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F5-RES Rules discussion


martynk

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1 hour ago, mikef said:

You should use a piece of balsa that has the same weight, width and thickness as your balsa/carbon/balsa sandwich for a true comparison.

I would look at 0.4mm ply skins if you want stiff spoilers or, heavyweight tissue/dope over light quarter grain balsa.

My original enquiry was about the use of carbon for spoilers and if not used openly then it could be used covertly. The photo was of some I do use (in a very valid way) and “could” be used for a spoiler.

The ava spoiler is carbon around a foam core. I personally would use thin carbon on a 3mm Depron core. But we are talking about the rules and not structural techniques.

I would be absolutely delighted if you would join me on my Facebook page “Gliding North West,” where we could discuss the structural use of the latest materials, to our heart's content – which I do test.

 

SpoilAva.JPG

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Thanks for your comments. 

 

I think in F3RES or F5RES carbon stiffened spoilers would be illegal. 

Anthony, you are not restricted to stay 10m away from your landing marker. However only the pilot and 1 helper can move within 10m of the landing marker providing they don't obstruct any other pilot or model

Mike thanks for the note on the spinner radius. That's very useful.. Still not totally clear on what happens on a re-flight, I'll need to re-read and think about it.. 

 

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On 09/12/2020 at 08:48, mikef said:

5.3.  This is standard practice in the F3K rules and probably other classes - I would need to check.

The pilot(s) getting a reflight in a round, fly in a new group composed of the reflght pilots and made up to a full group with pilots chosen at random from the rest of the competitors.  A pilot selected at random can decline to fly.  The reflight pilots get the score they achieve on the reflight.  The random pilots get the better of their existing round score and their reflight score.

Hi Mike

I think that I understand this now. The reflight group only exists for one round and then the participants to back to their original groups for the next preliminary round. Is that correct?

How are the scores amalgamated with their original groups? Those drafted in to make the group up could have improved scores and it is also feasible that two pilots could have 1000 normalised points. A reflight group score could make an impact on the final standing for one of the draftees who could benefit from being coopted.

 

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The pilot(s) having a reflight get the score they achieve in the reflight.  The random drawn pilots get the better of their existing score from that round and their score in the reflight group.  Yes, you can improve your score if you accept the risk of flying in the the reflight group.  (If you already had 1000, you would be risking model loss/damage needlessly if you flew.). You don't need to ‘amalgamate’ anything the score is the score for that pilot for that round.

Yes there can be more 1000s scored in a round that there were planned groups flown.

You say, “go back to their original groups” but every pilot is in a 'new' group for each round.  The groups are 'matrixed' before the start to try to ensure individual pilots meet the others in different combinations an equal number of times as far as possible.  (So you never fly with the same group in every round.). The reflight group is an extra group flown at the end of a round if required.  It is outside the pre-matrixed set of groups.

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  • 5 weeks later...

Can anyone tell me if there are to be any rule changes for 2021?

I recall there was some discussion about lowering the F5J hight from 200m to 180m. 

There has been plenty of discussion on another thread about F5/3res, anybody know the final outcome? 

Have to ask, I might get another model this year. 

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The FAI Rules are here SC4_Vol_F5_Electric_21 (fai.org)

There isn't a limited start height in F5J the rules are

e) Each metre of the recorded Start Height results in a deduction of half (0,5) a point up to 200m and three (3) points above it.

(The now redundant  "Bartletts/BARCS ELG rules did have a nominal 200m height without any loss of points and this limit could at the CD's discretion be reduced to say 175m)  

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  • 2 weeks later...
John Minchell

I believe there is going to be an article about the rules/competition by Andy Sephton appearing in the next (imminent) BMFA News magazine.

Hopefully they will be the same as what you have proposed on here Martyn, otherwise confusion will reign. 

Also, are the ISA club F3RES and F5RES rules the same?

John M

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On 18/01/2021 at 03:39, martynk said:

Does anyone have any further comments on the F5RES proposed rules?

Are they clear enough?

If I recall correctly, one of my recent  RES kits had wire wing joiners.    This was a bit of a puzzle for me as I understood that extra weight is not desirable.     I wondered if composite joiners are not allowed.  I can't find any mention of wing joiners in your last draft.    Are wing joiners considered as part of the spar, and so can be composite?        

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This is from the latest iteration.....

2.2.1.Open ribbed wing surface, solid wood surface, “D-box” wood surface, or a combination of solid wood and ribs.

2.2.2.Leading edges, spars, and spar caps of composite such as carbon are allowed, if formed of rods or extrusions.

Carbon spars are allowed, as above. I and many others use carbon tube spars, being far easier than making wood spars with carbon caps and binding with kevlar or kevlar sock.

It does not say tube or rod for the spars. A carbon tube with a carbon rod inside is just the same as a carbon rod spar......... So no problem.

The harder one is the use of a steel joiner as there is no mention of one.

A steel joiner is far easier and cheaper, being a piece of steel rod, bent in the middle. A piece of sheet steel cut in a “V” shape and some joiner boxes may be harder to justify.

The harder one is the covering of a wood fuz in carbon (or other composite). This would then allow the inner “wood fuselage” to be substantially removed.

I am thinking here about making a fuz from 1/16 or even 1/32 balsa and covering in carbon. The original “wood fuz” would NEVER be strong enough to be flown on its own, so it would be a carbon fuz in reality. It then becomes a question of – Is the original fuz a mould ?

2.2.6.The wood fuselage may be covered with composite material such as fiberglass, carbon, or Kevlar, for strength. Otherwise, covering is the same as for the wing and tails.

The above should read - “The wood fuselage may be covered with composite material such as fiberglass, carbon, or Kevlar, but covering no more than 50% . Otherwise, covering is the same as for the wing and tails.

