BOM discussion from the TT thread

[Mike Foley]

  Wasn't this whole BOM thing clarified a year or so ago by the AMA.  Where as bottom line, ARFS dont qualify but ARCs do qualify for appearance points. Thie AMA ruling is what the Columbia Basin Control lners are going by to determine appearance points come contest time next week. "As voted on by club members"

ARFS, don't claim BOM
ARCS, do claim BOM

[Mark Scarborough]

Mike,
very true, but the question at this point is more about things like the Yatsenko Sharks or prefab sheeted foam wings and what actually defines an ARC versus and ARF. IOW where to draw the line as to what is and what isnt an ARF or ARC and some people still dont buy into the AMA definition.

[Mike Foley]

Mark,

And what are you doing on Stung Hanger in the middle of the day when you should be at work?  Me, I'm sitting on a hill top overlooking the metropolis of Pomeroy taking a coke and smoke break

[Clancy Arnold]

I think some people are forgetting what ARC and ARF stand for.

ARF - Allmost Ready to Fly
ARC - Almost Ready to Cover

If the AMA allows ARC in the BOM classes then the modeler must have covered and finished the model as a minimum.

An ARF is bought all ready covered and by definition only requires a few hours of final assembly.

Clancy

[Doug Moon]

I guess my main concern over these composite models is, who on this forum is qualified to decide what is legal and what is not? How many people commenting about these models have ever carved plugs, made molds and then pulled excellent parts from those molds? I think the point that is being overlooked most is the FACT that it is a lot easier to fly a competitive stunt pattern with a model that is straight and true. Learning to build a model like that takes time and energy.
Since we were not competing in stunt at the time that this composite decision was made, would someone please tell me, did one person make the decision or was it by committee?

     Arch

Arch,

I have built fully composite wings from a mold. You have to make a male, then pull a female and on and on.  If you buy composite parts you are buying about 90% of the work. 

I listed a step by step process to building my wings over on SSW.  I will see if I can find it and post it.

[John Miller]

I think one tack to take would be to dissect the time involved in building a top level stunter from naked balsa sticks to a finished airplane. Break it down into percentagesper stage. Randy of building a plane what percentage of the time is alignment and Assembly? Finish? Its a hard thing to quantify but I think that if it were examined one would find that alignment and finish comprise the greatest share of the time IMHO. Not to say that fabrication and assemble are any less important. I was speaking to a respected member of our community the other day,I will let him jump in if he wants, His suggestion was to break the points down different. something along the lines of 0 to 10 if its an arc and you did a great job assembling, and adding trim. 5 - 15 for an ARC again depending on how you trimmed and finished it and then 10 to 20 if its a scratch built. On the surface it really sounds workable. HOWEVER in retrospect, it really doesn't address the key point and problem as I See it here. That being defining what constitutes an ARC~ARF~ or scratch built. In an ideal world, someone who designs and innovates, Randy comes to mind, should be rewarded for stepping outside the box. whereas someone who builds a box stock impact is exhibiting craftsmanship but are they really being creative? (um added PW aside since he did design it) Personally I think if it were divided into Creativity points and craftsmanship points it would become a mute point. If you do an ARC or ARF there is NO creativity points however you still have craftsmanship points if you really did a good job. If on the other hand you designed and or scratch built the beast your owndarnself, then you also vie for Creativity points. Again, this is dependent upon the honesty of the individual in question so is not a "perfect" system.

Good points Mark, but consider a kit, commonly defined as an ARC as one end of the spectrum, and a builder like Randy,(only because we both know how he is ) at the other end.  Somewhere in between, lies the average. If we want to, we can be exclusionary and specify the end we find Randy at, or anywhere in between, including the other end of the spectrum.

By allowing the extreme, as AMA has already done, Then it makes good sense to address the issue of appearance points awarded under this broader definition. It also recognises the fact that for years prior to ARC's and ARF's, pre built components were routinly used and accepted.

I believe that a careful moment of thought will see the wisdom of what I'm suggesting.

