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Author Topic: BMFA Peanut Rules  (Read 1596 times)
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Slowmatch
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« Reply #75 on: May 18, 2022, 06:10:45 AM »

I’m still not quite there with this though:
Undercarriage is more than aerodynamic drag-factor - it also limits prop diameter which can with many subjects be a significant impediment to duration, so the ROG bonus is key. Smiley
Surely undercarriage doesn’t limit prop diameter at all. It’s the rules that limit prop diameter for wheeled subjects (specifically, the ROG bonus rule). Perhaps the real question then is, “Why restrict prop diameter?”

Biggest possible prop diameter is critical for duration. There aren't many peanuts with prop clearances above 4-5" unless you have stalky non-scale UCs which is penalised by only a static mark or two. A 6" prop + handlaunch would have at least a 10 second advantage over a 4" prop + ROG.

I was looking back at results again: can anyone remember if Mike's Bucker ROGs? Or Richard's Stuka?
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Skymon
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« Reply #76 on: May 18, 2022, 07:10:29 AM »

You only lose 2 points for modifying the undercarriage to allow large prop clearance.
ROG scores will penalise planes whith retractable undercarriage as they will have to fly with the wheels down.

I've been on the edge of Peanut for many years, the rules have never been the thing that stops me competing.
It's getting around to it. I have flown indoor duration for several years though, so I am aware of the indoor scene.

I've never really understood the weighting applied to "unusual" subjects in order to encourage different models.
If you look at autogiros there are less than half a dozen that would work as rubber models.
These esoterica tend to be more difficult to build and fly, but look like a nice points grabber for a first model.
Not a great intro for a new flier, to pick something potentially points winning but a pain to build and fly.

I realise the contra argument is everyone will be flying Piper Cubs* but if they did then you'd need to build one that flew really well with some superb scale detail to win. Isn't that what Peanut is about?

Sorry to just wade in as a non peanut flier. Just my thoughts.
I a considering a Piper cub Smiley

*Fike, Chambermaid, Cassutt, etc...
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Pete Fardell
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« Reply #77 on: May 18, 2022, 07:18:41 AM »

I was looking back at results again: can anyone remember if Mike's Bucker ROGs? Or Richard's Stuka?
Yes and no respectively, I think. Although I don't know if that's always the case for either.

The Hadland Jungmann ROG from 2017 (at 3:51 into Monz's vid): https://www.youtube.com/watch?v=tqbpaGq6k3o&t=9s
The Crossley Stuka hand launched (videoed by Mike Stuart right back in 2010; is this the same Stuka?): https://www.youtube.com/watch?v=zuvH2nKaOTU
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Squirrelnet
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« Reply #78 on: May 18, 2022, 08:13:13 AM »

Also Mike Hadland this year in this video ROG 7'10"

https://www.youtube.com/watch?v=L2ior65DF54&t=702s

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Nigel M
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« Reply #79 on: May 18, 2022, 10:58:08 AM »

I was looking back at results again: can anyone remember if Mike's Bucker ROGs? Or Richard's Stuka?
Yes and no respectively, I think. Although I don't know if that's always the case for either.

The Hadland Jungmann ROG from 2017 (at 3:51 into Monz's vid): https://www.youtube.com/watch?v=tqbpaGq6k3o&t=9s
The Crossley Stuka hand launched (videoed by Mike Stuart right back in 2010; is this the same Stuka?): https://www.youtube.com/watch?v=zuvH2nKaOTU
It must have done because he scored >50 in flight scores, but I observed he was experimenting with duration props on a previous occasion. He said 'they' said it would improvce duration.
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Nigel M
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« Reply #80 on: May 18, 2022, 11:08:25 AM »

You only lose 2 points for modifying the undercarriage to allow large prop clearance.
ROG scores will penalise planes whith retractable undercarriage as they will have to fly with the wheels down.
Hi Skymon, I don't think flying with u/c down is penalised in the rules - happy to be corrected. The extra drag will affect trimming perhaps but is surely no more than fixed u/c aircraft? Good point that an exaggerated (or any!) u/c allows an extra 30 points from a ROG whereas 2 potential points can't be gained. Does that point towards the ROG bonus needing adjustment?

Nigel (another wannabe  Smiley)

Worth noting it's low thrust not low wingers necessarily that are compromised by needing to ROG.
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Nigel M
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« Reply #81 on: May 18, 2022, 11:13:45 AM »

Yes I agree it's a better indication of the emphasis but not correct mathematically speaking. That's where my mind operates but it must be clear to everyone. I think a rule book should be unambiguous, don't you agree?  Grin
Yes, probably better not to give a ratio at all than a potentially ambiguous one.
Apologies, Peter, that response was written somewhat in haste. I did not mean to diminish your point... thankfully the conversation has moved on   Undecided

For everyone: I'd like to broaden the debate about multipliers applied to flight scores vs static scores. Let me suggest the Open classes are the pinnacle because they require the highest commitment of time and probably the highest level of skill. No-Cal is (almost) pure duration.

