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Author Topic: Computer Aid in Building Scale Models  (Read 1823 times)
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Andy Sephton
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« on: July 25, 2013, 05:40:13 AM »

In another thread we've been discussing the why's and wherefores of using computer technology such as 3D printed parts, printed tissue, etched parts, cutter produced masks and other various means of electronic wizardry.

In the UK, models are static judged to a schedule that takes into account the workmanship of the builder of the model. Discussion has been started on how technology input should be marked when compared to hand-built components.

the current thoughts of the BMFA Scale Tech Committee are for the builder to include what he/she has done on the declaration form so that it can be judged accordingly. I'd appreciate your thoughts and input as to how this should progress......

Over to you!
Andy
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« Reply #1 on: July 25, 2013, 06:27:16 AM »

Can of worms getting prised open here I fear Andy.  No answers, but a couple more questions.....

Someone like George Kandylakis or Laurence Marks who are professionals with CAD have a distinct advantage over those people who do not use it, or do not have the financial wherewithal to purchase a programme and the time to learn how to use it.  Not just on the 3D printing of engines and details but on 2D for printed tissue and markings etc.

It is similar to the graphic artist or professional model maker (like Richard Crossley or Charlie Newman) who are professionals with an airbrush.  They will always produce better painted finishes than the guy who is not skilled with an airbrush.

The competitors who declare the use of such parts purchased from a 3rd party will be down marked.
The professional users will not have to do that because it is all their own work - the CAD and the CAM.
So do you now have to decide that professionals get downmarked as well? Does it lead to a carpenter, being a professional with wood, suffering a judging problem when he builds a balsa model, but not when he makes a foam one?

As I said - a can of worms but one which needs to be addressed somehow.

Having said the all of the above, I thought George's thread on the Avro engine 3D printing absolutely superb and seeing it in Nottingham at the Nats it was so realistic.  However only one or two people will be able to compete at that level.

Regards John
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billdennis747
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« Reply #2 on: July 25, 2013, 06:56:48 AM »

Although I kicked this discussion off, I am fairly sanguine about things (and yes, let's not lose sight of the fact that George's work is exceptional - computer or no). I don't think it will make much difference really. In static marking, the big points available are for shapes, and a computer doesn't help much there. And then it has to fly.

There are much more serious holes in the judging system but it is largely limited to RC. Take for example, models built from designs by Mick Reeves or Brian Taylor. The builder has had no hand in getting the shapes right but will garner high marks because the model will be extremely accurate. It will place higher than most own-design models.

None of this compares with the situation in Internationals where, as a judge, I was seeing models - usually jets - built from kits where all the major components were reddi-bilt, and by someone other than the flyer.

Andy, I would counsel doing nothing, other than to give more specific guidance for the Static judge. John makes good points. What you can do, if you are a hacker like me, is to concentrate on what you are good at, or where you can beat the super model. This is usually flying.
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« Reply #3 on: July 25, 2013, 07:02:23 AM »

Hi Andy,
            We are watching this one because eventually it will arrive down under as the technology becomes affordable. My view is that the effort put into making an item by hand has to be recognised but excluding any of the new processes will not help our dwindling numbers. Judging weather we like it or not has a level of subjectivity and there no way to get around it. What does matter is that declarations have to have this information provided otherwise it is almost impossible for the judges to determine what has been made by the modeller. The recent NSW meeting was a bit slack in this area, but there is a bit of learning going on for this group. Importantly there is increasing interest.
We would be interested in the views on large electric scale models with a lot of electronics on board as the SIG here are of the feeling there is a mis match when put up against CO2.  We are trying to sort this one out before there is an incident. As the Americans say there is no substitute for cubic inches.    
    I hope your splendid weather continues until the National and beyond.
   Ricky
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Rich Moore
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« Reply #4 on: July 25, 2013, 07:12:00 AM »

Can of worms indeed.

Technology has already crept into the hobby with tissue printing and 2D cutting plotters. Laser cut parts have been around for a while, though not so accessible 'to order'. Not many people could afford there own laser printer.

