Future balsa supplies in UK

[Peter Miller]

Speaking as someone who designs most of my own models I am already wondering if I can design a reasonably light model using the minimum of balsa and a lot of liteply and possibly some other materials.

One possible option would be to explore obechi and spruce in carefully chosen cross sections used to put the strength in the correct directions.

It may mean a lot of extra hours on the scroll saw but it should be possible

I have to design because when I build from a kit or plan, even very good ones, I keep saying to myself "I wouldn't have done it that way!" Even if it is a perfectly good and effective way of doing something.

A recent example being a Mantua Mini Kosmo. A really good quality kit that flew very well indeed but I kept thing "I wouldn't.....!" even though it all went together well with no problems.

Edited By Peter Miller on 28/09/2020 08:06:33

[Matt Carlton]

I was looking at that as an idea Peter.

SLEC do spruce and basswood down to 1/32". I'm not sure of the density, but, for example, if one made a typical 'box' fuselage using spruce longerons and 1/16" bass or liteply sides, fretted out for lightness, how would that compare to a more typical 3/16" balsa fuselage side?

Instead of thick block decking, maybe curving 1/32" bass over formers would work? Or 1/64" ply?

Leading edges could be smaller section spruce. Sheeting with Obechi seems possible maybe? Might need a soak in an ammonia solution, but doable, especially if you used two laminations for a d-box for example?

I guess there's as much 'adventure' in that.

Then I suppose we have the old "BPCF" method that I think Chris Golds pioneered?

I'd love to design more of my own models. I've designed many, but I've never had the faith in them to go ahead and build them. Maybe this is the impetus to do just that.

Got a more positive head on today.

[Stuart Z]

Matt

From what I recall there was precious little balsa in a Hi-Boy. Flew like a brick but loads learnt to fly with it.

S

[Former Member]

[This posting has been removed]

[Peter Miller]

Matt (an others)

Designing is easy. To start use a proven basic layout of nose length, aprox wing chord and area tail moment and CG.

This is called basic research. Then design a box from the firewall back to the trailing edge of the wing and a tapered box from there back.

After that add any cosmetic shapes you like.

THen trust what you have done and build it.

You will make mistakes but unless you actually build and fly you wil never know.

No one ever told me that it was hard so I just went ahead. Some worked, some didin't (I remember a light weight model that developed violent flutter and shook its self to bits.

Of course small control liners were cheaper and we risked less but it was the start.

[Eric Robson]

I drew up and made this Seafury in 2015 the basic structure is 1/4 balsa sides with 1/4 balsa sq. going to the tail with 1/4 balsa tailplane supports ,all which could have been made in light ply the formers are 1/4"depron which could now be foamboard the tail plane ,fin and rudder are 1/4 depron , the wing is 1/8"light ply main spar with some depron ribs some light ply and the aileron spars balsa the fuselage from the start of the stripes rearward is 1/16" balsa as I could not get the depron to form without cracking , wing fillets are stiff card.. The cowl is 1/16" balsa wrapped around light ply formers and the front is layers of depron . It is 48" span electric powered with 3s 2200 lipo and fly's great hand launch no u/c. Pity depron is no longer available but I am sure there is an alternative waiting to be found. my biggest worry is for the suppliers of balsa and the few kit manufacturers we have left they have served us well for many years I hope they can do so for many more.

[Geoff S]

Posted by Peter Miller on 28/09/2020 10:08:48:

Matt (an others)

Designing is easy. To start use a proven basic layout of nose length, aprox wing chord and area tail moment and CG.

This is called basic research. Then design a box from the firewall back to the trailing edge of the wing and a tapered box from there back.

After that add any cosmetic shapes you like.

THen trust what you have done and build it.

You will make mistakes but unless you actually build and fly you wil never know.

No one ever told me that it was hard so I just went ahead. Some worked, some didin't (I remember a light weight model that developed violent flutter and shook its self to bits.

Of course small control liners were cheaper and we risked less but it was the start.

