Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
December 16, 2017, 09:47:46 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 2 3 [4]   Go Down
Print
Author Topic: P-18  (Read 4718 times)
0 Members and 1 Guest are viewing this topic.
dslusarc
Gold Member
*****

Kudos: 21
Offline Offline

United States United States

Posts: 722



Ignore
« Reply #75 on: March 08, 2017, 07:15:26 PM »

If someone wants to cheat they are going to cheat. Who is to say I don't weigh in my F1L at West Baden then go back to my desk and slide off the ballast and take a flight and when walking back put the ballast back on? There is an honor system when we fly. Just like when golfing and your alone and your ball is 1 ft past the out of bounds marker. I would feel sorry for a person who feels that they needed to cheat in a P18 contest. I recall at one of the Kent contest Tom Sova having a great F1D flight going then realized he forgot part of his motor spacer so his model was underweight. He disqualified himself on that flight. That is the type of indoor people I have known since flying indoor.  

The unmodified prop rule in this event is really something new to the indoor community. The intent I have been told was to parallel the P30 style rules of outdoor which means nothing to me personally as other than seeing the name P30 before in magazines and a few picture I have no knowledge of the event as I do not have much interest in outdoor FF events. So I expect those of us who do not participate in outdoor events to have any familiarity with how that type of rule has been practically interpreted over the years. So I guess we will all see how it works out over the next two years in the indoor world.

This is a perfect opportunity for a person to build a better mousetrap. To develop a better 6" prop than what is currently being sold. About 8 years ago I was not happy with the poor selection of electric motors sold for small electric RC jets. So I found a motor manufacture and developed a special motor and eventually sold over 6000 of them. So this can be the same type of thing  Grin  Instead of the Ikara prop why not the Kirda prop or Leo prop etc  Grin

Don S  



 
Logged
ram
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 234



Ignore
« Reply #76 on: March 08, 2017, 08:15:32 PM »

Bill,  It would be great if you could take a few measurements!  Thanks!

BTW, Are you coming to West Baden in a few weeks?

Rey

Has anyone had one of these in their hands:

http://www.pitsco.com/Propeller_Assembly

They come in packs of 35 for $15.  I would be interested in what pitch the blades have at 2" radius or thereabouts and how much they weigh.  If no one has seen them I'll go ahead and order and measure myself.  If they are useable I'll bring to West Baden and Rantoul and pass them out to whoever wants to try them.  After shipping they are only .60 each.

I did contact the company who replied that they have no data to share with me.

Rey
Rey,
I have a bunch of these at school and will measure the pitch and weight tomorrow.  I'll weigh one with and without the factory hanger.  If you want to try one, I'll mail it to you.
Billy
Billy
Logged
frash
Gold Member
*****

Kudos: 11
Offline Offline

United States United States

Posts: 403



Ignore
« Reply #77 on: March 08, 2017, 10:05:27 PM »

Obviously not legal for P-18, but for Bostonian, Embryo, and small rubber scale, look at the four sizes of prop making kits from RetroRC. The blades are thin styrene molded around a coffee mug using hot water in the mug. Jig for drilling a 1/32-in shaft hole in 1/8-in Al tubing hub and laser-cut prop blade spars are included for five props.

Obviously a match for me since I recently took a inventory of props for 2 old Bostonians. I had 18, mostly Bucket props. Now we know another manifestation of obsessive compulsive disorder. You may have your own unique variation! <GRIN>

Fred Rash
Logged
aardvark_bill
Bronze Member
***

Kudos: 0
Offline Offline

United States United States

Posts: 35



Ignore
« Reply #78 on: March 09, 2017, 03:39:30 PM »

Rey,
The Pitsco black props are 3.3g with the hanger and shaft and 2.75 bare.  The blade angle at a 2" radius is about 22 degrees and the tip angle around 13.  I can mail you a couple if you want to give 'em a try, just PM me with your address.  I already have an envelope in hand...
And yes, I'm going to West Baden and I'm really looking forward to it!  I'm going for my 1st 7 minute flight with, well, anything.  Should be fun trying anyway.
Billy
Logged
ram
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 234



Ignore
« Reply #79 on: March 09, 2017, 03:59:32 PM »

Rey,
The Pitsco black props are 3.3g with the hanger and shaft and 2.75 bare.  The blade angle at a 2" radius is about 22 degrees and the tip angle around 13.  I can mail you a couple if you want to give 'em a try, just PM me with your address.  I already have an envelope in hand...
And yes, I'm going to West Baden and I'm really looking forward to it!  I'm going for my 1st 7 minute flight with, well, anything.  Should be fun trying anyway.
Billy

Thanks for taking the time to measure that Bill!  That equates to a pitch of 5.1" at 2" radius and 4.4" at 3" radius.  I was hoping for a lot higher.  If you can, bring one to West Baden and we can still give it a shot.

Thanks again,

Rey
Logged
ILM Tarheel
Silver Member
****

Kudos: 8
Offline Offline

United States United States

Posts: 169



Ignore
« Reply #80 on: March 09, 2017, 05:55:38 PM »

The Pitsco website catalog says that the 6" black props in the bulk bag of 35 are used with the AMA Dart, Shoebox ROG, and Right Flyer. All three of these kits are manufactured by Midwest so it stands to reason that the props probably are the same as the ones we are familiar with in these kits.

Jimmy J
Logged
dslusarc
Gold Member
*****

Kudos: 21
Offline Offline

United States United States

Posts: 722



Ignore
« Reply #81 on: March 09, 2017, 06:22:15 PM »

Rey,

Here are the variations I have in 6" props.  Will post weights when I get back from SO flying.

