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Re: Wright Stuff C

Posted: February 27th, 2020, 11:44 am
by paschw30
Anyways...
Has anyone measured the pitch of the new ikara props?

Re: Wright Stuff C

Posted: February 27th, 2020, 1:02 pm
by lechassin
bjt4888 wrote: February 27th, 2020, 11:30 am There are a couple of the General Rules and references in the Build Policy that somewhat clarify this.
Yeah, I'm quoting the Building and Tools Policy on soinc.org: "The process of design and resultant product is the students’ responsibility."

Same contradiction. Use the kits, they are allowed. Just don't come after us for what we're doing. We designed and built our planes, props, winder, and torque meter from scratch, starting with only the info we got here. I'm grateful for that info, but anyone just here to give us grief just pi$$es me off.

I'm thinking of deleting everything and you can all go to He-ll

Re: Wright Stuff C

Posted: February 27th, 2020, 1:20 pm
by MadCow2357
lechassin wrote: February 27th, 2020, 1:02 pm
bjt4888 wrote: February 27th, 2020, 11:30 am There are a couple of the General Rules and references in the Build Policy that somewhat clarify this.
Yeah, I'm quoting the Building and Tools Policy on soinc.org: "The process of design and resultant product is the students’ responsibility."

Same contradiction. Use the kits, they are allowed. Just don't come after us for what we're doing. We designed and built our planes, props, winder, and torque meter from scratch, starting with only the info we got here. I'm grateful for that info, but anyone just here to give us grief just pi$$es me off.
Lol I think speak for everyone here when I say we all respect you a ton... truly heart-warming to see a parent care so much SO (much like Len). There is a delicate balance between not caring at all and adults basically doing the build themselves, a balance which I think you have achieved very nicely (true coaching right there). I don't think anybody is trying to step on your toes, so let's all just relax 8-)

Re: Wright Stuff C

Posted: February 27th, 2020, 3:29 pm
by bjt4888
lechassin wrote: February 27th, 2020, 1:02 pm
bjt4888 wrote: February 27th, 2020, 11:30 am There are a couple of the General Rules and references in the Build Policy that somewhat clarify this.
Yeah, I'm quoting the Building and Tools Policy on soinc.org: "The process of design and resultant product is the students’ responsibility."

Same contradiction. Use the kits, they are allowed. Just don't come after us for what we're doing. We designed and built our planes, props, winder, and torque meter from scratch, starting with only the info we got here. I'm grateful for that info, but anyone just here to give us grief just pi$$es me off.

I'm thinking of deleting everything and you can all go to He-ll
Eric,

Actually, I am agreeing with you and Chuck and others that coach recommended designs and design elements are allowable. This has been the the SO practice for all the years that I have been involved.

My read on the combination of all these rules for Wright Stuff is that the process of design is the responsibility of the student, and the process of design for Wright Stuff can include selecting a kit, using published plans or other design sources, including ideas offered by a coach (paraphrasing the Building and Tools Policy).

A number of years ago, I submitted a question to the official FAQ to ask for clarification on WS Rule 3a, asking, “May the airplane be constructed from other design sources, like a coach design? Or, is the intent of this rule to limit the three sources of airplane design to “...published plan(s), commercial kits, and /or a student’s design.”? The response I received was, “Yes, other design sources are acceptable”.

The General Rules note that “actions and items (eg. tools, notes, resources...)are permitted unless they are explicitly excluded in the rules...or violate the spirit of the problem”.

So, I am a supporter of your work on the forum.

Brian T

Re: Wright Stuff C

Posted: February 27th, 2020, 3:55 pm
by Airco2020
paschw30 wrote: February 27th, 2020, 11:44 am Anyways...
Has anyone measured the pitch of the new ikara props?
40deg 3.5 cm from the center. I modified the freedom flight pitch guage I had from last year. Not really sure where the proper measurement should be taken but that's where I have it now.

Re: Wright Stuff C

Posted: February 27th, 2020, 3:58 pm
by paschw30
Ok, thanks.

Re: Wright Stuff C

Posted: February 27th, 2020, 5:22 pm
by coachchuckaahs
Airco2020 wrote: February 27th, 2020, 3:55 pm
paschw30 wrote: February 27th, 2020, 11:44 am Anyways...
Has anyone measured the pitch of the new ikara props?
40deg 3.5 cm from the center. I modified the freedom flight pitch guage I had from last year. Not really sure where the proper measurement should be taken but that's where I have it now.
That's a lot of pitch! About 8.6 inches, if I did the math right. P/D of 2.75.

Worth a try, but as with any prop, you will want to optimize the pitch based on stopwatch, and concurrently optimize rubber width

Coach Chuck

Re: Wright Stuff C

Posted: February 27th, 2020, 5:45 pm
by xiangyu
coachchuckaahs wrote: February 27th, 2020, 5:22 pm
Airco2020 wrote: February 27th, 2020, 3:55 pm
paschw30 wrote: February 27th, 2020, 11:44 am Anyways...
Has anyone measured the pitch of the new ikara props?
40deg 3.5 cm from the center. I modified the freedom flight pitch guage I had from last year. Not really sure where the proper measurement should be taken but that's where I have it now.
That's a lot of pitch! About 8.6 inches, if I did the math right. P/D of 2.75.

Worth a try, but as with any prop, you will want to optimize the pitch based on stopwatch, and concurrently optimize rubber width

Coach Chuck
I compared the pitch of this new prop with the regular Ikara props and I think the pitches about the same. Testing it this Sunday. Will try to get video + explain my findings.

Re: Wright Stuff C

Posted: February 27th, 2020, 6:26 pm
by coachchuckaahs
Remember, the regular Ikara. Is cut down, so the pitch would be higher to match larger diameter. Probably want to re pitch to around 2.0 P/D, then vary from there. Probably between that and 1.5, but we are not using those props, so you need to test.

We are generally between 30 and 40 degrees at 1"radius, but the pitch is definitely specific to the prop planform. I've seen some much higher, some much lower, depends on prop.

Coach Chuck

Re: Wright Stuff C

Posted: February 27th, 2020, 7:18 pm
by xiangyu
coachchuckaahs wrote: February 27th, 2020, 6:26 pm Remember, the regular Ikara. Is cut down, so the pitch would be higher to match larger diameter. Probably want to re pitch to around 2.0 P/D, then vary from there. Probably between that and 1.5, but we are not using those props, so you need to test.

We are generally between 30 and 40 degrees at 1"radius, but the pitch is definitely specific to the prop planform. I've seen some much higher, some much lower, depends on prop.

Coach Chuck
Huh, I didn't realize that :lol:. Well, it's been working so I never really thought about it.

Thanks for the new insight.

In terms of increasing flight times, what should I try next? My propeller I have rn is pretty much matched up to the rubber and I can fly consistent 1:35-1:40 or 1:50 probably if I "risk wind". Also, I am currently using a 39 inch rubber loop and ending up with very little winds when the plane lands. If I keep increasing the length of the loop (which would pack more winds), what might happen, would it keep increasing my flight time until the extra weight of the long rubber outweighs the power from the extra winds? (I'll be testing by experiment this weekend, but just curious atm)

Xiangyu