Bring back Originality to recognise not only those modelers who start with a blank sheet of paper, as well as those who take the time to modify an existing design, and every where in between, Even if it's an ARC that was improved upon.

Keep building and construction, to reward those who do the job at higher levels. The better the job, the fits, the execution as we can call it, should be rewarded as well.
To my way of thinking, finishing is part of the building and construction, but I see no reason why finishing couldn't stand by itself.

These are compromise positions I realize, but I believe some of the ant-BOMers are correct when they site the need for better definition of terms.

[Randy Powell]

John,

I agree with what you're saying (though guys like Ron Burn are further off the edge than I am  ). I think the idea of spliting the points between originality and craftsmanship is a nice thought. It includes what Pat Johnston calls Charisma points. Certainly the idea is to be inclusive as much as possible. Perhaps the idea of increasing the appearance points and including anything that is brought. Sort of a scale with an ARF at one end (hey, the guy had to assemble and align the thing) and the built from scratch, original design at the other. Points awarded in two catagories: Originality and Craftsmanship. Again, it's at least trying to include as many as possible. I'm sorry, if you bought your plane from Al's plane building service, no points. 

[John Miller]

snip> Points awarded in two catagories: Originality and Craftsmanship. Again, it's at least trying to include as many as possible. I'm sorry, if you bought your plane from Al's plane building service, no points. 

Thanks Randy, I see you're getting it. Buying a Ready To Fy from Al's plane building service may not get you points for originality, construction, or finish, but, you can still fly it in PAMPA classes, so all's not lost.

[catdaddy]

For those that are not aware. the BOM rule came about during the late 40's at a NATS. It was all about "daddy built" models. Now it is about ARFS, etc. There is an article all  about it in MAN, but I forget the year and issue, but it was in the 48 or 49 era. Maybe someone with more time to look it up will find it. Besides all that, it was aimed at a Junior showing up with a plane he obvioulsy didn't build. Seems he outflew some "olde guys" so the olde guys came up with the BOM rule so they could beat the "kid" that out flew them. Ring a bell anyone??  And it was in "stunt", befoe CLPA.  Saber dances, hankey pick ups, spot landing, all that jazz.

THANK YOU TY!
The juniors name was Davey Slagle and he was a 3 time Walker cup winner. BOM HAS NOT BEEN APART OF CLPA FROM THE INCEPTION.

[catdaddy]

If you want to see what has happened to CL events that have thrown out the BOM and gone almost completely to buy and fly to compete effectively, check out Combat and FAI Team Race etc. at the Nats.  Or, try to find a contest for either in the US other than the handful of $$$$ meets for the handful of still active combat flyers.

You could hold all the other C/L events at the Nats in a corner of the L-Pad parking lot filled with the cars of competitors and supporters for CLPA, even with (especially with, from my point of view) the continued presence of the evil BOM and Appearance Points.  That's what you call evidence, Ron ... not a personal preference.

If you want to try your hand at crystal balling something in the future, how many people would you expect to show up at a future "nostalgia event" in which only ARFs were eligible.  Think it would knock the current VSC off the list of favorite winter destinations?

Stunt a flying only event?  No way.

Ted

LMAO
Fancher,
You have NO idea what you're talking about on the topic of combat and who and how many are participating and at what type and level of contests.
I've actually heard dozens of combat flyers say they don't go to the NATS because there are too many stunt flyers running around.

[Arch Adamisin]

Doug,
I'd bet that you and I are in the minority. I've molded several hundred composite models and the most important things about them is they are all the same. Straight, true and light. They come out of the molds painted and none of them required any trim. other than locating the proper cg. I guess the point I'm trying to make is, no one that has no working knowledge of hollow composites should be making any kind of decisions concerning the legality of those technologies in reguards to the current BOM rule.
I'd like to read your write up for your hollow parts, I'm always looking for better ways to make parts.

     Arch

     

[catdaddy]

Ron,


If you want to try your hand at crystal balling something in the future, how many people would you expect to show up at a future "nostalgia event" in which only ARFs were eligible.  Think it would knock the current VSC off the list of favorite winter destinations?

