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Indoor Free Flight Forum => A-6, P-24 => Topic started by: wcarneyjx on March 25, 2016, 06:28:37 PM



Title: P-18
Post by: wcarneyjx on March 25, 2016, 06:28:37 PM
P-18 Cruiser for provisional AMA event. Anybody else fooling with these/


Title: Re: P-18
Post by: skyraider on March 25, 2016, 07:37:41 PM
Nice looking Curiser Bill. Didn't know you were an AMA member.


Skyraider


Title: Re: P-18
Post by: wcarneyjx on March 25, 2016, 07:57:16 PM
Video of the Cruiser flying at Wigs Over the Rockies

https://m.facebook.com/story.php?story_fbid=1279528575410320&id=100000595697131
Ì


Title: Re: P-18
Post by: wcarneyjx on March 27, 2016, 02:43:33 PM
Well shoot. It seems thee is an error in the Original P-18 Cruiser plan I uploaded yesterday. Ugh. I failed to show the wing offset in the posted drawing. I have corrected this issue and posted a corrected version in The Gallery.

Bill C


Title: Re: P-18
Post by: Indoorflyer on March 27, 2016, 06:22:45 PM
Nice job Bill!  Nice to see your handiwork back in action; the video is a good pitch for your design.  Just downloaded your revised plan and may have to slice some balsa after the Easter egg and chocolate buzz wears off ::)

I think there's an old Peck ROG prop assembly in my indoor box of leftovers, don't recall its Ø offhand, but maybe that'll meet spec...

Thanks for posting.


Title: Re: P-18
Post by: wcarneyjx on March 27, 2016, 07:23:59 PM
How about the venue we get to fly in?!


Title: Re: P-18
Post by: aardvark_bill on May 31, 2016, 12:30:45 PM
Can someone tell me when P-18 will be flown at Nats?  I am guessing that it will be with the other heavier models on Saturday or Sunday but I don't see it on the version of the schedule that I have.
Thanks,
Billy


Title: Re: P-18
Post by: BudWorld on May 31, 2016, 05:34:22 PM
Hi, I'm Bud LAYNE, this years CD for the Indoor NATS. P!8 is scheduled for Saturday morning, goes on until noon. I have 50 kits from Mr. Marcos which are the same kits as last year. There's no entry fee for kids. Tables and chairs are provided as well as everything they need to fly, winders, etc. so come! You are welcomed.   :)


Title: Re: P-18
Post by: mkirda on May 31, 2016, 05:42:58 PM
Can someone tell me when P-18 will be flown at Nats?  I am guessing that it will be with the other heavier models on Saturday or Sunday but I don't see it on the version of the schedule that I have.
Thanks,
Billy

Following up with the AMA as I thought this was already posted, but it seems not. Hopefully in the next day or two.

I know Bud typed Mr. Marcos above, but these are from John McGrath from lasercutplanes.com.

Regards.
Mike Kirda


Title: Re: P-18
Post by: aardvark_bill on May 31, 2016, 09:57:57 PM
Thanks guys!  One of my former students and I are planning to be there Thursday afternoon through Sunday.  We are planning to fly - or, at least attempt to fly -  LPP, A6, Wright Stuff, and maybe ministick.  P18 looked like it would fit within our limited skill set and I wanted to make sure we weren't missing it by getting there later in the event.
My kids fly the TSA HS event - would it be a bother if my student brought his TSA plane too?   


Title: Re: P-18
Post by: mkirda on May 31, 2016, 10:05:00 PM
I would say to go for it. They are roughly similar to Wright Stuff are they not?


Title: Re: P-18
Post by: aardvark_bill on May 31, 2016, 10:12:32 PM
Great!  They're very similar except ROG and a 170 mm commercially-available (trimmed or modified as desired) plastic prop. 


Title: Re: P-18
Post by: mkirda on June 01, 2016, 10:41:19 AM
Thanks guys!  One of my former students and I are planning to be there Thursday afternoon through Sunday.  We are planning to fly - or, at least attempt to fly -  LPP, A6, Wright Stuff, and maybe ministick.  P18 looked like it would fit within our limited skill set and I wanted to make sure we weren't missing it by getting there later in the event.
My kids fly the TSA HS event - would it be a bother if my student brought his TSA plane too?   

Looking at the last copy of the schedule I have, Thursday afternoon will be the light stuff, F1D, etc.
You can certainly can use some of the surrounding low bay space to practice as you wouldn't want to run into an F1D.
Friday Saturday and Sunday all have viable time slots where these could be flown.