3D printing has developed very quickly and I suspect it will feature within the hobby with increasing frequency. As a technology, it is cheaper than many might think and already 3D printers are being produced within an 'affordable' bracket for the domestic market. The cost is likely to fall even further. Software wise, it is possible to use 3D packages such as Google sketch-up, which is available as a free download and relatively easy to use.

Personally, I think perhaps CAD/ CAM produced details, that are the work of the modeller, should be credited but on a different 'mark scheme' to hand crafted details. But then there is the problem of repetition - A subsequent model that uses the same engine, should be viewed upon in the same way as a shop bought part because there is no skill required to simply print another, even to a different scale. As soon as you make another it becomes a manufactured part. This is very difficult to 'police' and would be reliant on the honesty of the declaration.

What is also tricky, is how to award points to a detail that combines 3D printed technology with hand crafted parts, eg printed engine cylinders but hand made linkages and minute details. I guess a judge would have to make a judgement!

Sorry there isn't any kind of conclusion or suggestion here, just my initial blurb. Needs careful thought, as I do think more 3D printing is coming and should be embraced not penalised, but how to do it fairly? I don't really know...
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Andy Sephton
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« Reply #5 on: July 25, 2013, 07:20:17 AM »

Thanks for the responses so far, they are all very helpful.

It's turning into a brainstorming session which is an ideal way to bring all the issues and possible solutions onto the table. However, I'll leave it until we have some more posts before I input again.

Andy
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« Reply #6 on: July 25, 2013, 08:08:47 AM »

As long as full declaration of techniques is made I can't see the difference between this and William's engine details or pre-painted Banks pilots. The first thing everyone asks when looking at a model is "how did you do the engine/markings/finish etc...?"

In the end it's the competitors skill level is being judged. If the skills are evident (like George's) then the techniques shouldn't be penalised. If I bought a finished 3D engine from someone and my total skill level was the use of a bit of super glue then I would not expect the same marks!

When considering individual techniques as to which is considered more skillful, then that is the judges decision. Clarity in the rules would help though. This came up in Kit scale with printed tissue vs cut tissue markings.
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« Reply #7 on: July 25, 2013, 09:14:03 AM »

Re: 3D printers

Check out the latest issue of 3D Artist magazine; Issue 57, it has the word MODO and an image of a robot on the cover.

Issue 57 features a review of some low cost 3D printers. The resolution is improving all the time. I made a statement elsewhere that the cheapies may not be good enough but things have changed.

Paul
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g_kandylakis
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« Reply #8 on: July 25, 2013, 06:27:15 PM »

We would be interested in the views on large electric scale models with a lot of electronics on board as the SIG here are of the feeling there is a mis match when put up against CO2.

It is rather late here for my views on the issue of CAD (Computer Assisted Details  Grin).
But I do want to open another can of worms, taking the oportunity from the quote...

I already told my opinion at the BMFA Nats, CO2 and electric are (to me, at least) no longer compatible classes. IMO they should be separated. The electric used to be the outsider, now it is the dominator. The average CO2 model will always do much worse than the average electric model.

But I have an even "better" scenario:

Imagine a model that can be flown both as RC and as free flight (my dH9 being an example).
Next imagine somebody who is an electronics expert, and comes up with a system that can "save" all the parameters of a successful RC  flight and "replay" them in free flight mode. Would that still be considered "free flight"? It is mainly a pre=programmed flight

We already have programmable timers, with a maximum of two phases. What if we has four or five, or more? What if the timer gave out movement commands to on-board servos as well? The technology is there, it is just the matter of the right electronic nut doing it.

True, a little advanced and far too complicated, but if someone did it, how would it be received? And, regardless if the technology became available to all (like the Atomic timers), wouldn't the expert have an upper hand?

Of course, the first reply that comes to mind is, have a look at the result list, with Graham Banham's "simple" and "technologically unadvanced" Fairchild, that sweeps the competition on a regular base... Not to mention that it is in the true spirit of indoor free flight...

But what if somebody did come up with a solution like that, regardless of contest result... What would be the reaction?