Stunt a flying only event?  No way.

Ted

I don't know about Ron and his crystal ball, but I can pretty much guarantee that with-in the next 5-10 years the attendance to the VSC is going to start to decrease signifigantly. I would also say in about 15 years the number of stunt pilots to combat pilots will probably be about equal. If I'm wrong I'll buy you a Trival Pursuit ARF, they should have one by then.

BTW when was BOM ever a part of combat?

[Marvin Denny]

[
BTW when was BOM ever a part of combat?


  50s, 60s, and 70s.  Fudging was RAMPANT as was cheating and outright lying.  There was t time in there that an entrant was only allowed TWO  planes per contest too.

  Bigiron

[Doug Moon]

Doug,
I'd bet that you and I are in the minority. I've molded several hundred composite models and the most important things about them is they are all the same. Straight, true and light. They come out of the molds painted and none of them required any trim. other than locating the proper cg. I guess the point I'm trying to make is, no one that has no working knowledge of hollow composites should be making any kind of decisions concerning the legality of those technologies in reguards to the current BOM rule.
I'd like to read your write up for your hollow parts, I'm always looking for better ways to make parts.

     Arch

     

Arch,


Here is my reply to Frank Williams from a few weeks ago about what goes into composite parts.  If you have built 100s then you are way ahead of me I am sure.  Tell me what you think.

Frank,

You are right. They are not carbon. They are glass balsa sandwich. Top and bottom halves ready to take paint. I am told they come from the mold filled. That is how I built mine. Top and bottom halves glass balsa sandwich complete span wise parts. Left me two parts to glue together. Glued them together in the cradle the foam male parts were cut from, using thin CA! Straight as an arrow! NO RIBS IN MINE!!! Weight was about 2-3 oz heavier than balsa tissue but I went straight to paint, NO FILLER!! Put that wing I made in a HUGE profile and it flew AWESOME!!

If someone were to buy those halves from me I would have been the one who did about 90% of the building. Here's how it goes.
1. I made the design, cut the male part from foam, sheeted the male part, filled the male part, primed the male part, clear coated the male part, buffed and polished the male part. The male part is finished in the same fashion as your full on stunter. It has to be as clean and smooth because it dictates the finish you will have in your female mold. That has to be perfect! That alone is a total build in itself. Then attach it to a perfectly flat strait piece of SUPER HARD wood as a base.
2. Then I pulled a female mold from the male part (there is another 8 or 10 steps in making the female mold), then prepped the mold, made a few test vacuums to get the mold ready for use. This is a huge undertaking on a wing.
3. Lets not forget the whole vacuum setup and all that is needed to actually even attempt this in the first place.
4. Then cut the glass, cut the balsa to create perfect fitting skins, and cut the next layer of glass. Set these aside for now.
5. Then wax the mold, several coats for sure.
6. Then spray release agent in the mold, then second coat, then third coat, then fourth coat, you go until it is light green and no flaws, sometimes you have to clean it all off and spray it again, yes spray it with a spray rig no brushing here. Spray at about 60-80psi.
7. Then spray in the primer coat, whatever color you like, use a weighted amount to get the weight you want within a few grams per wing half. Let this completely dry.
8. Then in goes the epoxy, spread it all around as thin as possible using a roller as not to damage the primer and more importantly the release agent below the primer. It is very lightly attached the mold and will move with the slightest pressure of a sharp edge of any kind.
9. Lay in the what is to be the outer coat of glass, the tightest weave you have, I used 2oz crows foot weave. Roll it in and let the epoxy soak in. There can be no wrinkles in the glass. It is gluing to the primer you just sprayed in. That is how it comes out ready for paint!
10. Squeeqy out all the epoxy, there should be so little left you can barely feel it. Now you can pull it down in the vacuum from here with a bleeder cloth to get out all the epoxy and then come back for a second pull with the rest or you can do it all in once. If you have you act together you can do it all in once but it can make for a heavier half if you do so. I pull it twice.
11. I then add in some carbon on the tip since it is a compound and wood wont go there. Talk about the perfect hollow tip!!
12. The mold is placed in the vacuum bag and pulled at 15 for about 30 hours. This is the first pull. I use teflon bleeder cloth placed over the glass to remove excess epoxy. If you put in the balsa skin and pull all at once I cant get out the excess epoxy from the top/first layer of glass. The balsa will absorb it and it will be heavy. I use proset super slow epoxy to give me the longest potlife when setting up the wing.
13. Remove the wing/mold 30 hours after initial vacuum. Remove teflon bleeder cloth. BE VERY CAREFUL not to move the part. Remember the release agent it is very slippery stuff and the part will come out of the mold. NOT GOOD!
14. Roll in more epoxy and place in the balsa skin.
15. Lay out your next layer of glass on wax paper and roll the epoxy there and squeegy off as much as you can. I mean the glass should feel almost no epoxy on it. But you dont want to EVER directly touch the stuff! You do this out of the mold so the balsa doesnt absorb excess epoxy. Or you could use Roecell! I have. It works killer but is brittle anyone squeezes on launch and your wing gets crushed.
16. Lay in that pre-prepped layer I used 1oz cloth here.
17. Back in the bag for 30 more hours at 15.
18. Now the excitement is building. All day at work just wanting to get home and get that part out. Remove the mold from the bag pull the bleeder cloth. Very carefully lift the part out. It will just slip right out if the release agent is properly sprayed in the mold.
20. Wash the part off with water and trim the flashing. Being extra careful not trim into the seam so it will be straight!! That is very important.
21. Then repeat the process from 4 on to get you another wing half.