Regards.
Mike Kirda


Title: Re: P-18
Post by: aardvark_bill on June 01, 2016, 11:37:23 AM
Thanks!  We only plan to watch on Thursday - never seen an F1D or any of the really light models fly except in videos so it will be a thrill for us just to spectate.


Title: Re: P-18
Post by: OZPAF on June 02, 2016, 04:54:42 AM
I have only just caught this. Great video, beautiful trim - terrific place to fly and entertain kids. i did think you were being brave though, flying with the fans running.

John


Title: Re: P-18
Post by: aardvark_bill on June 22, 2016, 10:09:57 PM
My former student that is coming to the Nats with me flew his Carney P18 today in our 18-foot gym.  Consistent 1:30 on 20" loop of 0.070 rubber and very heavy at 9.5 grams w/o the motor.  He plans to build another lighter one before Rantoul.  We can't wait try it in a 45' site.
Same young man flew his A6 4:13 a couple weeks ago.  We're both looking forward to our first big contest.


Title: Re: P-18
Post by: Maxout on June 23, 2016, 06:19:05 AM
Same young man flew his A6 4:13 a couple weeks ago.  We're both looking forward to our first big contest.

That's impressive. He will do great at USIC.


Title: Re: P-18
Post by: jcobbs on July 23, 2016, 08:25:05 PM
Billy

Let me know how you and your student do/did. 
I just started a new TSA flight endurance student today.  Just starting the transition from gliders to rubber power.

Jim


Title: Re: P-18
Post by: mkirda on July 25, 2016, 09:30:29 AM
If this is who I think it is, he set a new record for A6 in Senior Cat2.



Title: Re: P-18
Post by: pubguy on November 12, 2016, 10:19:29 AM
I have a question about the tail fin. The plans show it offset to the left but the images on this site appear to have the fin inline with the fuselage. Which is the best way to go. Thanks


Title: Re: P-18
Post by: jcobbs on November 12, 2016, 10:47:13 AM
The planes we made from Don Mace's P-18 Hawk plans used an offset fin.
Jim


Title: Re: P-18
Post by: kittyfritters on January 27, 2017, 01:41:26 PM
The O.F.F.C. (Old Farts Flying Club) holds a P-18 contest every year as one of the monthly contests.  It is one of the more popular events.  The next one will be 02.01.17 at the Stonehurst Recreation Center gym, 9901 Dronfield Ave, Sun Valley, California.  The meeting is at 9:00AM and the contest runs from 10:00 to 11:45.  Spectators, and new fliers are welcome.  This year's contest is restricted to the P-18 Hawk design, built per plan, but any front end and prop are allowed, and an 8 gram minimum.  (We let the CD set the rules for the particular session.)

Attached is a picture of the contestants from last year's contest.  Also, we do have a formal weigh in to get on the timing sheet.  In the other picture that's Will Woods with the plane on the scale with Pete Bassone the time keeper.




Title: Re: P-18
Post by: kittyfritters on February 06, 2017, 05:10:30 PM
The P-18 contest was held February 01.  It went very smoothly thanks to the efforts of the CD, Barry Dougherty.  The contest was P-18 Hawk, per plan, with any prop and front bearing allowed. (Per CD's discretion.)  All were scratch built except for Dave Gee's entry which was a Laser Cut Planes kit.

The results were:

1. Lowell Norenberg                    234.6 seconds
2. Don Martin                            228.1
3. Stan Christopher                    224.2
4. Pete Basone                          172.0
5. Wynn Hammer                        129.7
6. Dave Gee                              121.7
7. Bud Matthews                        119.9
8. John Buntin                            107.9


Some pictures,  Dave Gee launching,  John Buntin weighing in with Barry Dougherty at the scale, and Barry totaling the scores under the watchful eyes of Don Martin and myself.


Title: Re: P-18
Post by: leop on February 06, 2017, 11:26:10 PM
Are the times the best single flight or the sum of the two best flights?

LP


Title: Re: P-18
Post by: kittyfritters on February 07, 2017, 02:52:26 PM
Are the times the best single flight or the sum of the two best flights?

LP


The times are the sum of the two best of five attempts.

This is a somewhat difficult room for the lighter, slower model classes since we have no control over the HVAC system.  Everyone would get better times if we could turn it off.  Bye the way, two of the guys in that list of contestants are over 90 years old!