Good night to all,

George


 allows to "store" all the movements of an RC flight
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billdennis747
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« Reply #9 on: July 26, 2013, 02:16:50 AM »

Hi George,
Would there now be sufficient CO2 entries to make separate classes viable? In theory I agree, and both could probably run together for the flying, but we could not have a Nationals class with two or three entries.
I like CO2 and would still fly it if you could still buy Telcos. I have lost track of the current state of the art.

As for the pre-programmed flight, it is just a logical development of the programmable timer. Outdoors, people have tried cam-controlled engine control, retracts etc. When I first began flying in the late 60s, the rules gave bonuses for figure 8 and loops, although I never saw it tried. No different really to current F1A technology. How would it be received? Badly, I expect.
Bill

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DHnut
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« Reply #10 on: July 26, 2013, 03:52:08 AM »

George,
            The programmable functions already exist. Tahn Stow has a Hurricane with an electronically programmed undercarriage which could easily be extended to other functions. How for instance would using the now available gyros figure if they are used to stabilise a model. As I see it this is no longer a free flight model as there is external stabilisation of the model.
Your comment on CO2 is valid and we have addressed it in New Zealand by limiting electric in our small power class to 3 cells NiMh and 110 mah or a single cell LiPo of the same capacity. This levels the playing field a lot.
Gary Sutherland (Victoria Australia) had a DH4 that was intended for free flight and used radio for the initial trimming but came to grief when set at a different power level in free flight .     
         
                  Ricky
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billdennis747
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« Reply #11 on: July 26, 2013, 04:47:27 AM »


Gary Sutherland (Victoria Australia) had a DH4 that was intended for free flight and used radio for the initial trimming but came to grief when set at a different power level in free flight .     
         
                  Ricky

Yes. Pete McDermott found it very difficult converting between RC and FF with his DH9A.

I guess the pendulum was a primitive attempt at a gyro!
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DHnut
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« Reply #12 on: July 26, 2013, 06:38:04 AM »

Bill,
      The thought of the role of the pendulum did cross my mind, but in control terms it is a very crude first order system while the new gyros are third order systems which are an entirely different animal.
CO2 has moved on beyond Telcos which I still use, to Gasparins which are a totally different kettle of fish. The Comper at the Nats was a GM120 powered and is just sufficient for the model while the bigger Gasparins as Charlie uses even easier to handle. I admit to using Williams cylinders for the Pobjoy as they are a good match with a suitable handmade head. I will declare the commercial parts!
            Ricky   
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Andy Sephton
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« Reply #13 on: July 26, 2013, 12:49:31 PM »

To help the discussion, I'd like to remind you all of the following rule in the BMFA Scale Rule Book for 2013:

"6.1.1.20 Electronic motion stabilising devices or Gyros

The use of all types of electronic motion stabilising devices is forbidden, (with the exception of Scale R/C Indoor models where a penalty is applied to the flight score).

N.B. The FAI Scale R/C classes no longer ban the use of these devices, therefore in order not to disadvantage our international team, the FAI rules will apply to the Scale R/C Team Trials"

Pendulums and programming the sequence of various functions on a (electronic) timer are currently acceptable, but electronic stabilisation and gyros are not.
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g_kandylakis
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« Reply #14 on: July 26, 2013, 02:21:34 PM »

Bill,

Reagarding CO2 participation, what do you compare it with?

Here is a quick statistic from the BMFA indoor scale nats. (The question marks are where I am not sure)

Year     total entries   CO2 entries
2009           8            1 (?)
2010           7            2 (?)
2011           9            1
2012           7            1 (?)
2013           7            3 (2 from abroad)

Already the total numbers are not that high...

And already the CO2 model has been virtually phased out. Apart for Chris Stachan and the Czechs, noone else seems to be using it.

And it makes sense not to: why would anybody want to compete with a CO2 model against the electric programmable and repeatable and smoother running and... electic models? Not to mention relative ease of installation, reduced weight etc. So, CO2 is doomed as it is.

Who would enter in a separate class? For a start, I magine many who already fly electric, would also participate in a separate CO2 class, on a level playing ground. Also, newcomers with simpler models than the "expert" electrics.