How should the classes inbetween be differentiated? Should it be only via static scoring rules? Would you retain Intermediate having a longer flight minimium duration than Open? Should Peanut/Pistachio be created as basically a pair of mini-Intermediates?

Reading the full set of indoor scale classes, there's a clear progression from the Open classes down to the No-Cal Duration class from equal weighting to almost pure duration. Does that not offer the opportunity for each person to decide which emphasis plays to their strengths and preferences?

Nigel
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Nigel M
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« Reply #82 on: May 18, 2022, 11:19:07 AM »


I’m at severe risk of flogging a dead horse here I know, 
Keep going please, I think the debate is adding value, particularly in clarification of the nuances of the scoring scheme.
Nigel
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Nigel M
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« Reply #83 on: May 18, 2022, 11:24:40 AM »

This is addressed at no one in particular but is meant to clarify why a max is a good idea for the system of combined scores.

Basically, without a max, to beat Mike H's supreme Bucker, I would only need to fly for 15s longer than him which I would do by building a super-lightweight duration model with no regard for needing any static marks. The max allows the balance between flight duration and static score to be controlled.

15s is calculated because Mike's static score was 44 which is compared to 3x my hypothetical flight score which is rounded down to the nearest second.

HTH
Nigel
Curiously, reflecting on that post finally led a penny to drop regarding the microfilm/Mylar rule.

A person of relevance told me they didn’t think plastic films represented the finish of aircraft well and I assumed the purpose of the microfilm/Mylar rule was a badly worded attempt to remove their use, i.e. the use of all plastic films.

I now think the rule means just what it says and the purpose is to provide another way to avoid entrants creating super lightweight duration models having only a nod to scale fidelity.

Apologies to anyone else my comments may have misled or confused.

For my part, I think glossy plastic films could well represent the sheen on heavily restored classics, modern reproductions, bare metal on unpainted aircraft or cowlings, or painted composite or metal aircraft. The greater difficulty might be achieving a good colour match, colour depth, texture if any, etc, as well as applying them to a lightweight frame without excessive distortion during heat shrinking.

HTH
Nigel
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billdennis747
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« Reply #84 on: May 18, 2022, 02:29:31 PM »

A person of relevance told me they didn’t think plastic films represented the finish of aircraft well and I assumed the purpose of the microfilm/Mylar rule was a badly worded attempt to remove their use, i.e. the use of all plastic films.
They need to see Ralph Sparrow's silver mylar models.
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Pete Fardell
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« Reply #85 on: May 18, 2022, 02:49:55 PM »

A person of relevance told me they didn’t think plastic films represented the finish of aircraft well and I assumed the purpose of the microfilm/Mylar rule was a badly worded attempt to remove their use, i.e. the use of all plastic films.
They need to see Ralph Sparrow's silver mylar models.
Such as this one in this pic from Mike’s site http://www.ffscale.co.uk/page3ai.htm
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Re: BMFA Peanut Rules
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RalphS
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« Reply #86 on: May 19, 2022, 10:12:13 AM »

Just came across this.  Is the mylar ban just for Peanut class or all indoor scale classes?  The only times that I flew were 2016 and 2017 and think that my models were the only mylar covered ones so "was it me" who caused this minor rumpus and why?

Do the Scale tech committee publish minutes of their meetings? 

I found that I got different static scores between the years for the same model. That put me off. 

As well as silver mylar I have used clear mylar with acrylic paint on my Bristol Scout Peanut to get the see-through effect.  The Avro Avis did use silver mylar.  It is still largely unflown due to the Covid interruption.  Both builds here in the indoor scale/ Peanut sections.

Ralph

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SP250
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« Reply #87 on: May 19, 2022, 10:31:07 AM »

Ralph

It definately wasn't you who caused the mylar ban.
STC minutes are published on the BMFA SharePoint website and there is a link on the Scale BMFA Website under documents tab.
Different scores on different years is normal from different judges.  Everyone else's models will also get different scores. 
As long as they are all judged by the same judges on the day, then all the models will be coming out around the same place relative to each other.
My peanut Lacey M10 with dull side of the mylar out looked just right for the original colour scheme before the white and red one. 
Now I have stripped it all off to tissue cover and the silver tissue is horrendous to use.

John M
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Nigel M
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« Reply #88 on: May 19, 2022, 01:28:30 PM »

A person of relevance told me they didn’t think plastic films represented the finish of aircraft well and I assumed the purpose of the microfilm/Mylar rule was a badly worded attempt to remove their use, i.e. the use of all plastic films.
They need to see Ralph Sparrow's silver mylar models.
Such as this one in this pic from Mike’s site http://www.ffscale.co.uk/page3ai.htm
Thanks. I happen to own that yellow wingtip now  Grin still far better than anything I can build. Kudos for anyone who can ID it (Dan Mellor is excluded from the comp  Cheesy)
« Last Edit: May 19, 2022, 01:47:27 PM by Nigel M » Logged
Nigel M
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« Reply #89 on: May 19, 2022, 01:45:31 PM »

One more post from me, then I'm off for a lie down. Sorry it's long, happy to be fact-checked, assumptions dismissed, sums altered or whatever else.