I can recommend a book I have on my workshop bookshelf. It's called 'Designing Model Aircraft'. Trying to think who wrote it but ... ah yes, some unknown character called Peter Miller

Geoff

[Matt Carlton]

The design part is something I really enjoy. It's having the confidence to invest in building it. But as you rightly say Peter, there's only one way to find out.

[Peter Miller]

By the way, just been talking to a friend who was building models before the war. He was saying that in the war they used to use Obechi which was pure murder to cut with a razor blade but it would be viable to radio models

SLEC stock obechi!!

[Matt Carlton]

In typical 'balsa sheet' sizes as well I see.

I wonder what 1/32" obechi wing ribs would be like.

I'm assuming that it could be laser cut just as well as balsa...

[Erfolg]

Eight months ago the world was very different, there was a report of some flu like problem in China. Later it became apparent the flu like illness was here, having come in from Europe, and now had a name.

My first concern was the many deaths of so many, older people. Then I found that i was confined to home, the weather was good, I sat outside, had a beer, could not get a slot for home food deliveries. The world continued to change, although remaining the same, politicians pledged support in the national interests, whilst doing anything but. Issues in other countries were sensationalised or ignored for a variety of reasons.

In this period I started a new build, as post from other countries became much slower, the current build was put on the back burner due to these types of issue. Covid was now seen as an issue, although not really effecting my hobby, other than I had not been flying, through some of the best early spring weather for years.

I noticed this thread, a little time back, I have followed it, reading various thoughts, with an increasing realisation that Covid was going to have an impact I never expected.

I do have concerns for the hobby, as our model distribution trade, will have some very difficult decisions and time ahead. Many of their kit suppliers will also find the situation disruptive to their product range. What will the modeling punters buy? How much will they be prepared to pay?

Unlike many, being now pretty old, I have watched many pensioners deciding what they can afford to buy, as they trundle around the supermarket. It is apparent not every one, particularly with a fixed income, will have the free cash available to pay more , when pursuing their hobby. Yet the trade also needs income, to survive. Increasingly in the UK the model trade seems to move towards small traders, who are engaged in manufacture and distribution out of love of a hobby.

The Corona Virus has had an impact that I had never envisaged, with future consequences I personally can only vaguely guess.

[Geoff S]

Posted by Matt Carlton on 28/09/2020 11:40:56:

In typical 'balsa sheet' sizes as well I see.

I wonder what 1/32" obechi wing ribs would be like.

I'm assuming that it could be laser cut just as well as balsa...

I would have thought foam board might be better?

There was a period when Correx was popular. IIRC Peter designed a model which was largely Correx - can't recall the name.

Geoff

[Matt Carlton]

Whilst I agree that affordability could potentially be an issue, that has to be tempered by the fact that the RC hobby is generally much more affordable than it ever has been as a proportion of income.

A quick look at Radio Modeller in 1990 is quite interesting. Adjusted for inflation (using Bank if England historic inflation calculator) Futaba S148 servos were the equivalent of £25 each. The last ones I bought were £8.50 each.

We think of kits being more expensive now, but in 1990, a Gangster 63 kit was the equivalent of £142. Today's price? £139

Yes, foam board would work, but on an open structure, traditional build, the visual effect of the structure is important and foam board and correx just don't cut it aesthetically. For me anyway!

 

Edited By Matt Carlton on 28/09/2020 12:59:55

[Former Member]

[This posting has been removed]

[Bob Cotsford]

Obeche would, I believe, be about double the density of medium-hard balsa at around 24lb/cu.ft. I remember it as being quite short grained so no good for spars or longerons and was mainly known as a veneer for foam wings. Poplar or cedar would be similar density though I've never tried working these.

I happily use foam wings and I have 4 or 5 foamies and even tried building a Polaris in Depron but I do get occasional twinges in my conscience over promoting the use of these hard to recycle plastics. My local waste management centre (AKA "the tip" ) can't even recycle balsa models owing to the proportion of other materials unless I strip off all covering and remove the plastic and metal fittings.

Edited By Bob Cotsford on 28/09/2020 13:16:29

[Matt Carlton]

If spruce comes in at about 27lb/cu.ft, and hard balsa at around 9.