Negative factors-side effects:
Lack of commercially available CO2 motors. True, but there are many appearing on eBay, plus, I imagine most seasoned modelers must have accummulated quite a number over the years, which are now left rather useless, so why not give-sell to any who might need one?

difficulty of getting CO2 gas. In do not know how hard it is in the UK, I was told it got harder with the years. No comment on that one

Extra strain for the judges. True but the same would happen with increased participation, which is what everybody is hopping for, isn't it?

Anyway, enough about that from me...
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g_kandylakis
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« Reply #15 on: July 26, 2013, 02:32:11 PM »

Regarding programmable flight...

Very useful input by Andy, regarding the ban of electronic stabilising systems. But the use of a preprogrammed unit which controls surfaces, is allowed...
I am not talking about programming 1-2 functions, like Richard Crossley with his Douglas Dauntless in Interscale 2004, but for a complete circuit, with curves for each servo/function, programmable via a laptop etc...Too science fiction? Maybe...

Food for thought... Not for me, I cannot do it, nor do I want to do it... But the question about the feasibility did cross my mind... And if an electronics expert, or someone with help from one, does it, that will be interesting... Both as an accomplishment and as a reaction from the rest.

I did and still do seriously consider using a timer for retractable undercarriage. After all, it is a timer, just like a mechanical one. With one function, wheels up - wheels down... For a future project...
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g_kandylakis
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« Reply #16 on: July 26, 2013, 03:01:14 PM »

And finally, to the initial theme of the topic...

I cannot say I am 100% for yes. But the problem is exactly that of percentages...

For example, lets assume I want to build a dummy aircooled engine (my main focus for 3D printing application) and I want to dublicate the finned cylinders:

Option #1 - traditional, balsa body, twin thread wrap, then unwrap one thread and you have a basic representation of a dummy cylinder.
Option #2 - standard, take a Williams cylinder, modify, cut, glue or do whatever it needs, using it as a base.
Option #3 - Manual, cut balsa or ply or plastic disks of two varying diameters, with sharpened tubes, glue them alternating one after the other and simulate a cylinder
Option #4 - Semi-modern, laser cut the disks and glue them, as before
Option #5 - high tech, 3D print the components, glue them, together with many other parts that make up the engine
Option #6 - Buy the finished engine

For me, everything except 6 is acceptable. 4 and 5 is acceptable, since I am the one who decides how the engine will be, what stresses it has to take, how it will be assembled... The machine (laser cutter, 3D printer is a tool. A sophisticated one, but still a tool)

Same as using a lathe to make a cylinder out of aluminium. And then using it as a master for a silicone mold. And then casting cylinder copies...Why is it allowed to use a big lathe for someone who has the skill and the experience?

Printed decals
I remember a report in an ancient Model Builder by Mark Fineman. The model I think was The Lockheed Vega "Winnie Mae". In it he explained, among others, how he did the tiny lettering on the fuselage (I think it was Mark Fineman, or was it Fernando Ramos ?)
http://en.m.wikipedia.org/wiki/File:Lockheed_Vega_Winnie_Mae_2.jpg

He used "letraset" letters (Older people should remember them, I do not know if they still exist for the younger guys...) A bought letter...

Now we have printers and decals, we can do them better, quicker, cheaper... But, with a printer... And we can do much much more... Should this be penalised?


Printed tissue...

I do not mind, nor have I tried it, perhaps because it will never look better than a painted finish...(Never? until some expert finds a way and does a magnificent job of it...)

Pilots:
The best option, carved and paint one yourself.
Next best, buy perhaps a Dave Banks and paint it
Worst, buy a ready painted one and put it on the model

Question: If i model one in a 3D software (very very difficult) and have a machine cut it, then work on it to make it better (machines are not perfect) and use it as a master for a silicone mold and make a pilot using the mold, is this to be penalised?
My latest models still don't have pilots  Embarrassed


And I could go on with wheels etc.

Long messages...

In short, If you do something, in any way and do not buy the complete finished item, but invest some amount of time, skill and effort for the final result, than I am fine with it...