From here on is where you the customer would take over the project.

22. Once you have 2 halves then you lay one halve in the foam cradle.
23. Install bell crank.
24. Install line slider, make sure it will attach to the top skin when you join them.
25. Install TW box.
26. Install wing gear blocks if you go that route.
27. Top wing half is placed on top of the bottom wing halve. Put epoxy on the top of the slider so it will attach to the top of the wing. Hobby epoxy is ok here. It should lay there with no pressure and be lined up all the way around. Having the cradle makes it a snap. A FLAT TABLE IS A MUST. You cannot do this properly without it! I build on a marble slab.
28. Use CA to attach the halves together. Glue on one end, then the other opposite, then work your way around the wing gluing it together at points not one continuous bead. Take your time. It took me well over an hour right here.
29. Once the wing is CA together all the way around with no gaps you are done.
30. Install hinges and flaps and stick it in the fuse.
31. When finishing the fuse you will cover the wing because it is fully ready for paint when you receive it.

I am fully confident the Yatsenko planes/parts, all of them, are built in a similar fashion/process. $2000-3000 bucks! Totally worth it. Take it from someone who has done it. You can also see where the greater chunk of the build is required.

I have built one and it was a total success. First try! And it was awesome. The next time I could make it way better from things I have learned during my first run and from what Windy has done with theirs and from what I have seen from the Yatsenkos. I had plans for more but it fell through as I dont have the time needed to stay after it on a project like this. But I do have all the stuff and can do it again. I do plan to one day revisit the whole thing when I can be more devoted to it.

Doug Moon

[Steve Helmick]

Here is my 2c worth.I think they should do away with the BOM rule except for OTS and Classic.

FYI, there is no BOM rule in OTS, just to keep the record straight.


Bob Reeves:  "A while back Canada went to FAI rules, I think we should follow Canada except with our skill classes."

Two Canadian contests I attended this July/August both used the FAI points system and PAMPA skill levels in the PA events, and including the 7 minute time limit. OTS was flown to PAMPA OTS rules. Classic was flown to PAMPA rules, in that 10-40 points used, no skill levels, and I believe no appearance points given for ARFS and purchased older models, but I don't belive they were excluded.

Seemed reasonable to me. I'm not that keen for the 1-10 points/no K-factors plot, or the 7 minute time limit. The 7 minute limit makes for more "attempts" be called, because of starting problems. And I'd rather use 10-100 points, which is only a minor decimal dropping. It's kinda strange to see somebody win with 120 points.  Steve