Howard


Title: Re: P-18
Post by: ram on March 05, 2017, 03:43:44 PM
I'm hoping to get my daughter to build a P-18. In the AMA P-18 rules it states unmodified commercially available "unit" (Max Dia 6").  Does this mean you have to use the plastic hanger that comes with them?   I have a box of old red plastic 5.5" props but not on hangers.  Can she use these with her own bearing or do I need to buy some fresh  "units"? What about 6" Tern Aero props or 6" Kaysun props?  I have several of those, also and they didn't come with hangers.  I don't mind buying some fresh prop "units" if I need too.   Is there a list of legal props?


Title: Re: P-18
Post by: dslusarc on March 05, 2017, 05:22:04 PM
Ray,

Putting my CD hat on, I read the rules to govern only the "prop" itself not the "prop assembly" or "prop with hanger assembly" etc. So as CD I would allow an unmodified 6" turn Aero prop to be used with a thrust bearing and prop shaft of your choice. The use of the term "unit" does not necessarily require anything more than the molded prop be considered as the "unit" as I looked up the definition of "unit'" and a unit can be "a single thing, person, or group that is a constituent of a whole". So that to me means the "commercial unit" can be just the prop or a prop/hanger assembly. I am assuming that it was worded that way to allow both styles to be legal. If not then it will have to wait until the next rules cycle for a clarification.   

Don


Title: Re: P-18
Post by: ram on March 05, 2017, 08:52:35 PM
Thanks Don. I had an off list suggestion that the 6" Ikara would be a good choice. I'll let her measure and compare all the props I have and then decide.  I had thought that the Ikara wouldn't be legal due to it being made up of several pieces,  but after reading what you had to say I tend to agree that it is legal.

Rey


Title: Re: P-18
Post by: ram on March 06, 2017, 09:36:01 AM
Also, in an off list response, it was mentioned that they glue the prop shaft into the prop.  I believe that in outdoor P-30 that would have been considered modifying the prop and not allowed.  It seems that attaching anything to the prop other than balance weight to one blade, which is specifically allowed, would be a modification.  It seems like the next step would be to add a gurney flap or maybe some blade area.  Thoughts?  Am I thinking about this too much?  If so just tell me to shut-up!!!

Rey


Title: Re: P-18
Post by: mkirda on March 06, 2017, 09:54:26 AM
Modifying the prop shaft is not disallowed, so I can see no reason why it would be DQ'ed. Assuming you are removing the Ikara shaft and replacing it with something else, i.e. longer or thicker.
This is different than say, cutting down the prop area or modifying the pitch distribution.

Regards.
Mike Kirda


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 10:46:02 AM
I went and read the P30 rules since I do not fly outdoor and the rules state the prop must freewheel in that event. So if you glued the shaft to the P30 prop then it will not freewheel so I can see that being illegal for P30. There is no such requirement in the P18 rules.  I would not consider installing a shaft into a prop as modifying the prop. How else is one expected to make the prop spin?


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 10:50:39 AM
The multiple pieces of the Ikara prop will satisfy a plastic prop rule but not a one piece molded plastic prop rule. P18 had no material requirement other than the prop must be commercially available. So if a person commercially sold wooden props they are legal as well.


Title: Re: P-18
Post by: ram on March 06, 2017, 10:56:41 AM
The multiple pieces of the Ikara prop will satisfy a plastic prop rule but not a one piece molded plastic prop rule. P18 had no material requirement other than the prop must be commercially available. So if a person commercially sold wooden props they are legal as well.

Like these?:  http://hobbyspecialties.com/product_info.php?products_id=33&osCsid=35cb99dabb318728b166da5ac41f1ce0

I'm not sure I like where this is going.

Rey


Title: Re: P-18
Post by: mkirda on March 06, 2017, 11:26:09 AM
A short run of balsa props with carbon hub that allows for adjustment of pitch maybe?

Yeah, I see where you are going, Rey. I thought the intent was plastic props, but the lack of restrictions of material make this sort of prop not only likely but inevitable.
In fact, the wheels are already turning...

Regards.
Mike Kirda


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 11:28:23 AM
As a CD I see nothing in the P18 rules to not allow those props. This is an example of why it should not have been quickly adopted as an AMA event. The rules should have been agreed upon then test flown to find the loopholes/omissions etc especially under AMA interpretation.  Now it is stuck as an AMA event in a 2 year rules cycle.