I for one think the whole exercise was worthwhile - thanks, Peter - and I look forward to the outcome of STC's deliberations. I'd better build something now I've had so much to say. All I'll say is it will definitely have a wingspan >13".

ROG value
One last contribution from me exploring the impact of the ROG bonus value on breadth of model choice alongside changing the flying score multiplier, within the combining scores system.
To recap; ROG bonus = 10s which is increased by the multiplier value 3 to equal 30 marks. This might be viewed as too rewarding compared to max possible static score which is around 45-60 marks, depending on the aircraft chosen, and hence causes too much bias in model choice, assuming an entrant wishes to at least enter with the possiility of winning, all else being equal. Can the ROG value or multiplier be altered to make model choice fairer, i.e. so a range of model types has an equal chance of winning?

What level of total ROG marks, consistently earned, would be seen as balanced compared to the static scoring system?

How about 15 (i.e. halve the 10 per ROG to 5)? Still too high?
How about 6 (i.e. marks per ROG = 2)? Still too high?

Looked at a different way, to maintain equal encouragement of different model types, it’s easy to compare the impact of the ROG bonus, and the flight time multiplier, upon different strategies. Here’s one strategy comparison as an example:

Compared to building a high wing monoplane, or a biplane, which can’t quite fit a good duration prop, the alternative strategy of building a low winger without undercarriage and foregoing ROG would score: +3 (low winger), -3 (no u/c), -1 (assuming extra dihedral), = -1 before foregoing the ROG bonus. But there’s nothing to prevent an accurate undercarriage being flown deployed though, so score = +2 before accounting for ROG. Overall effect = 2 – total ROG score.

However, an excellent duration-style prop could be used with hand-launch so we could assume flight time max is achieved which, when compared to Mike H’s Bucker, is worth +7+6+5 marks compared to his best flight times of 43, 44 and 45s. That’s either +15 to the low winger (or +18 if we change to combining top 3 flights).

Simplifying the above, low winger no u/c vs biplane using ROG: low winger scores +1 (low wing vs biplane), 0 (u/c modelled deployed), -1 (increased dihedral), +18 (flight times), -ROG bonus. To be equivalent, total ROG should score 18 (i.e. 6 per flight).

Even hand-launching the Bucker but using a better prop, Mike could have scored +15 or +18 (flight time maxes) – total ROG bonus. To be equivalent, ROG bonus would need to be 5 or 6 per flight.

Let’s consider changing the flight score multiplier to another arbitrary number, 2, and/or use top 2 flight scores.

Using the same numbers, comparing a low winger with extended u/c and slightly exaggerated dihedral that achieves max flight times, to Mike’s Bucker from ROG. Low winger flight score = +5+6 (or 2x +5). To be equivalent, divide 11 (or 10) by flight multiplier 2, ROG bonus must be 5.5 (or 5) per flight.

Let’s continue by removing the multiplier completely so flight time and static score are given equal weighting: low winger flight score = +5, to be equivalent, ROG bonus must be 5 per flight.

The downside from removing the multiplier and using single best flight time is it removes the reward for consistency. To regain the encouragement and reward of consistency, one could average the top 3 flight times (or top 2), and still sum flight and static scores without multipliers.

I think my conclusion is, within the combined flight seconds plus static marks system, there is a place for a ROG bonus to encourage diversity of strategies, to make it a more interesting competition. However, the bonus value needs to be changed and the value considered alongside other potential changes, particularly the flight time multiplier.

HTH
Nigel
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Skymon
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« Reply #90 on: May 23, 2022, 05:54:11 AM »

You only lose 2 points for modifying the undercarriage to allow large prop clearance.
ROG scores will penalise planes whith retractable undercarriage as they will have to fly with the wheels down.
Hi Skymon, I don't think flying with u/c down is penalised in the rules - happy to be corrected. The extra drag will affect trimming perhaps but is surely no more than fixed u/c aircraft? Good point that an exaggerated (or any!) u/c allows an extra 30 points from a ROG whereas 2 potential points can't be gained. Does that point towards the ROG bonus needing adjustment?

Nigel (another wannabe  Smiley)

Worth noting it's low thrust not low wingers necessarily that are compromised by needing to ROG.

Morning Nigel
The penalty I referenced as an aerodynamic one, not a points value one, apologies for any confusion.
The extra long UC legs would allow a bigger prop and an ROG. You can collect 30 points, lose 2 and end up with a strange looking plane, but one designed for this scoring system.

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