A 1/4 x 1/4 x 48 strip of hard balsa would weigh about 73g

That's roughly the same as a 3/16 x 1/8 Spruce spar.

Structurally, would they be equivalent?

[Peter Miller]

Posted by Geoff S on 28/09/2020 12:29:57:

Posted by Matt Carlton on 28/09/2020 11:40:56:

In typical 'balsa sheet' sizes as well I see.

I wonder what 1/32" obechi wing ribs would be like.

I'm assuming that it could be laser cut just as well as balsa...

I would have thought foam board might be better?

There was a period when Correx was popular. IIRC Peter designed a model which was largely Correx - can't recall the name.

Geoff

THat was Blue Movie. It WAS indestructible.

A little story.

Sortly after Blue Movie was published R/C ModelWorld had the auditors in doing their checks.

They summoned the editor and demanded to know why a payment for a "Blue Movie" had been made.

They would not believe that it was for a plan until they were shown the magazine with it in.

AS for the name, well it was very crude and very ugly but the performance was amazing!!!

[Former Member]

[This posting has been removed]

[Gary Clark 1]

Hahaha brilliant Peter!

On a serious note though, I think richard said things very well earlier. We really need to support the UK suppliers of kits and materials. In the past 10 years, the only non uk kit I had bought is a Sig King Kobra. I am not trying to get all high and mighty but having seen the lack of quality in some ARTF aircraft from abroad versus the quality of materials put in UK kits, I just can't buy anything else. When you see the effort guys like Richard put into preparing his Warbird Replica kits and the real personal feel you get from his company, it gives me real pleasure in sending my money to them rather than a huge company paying its staff peanuts to produce as many kits as possible in little time.

This potential shortage is a great time to get behind these companies and buy some stuff now so they have a financial cushion if things do start going bad. If things do get expensive, I am very confident these companies will only mark up prices where they have to and not to make extra profit so I know I will continue to buy from them for as long as they are selling.

I feel like painting my face blue and shouting freedom now and running angrily at chinese wind turbine blade producers instead of an English army....my imagination got carried away with itself there.

Gary

[Erfolg]

I do not pretend to be able to predict the future, other than, the older proportion of the population are more certain of their future. From what little I have seen, there is a large proportion of the Modeling population are over 60.

I also agree that many aspects of our hobby are now proportionally, adjusted for inflation, and so on, are much more affordable. Also much is of higher quality.

Recognising the various aspects, it is apparent that large increases in the cost of balsa will have an impact on many models, be it ARTF and kits. Normal influences on material costs will decided from what materials models will be made. The increased use of polymers seems a done deal, at least in the immediate future.

Cost and affordability does influences us all, all along the Modeling spectrum. In reality to what extent and where, I have not really got a clue,

[Matt Carlton]

Barrie: I'm sure you're right, I don't have the figures for bending strength of balsa Vs spruce, so I'm not sure what the difference would be, as in what the equivalent would be in terms of strength. I assume that a spruce soar could be smaller than a balsa one in terms of bending strength, but by how much, I don't know.

I suppose one could also run a strip of unidirectional CF along the spars.

[Former Member]

[This posting has been removed]

[Matt Carlton]

I was just digging around and found the last model I designed. Got plans drawn up for it somewhere.

[Stuart Z]

Matt,

Nice looking model. Did you ever fly it?

What size was it?

S

[RICHARD WILLS]

If you had said this was going to happen a year ago , I would have said you're barmy .

But what have we had ? The cottage industries and designers (like Peter and others ) have kept the balsa bashers happy with good honest wooden models since before the war , and yet since the end of the nineties we have been constantly undermined by a deluge of cheap models made by people on a pittance of a wage on the other side of the world . And then , when the many have been decimated , and the last gallant lads are still standing , they send us a global pandemic which only they seem to benefit from and as the final straw , they nick our bloody balsa !

I , for one , will be opening a Chinese laundry tout suite, What goes around , comes around .

All that ranting has put me right off me spring rolls . Prawn cracker anyone?