Title: Re: P-18
Post by: jakepF1D on March 06, 2017, 11:44:32 AM
Don,

It's not actually an AMA event per se, it's only a provisional event.  The intent was to get it in the rule book specifically so it could be flown at numerous contests, and issues like this could be discovered before it becomes an official event (assuming it actually does).  Also, the requirement for a commercially available prop is specifically to remove the need for a beginner to build a prop which many deem a barrier to entry.  If someone decides to sell a better prop at a reasonable price, then I don't see an issue with that.  The key is that it's widely available so anyone has access to it.  A one time run of 10 props does not qualify as commercially available.  If this becomes a problem, then the issue can be addressed in the next rules cycle.


Title: Re: P-18
Post by: ram on March 06, 2017, 11:47:17 AM
Isn't there an option of a formal rules interpretation being submitted to the contest board?  I wasn't involved in the formulation of the P-18 event so I don't know if the rule was meant to restrict to plastic props or not.

Rey


Title: Re: P-18
Post by: mkirda on March 06, 2017, 11:47:54 AM
What is a good adhesive for the plastic material mentioned in the rules?

Not used non-mylar plastics previously.

Regards.
Mike Kirda


Title: Re: P-18
Post by: jakepF1D on March 06, 2017, 11:58:05 AM
What is a good adhesive for the plastic material mentioned in the rules?

Not used non-mylar plastics previously.

Regards.
Mike Kirda

I used rubber cement which seemed to work reasonable well.


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 12:07:54 PM
Mike,

I used 3m77 spray adhesive with produce bag covering for my Science Olympiad which is essentially the same event.


Title: Re: P-18
Post by: mkirda on March 06, 2017, 12:10:19 PM
Great, thanks guys!



Title: Re: P-18
Post by: dslusarc on March 06, 2017, 12:20:07 PM
Jake,
I mean its a AMA event in the sense it must follow a 2 year cycle. If it was left outside the AMA constraints during this developmental  period it could have these issues adjusted much easier and immediately if needed. I do not think it was intended to allow wooden props but people have to be prepared to see them for the next two years provided they can be commercially bought.

Your comment of a one time run of 10 pieces not being "commercially available" is interesting as there was a similar argument used in regards to Y2K2 film not being commercially available years ago as there was a limited supply due to it being an experimental one time run of film. In F1D it makes no difference due to the rules but Pennyplane, LPP, Int stick, Manhattan, and EZB  have that  in it and records have been set with Y2K2 film covered planes with a film that can be considered by some as not commercially available.

It may be difficult for the indoor board to say on one hand Y2K2 is still commercially available but a short run of props is not. Perhaps the term needs clarification??


Title: Re: P-18
Post by: mkirda on March 06, 2017, 12:25:04 PM
It may be difficult for the indoor board to say on one hand Y2K2 is still commercially available but a short run of props is not. Perhaps the term needs clarification??

Also commercially available WHEN?
I've heard of older props from the 1970's timeframe that had better P/D ratios than what is currently available.
Are these no longer usable since they are no longer commercially available?
Or since they once were, they are still OK now?

Regards.
Mike Kirda


Title: Re: P-18
Post by: ram on March 06, 2017, 12:28:03 PM
In the similar vein to Don's comments above, I was having an off list discussion and posited the below:

As far as "old" props I have a red 5.5" that looks like a North Pacific / Sig, but has a pitch of 9.3" at the 2" radius!  All the others have a pitch just over 6".  It came out of a different mold than the others because the front has a recess in it.  I can't imagine that it would still be considered commercially available, but does that mean if all of a sudden Sig quits making props (or Ikara,etc.) those props become instantly illegal?

Rey

(Isn't this fun?!?...NOT!)


Title: Re: P-18
Post by: Bredehoft on March 06, 2017, 12:34:47 PM
Don and all,

Regarding "commercially available", limited production, etc., consider this - the North Pacific Sleek Streek Prop (and assembly) is a popular "unit".  However, the original, while mass produced in the thousands and thousands, is no longer available commercially.  (There is at least one reproduction, but the prop is not the same as the original NP prop.)

I know that is splitting hairs, but all rules discussions are just that.  This can apply to any item that is deemed to be commercially available, whether propellers, covering, or any other thing and the term is a slippery slope.

Even the P-30 requirement for "unmodified" causes discussion, even this long after the rule was made (ramps cannot be removed, additional clutches cannot be added, etc.).

