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Re: Wright Stuff C

Posted: April 25th, 2019, 10:23 pm
by coachchuckaahs
Just like in the beginning, you need to read the flight and the rubber.

How was the climb? The cruise? The let down?

A quick read is the number of turns remaining, assuming you got to altitude. If too many remaining, rubber is too thin, reduce pitch. If it runs out, rubber is too thick, increase pitch.

Coach Chuck

Re: Wright Stuff C

Posted: April 26th, 2019, 6:08 am
by xiangyu
coachchuckaahs wrote:Just like in the beginning, you Neff to read the flight and the rubber.

How was the climb? The cruise? The let down?

A quick read is the number of turns remaining, assuming you got to altitude. If too many remaining, rubber is too thin, reduce pitch. If it runs out, rubber is too thick, increase pitch.

Coach Chuck
Ok thanks. Just to confirm, I should start with winding forward the same amount then changing the number of windback to get to the same torque as before, correct? Would a "looser" rubber band make the plane go higher than before? I want to make sure I don't break anything by accidentally going too high of a torque.

Re: Wright Stuff C

Posted: April 26th, 2019, 6:55 am
by coachchuckaahs
You will need to test a peice of the new rubber to breakage. If the density or cross section changed, the number of winds likely changed. Be sure to use a torque meter.

Thinner rubber may not go as high, and may have faster letdown.

Coach Chuck

Re: Wright Stuff C

Posted: April 26th, 2019, 10:37 am
by jinhusong
We ran out of old batch and started new one the day before state competition. It was felt thinner and confirmed by measuring width and weight. Luckily, we had a prop with 5 degree less in the pitch. Just put on and we got back to the old timing. No time to do optimization.

It is better to plan ahead so you will have rubber from same batch.

Best,

Jinhu

Re: Wright Stuff C

Posted: April 26th, 2019, 10:58 am
by coachchuckaahs
Maybe that lesson will help someone else. Including us! We are almost at the end of our first half pound for this year, and I just got another pound. I better start cutting and testing from the new batch, and keep some of the older batch handy just in case!

Coach Chuck

Re: Wright Stuff C

Posted: April 26th, 2019, 11:45 am
by xiangyu
jinhusong wrote:We ran out of old batch and started new one the day before state competition. It was felt thinner and confirmed by measuring width and weight. Luckily, we had a prop with 5 degree less in the pitch. Just put on and we got back to the old timing. No time to do optimization.

It is better to plan ahead so you will have rubber from same batch.

Best,

Jinhu
THANKS! That is a huge help! I will try a prop with 5 degress less in pitch.

Re: Wright Stuff C

Posted: April 28th, 2019, 9:17 am
by coachchuckaahs
So, how did you do at state?

Coach Chuck

Re: Wright Stuff C

Posted: April 28th, 2019, 9:56 am
by jinhusong
We go second with raw time 2:53. We tried to follow yours and Jeff's advice.

Detail is in viewtopic.php?f=299&t=14119.

Best,

Jinhu

Re: Wright Stuff C

Posted: April 28th, 2019, 10:42 am
by klastyioer
jinhusong wrote:We go second with raw time 2:53. We tried to follow yours and Jeff's advice.

Detail is in viewtopic.php?f=299&t=14119.

Best,

Jinhu
nice time, congrats!
it says youre from ca but they already had states?

Re: Wright Stuff C

Posted: April 28th, 2019, 11:04 am
by klastyioer
oh shoot wait they didnt im stupid forgot ignore my question above