We have added another couple of stamps to our ‘famous’ montage — why not see if you can find them? Hint: they are featured in this month’s edition of ‘Stamps That Tell a Story’. Have a stamp you’d like to contribute? We’d love to hear from you.

Letters to the Editor

We have a couple of real nuggets in the mailbag this month.

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Peter Scott on the Value of Life Long Learning

RCSD goes from strength to strength. The mix in the latest September issue is superb.

Like you, I didn’t get on with the formal learning at school even though I went to some gooduns, in London and then a London suburb. It was aeromodelling that got me going on focussed learning — project learning — and around age 14 I started on aerodynamics for my free flight A/2 gliders. That needed drawing and maths and they in turn led to a life in science and engineering. Fortunately I then pretended to be an intellectual just in time to pass my A levels at age 18 and get to university. Uni was in those days free and even carried a cash grant. Only 5% of UK kids went to uni then, now approaching 50%.

In the UK we still lack respect and salaries for engineering in its highest sense of designer, so many clever young men and women think that the only higher education is uni, rather than the on-the-job education of apprenticeships. I ran a youth training company for a few years which got many people started in IT. It was magic to see them develop in just a few months. You will I know keep up the campaign to get young people interested in aeromodelling. It is a great way to start in science and we must hope that CAA/FAA stop their pressure to clear us out of the skies.

Yes you are dead right. We do love to learn. It is after all why we developed such a big brain and why intelligence has at least as much sexual attraction as a fine body. Best to have both if you can of course! One of the great pleasures of writing for RCSD is the rigour. I have to look again at the things I have learned in the past to make sure I understand it. There is nothing better than a public forum for making me ensure it is as correct as I can make it.

All the best,
Peter

Peter —thank you for that and your kind words about the September issue. Also I think this is a great place, what with all the readers assembled, to publically acknowledge and thank you for the yeoman service you have provided since RCSD relaunched. If my count is correct, you’ve written or curated 28 articles to date, which places you way atop the list of our contributors. Given that each of your articles teaches some new tip, trick or trap of the hobby — explained in some new, interesting and insightful way — it’s clear that the readers also love lifelong learning with you as their guide. Thank you so much for all your hard work. I can’t begin to tell you how much I appreciate it.— ~TCG

Why Do Those Mouldies Cost So Damn Much?

As a designer and manufacturer, many people ask me this question. Well, here’s why: I have done the cottage industry bit, and it has moved on to the large factory which is now being sorted. I’m possibly the most prolific model sailplane designer with more models produced, flown, flying, and in production than any other person on this planet, so I know something about this. Here’s a further explanation:

First you have a risk — you need to be a designer who really can back up his design criteria with technical stuff and explanations, because honestly the buyers have a right to it. Can you imagine buying a car and when you ask the salesman “what’s the intercooler for?” — he can’t tell you?

The most important point is you need to make an honest, good looking, nice flying model that does what it says on the tin, because it’s going to be a large investment of your time and your money. If it does not work, well then you are screwed. I know this — I have threads running up and down my back — and ‘re-curving’ other people’s stuff will not do either because time has shown that ‘me toos’ will not last the race.

As examples, look at the RCRCM Typhoon and Sunbird. Both original designs, now well over a decade old, but still selling well and being enjoyed by the buyers. There is no ‘my baby’ in this equation, because trust me, you might like your own design but it can be questionable whether others will.

Okay, Let’s look at some costs in time and money: Investment: Costs for CAD, CNC and production mould making: around $10,000 USD for a 2~2.5m model like a Forza or a Corsa. Then, there is what do we have to do and how long does it take to make the model. Here are some typical production processes and times for a 2m moulded model:

  • Cutting the glass/carbon kit — 1~1.5hr
  • Clean and polish the moulds — 1hr
  • Mask and paint the moulds Say 2hr — can be up to 6hr
  • Layup the moulds — 8hr but it can be more
  • Make the spars/sub spars — 4hr but also can be more
  • Join the wing moulds — 1hr
  • Oven time — 8hr but this interval can be used to cut glass/carbon kits and do other jobs
  • De-moulding — 1hr
  • Cleaning the moulded parts — 2hr
  • Aileron and flaps cutting and wipers — 3hr
  • Tailplane cutting and wipers — 1hr
  • QC assembly — 0.5hr
  • Fitting and small invisible defect rectification — 0.5hr
  • Cleaning and packing — 1hr
  • General housekeeping — 0.5hr
  • Total: (Average) 24~28hr with almost all labour hours per small model

In addition add the materials, facilities, utilities, CNC mould and labor costs to this production time. Materials bought in small quantities cost far more than larger purchases, and this is especially true of carbon fabrics, glass fabrics and epoxy resins.

Assuming you do have a great design for a one-man band, it’s really hard to produce one model per week at good quality, and it’s an eight hours-per-day, seven-day-per-week job where the actual outlay for the materials might be more than the finished model can be sold for.

For a factory, you have to have all of your costs well under control and your processes and SOP well documented and understood by the people working there. Added to that the entire enterprise must be very well supervised because when things go wrong — and they do believe me, corrective and preventative action has to be thorough and rapid. QC is of paramount importance.

Cheers,
Dr. James Hammond
何杰 博士

James — you completely read my mind. As I contemplate another winter building season — I’m still kind of a stick-and-solarfilm, man, I have to admit — I often find myself wondering why I don’t just buy the latest and greatest carbonfibre wonder. Then I look at the prices (gulp) and I’m instantly inclined to cyano another stick and heat up the iron. However, your explanation does provide ample objective evidence as to what justifies the price of these beauties. Thank you very much for that.

While I’m at it, this is also a great opportunity, as with my comment to Peter above, to publicly thank you for all your contributions to RCSD since the relaunch. This humble journal would not have been the same without you and I really mean that. And from the sounds of what you’ve hinted at for down the road, the best is yet to come! — ~TCG.

Send your letter via email to NewRCSoaringDigest@gmail.com with the subject ‘Letters to the Editor’. We are not obliged to publish any letter we receive and we reserve the right to edit your letter as we see fit to make it suitable for publication. We do not publish letters where the real identity of the author cannot be clearly established.

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