One restriction that some groups use is "one-piece plastic prop" - that eliminates Ikara indoor props (and most that Mike might be thinking of creating  ;) )  This rule does allow modifications to the one-piece plastic prop, such as trimmed to max diameter or shaving.

People will always try to find loopholes.  That is not always bad, especially in the world of limited production for Free Flight modeling.

(NOTE - Rey and Mike commented similarly while I was typing this!)

--george



Title: Re: P-18
Post by: Bredehoft on March 06, 2017, 12:38:28 PM
In a lighter vein,

Here is a video of a P-18 mass launch that occurred at an indoor contest in COlorado Springs yesterday.

It may only be visible if you have a facebook account - not sure....

https://www.facebook.com/groups/626401977506260/1089571764522610/?comment_id=1089579227855197&notif_t=like&notif_id=1488770981380927 (https://www.facebook.com/groups/626401977506260/1089571764522610/?comment_id=1089579227855197&notif_t=like&notif_id=1488770981380927)

--george


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 12:42:06 PM
It may be difficult for the indoor board to say on one hand Y2K2 is still commercially available but a short run of props is not. Perhaps the term needs clarification??

Also commercially available WHEN?
I've heard of older props from the 1970's timeframe that had better P/D ratios than what is currently available.
Are these no longer usable since they are no longer commercially available?
Or since they once were, they are still OK now?

Regards.
Mike Kirda



Mike,

I have some of those old red props, they are also much lighter about 1.7 grams compared to 3 grams or so for newer red props. They have a lot less plastic on the hub. The old style red prop is what is on my Phantom Flash :-)

Don


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 12:49:32 PM
This just shows how hard it is to write a set of rules!

Don


Title: Re: P-18
Post by: jakepF1D on March 06, 2017, 02:08:19 PM
Jake,
I mean its a AMA event in the sense it must follow a 2 year cycle. If it was left outside the AMA constraints during this developmental  period it could have these issues adjusted much easier and immediately if needed. I do not think it was intended to allow wooden props but people have to be prepared to see them for the next two years provided they can be commercially bought.

Your comment of a one time run of 10 pieces not being "commercially available" is interesting as there was a similar argument used in regards to Y2K2 film not being commercially available years ago as there was a limited supply due to it being an experimental one time run of film. In F1D it makes no difference due to the rules but Pennyplane, LPP, Int stick, Manhattan, and EZB  have that  in it and records have been set with Y2K2 film covered planes with a film that can be considered by some as not commercially available.

It may be difficult for the indoor board to say on one hand Y2K2 is still commercially available but a short run of props is not. Perhaps the term needs clarification??

I do think it would be beneficial to define commercially available.  To me there are two factors in play here.  One is defining when something is considered commercially available, and second is determining whether something that is no longer available still qualifies. 

On the first point, I could envision a couple ways to define commercially available, but I wouldn't want to go too far into the weeds.  This is something that would require a a fair bit of discussion to nail down.

On the second point, I think once something is deemed legal under the definition of commercially available, it should always be legal.  That is to say a model built 15 years ago when Y2K2 was still available shouldn't ever be made illegal.  Similarly anyone that happens to have a stash of Y2K2 should be able to use it.  If we begin banning things that are no longer available, then everyone would need to buy a new batch of rubber every few months.

These are of course just my opinions, and perhaps this should be discussed further among the indoor board members.


Title: Re: P-18
Post by: Olbill on March 06, 2017, 03:11:07 PM
IMHO the right way to solve this problem is to have one rule for props - 6" max diameter. Let the people who are competing decide what works best and how to get it.

I'm not familiar with this year's SO rules but recently there's been no restriction on the prop other than diameter. If it's good enough for SO then it should be good enough for AMA.


Title: Re: P-18
Post by: ram on March 06, 2017, 03:24:50 PM
I agree with Bill except I do think that it should be limited to plastic props since this is an introductory event.  Most, if not all, the SO/TSA kids are using Ikara props.  They are familiar and comfortable with them.  I believe the current SO plane meets the P-18 rules and I would be in favor of keeping them legal so that they could fly in an AMA contest.

Rey


Title: Re: P-18
Post by: mkirda on March 06, 2017, 03:33:05 PM
Hi Rey.

Kids are modifying Ikara props though and flying them in SO competition.

