY more turns in the motor without banging the ceiling.

Jeff Anderson
Livonia, MI
We have rubber from the Leading Edge kit. How's it been stored? in bags. Any cuts? no Lube? armor-all Torque meter in use? yes

Why not just not wind a couple of turns instead of unwinding?

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Re: Rubber

Postby calgoddard » March 26th, 2010, 5:40 pm

Littleboy:

Quoted directly from Jeff Anderson's post quoted in your post:

"By winding past the target launch torque and unwind [sic] back to it, you can get MANY more turns in the motor without banging the ceiling."

This is absolutely true!

By the way [sic] means that you are quoting someone without correcting the typo or grammatical error immediately before.

Jeff Anderson is awesome!

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Re: Rubber

Postby jander14indoor » March 26th, 2010, 5:48 pm

<SNIP> Why not just not wind a couple of turns instead of unwinding?
Because just winding adds torque and drives you into the ceiling. If you wind past the target torque say like ten cranks and you'll find in only takes like two unwinds to get back to the same torque, you'll find you have enough torque to get to the ceiling with extra turns.

Hope that's clear.

Jeff Anderson
Livonia, MI

PS, I am NOT awesome and being an injineer, fully appreciate spelling korrecshuns.


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