Wright Stuff C

Locked
newflight
Member
Member
Posts: 34
Joined: February 2nd, 2019, 8:48 pm
Has thanked: 0
Been thanked: 0

Re: regarding to propeller selection

Post by newflight »

CrayolaCrayon wrote:
newflight wrote:I have several propellers which are the same size with same pitch, however, the mass are very different, the heaviest is 2.3g and the lightest is 1.7. I would like to get some inputs on which propeller should be the best to use. I think the 1.7g should be the best, this will give the best weight balance. If I use 2.3g, it might make nose too heavy.
Are they ikara props? Just curious.
yes
User avatar
CrayolaCrayon
Member
Member
Posts: 346
Joined: October 25th, 2017, 8:24 am
Division: C
State: PA
Has thanked: 16 times
Been thanked: 5 times

Re: regarding to propeller selection

Post by CrayolaCrayon »

newflight wrote:
CrayolaCrayon wrote:
newflight wrote:I have several propellers which are the same size with same pitch, however, the mass are very different, the heaviest is 2.3g and the lightest is 1.7. I would like to get some inputs on which propeller should be the best to use. I think the 1.7g should be the best, this will give the best weight balance. If I use 2.3g, it might make nose too heavy.
Are they ikara props? Just curious.
yes
What are the bead colors?
MIT '25
MIT Wright Stuff ES '22
BirdSO Wright Stuff ES '22
newflight
Member
Member
Posts: 34
Joined: February 2nd, 2019, 8:48 pm
Has thanked: 0
Been thanked: 0

Re: regarding to propeller selection

Post by newflight »

CrayolaCrayon wrote:
newflight wrote:
CrayolaCrayon wrote:
Are they ikara props? Just curious.
yes
What are the bead colors?
red
jinhusong
Member
Member
Posts: 171
Joined: March 16th, 2017, 3:34 pm
Division: C
State: CA
Has thanked: 2 times
Been thanked: 2 times

Re: Wright Stuff C

Post by jinhusong »

After saw the message, I checked what we have, 2.20, 2.17 and 1.72g. All red bead.
User avatar
CrayolaCrayon
Member
Member
Posts: 346
Joined: October 25th, 2017, 8:24 am
Division: C
State: PA
Has thanked: 16 times
Been thanked: 5 times

Re: Wright Stuff C

Post by CrayolaCrayon »

Are red props discontinued from FF? I have a whole box of them, but am not sure how they differ from the yellow beads? Are they just vintage?
MIT '25
MIT Wright Stuff ES '22
BirdSO Wright Stuff ES '22
bjt4888
Member
Member
Posts: 882
Joined: June 16th, 2013, 12:35 pm
Division: C
State: MI
Has thanked: 0
Been thanked: 51 times

Re: Wright Stuff C

Post by bjt4888 »

Jinhusong,

Try testing the thickness of the plastic blades. This year, for the first time, we have discovered variations in the thickness ranging between .007” and .010”. It appears that the plastic stock is not being kept consistent as each different thickness material is that thickness over the entire blade.

The best way to determine best is to fly them.

Brian T
jinhusong
Member
Member
Posts: 171
Joined: March 16th, 2017, 3:34 pm
Division: C
State: CA
Has thanked: 2 times
Been thanked: 2 times

Re: Wright Stuff C

Post by jinhusong »

bjt4888 wrote:Jinhusong,

Try testing the thickness of the plastic blades. This year, for the first time, we have discovered variations in the thickness ranging between .007” and .010”. It appears that the plastic stock is not being kept consistent as each different thickness material is that thickness over the entire blade.

The best way to determine best is to fly them.

Brian T
Hi Brian,

You are right. I can even feel the difference by hand. The measured thickness matches your range.

More questions, what's the tolerance between two blades in pitch? We found 5 degree difference at the widest chord but 1 degree difference at 75%. Any method for us to test dynamic balance of the prop? I tried rotate with rubber band and winder, while hand holding the prop hanger, cannot tell.

Thanks for your help,

Jinhu




Best,

Jinhu
bjt4888
Member
Member
Posts: 882
Joined: June 16th, 2013, 12:35 pm
Division: C
State: MI
Has thanked: 0
Been thanked: 51 times

Re: Wright Stuff C

Post by bjt4888 »

Jinhusong,

Good job measuring and testing. The out of the box pitch variation you mention is typical. My teams will twist the center spar (as shown in the Freedom Flight kit instructions) both to get pitch to match within 1-2 degrees at a predetermined radius and to change pitch overall for testing. Also, twisting the blade in localized areas to make the pitch equal all along the blade will give you a helical pitch distribution. Helical pitch distribution is fairly efficient and equal pitch along each blade (or, at least, known pitch along each blade) improves analysis of testing results.

Good question.

Brian T
bjt4888
Member
Member
Posts: 882
Joined: June 16th, 2013, 12:35 pm
Division: C
State: MI
Has thanked: 0
Been thanked: 51 times

Re: Wright Stuff C

Post by bjt4888 »

Jinhusong,

Sorry, missed the dynamic balance question. Very even pitch between the two blades, combined with perfect static balance and perfectly straight shaft will improve the let down duration. This is a very fine adjustment, of course and not nearly as important as matching propeller to rubber, having a very good propeller and winding correctly. I would gues that having a perfectly balanced propeller (dynamically and static) might be worth 5 seconds.

Brian T
jinhusong
Member
Member
Posts: 171
Joined: March 16th, 2017, 3:34 pm
Division: C
State: CA
Has thanked: 2 times
Been thanked: 2 times

Re: Wright Stuff C

Post by jinhusong »

bjt4888 wrote:Jinhusong,

Sorry, missed the dynamic balance question. Very even pitch between the two blades, combined with perfect static balance and perfectly straight shaft will improve the let down duration. This is a very fine adjustment, of course and not nearly as important as matching propeller to rubber, having a very good propeller and winding correctly. I would gues that having a perfectly balanced propeller (dynamically and static) might be worth 5 seconds.

Brian T
Hi Brian,

Got it.

Thanks,


Jinhu
Locked

Return to “Wright Stuff C”

Who is online

Users browsing this forum: No registered users and 3 guests