At Racine last week, the best flying plane flew a full minute longer than the rest using standard SIG props.
It was some variation on Ikara. I am not sure what exactly as I did not examine it.

Regards.
Mike Kirda


Title: Re: P-18
Post by: ram on March 06, 2017, 03:41:33 PM
Mike,

I think that is perfectly fine.  A plastic prop of max 6" diameter.  Encourages experimenting. 

I know my daughter would be bored if it was so restrictive that everyone had the exact same plane.  She just competed in a balsa bridge competition put on by the ASCE chapter here and loved it because the parameters allowed a lot of variation.  She designed and built her own bridge (with NO help from me) and, even though she didn't win, had a blast and is already planning her next "more improved" one.

Rey


Title: Re: P-18
Post by: Olbill on March 06, 2017, 03:49:16 PM
But wood props are legal in SO. Most of the SO fliers I've heard about are using plastic props either for simplicity or b/c they think they work better. I'd like to see the same choice allowed in P-18.

Also, if this event is supposed to make people want to fly more advanced indoor F/F I'd like to see some level of thinking involved. Once you leave P-18 the "little gray cells" that Poirot talked about are going to have a big work load.

So I can see this scenario for P-18 at a series of AMA contests:

Ist contest
Flier #1 uses a solid plastic prop.
Flier #2 uses a modified Ikara prop and wins by 5 seconds.

2nd contest
Flier #1 uses a modified Ikara prop
Flier #2 also uses a modified Ikara prop
Flier #3 uses a home made balsa prop and wins by 5 seconds.

3rd contest
All fliers use home made balsa props
All fly well but the winner located some good rubber since the last contest.
Then:
Fliers 1-4 notice how much nicer the LPP's fly than their P-18's
Fliers 1-4 know how to build balsa props and decide that building an LPP can't be all that difficult.
And if we are lucky one of those fliers will get hooked on iindoor F/F


Title: Re: P-18
Post by: Olbill on March 06, 2017, 03:53:41 PM
As we speak Don Deloach has put forth an interpretive rule change to limit props to one piece unmodified plastic props with only weight added for balancing to be allowed.


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 04:01:37 PM
The current SO models do not necessarily meet P18 rules. They are close but not the same. Most SO models are not legal for P18 due to motor sticks being longer than 10", overall length greater than 18", and cut down and or repitched Ikara props.  Trying to make P18 parallel with SO will not works as SO changes every year. Next year could be 8" prop or 3" chord etc. Best to give  P18 it's own identity I think.


Title: Re: P-18
Post by: aardvark_bill on March 06, 2017, 05:56:28 PM
As we speak Don Deloach has put forth an interpretive rule change to limit props to one piece unmodified plastic props with only weight added for balancing to be allowed.

So the 150 mm Ikara won't be legal under this interpretive rule, correct, because it is not one piece?


Title: Re: P-18
Post by: mkirda on March 06, 2017, 06:03:23 PM
If it is sold as one piece, isn't it one piece?


Title: Re: P-18
Post by: Olbill on March 06, 2017, 07:05:42 PM
Sounds like the interpretive rule might need some more interpretation.


Title: Re: P-18
Post by: ram on March 06, 2017, 07:43:17 PM
I think it's clear enough except for the "commercially available" part that is undefined. The Ikara is plastic, within 6", available, and comes in one piece as opposed to separate parts (blades and spar).


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 08:06:07 PM
As an example on another event, for FAC Phantom Flash they worded it as "one piece molded plastic" so my old Ikara prop was illegal as it was not molded. So P18 perhaps should be re-worded as:

"The propeller shall be an unmodified commercially available one piece molded plastic prop with a maximum diameter of 6 inches. Weight may be added to the blade for balancing."

Don


Title: Re: P-18
Post by: ram on March 06, 2017, 08:43:25 PM
As an example on another event, for FAC Phantom Flash they worded it as "one piece molded plastic" so my old Ikara prop was illegal as it was not molded. So P18 perhaps should be re-worded as:

"The propeller shall be an unmodified commercially available one piece molded plastic prop with a maximum diameter of 6 inches. Weight may be added to the blade for balancing."

Don

But that gives us who happen to have a special  molded plastic prop with higher than normal pitch an advantage while the Ikara levels the field.