George

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Dave Andreski
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« Reply #17 on: July 26, 2013, 03:31:34 PM »


Printed decals
I remember a report in an ancient Model Builder by Mark Fineman. The model I think was The Lockheed Vega "Winnie Mae". In it he explained, among others, how he did the tiny lettering on the fuselage (I think it was Mark Fineman, or was it Fernando Ramos ?)
http://en.m.wikipedia.org/wiki/File:Lockheed_Vega_Winnie_Mae_2.jpg

He used "letraset" letters (Older people should remember them, I do not know if they still exist for the younger guys...) A bought letter...

George

It was Mark Fineman in Model Builder, March, 1985.
"Letraset" was mentioned but, that's not what he used.

Dave

George,
Please keep up the good work!
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g_kandylakis
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« Reply #18 on: July 26, 2013, 03:37:49 PM »

Thanks Dave...

But what did he use?
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Dave Andreski
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« Reply #19 on: July 26, 2013, 03:46:47 PM »

Thanks Dave...

But what did he use?

George,
Something called "Decalon".
The process is 'interesting' but probably doesn't have anything to do with this thread. Sorry.
PM an e-mail address and I'll send the article.

Dave
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Art356A
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« Reply #20 on: July 26, 2013, 03:58:30 PM »

I'm completely 19th Century here. My ideal model, the one to try to emulate, was an A-20 built by a guy named Duco Guru, who used to be here. Everything done by hand, cut out numbers, letters, insignias and invasion stripes, all applied like decoupage. Nothing painted (I know that differs from British Rules). Elegant!

Or anything by John Ernst.

So I've been forced to pick my subjects by simplicity of adornment, like the Curtiss triplane (none at all) or the Miles M5 (next-to-none).

Okay. Back to the Future now.

a.
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« Reply #21 on: July 26, 2013, 04:04:57 PM »

The process is 'interesting' but probably doesn't have anything to do with this thread. Sorry.

Thank you Dave, for the immediate reply and the article pages.

How wrong you are... it has everything to do with this thread... The only difference being, since this was 1985 that not a computer, but a xerox copier was used...
Mr. Fineman used the existing plan lettering and xeroxed it on to the Decalon. In essence the same as a modern day printing of a computer generated text...
He did use a machine, he could repeat it many many times... Next he applied the Decalon in the same way we apply water slide decals, like the ones we print.

So, for example, was it or was it not ok to use this method? Was there "traditional" skill needed?


George
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« Reply #22 on: July 26, 2013, 04:09:33 PM »

Everything done by hand, cut out numbers, letters, insignias and invasion stripes, all applied like decoupage. Nothing painted (I know that differs from British Rules). Elegant!

Art, I agree. This is stick and tissue modelling. British prefer opaque finish. Europe seems to be following them. It is the same, you only hand cut masks instead of tissue and spray paint... You still do most / all of the work...


So I've been forced to pick my subjects by simplicity of adornment, like the Curtiss triplane (none at all) or the Miles M5 (next-to-none).

But what if you like a complex subject or one with some complex parts?

George
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billdennis747
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« Reply #23 on: July 26, 2013, 04:28:29 PM »

Nothing painted (I know that differs from British Rules).



a.
We have no rules for types of finish. People can do as they wish, but they are formulated to reward realism, both in static and flying. The static rules in fact are the FAI rules and are the same for everything from indoor to F4C.
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« Reply #24 on: July 26, 2013, 04:31:51 PM »

The process is 'interesting' but probably doesn't have anything to do with this thread. Sorry.

Thank you Dave, for the immediate reply and the article pages.

How wrong you are... it has everything to do with this thread... The only difference being, since this was 1985 that not a computer, but a xerox copier was used...
Mr. Fineman used the existing plan lettering and xeroxed it on to the Decalon. In essence the same as a modern day printing of a computer generated text...
He did use a machine, he could repeat it many many times... Next he applied the Decalon in the same way we apply water slide decals, like the ones we print.

So, for example, was it or was it not ok to use this method? Was there "traditional" skill needed?


George

George,
Sorry about being 'wrong'.
Until today, I was one of your fans.
Dave
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