Don
Attached files Thumbnail(s):
Re: P-18
Logged
ram
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 234



Ignore
« Reply #82 on: March 09, 2017, 09:27:15 PM »

Don,  While you were out flying I took a pic of what I have.  Pitch measured at 2" radius on A to Z style gauge.

From left to right:

Williams Bros. 5.5" 2.57g 5.9"P
Peck                 6"  1.81g 3.8"P
Kaysun              6" 2.72g 6.1"P
Tern Aero           6" 2.95g 6.1"P
OS-150         5.75" 1.84g 5.3"P
Unknown         5.5" 1.60g 6.7"P
Unknown       5.375" 1.79g 9.1"P

I actually have multiples of most of these except the last one.  Some aren't useable unless I were to tweak the blades pitch to equalize them, but I'm guessing that's considered modifying the prop.

The last prop has a counterbore molded into the front and a "1" molded on the back of one of the blades.  Wish I knew where this came from.  Anyone have any ideas???

Rey
Attached files Thumbnail(s):
Re: P-18
« Last Edit: March 09, 2017, 10:30:59 PM by ram » Logged
calgoddard
Gold Member
*****

Kudos: 13
Offline Offline

United States United States

Posts: 781


FAC Member



Ignore
« Reply #83 on: March 09, 2017, 11:18:12 PM »

The sixth from the left might be a SIG prop. It has a P/D of 1.2 which is low for an indoor duration stick airplane.  That P/D is pretty conventional for a beginner outdoor stick airplane, like a SLEEK STREEK. I thought that the seventh prop might be a COMET prop, but the blade outline does not match. So I am not sure what the seventh prop is.
Attached files Thumbnail(s):
Re: P-18
« Last Edit: March 09, 2017, 11:30:39 PM by calgoddard » Logged
adanjo
Silver Member
****

Kudos: 3
Offline Offline

Japan Japan

Posts: 112



Ignore
« Reply #84 on: March 14, 2017, 03:08:38 AM »

I took a pic of what I have though I have only 1, 2 or 3 each.  Pitch measured at 50mm radius and there must be errors that might not be small.

From left to right:

Diamond 15, D=150 P=160, 2.4g, Max width 25mm, For 1.2mm shaft
U150 (Union), D=150 P=150, 3.0g, 25mm, 1.0mm
TSUBASA15cm, D=150 P=150, 2.0g, 22mm, 1.2mm

Aki
Attached files Thumbnail(s):
Re: P-18
Logged
Wind-it-up
Bronze Member
***

Kudos: 5
Offline Offline

United States United States

Posts: 19



Ignore
« Reply #85 on: August 27, 2017, 11:57:04 AM »

I just read this whole thread (I know; it's a bit old now) because I'm working on a P-18 model for the upcoming indoor season.

I thought that the main idea of P-18 was as a beginners event, and that the rules called for a commercially available prop assembly to remove complications for the beginner and level the playing field a bit.  IMHO, allowing more advanced props would result in wider performance gaps and tougher experiences for true beginners using typical assembly types, which would potentially discourage their future participation.  If P-18 is supposed to be for beginners, let's do everything possible to make it that way and let the other more advanced events be the place for more advanced engineering. 

Perhaps Don D. can update us on the rules, but I for one hope that we keep this event simple and beginner-oriented!  Smiley
Logged
ram
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 234



Ignore
« Reply #86 on: August 27, 2017, 12:23:13 PM »

See below for rule outcome.  It has been kept simple. 

I'm not sure that there is a "best" prop for this event.  As with all indoor FF events, it comes down to matching the rubber motor to whatever prop you choose (and having a properly trimmed airplane).  With the high minimum weight, it is very easy to build this airplane to 7.5 grams using any prop you choose.  On mine I chose the Ikara which meant I needed to add 2 grams of ballast even using 8 - 10 lb wood for everything.  It is covered in veggie bag material from our local grocery store.

Rey

For any that may be wondering what happened with the P-18 propeller rule being discussed above, it was discovered that the full text of the approved rules proposal for the P-18 propeller was inadvertently left out of the final print version.  It has since been corrected in the rule book and noted as such at the front of the book on page i.  The entire AMA Indoor rule book is here: 

https://www.modelaircraft.org/files/IndoorFreeFlight2017-2018.pdf

The relevant language is now: 

25.4.
The propeller shall be an unmodified commercially available plastic prop with a nominally maximum diameter of 6". If the propeller is advertised as being a 6" unit, it is acceptable for this event. Weight may be added for balancing.

Rey
Logged
Wind-it-up
Bronze Member
***

Kudos: 5
Offline Offline

United States United States

Posts: 19



Ignore
« Reply #87 on: August 27, 2017, 12:40:18 PM »

Thanks Rey - somehow I missed the outcome...guess I didn't read the thread closely enough.  Wink I'm encouraged by your comments also since I've not done much with indoor flying!  Thanks.
Logged
ram
Silver Member
****

Kudos: 3
Offline Offline

United States United States

Posts: 234



Ignore
« Reply #88 on: August 27, 2017, 01:41:15 PM »

Glad I could help a little. 

Nothing beats having someone near you to help with advice.  If you're comfortable, let us know what part of the country you're in.

I'm in Southwestern Indiana.

Rey 
Logged
Wind-it-up
Bronze Member
***

Kudos: 5
Offline Offline

United States United States

Posts: 19



Ignore
« Reply #89 on: August 29, 2017, 11:32:14 PM »

Thanks Rey - I'm in Connecticut, and there's a good indoor group here they're always willing to help. 

We still have a couple more outdoor flying months before indoor season here...if only the way wind calms down!
Logged
Pages: 1 2 3 [4]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!