Title: Re: P-18
Post by: dslusarc on March 06, 2017, 09:27:26 PM
The Ikara's vary in pitch as well, sometimes one blade to another! I will say in regards to the Ikara prop on SO models, those 6" ones spin around 1000 rpm and the 7.5 gram models can and do easily damage them when landing or hitting. The blades get bent back where the prop spar ends. The kits they started with had small wood spar extension they glued on. If a blade gets broken then my guess is repairing would not be allowed as it is has then been modified??? Just a thought.  

In my discussion with Don DeLoach in regards to his Interpretation Proposal he has put forth to the Indoor Board, he told me the original intent was to use the 5.5" one piece molded props with the hangers (like on an AMA Delta Dart) then during the cross proposals the hanger part was dropped etc and left with a 6" plastic prop that the builder can install their own shaft and use their own prop hanger. I was not on the Indoor board at that time and there are no records of board communications I can see for current board members to look at (an archive so to speak) to see what all was discussed.

I was just reading the board procedures when I got home after work and an interpretation proposal by definition "does not change the existing rule but provides information designed to clarify it. It deals with interpretations of the rules, or ways in which the rules are applied in the field, where situations are not clearly dangerous."

Consequently I do not think adding the terms "single piece plastic" is an interpretation of the current rule, it seems to me like a changing of the existing rule from just a prop made from any material to a plastic prop. To me an interpretation would be if the rules said "plastic prop" and the interpretation was that "plastic prop" means the prop can be made from plastic material (like and Ikara) or molded from plastic (like SIG red prop).

I believe this to be especially in light of the fact that an urgent proposal is defined as follows:
"Urgent proposals are not an interpretation of existing rules or necessarily related to safety. Urgent proposals are proposals that cannot wait for the normal rules change cycle due to there being a problem with the current rules that adversely affects the event in some manner. An Urgent proposal will constitute an actual change in the rules, and therefore the justification for this type of proposal must be very closely scrutinized to prevent abuse."

I think changing from any commercial 6" prop to a commercial single piece plastic prop is a rule change not an interpretation. So my question is then did the board intentionally leave the wording of plastic out on purpose? Or was it an oversight during the cross proposal process? This will affect how I vote on any urgent proposal. If the printed rule book is not the voted on and agree rules by the board then it needs to be fixed with an urgent rule change. If the rules are as voted on then I think they should be left alone for now until the next cycle where people can submit changes like normal.  

Don




 
  


Title: Re: P-18
Post by: Olbill on March 06, 2017, 11:02:26 PM
I'm leaning towards voting against the "clarification".


Title: Re: P-18
Post by: ram on March 07, 2017, 05:54:21 PM
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


Title: Re: P-18
Post by: leop on March 07, 2017, 07:50:37 PM
The addition of the words "one piece molded" is the proposed "clarification."  Or not a "clarification" but an additional restriction that should await and follow the two year rule change cycle.

The proponent of the "clarification" should probably have proposed "molded in one piece" if I understand the intent of the additional restriction.

The current rules clearly allow the 150cm Ikara prop.  Please note that many plastics, including many used for injection molding are not pure resins but have fillers, including fibers, for additional strength, toughness, and bulk, etc. (as well as to reduce cost).  Also, please remember that epoxy and polyester are plastics.

By the way, a prop with tubes for adjustable pitch would probably fall afoul of the unmodified restriction as any pitch change would be a modification of the prop. 

Finally, "commercial available" is the term of art used in the AMA Builder of Model rule.

LP


Title: Re: P-18
Post by: dslusarc on March 07, 2017, 08:43:35 PM
Leo,

Once the missing text was found to be a clerical issue the Interpretaiton Proposal that was submitted was withdrawn by the submitter. So the Ikara props are legal. Redefining "plastic prop" to a "one piece molded plastic prop" or similar would have to be introduced next rules cycle.    

Don



Title: Re: P-18
Post by: Olbill on March 08, 2017, 08:24:44 AM
I'm a little confused as to how a CD would detect a prop pitch change. Or why a pitch change would be illegal in the first place.


Title: Re: P-18
Post by: leop on March 08, 2017, 12:37:49 PM
The commercially available prop must be "unmodified."  Changing the pitch is a modification from the shape or form present when purchased.  With tubes, such a pitch change is easy (but one still may add glue to keep the pitch stable - also not allowed) .  However, even one piece injection molded plastic props can have their pitch distributions modified using a bit of gentle manipulation and, perhaps, a heat gun.  This can easily be done without leaving the tell tail lightening of the strained plastic.