The original says “for strength” where the wood fuz should be strong enough, so it should NOT be used for strength, but rather to stop gravel rash.

Attached is a photo of a canopy off a REF model I have. (The dark square in the middle is a camera) It is very strong and I would be happy with a fuz made in the same way for a F5RES model. It is one layer of very light carbon, that is why I would like to have either moulded fuselages or if only wood, then ONLY limited usage.

CarbCan.thumb.JPG.e439a51f585d4591ae2ac4f6087c42f4.JPG

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2 hours ago, DaveH said:

If I recall correctly, one of my recent  RES kits had wire wing joiners.    This was a bit of a puzzle for me as I understood that extra weight is not desirable.     I wondered if composite joiners are not allowed.  I can't find any mention of wing joiners in your last draft.    Are wing joiners considered as part of the spar, and so can be composite?        

There is no restriction on joiners. Logically, they are part of the spar and composite spars are permitted.  I use a carbon joiner in calm conditions and a steel joiner in less calm flying days. 

Does that make sense? 

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47 minutes ago, AnthonyB said:

This is from the latest iteration.....

2.2.1.Open ribbed wing surface, solid wood surface, “D-box” wood surface, or a combination of solid wood and ribs.

2.2.2.Leading edges, spars, and spar caps of composite such as carbon are allowed, if formed of rods or extrusions.

Carbon spars are allowed, as above. I and many others use carbon tube spars, being far easier than making wood spars with carbon caps and binding with kevlar or kevlar sock.

It does not say tube or rod for the spars. A carbon tube with a carbon rod inside is just the same as a carbon rod spar......... So no problem.

The harder one is the use of a steel joiner as there is no mention of one.

A steel joiner is far easier and cheaper, being a piece of steel rod, bent in the middle. A piece of sheet steel cut in a “V” shape and some joiner boxes may be harder to justify.

The harder one is the covering of a wood fuz in carbon (or other composite). This would then allow the inner “wood fuselage” to be substantially removed.

I am thinking here about making a fuz from 1/16 or even 1/32 balsa and covering in carbon. The original “wood fuz” would NEVER be strong enough to be flown on its own, so it would be a carbon fuz in reality. It then becomes a question of – Is the original fuz a mould ?

2.2.6.The wood fuselage may be covered with composite material such as fiberglass, carbon, or Kevlar, for strength. Otherwise, covering is the same as for the wing and tails.

The above should read - “The wood fuselage may be covered with composite material such as fiberglass, carbon, or Kevlar, but covering no more than 50% . Otherwise, covering is the same as for the wing and tails.

The original says “for strength” where the wood fuz should be strong enough, so it should NOT be used for strength, but rather to stop gravel rash.

Attached is a photo of a canopy off a REF model I have. (The dark square in the middle is a camera) It is very strong and I would be happy with a fuz made in the same way for a F5RES model. It is one layer of very light carbon, that is why I would like to have either moulded fuselages or if only wood, then ONLY limited usage.

CarbCan.thumb.JPG.e439a51f585d4591ae2ac4f6087c42f4.JPG

Hi Anthony

The two points you have raised. 

Joiners. No problem with the carbon as per my previous post. Regarding steel, its not a composite material so not explicitly included. However it does not affect any of the restrictions and goes not affect the predominantly wood rule so I guess you could have a joiner of any material up to 49.9% of the volume of the wing.   If you want I will add a steel joiners are permitted rule but I font think its required. 

Regarding the pod.  The rules are a direct translation from the continental rule set.  I agree that the intention is to provide abrasion or wear protection and possibly some local stiffening around the motor mount. 

I agree with your proposal although I am reluctant to use 50% as that would be difficult to measure. 

I'll find some suitable weasel words. 

It is interesting that this rule does not appear in the F3-RES rules.. 

Thanks

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Thanks Martyn, if there is a competitive element, then it is your duty to push for the best possible structure (for yourself).

This is more of an entry level class and it would be best to be inexpensive, without all the really dear carbon bits. As such it is better to have the rules in place.

Where a single carbon / glass tube is used as a spar, it would be a great place to add a big steel joiner on windy days.

In keeping with the aims of the class, steel joiners go without saying.

So, as you say, a way of saying a wood fuz – and “some” composite to vulnerable areas.

 

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Thanks for the clarification...          Partly as a change from the norm (not that I've tried RES), I have a RES-DART ordered. This flying wing has carbon fibre wing joiners and the build instructions suggest the fuz is covered in GF/CF.   It looks as if it will be compliant except for a short tube on each wing tip that form a "DSA" tip (something to do with reducing drag).  The tubes in the (remaining) kits available are CF, so make it non-compliant.  

 

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That sounds interesting, I would love to know how you would get on with the RES-DART. According to the description, the design is compliant with the German F3-RES regs, which the UK regs are based upon. PLEASE, keep us updated on how you go on.

 

Best wishes

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John Minchell

Dave H

You could just substitute the carbon DSA wingtip tubes with glass fibre tube or rolled plywood tube to be F3/5RES compliant.

John M

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1 hour ago, John Minchell said:

Dave H

You could just substitute the carbon DSA wingtip tubes with glass fibre tube or rolled plywood tube to be F3/5RES compliant.

John M

Yes, I hope to roll my own in thin ply..   There is a version that has rolled ply tubes, but they seem to sell out quickly.    Maybe glass fibre is also not allowed?        I could print some on my 3d printer, but that would also be "not wood".    

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John Minchell

Ply it is then.

I'm interested to hear how you get on with the Dart - a mate of mine is building one and doesn't like the lack of a plan and using google translate to get English instructions.

John M

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