The detection of such modifications is different thing.  It might be hard for a CD to detect such a change but it is a change or modification nevertheless.  The competitor knows that the modification has been done. 

Or, if a rule violation is undetected by the CD, does this mean there is no rule violation?

LP


Title: Re: P-18
Post by: ram on March 08, 2017, 01:01:22 PM
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


Title: Re: P-18
Post by: Olbill on March 08, 2017, 02:28:13 PM
The commercially available prop must be "unmodified."  Changing the pitch is a modification from the shape or form present when purchased.  With tubes, such a pitch change is easy (but one still may add glue to keep the pitch stable - also not allowed) .  However, even one piece injection molded plastic props can have their pitch distributions modified using a bit of gentle manipulation and, perhaps, a heat gun.  This can easily be done without leaving the tell tail lightening of the strained plastic.

The detection of such modifications is different thing.  It might be hard for a CD to detect such a change but it is a change or modification nevertheless.  The competitor knows that the modification has been done. 

Or, if a rule violation is undetected by the CD, does this mean there is no rule violation?

LP


I wasn't advocating for cheating. I just think it's a silly restriction and difficult to enforce.


Title: Re: P-18
Post by: leop on March 08, 2017, 05:16:00 PM
Bill,

I agree that having a rule that is difficult to enforce could be a problem and, in some cases, is silly.  I think that the enforcement of a rule, including the methods of ensuring compliance, should be a prime consideration in the deliberations and vote of the Indoor Contest Board.  Indoor duration flying depends on the honor system to provide for orderly and smooth competitions.   However, the honor system should be backed up by at least the possibility of enforcement.  Rules such as the P18 unmodified prop restriction do not lend themselves to such a backup.

As I think someone said earlier in this thread, making rules is not all that easy.

LP


Title: Re: P-18
Post by: mkirda on March 08, 2017, 05:20:34 PM
It is also not unheard of to have a manufacturer tweak another's product.
An example from Outdoor:

GizmoGeezer sells a nice prop unit for the P-30 event where the prop is advertised as a re-pitch Peck Polymers 9.5" prop.

Wouldn't be that difficult to do the same in Indoor. Is that now cheating if I sell repitched props?

Regards.
Mike Kirda


Title: Re: P-18
Post by: leop on March 08, 2017, 05:49:38 PM
The seller of the modified, re-pitched prop would not be cheating.  How this applies to the "knowing" purchaser and user is another thing.  But, my initial comment on this matter was purposely a "draw in" along a path that led to Bill's "silly" comment.  The rules makers need to consider such things. 

In the "remanufactured" example given, one could take this further and have even more remanufacturing, such a lightening and reshaping, done to the prop than just gentle repitching.  So, it is okay if someone purchases and uses such remanufactured props but not okay for the competitor to do the same thing for him or herself.  I guess the out for any competitor is so offer his or her own "remanufactured" props for sale, say at $1,000 each if the sale is not really desired.   This latter point is the true "silliness" of having such an unmodified commercially available rule.  I suspect that everything is "commercially available" at some price.

BTW, there is another thread in the general section of this indoor forum concerning the BOM (builder of model) rule.  That discussion is going along a path not all that dissimilar to this one.

LP


Title: Re: P-18
Post by: aardvark_bill on March 08, 2017, 06:38:01 PM
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


Title: Re: P-18
Post by: dslusarc 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  ;D  Instead of the Ikara prop why not the Kirda prop or Leo prop etc  ;D

Don S  



 


Title: Re: P-18
Post by: ram 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


Title: Re: P-18
Post by: frash 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


Title: Re: P-18
Post by: aardvark_bill 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


Title: Re: P-18
Post by: ram 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


Title: Re: P-18
Post by: ILM Tarheel 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


Title: Re: P-18
Post by: dslusarc 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


Title: Re: P-18
Post by: ram 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


Title: Re: P-18
Post by: calgoddard 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.


Title: Re: P-18
Post by: adanjo 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


Title: Re: P-18
Post by: Wind-it-up 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!  :)


Title: Re: P-18
Post by: ram 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


Title: Re: P-18
Post by: Wind-it-up on August 27, 2017, 12:40:18 PM
Thanks Rey - somehow I missed the outcome...guess I didn't read the thread closely enough.  ;) I'm encouraged by your comments also since I've not done much with indoor flying!  Thanks.


Title: Re: P-18
Post by: ram 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 


Title: Re: P-18
Post by: Wind-it-up 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!